"Bovine-derived bone mineral demonstrated good osteoconductive properties as grating material for maxillary sinus floor elevation, but the long-term behavior of this material has not been reported. The purpose of this report was to analyze and compare histomorphometric measurements of new bone, bone graft, and medullar spaces 6 months, 12 months, and 20 years after grafting. In the grafted area, the amount of mineralized bone was 16.96% at 6 months, 22.53% at 12 months, and 22.05% at 20 years, respectively. The amount of bovine-derived bone mineral ranged from 35.87% to 4.85% in the same period. The volume of the newly formed mineralized bone does not increase over time, conversely to nonmineralized bone."

BACKGROUND: A sinus floor augmentation may be indicated when a lack of hard tissue impedes implant placement. Although clinically successful, evidence supporting the long-term three-dimensional stability of the grafted volume is scarce. Second, evidence on the patient's acceptance of this type of treatment is limited.

 

PURPOSE: First is to evaluate the changes in graft volume after lateral wall sinus lifting based on superimposed cone beam computed tomography (CBCT) images and then to assess patient-reported outcome measures (PROMs) and clinical outcomes.

 

MATERIALS AND METHODS: Partially edentulous patients in need of a sinus lift and fixed reconstruction on at least two neighboring implants were selected for a prospective case series. Lateral wall sinus augmentation was performed using deproteinized bovine bone mineral (DBBM) as the only filling material. Volumetric changes were quantified on the basis of a preoperative CBCT and three postoperative CBCTs (at 2 weeks, 3 months, and 2 years). PROMs and clinical parameters were registered.

 

RESULTS: Twenty-two patients (7 males, 15 females; mean age 59 years) participated of which three patients dropped out during the follow up. Graft volumes amounted to 1418.26 mm3 at 2 weeks, 1201.21 mm3 at 3 months, and 1130.13 mm3 at 2 years postoperative pointing to a relative graft volume stability of 79.7%. Swelling was the leading symptom during the first week. A peak in visual analogue scale scores was observed for pain, swelling, and hematoma the day of surgery and 1 day postoperation with a statistically significant decline between days 3 and 7. Hemorrhage and nose bleeding occurred in 18.2% and 27.3% of the subjects, respectively. About 95.5% of the subjects would undergo the treatment again. All implants integrated successfully and demonstrated healthy clinical conditions.

 

CONCLUSION: Lateral wall sinus augmentation using DBBM as the only filling material is a viable treatment concept given limited graft resorption, good patients' tolerance, and clinical outcomes.

AIM:
The primary objective of this study was (1) to evaluate the 5-year clinical outcome of regenerative periodontal therapy (RPT) using minimally invasive surgery and a collagen-enriched bovine-derived xenograft and (2) to identify predictors for clinical attachment level (CAL) gain and vertical radiographic bone (RB) gain.

MATERIALS AND METHODS:
Ninety-five non-smoking patients with ≤ 25% full-mouth plaque and bleeding presenting ≥ 6 months after initial periodontal therapy with ≥ 1 isolated interdental infrabony defect were recruited. Minimally invasive surgery (MIST or M-MIST) and a collagen-enriched bovine-derived xenograft were used in all patients. Patients were surgically treated by the same clinician and evaluated up to 5 years of follow-up. Multivariate analyses were used to identify predictors for CAL gain and RB gain.

RESULTS:
Before surgery, mean probing depth (PD) was 7.8 mm, CAL was 10.0 mm, and defect depth amounted to 5.2 mm. Seventy-one patients (33 men, 38 women, mean age 52) could be evaluated at 5 years. Mean PD reduction was 3.3 mm (SD 2.2), CAL gain was 3.0 mm (SD 2.1), and RB gain was 57% (SD 38). Forty-five percent showed ≥ 4 mm CAL gain, whereas 24% were considered failures (≤ 1 mm CAL gain). Forty-eight percent showed considerable RB gain (≥ 75%). Regression analyses showed that plaque was a significant predictor for CAL gain (p = 0.001) and RB gain (p = 0.005). Patients' compliance had a significant impact on RB gain (p < 0.001).

CONCLUSION:
Only patients with perfect oral hygiene and excellent compliance should be considered for RPT. Especially, the latter can only be assessed after sufficient follow-up following initial periodontal therapy.

CLINICAL RELEVANCE:
RPT failed in 24% of the patients after 5 years. Regression analyses demonstrated a significant impact of plaque and patients' compliance on the long-term outcome. Only patients with perfect oral hygiene and excellent compliance should be considered for RPT. Patients should not be treated too soon following initial therapy, since compliance can only be reliably assessed after sufficient follow-up.

AIM: To evaluate the 5-year aesthetic outcome of single implants following alveolar ridge preservation (ARP) and connective tissue graft (CTG) at the buccal aspect.

MATERIALS AND METHODS: Thirty-seven periodontally healthy non-smoking patients received flapless tooth extraction, ARP with a deproteinized bovine bone mineral with 10% collagen (DBBMC), implant placement (4-6 months later), a provisional screw-retained crown and CTG at the buccal mucosa (3 months later) and a permanent crown (3 months later). The aesthetic results were the primary outcome and the clinical results the secondary outcome of the study. Both outcomes were compared to those after 1 year. Mucosal thickness (MT) was registered using a non-invasive ultrasonic device.

RESULTS: Thirty-two patients attended the 5-year re-assessment, and all implants survived. Mean marginal bone loss was 0.53 mm at 1 year and 0.47 mm at 5 years (p = 0.439). Mesial Papilla showed a further re-growth between 1 and 5 years (p = 0.043). Mid-facial recession amounted to 0.05 mm and 0.12 mm at 1 and 5 years, respectively (p = 0.161). The Pink Esthetic Score was 11.00 and 11.17 at 1 and 5 years, respectively (p = 0.596). MT gain amounted to 0.97 mm (relative stability: 90.5%) and 0.91 mm (relative stability: 85%) at 1 and 5 years, respectively (p = 0.249).

CONCLUSION: ARP and CTG resulted in favourable clinical and aesthetic outcomes. CTG substantially increased MT with acceptable stability over a 5-year period.

Purpose: This study was designed to clinically and histologically evaluate the integration of titanium implants in different grafting materials used for maxillary sinus augmentation procedures.

The use of bone replacement grafts with barrier membranes in class II furcation defects are aimed at improving the outcome of the regenerative technique. In this regard, however, there is a paucity of studies comparing the results obtained with bone grafts alone or in combination with barrier membranes. The aim of this study was to clinically compare an anorganic bovine bone graft plus 10% collagen (BOC) with or without a bioresorbable collagen barrier (BG) in human mandibular molar class II furcation defects.

Methods and Materials: Twenty mandibular class II furcation defects (ten patients with bilateral defects) were treated either with BO (group I) or a combination of BO/BG (group II). Each defect was randomly assigned to either group I or group II. The soft tissue and hard tissue measurements including vertical probing depth (VPD), horizontal probing depth (HPD), clinical attachment level (CAL), gingival recession (GR), vertical depth of furcation defect (VDF), and horizontal depth of furcation defect (HDF) were recorded at baseline and six months after surgery.

Results:  Both treatment procedures resulted in statistically significant reduction in VPD and HPD, gain in CAL, and reduction in VDF and HDF. There was a statistically significant difference between group I and group II in all soft and hard tissue parameters with the exception of VPD reduction and gingival recession.

Conclusion: The findings of this study suggest superior clinical results with BO/BG treatment when compared to BO treatment in mandibular class II furcation defects.

Background: The aim of the present study is to evaluate the use of anorganic bovine bone (ABB) associated with a collagen membrane (CM) for a sinus graft by means of clinical, histologic, and radiographic parameters in cases with bone availability < or =7 mm. A preliminary evaluation consisted of a clinical examination, computed tomography (CT), and a panoramic x-ray.

Methods: Ninety-two patients requiring bilateral sinus grafts and 222 requiring unilateral procedures (total: 406 sinuses) participated in this study. A total of 1,025 implants were placed in the grafted sinuses. A total of 118 implants were placed simultaneously with the sinus graft (one stage), and 907 implants were placed in a subsequent surgery (two stages), 6 to 12 months after the graft was performed. In seven cases, a biopsy was harvested for histomorphometric analysis. Recall appointments were scheduled every 6 months and panoramic and periapical x-rays were required every year for 3 years.

Results: Among 1,025 implants, 19 were lost (survival rate: 98.1%). The difference in survival rates for implants placed in native bone < or =3 mm (98.1%), >3 to < or =5 mm (98.6%), and >5 to < or =7 mm (97.0%) was not statistically significant (P = 0.3408). The survival rates for implants with rough and machined surfaces (98.6% and 97.0%, respectively) were not statistically significant (P = 0.0840). The histomorphometric analysis showed new bone formation (39.0% +/- 12%), marrow space (52.9% +/- 9.3%), and residual ABB (8% +/- 2.7%).

Conclusion: Our results indicated that 1,025 implants placed in sinuses grafted exclusively with ABB combined with CM led to an excellent and predictable survival rate of 98.1%.

BACKGROUND:

This clinical report compares the use of an enamel matrix derivative (EMD) and bioabsorbable barrier membrane to enhance healing following the immediate placement of transmucosal implants into extraction sockets.

METHODS:

Thirty-two adult patients scheduled for tooth replacement with dental implants agreed to participate. Following the insertion of a transmucosal implant into the extraction site, the subjects were assigned to one of two treatment alternatives of the remaining bone defects around the implants: 1) the residual bone defects were filled with EMD (EMD group) or 2) the residual bone defects were covered with a bioabsorbable membrane (membrane group). Flaps were then coronally positioned around implant cover screws. Patients followed weekly maintenance recalls for the first 6 weeks and then monthly recalls until the final prosthetic restoration was completed (after 6 months). The treatment outcome was evaluated after 12 months by the use of clinical variables. The null hypothesis of no treatment group differences was tested by the use of analysis of variance (ANOVA).

RESULTS:

At a 12-month follow-up, all of the implants were completely osseointegrated and successfully functioning, showing a success rate of 100%. The membrane group showed a significantly lower mean probing attachment level than the EMD group at proximal (0.60 mm, standard deviation (SD) 0.37 versus 1.19 mm, SD 1.10), buccal (0.80 mm, SD 0.79 versus 1.77 mm, SD 1.16), and lingual sites (0.44 mm, SD 0.52 versus 1.48 mm, SD 1.46). The difference was statistically significant at all sites (P < 0.05). With respect to the position of the soft tissue margin around the implant shoulder, the membrane group showed a consistently higher value than the EMD group at, respectively, proximal (1.30 mm, SD 2.37 versus 1.16 mm, SD 1.0), buccal (0.90 mm, SD 1.29 versus 0.22 mm, SD 1.47), and lingual sites (1.12 mm, SD 1.10 versus 0.55 mm, SD 1.42).

CONCLUSIONS:

The membrane group obtained more favorable results in terms of both the probing attachment level and peri-implant position of soft tissues compared to the EMD group. The use of a bioabsorbable membrane around immediately placed transmucosal implants enhanced soft and hard tissue healing and might be an advisable treatment choice particularly in areas with high esthetic demands.

Purpose: To compare the efficacy of two different techniques to augment maxillary sinuses using a lateral window approach: rigid synthetic resorbable barriers (Inion) versus granular anorganic bovine bone (Bio-Oss). Materials and Methods: Ten partially edentulous patients having bilaterally 1 to 5 mm of residual bone height and at least 5 mm bone width below the maxillary sinuses, as measured on computed tomography (CT) scans, were randomised to receive two different 2-stage sinus lift procedures using the lateral window approach. In one side, the sinus lining was raised by placing a resorbable rigid Inion barrier without any bone substitute whereas the contralateral side was loosely packed with 100% granular Bio-Oss. After 6 months, 2 to 3 implants were inserted at each side and submerged for 4 months. Implants were loaded with provisional acrylic prostheses and replaced after 4 months, by definitive screwretained metal-ceramic prostheses. Outcome measures were: time necessary to complete the augmentation procedure, bone gain on CT scans, histomorphometry, any complication, implant and prosthetic failures, and clinician and patient preference assessed by a blinded outcome assessor. All patients were followed up to 5 months after loading.

Results: No patient dropped out. There was no significant difference in time to complete the augmentation procedure (19.8 minutes for Inion versus 20.5 for Bio-Oss). After 6 months, both interventions gained bone in a highly statistically significant way (14.4 mm for Inion versus 14.1 mm for Bio- Oss) with no significant differences between the procedures. Histologically, more new bone formed at Bio-Oss treated sites (36.1% versus 24.2%), the difference being highly statistically significant (P = 0.002). There were no differences in complications between groups (2 perforations of the maxillary lining at Inion treated sites versus 1 at a Bio-Oss site), however, in one of the patients where a perforation occurred at the Inion site, at implant placement, the sinus was two-thirds filled with soft tissue and the site was successfully retreated with Bio-Oss. No implant failed. The clinician preferred Bio-Oss because it was simpler to handle. There were no statistically significant differences in patient preference 1 month after surgery and 1 month after delivery of definitive prostheses: 8 patients had no preference while 2 preferred the Bio-Oss treated side.

Conclusion: Although bone grafting is not needed to augment atrophic maxillary sinuses since it is sufficient to keep space with a rigid barrier, bone was histologically more mature and appeared to be clinically harder when using Bio-Oss. Moreover, it was judged simpler to fill sinuses with a bone substitute than to position a rigid barrier for maintaining space.

The purpose of this study was to evaluate the clinical effectiveness of a bovine porous bone mineral used in combination with a porcine derived collagen membrane as a barrier in promoting periodontal regeneration in intrabony defects in humans. The study employed a split-mouth design. 22 paired intrabony defects were treated and surgically re-entered 6 months after treatment. Experimental sites were grafted with bovine porous bone mineral and received a collagen membrane for guided tissue regeneration. Control sites were treated with an open flap debridement. Preoperative pocket depths, attachment levels and trans-operative bone measurements were similar for control and experimental sites. Post surgical measurements revealed a significantly greater reduction in pocket depth (differences of 1.89±0.31 mm on buccal 0.88±0.27 mm on lingual measurements) and more gain in clinical attachment (differences of 1.51±0.33 mm on buccal and 1.50±0.35 mm on lingual measurements) in experimental sites. Surgical reentry of the treated defects revealed a significantly greater amount of defect fill in favor of experimental sites (differences of 2.67±0.91 mm on buccal and 2.54±0.87 mm on lingual measurement). The result of this study indicate that clinical resolution of intrabony defects can be achieved using a combination of bovine porous bone mineral and an absorbable, porcine derived collagen membrane when employing a technique based on the principles of guided tissue regeneration. The nature of the attachment between the newly regenerated tissue and the root surfaces needs to be evaluated histologically to confirm the presence of new attachment.

Background: Anorganic bovine bone (ABB) has been shown to have osteoconductive properties and no inflammatory or adverse responses as grafting materials used in sinus augmentation procedures. Despite these successful results, histologic data in humans over the long-term period are scarce. The purpose of this study was to analyze the histomorphometric data 9 years after surgery in a case of maxillary sinus augmentation using ABB.

Methods: The histologic evaluation was performed in five different thin sections of the specimen, comparing histomorphometric measures for newly formed bone, marrow spaces, biomaterial particles remnants, and number of osteocytes embedded in both trabecular bone and bone tissue near the ABB. The investigation was carried out by means of scanning electron microscopy and brightfield and circularly polarized light microscopy.

Results: We observed a mean amount of newly formed bone of 46.0% +/- 4.67%, ABB remnants of 16.0% +/- 5.89%, and marrow spaces of 38.0% +/- 8.93%. The osteocyte index was 4.43 for bone around ABB and 3.27 in the trabecular bone at a distance from the particles.

Conclusion: After 9 years, the tissue pattern appeared composed by residual ABB particles in close contact to the newly formed bone. The bone mineralized matrix around the ABB had collagen fibers randomly oriented and more osteocytes embedded. The results demonstrate both a high level of osteoconductivity and a "biomimetic" behavior over the long term.

The objective of this study was to examine wound healing in extraction sockets following ridge preservation and the outcome of implants placed in those sites. Extraction sockets (N = 31) were grafted with anorganic bovine bone mineral (ABBM) and covered with dense polytetrafluoroethylene membrane. Bone cores obtained during implant placement were examined histologically and histomorphometrically. Percentages of vital bone and residual graft were 37.5% ± 21.3% and 12.5% ± 8.9%, respectively. New vital bone showed a negative correlation with patient age. Percentage of vital bone formation in sockets was correlated with neither postgraft wound healing time nor peri-implant marginal bone level.

OBJECTIVE:
To histomorphometrically compare the use of collagen-stabilized anorganic bovine bone (ABBM-C) (test) to anorganic bovine bone + autogenous bone (ABBM + AB) (control) in maxillary sinus augmentation.

MATERIALS AND METHODS:
Forty (n = 40 sinuses) patients underwent sinus augmentation and received either control (20 sinuses) or test bone graft (20 sinuses). Bone samples were harvested from the augmented sinuses 5 months postgrafting. The samples were processed for histomorphometry, which assessed within the primary region of interest (ROI-1), the area fraction of new bone (%NB), graft particle osseointegration (% OI), residual graft (%RG), and soft tissue components (% STM). The same analysis was also carried out in a second region of interest (ROI-2) located in a zone 1 mm proximal to the previous maxillary sinus floor.

RESULTS:
In both ROI-1 and ROI-2, the mean % NB, %RG, and %STM in the control group were similar to mean values in the test group. The % OI was significantly greater in the control group (42.0 +/- 26.8) when compared to the test group (19.6 +/- 27.3) in ROI-2 (P < 0.05). No statistically significant differences were seen when ROI-1 and ROI-2 were compared except for improved %OI in ROI-2 in the control group. The mean proportion of lamellar bone to woven bone in the control group (1.22 ± 1.48) was significantly greater than the test group (0.38 ± 0.29) (P < 0.05).

CONCLUSION:
ABBM-C exhibited very similar histomorphometric parameters to the composite graft of ABBM + AB. The ABBM + AB group was more mature as indicated by the significantly greater proportion of lamellar bone when compared to the ABBM-C. Improved % OI was seen in the zone proximal to the resident bony floor in the ABBM + AB group. Based on histological assessment, ABBM-C is a suitable bone substitute for the purposes of maxillary sinus augmentation. Its clinical utility may be indicated in cases of sinus membrane perforation and insufficient autogenous bone in the local area.

Several grafting materials have been used in sinus augmentation procedures including autogenous bone, demineralized freeze-dried bone (DFDBA), hydroxyapatite, beta-tricalcium phosphate (beta-TCP), anorganic deproteinized bovine bone and combination of these and others. Up to now a subject of controversy in maxillofacial surgery and dentistry is, what is the most appropriate graft material for sinus floor augmentation. Purpose: The aim of this study is to provide a body of evidence-based data regarding grafting materials in external sinus floor elevation concerning the fate of the augmented material at the histomorphological level, through a meta-analysis of the available literature.

Materials and methods: The literature searches were performed using the National Library of Medicine. The search covered all English and German literature from 1995 until 2006. For analyzing the amount of bone the parameter "Total Bone Volume" (TBV) was assessed. TBV is determined as the percentage of the section consisting of bone tissue.

Results: In a relatively early phase after implantation the autogenous bone shows the highest TBV values. Interestingly, the different TBV levels approximate during the time. After 9 months no statistically significant differences can be detected between the various grafting materials.

Conclusion: From a clinical point of view, the use of autogenous bone is advantageous if a prosthetic rehabilitation (with functional loading) is expected within 9 months. In other cases the use of anorganic deproteinized bovine bone in combination with autogenous bone seems to be preferable. Donor side morbidity is ignored in this conclusion.

Objectives: To evaluate healing of marginal defects in immediate transmucosal implants grafted with anorganic bovine bone, and to assess mucosal and radiographic outcomes 3-4 years following restoration. Material and Methods: Thirty immediate transmucosal implants in maxillary anterior extraction sites of 30 patients randomly received BioOss (N=10; BG), BioOss and resorbable collagen membrane (N=10; BG+M) or no graft (N=10; control).

Results: Vertical defect height (VDH) reductions of 81.2+/-5%, 70.5+/- 17.4% and 68.2+/-16.6%, and horizontal defect depth (HDD) reductions of 71.7+/-34.3%, 81.7+/-33.7% and 55+/-28.4% were observed for BG, BG+M and control groups, respectively, with no significant inter-group differences. Horizontal resorption was significantly greater in control group (48.3+/-9.5%) when compared with BG (15.8+/-16.9%) and BG+M (20+/-21.9%) groups (P=0.000). Ten sites (33.3%) exhibited recession of the mucosa after 6 months; eight (26.7%) had an unsatisfactory esthetic result post-restoration due to recession. Mucosal recession was significantly associated (P=0.032) with buccally positioned implants (HDD 1.1+/-0.3 mm) when compared with lingually positioned implants (HDD 2.3+/-0.6 mm). In 19 patients followed for a mean of 4.0+/-0.7 years, marginal mucosa and bone levels remained stable following restoration.

Conclusion: BioOss significantly reduced horizontal resorption of buccal bone. There is a risk of mucosal recession and adverse soft tissue esthetics with immediate implant placement. However, this risk may be reduced by avoiding a buccal position of the implant in the extraction socket.

OBJECTIVE:
Compare maxillary sinus augmentation (MSA) using two different materials-anorganic bovine bone mineral (ABBM) + autogenous bone (AB) (control group) vs. collagen-stabilized ABBM (test group) in terms of complications, patient-reported outcome measures (PROMs) and volumetric analysis.

MATERIALS AND METHODS:
Sixty patients underwent sinus augmentation (30 control + 30 test group). Intra- and postoperative complications were recorded. PROMs measured the impact of grafting on daily activities, pain and morbidity. CT scans were used to measure graft volume, ridge height, material selection and degree of contact of graft-to-surrounding sinus walls. Dental implant placement parameters were also recorded.

RESULTS:
All complications were minor and did not prevent completion of the augmentation or subsequent implant placement. Schneiderian membrane perforation was the most frequently encountered complication. Both treatment groups reported moderate limitation in the 1st 48 hr post-surgery but little or none by day 3 or 4. Jaw opening, chewing and bruising were significantly higher in the control group. The impact on work and social life was moderate initially but reduced to little or none by the 2nd day. Mild to moderate pain and interference to daily activities were reported for the first 3 days requiring the use of NSAIDs only. A mean graft volume of 1.46 cm3 (±0.77) was calculated in the control group and 1.27 cm3 (±0.65) in the test group. Extent of contact between graft and surrounding sinus walls had a significant impact on bone volume. Shorter (8 mm) implants were utilized more frequently in the test group, which was also more likely to require additional vertical augmentation, but this was not statistically significant.

CONCLUSION:
MSA using a lateral wall approach is safe and associated with mild to moderate pain and restrictions to daily activities for 48-72 hr. Patients' reports of morbidity were greater with autogenous bone harvesting. Collagen-stabilized ABBM provides comparable bone volume to AB + ABBM that is sufficient for placement of implants of adequate size with no need for further vertical augmentation. Engaging the surrounding sinus walls had a significant positive impact on graft volume.

Purpose: The aims of this prospective study were to: (1) determine clinical and radiographic success and survival rates of implants placed in a staged procedure after sinus augmentation; and (2) compare the success and survival rate of implants in two patient groups with different ridge height prior to treatment (those with minimal residual crestal bone [=/< 3.5 mm] below the sinus and those with moderate residual crestal bone [> 3.5 mm]).

Materials and Methods: The study used anorganic bovine bone-derived mineral and autogenous bone for the sagittal sandwich bone augmentation technique, a collagen membrane to protect the sinus window, and a staged approach for implant placement; all implants featured an anodized surface.

Results: Two hundred forty-five implants were placed in 100 sinus sites (79 patients), and 244 have survived to date. The cumulative success and survival rates of all implants overall at 5 years were 96.5% (SE 2.0%) and 99.6% (SE 0.4%), respectively. The overall success and survival rates at 5 years for implants placed into minimal residual crestal bone were 94.1% (SE 3.4%) and 99.4% (SE 0.6%), respectively. For implants placed into moderate crestal bone, overall success and survival rates were both 100.0% (SE 0.0%).

Conclusion: Success of implants placed after sinus augmentation appears similar to implants placed in native bone when a classical submerged implant healing time of 6 months is used. The success and survival rates and crestal bone remodeling of implants placed in minimal residual crestal bone were comparable to those of implants placed in moderate residual crestal bone. 

"This study was performed to investigate sinus floor augmentation with two different particle sizes of demineralized bovine bone mineral (DBBM) by means of histological and immunohistochemical (IHC) analysis. A randomized clinical trial was conducted involving 10 individuals requiring two-stage bilateral maxillary sinus augmentation for implant installation. The patients were randomly divided into two groups following a split-mouth design: the maxillary sinus on one side was filled with small-sized particles (0.25-1mm) and on the contralateral side with large-sized particles (1-2mm). After a healing period of 8 months, 25 implants were placed. During implant site preparation, bone biopsies were obtained from each sinus, perpendicular to the long axis of the implant (buccal-palatal direction), for descriptive and histomorphometric analyses. IHC staining for protein expression of osteocalcin (OCN), vascular endothelial growth factor (VEGF), and tartrate-resistant acid phosphatase (TRAP) was also performed. Histomorphometric analysis revealed no statistically significant difference in the percentage of biomaterial (32.4±8.56% and 38.0±6.92%), newly formed bone (36.1±9.60% and 36.7±5.79%), or connective tissue (30.4±8.63% and 23.8±6.16%) between the small- and large-sized particle groups, respectively. IHC analysis did not reveal differences in the expression of OCN, VEGF, or TRAP. These findings suggest that both particle sizes of DBBM are effective for bone augmentation in the maxillary sinus."

PURPOSE:
The aim of the present randomized controlled clinical study was to test whether small bony dehiscence defects (≤5 mm) left to heal spontaneously result in the same clinical and radiological outcome as defects treated with guided bone regeneration (GBR).

MATERIALS AND METHODS:
Twenty-two patients who received at least one implant with a small bony dehiscence defect were enrolled in the study. If the defect height was ≤5 mm, the site was randomly assigned to either the spontaneous healing (SH) group or the GBR group. In the SH group, the defect was left without any treatment. In the GBR group, the defects around the implants were grafted with deproteinized bovine bone mineral (DBBM) and covered with a native collagen membrane. Clinical and radiographic measurements were performed 6 months after implant placement with a reentry surgery and at the time of crown insertion and the subsequent follow-up appointments at 3, 6, 12 and 18 months after loading. For statistical analyses, the mixed linear model was applied for the clinical and radiographic measurements observed around the implants. Simple comparisons of the location of the measurements in the two independent groups are performed with the Mann-Whitney U-test. In addition, the mixed model assumptions were checked.

RESULTS:
The implant and crown survival rate 18 months after loading was 100%, revealing no serious biologic or prosthetic complication. The mean changes of the buccal vertical bone height between implant placement and reentry surgery after 6 months revealed a small bone loss of -0.17 ± 1.79 mm (minimum -4 mm and maximum 2.5 mm) for the SH group and a bone gain of 1.79 ± 2.24 mm (minimum of -2.5 mm and maximum of 5 mm) for the GBR group, respectively (P = 0.017). Radiographic measurements demonstrated a slight bone loss of -0.39 ± 0.49 mm for the SH group and a stable bone level of 0.02 ± 0.48 mm for GBR group after 18 months. All peri-implant soft tissue parameters revealed healthy tissues with no difference between the two groups.

CONCLUSION:
Small bony dehiscence defects left for spontaneous healing demonstrated high implant survival rates with healthy and stable soft tissues. However, they revealed more vertical bone loss at the buccal aspect 6 months after implant insertion and also more marginal bone loss between crown insertion and 18 months after loading compared to sites treated with GBR.

AIM:
To compare guided bone regeneration (GBR) with connective tissue graft (CTG) to re-establish convexity at the buccal aspect of single implants.

MATERIALS AND METHODS:
Patients with a single tooth gap in the anterior maxilla and horizontal alveolar defect were enrolled in a single-blind RCT. Sites had to demonstrate buccopalatal bone dimension of at least 6mm prior to surgery to ensure complete embedding of an implant without the need for bone augmentation. All received a single implant and were randomly allocated to the control group (GBR) or the test group (CTG). Cross-sectional CBCT images at t0 (before surgery), t1 (two weeks after surgery) and t2 (one year after surgery) were used to evaluate the buccal soft tissue profile (BSP). Secondary outcome variables were buccal bone thickness (BB), buccal soft tissue thickness (BST), vertical bone loss (VBL) and clinical parameters.

RESULTS:
Twenty-one patients were included per group (control: 11 females, mean age 51; test: 9 females, mean age 48). At t2, a significant increase in BSP between 0.7 mm and 1.5 mm was observed in each group (p ≤ 0.010). There was no significant difference between the groups at 1 year (p ≥ 0.126). The increase in BSP in the control group was basically the result of BB gain ranging from 0.69 mm to 1.15 mm. BSP gain in the test group was the result of an increase in BST ranging from 0.67 mm to 1.38 mm. VBL did not differ significantly between the groups (p ≥ 0.644). Implants demonstrated healthy clinical conditions with no significant differences between the groups for any of the parameters (p ≥ 0.095).

CONCLUSION:
Within the limitations of superimposed CBCT images, GBR and CTG are effective to re-establish convexity at the buccal aspect of single implants in the short term. This article is protected by copyright. All rights reserved.

BACKGROUND:
The standard of care for increasing keratinized tissue (KT) and vestibular area is an autogenous free gingival graft (FGG) and vestibuloplasty; however, there is morbidity associated with the harvest of autogenous tissue, and supply is limited. The purpose of this study is to determine if a xenogeneic collagen matrix (CM) might be as effective as FGG.

METHODS:
This study is a single-masked, randomized, controlled, split-mouth study of 30 patients with insufficient zones of KT (<2 mm). It uses a within-patient treatment-comparison design to establish non-inferiority of the test (CM) versus control (FGG) therapy. The primary efficacy endpoint was change in KT width (∆KT) from surgery to 6 months post-surgery. Secondary endpoints included traditional periodontal measures, such as clinical attachment level, recession, and bleeding on probing. Patient-reported pain, discomfort, and esthetic satisfaction were also recorded. Biopsies were obtained at 6 months.

RESULTS:
Surgery and postoperative sequelae were uneventful, with normal healing observed at both test and control sites. The primary outcome, ∆KT width at 6 months, did not establish non-inferiority of CM compared to FGG (P = 0.9992), with the FGG sites averaging 1.5 mm more KT width than CM sites. However, the amount of new KT generated for both therapies averaged ≥2 mm. Secondary outcomes were not significantly different between test and control sites. All site biopsies appeared as normal mucoperiosteum with keratinized epithelium. CM sites achieved better texture and color matches, and more than two-thirds of patients preferred the appearance of their CM sites.

CONCLUSION:
With the proviso of sufficient KT (≈2 mm in width) and study goals of lower morbidity, unlimited supply, and patient satisfaction, CM appears to be a suitable substitute for FGG in vestibuloplasty procedures designed to increase KT around teeth.

AIM:
To compare the effectiveness of two-ridge preservation treatments.

MATERIALS AND METHODS:
Forty subjects with extraction sockets exhibiting substantial buccal dehiscences were enrolled and randomized across 10 standardized centres. Treatments were demineralized allograft plus reconstituted and cross-linked collagen membrane (DFDBA + RECXC) or deproteinized bovine bone mineral with collagen plus native, bilayer collagen membrane (DBBMC + NBCM). Socket dimensions were recorded at baseline and 6 months. Wound closure and soft tissue inflammation were followed post-operatively, and biopsies were retrieved for histomorphometric analysis at 6 months.

RESULTS:
Primary endpoint: at 6 months, extraction socket horizontal measures were significantly greater for DBBMC + NBCM (average 1.76 mm greater, p = 0.0256). Secondary and Exploratory endpoints: (1) lingual and buccal vertical bone changes were not significantly different between the two treatment modalities, (2) histomorphometric % new bone and % new bone + graft were not significantly different, but significantly more graft remnants remained for DBBMC; (3) at 1 month, incision line gaps were significantly greater and more incision lines remained open for DFDBA + RECXC; (4) higher inflammation at 1 week tended to correlate with lower ridge preservation results; and (5) deeper socket morphologies with thinner bony walls correlated with better ridge preservation. Thirty-seven of 40 sites had sufficient ridge dimension for implant placement at 6 months; the remainder were DFDBA + RECXC sites.

CONCLUSION:
DBBMC + NBCM provided better soft tissue healing and ridge preservation for implant placement. Deeper extraction sockets with higher and more intact bony walls responded more favourably to ridge preservation therapy.

OBJECTIVES: This work aimed to comparatively evaluate the three modalities of vestibuloplasty around implants in the posterior mandible.

MATERIALS AND METHODS: Forty patients who presented with a shallow vestibule and insufficient keratinized gingiva were divided into three groups: apically positioned flap only (APF group), APF with free gingival graft (FGG group), and APF with collagen matrix (CM group). The width of KT was measured at baseline, immediately after surgery (T0), and 6 months (T6) and 12 months after surgery (T12). An esthetic evaluation (color match, contour, and texture) was conducted.

RESULTS: Most of the shrinkage occurred within 6 months. The FGG group demonstrated less shrinkage of KT up to 12 months compared to the APF and CM groups. The APF and CM groups exhibited a prolonged and similar rate of shrinkage. The APF and CM groups also showed significantly better esthetic profiles.

CONCLUSIONS: Within the limitations of the present study, FGG may be the most predictable modality for increasing KT in the posterior mandible, but it should be emphasized that the posterior mandible does not require high esthetics.

CLINICAL RELEVANCE: The effect of apically positioned flap and collagen matrix may be diminished by several factors in posterior mandible, such as low vestibule and high muscle pull. For increasing the dimension of keratinized tissue in posterior mandible, conventional free gingival graft may be more predictable compared to other options.

PURPOSE: This case series illustrates a simplified soft tissue management, namely, the subperiosteal peri-implant augmented layer (SPAL), to increase hard and soft tissue dimensions at the most coronal portion of an implant.

MATERIALS AND METHODS: Twenty-seven implants in 16 patients presenting either a buccal bone dehiscence or a thin (< 1 mm) buccal cortical bone plate (BCBP) were consecutively treated. Briefly, a split-thickness flap (namely, the mucosal layer) was raised on the buccal aspect. Then, the periosteal layer was elevated from the bone crest. A full-thickness flap was elevated on the oral aspect. After implant site preparation, a xenograft was used to fill the space between the periosteal layer and the BCBP and/or exposed implant surface and, if present, to completely correct the bone dehiscence. The periosteal layer was sutured to the oral flap. The mucosal layer was coronally advanced and sutured to submerge both the graft and the implants. At 3 to 6 months, a re-entry procedure for implant exposure was performed.

RESULTS: Healing was uneventful, with no signs of infection in all cases. A wound dehiscence was observed in three implants in two patients at 2 weeks postsurgery. Out of 15 implants showing an initial bone dehiscence, 12 implants (80%) showed a complete resolution, with a subperiosteal tissue thickness (SPTT) at the time of re-entry of 3.1 ± 1.0 mm. Three implants presented a residual dehiscence of 1 mm (two implants) or 2 mm (one implant), with a SPTT of at least 2 mm. Out of 12 implants showing a thin BCBP at implant placement, 10 implants (90%) revealed a SPTT ≥ 2 at the time of re-entry. Two implants revealed a SPTT of 1 mm.

CONCLUSION: The SPAL technique represents a valuable simplified surgical approach associated with a low rate of complications in the treatment of peri-implant bone dehiscence and in the horizontal augmentation of peri-implant tissue thickness.

The objective of this investigation was to determine the fate of thin buccal bone encasing the prominent roots of maxillary anterior teeth following extraction. Resorption of the buccal plate compromises the morphology of the localized edentulous ridge and makes it challenging to place an implant in the optimal position for prosthetic restoration. In addition, the use of Bio-Oss as a bone filler to maintain the form of the edentulous ridge was evaluated. Nine patients were selected for the extraction of 36 maxillary anterior teeth. Nineteen extraction sockets received Bio-Oss, and seventeen sockets received no osteogenic material. All sites were completely covered with soft tissue at the conclusion of surgery. Computerized tomographic scans were made immediately following extraction and then at 30 to 90 days after healing so as to assess the fate of the buccal plates and resultant form of the edentulous sites. The results were assessed by an independent radiologist, with a crest width of 6 mm regarded as sufficient to place an implant. Those sockets treated with Bio-Oss demonstrated a loss of less than 20% of the buccal plate in 15 of 19 test sites (79%). In contrast, 12 of 17 control sockets (71%) demonstrated a loss of more than 20% of the buccal plate. In conclusion, the Bio-Oss test sites outperformed the control sites by a significant margin. No investigator was able to predict which site would be successful without the grafting material even though all were experienced clinicians. This leads to the conclusion that a patient has a significant benefit from receiving grafting materials at the time of extraction.

The objective was to test the hypothesis of no difference in long-term (≥5 years) implant treatment outcomes after maxillary sinus floor augmentation (MSFA) with autogenous bone graft compared to a mixture of autogenous bone graft and bone substitutes or bone substitutes alone. A MEDLINE (PubMed), Embase, and Cochrane Library search in combination with a hand-search of relevant journals was conducted. Human studies published in English between January 1, 1990 and October 1, 2016 were included. Nine studies fulfilled the inclusion criteria. The survival of suprastructures has never been compared within the same study. The 5-year implant survival after MSFA with autogenous bone graft was 97%, compared to 95% for Bio-Oss; the reduction in vertical height of the augmented sinus was equivalent with the two treatment modalities. Non-comparative studies demonstrated high survival rates for suprastructures and implants regardless of the grafting material used. Meta-analysis revealed an overall estimated patient-based implant survival of 95% (confidence interval 0.92-0.96). High implant stability quotient values, high patient satisfaction, and limited peri-implant marginal bone loss were revealed in non-comparative studies. No long-term randomized controlled trial comparing the different treatment modalities was identified. Hence, the conclusions drawn from the results of this systematic review should be interpreted with caution.

"The objective was to test the hypothesis of no difference in long-term (≥5 years) implant treatment outcomes after maxillary sinus floor augmentation (MSFA) with autogenous bone graft compared to a mixture of autogenous bone graft and bone substitutes or bone substitutes alone. A MEDLINE (PubMed), Embase, and Cochrane Library search in combination with a hand-search of relevant journals was conducted. Human studies published in English between January 1, 1990 and October 1, 2016 were included. Nine studies fulfilled the inclusion criteria. The survival of suprastructures has never been compared within the same study. The 5-year implant survival after MSFA with autogenous bone graft was 97%, compared to 95% for Bio-Oss; the reduction in vertical height of the augmented sinus was equivalent with the two treatment modalities. Non-comparative studies demonstrated high survival rates for suprastructures and implants regardless of the grafting material used. Meta-analysis revealed an overall estimated patient-based implant survival of 95% (confidence interval 0.92-0.96). High implant stability quotient values, high patient satisfaction, and limited peri-implant marginal bone loss were revealed in non-comparative studies. No long-term randomized controlled trial comparing the different treatment modalities was identified. Hence, the conclusions drawn from the results of this systematic review should be interpreted with caution. "

Objectives: The objectives of this systematic review were to assess the survival rate of grafts and implants placed with sinus floor elevation.

Material and Methods: An electronic search was conducted to identify studies on sinus floor elevation, with a mean follow-up time of at least 1 year after functional loading.

Results: The search provided 839 titles. Full-text analysis was performed for 175 articles resulting in 48 studies that met the inclusion criteria, reporting on 12,020 implants. Meta-analysis indicated an estimated annual failure rate of 3.48% [95% confidence interval (CI): 2.48%-4.88%] translating into a 3-year implant survival of 90.1% (95% CI: 86.4%-92.8%). However, when failure rates was analyzed on the subject level, the estimated annual failure was 6.04% (95% CI: 3.87%-9.43%) translating into 16.6% (95% CI: 10.9%- 24.6%) of the subjects experiencing implant loss over 3 years.

Conclusion: The insertion of dental implants in combination with maxillary sinus floor elevation is a predictable treatment method showing high implant survival rates and low incidences of surgical complications. The best results (98.3% implant survival after 3 years) were obtained using rough surface implants with membrane coverage of the lateral window.

This paper introduces a three-stage split-crest (TSSC) technique for horizontal ridge augmentation in the atrophic posterior mandible. The first stage consists of splitting the ridge. Following a 3- to 4-week healing interval, the second stage consists of expansion of the cortical plate (without elevating the periosteum) and placement of a bone replacement graft material. After 3 to 4 months of healing, the implants are placed. The advantages of this three-stage technique are increased vascularization to the surgical area, a decrease in procedure complications, and improved implant survival rates. An extended treatment time is the main disadvantage. The purpose of this retrospective case series is to review and discuss a new step-by-step surgical procedure of a TSSC technique using a delayed implant placement protocol. The results, advantages, and limitations were also presented.

Objective: This prospective animal study examined the de novo bone formation following application of deproteinized bovine bone matrix (DBBM) with or without autogenous bone (AB) to osseous defects.

Study Design: Defects of defined size were created in the frontal skull of domestic pigs and filled with DBBM alone (group A) and DBBM+25%AB (group B). De novo bone formation was analyzed qualitatively and quantitatively at 9 different times (0.5, 1, 2, 3, 4, 6, 8, 12, 26 weeks) by means of light microscopy, microradiography, and statistical analysis.

Results: Histological analysis indicated sufficient osseointegration of DBBM in both groups. Microradiography demonstrated a significant increase of bone formation in group B after 6 weeks (P = .0159) and 8 weeks (P = .0317).

Conclusion: The addition of 25%AB to DBBM results in accelerated de novo bone formation in osseous defects. This effect is likely caused by osteoinductive properties of cellular elements transplanted with the autogenous bone.

Purpose: To evaluate aesthetic and patient satisfaction after tooth extraction using a bone substitute (and soft tissue grafting when tissue thickness was lacking) under a pontic to preserve the alveolar ridge for aesthetic purposes. The contralateral natural tooth acted as internal control.

Materials and Methods: All patients at least one site under a pontic augmented with Bio-Oss® or Bio- Oss Collagen® with or without a concomitant connective tissue graft with at least a follow-up of 6 months after the ridge preservation procedure were eligible for the present retrospective study. Sites with a damaged buccal wall were excluded. Outcome measures were: aesthetics (pink with esthetic score, [PES]) evaluated by an independent and blinded dental hygienist on the basis of clinical pictures, patient satisfaction, patient preference and complications.

Results: Twenty-six patients were consecutively treated, and 23 patients attended the evaluation visit. In seven patients, soft tissue grafts were performed in conjunction with Bio-Oss placement. Eight to 86 months after the ridge augmentation procedure (mean 38 months), there were no statistically significant differences observed in PES between preserved sites and control teeth. Patient satisfaction did not show any statistically significant difference between the two groups either. All patients declared they would undergo the same procedure again.

Conclusion: Bio-Oss placement in post-extractive sites with a remaining buccal bone plate lead to a good aesthetic result. Randomised clinical trials with suitable control groups are needed to identify the most effective techniques and/or materials to preserve ridges under pontics.

Aim: To evaluate the soft tissue and the dimensional changes of the alveolar bony crest at sites where deproteinized bovine bone mineral (DBBM) particles, concomitantly with the placement of a collagen membrane, were used at implants installed into sockets immediately after tooth extraction.

Material and Methods: the pulp tissue of the mesial roots of (3) P(3) was removed in six Labrador dogs, and the root canals were filled. Flaps were elevated bilaterally, the premolars hemi-sectioned, and the distal roots removed. Recipient sites were prepared in the distal alveolus, and implants were placed. At the test sites, DBBM particles were placed in the residual marginal defects concomitantly with the placement of a collagen membrane. No treatment augmentation was performed at the control sites. A non-submerged healing was allowed. Impressions were obtained at baseline and at the time of sacrifice performed 4 months after surgery. The cast models obtained were analyzed using an optical system to evaluate dimensional variations. Block sections of the implant sites were obtained for histological processing and soft tissue assessments.

Results: After 4 months of healing, no differences in soft tissue dimensions were found between the test and control sites based on the histological assessments. The location of the soft tissue at the buccal aspect was, however, more coronal at the test compared with the control sites (1.8 +/- 0.8 and 0.9 +/- 0.8 mm, respectively). At the three-dimensional evaluation, the margin of the soft tissues at the buccal aspect appeared to be located more apically and lingually. The vertical dislocation was 1 +/- 0.6 and 2.7 +/- 0.5 mm at the test and control sites, respectively. The area of the buccal shrinkage of the alveolar crest was significantly smaller at the test sites (5.9 +/- 2.4 mm (2)) compared with the control sites (11.5 +/- 1.7 mm (2)).

Conclusion: The use of DBBM particles concomitantly with the application of a collagen membrane used at implants placed into sockets immediately after tooth extraction contributed to the preservation of the alveolar process.

The aim of the present study was to investigate the healing of alveolar ridge defects augmented with cancellous bovine bone mineral. In six partially edentulous patients, bone augmentation was necessary prior to implant placement because of severe alveolar ridge resorption. The defect sites, all located in the maxilla, were filled with Bio-Oss® and covered with the resorbable collagen membrane Bio-Gide®. Biopsies were obtained from the defect sites 6 to 7 months following grafting and were processed for ground sectioning. The histologic analysis revealed that the Bio-Oss® particles occupied 31% of the total biopsy area. An intimate contact between woven bone and Bio-Oss® was detected along 37% of the particle surfaces a mixed type of bone was found; it contained woven bone and parallel-fibered bone, which demonstrates features of remodeling activity. Signs of resorption of the grafting material were observed in the histologic sections, which indicate that the material takes part in the remodeling process. It is suggested that Bio-Oss® may be a very suitable material for staged localized ridge augmentation in humans.

Background: Recently, the use of bovine bone mineral (BBM) in combination with autogenous bone for alveolar ridge augmentation before implant placement has increased in favor because of concerns over morbidity associated with extraoral donor sites. The aim of this prospective study was to evaluate the clinical and radiographic parameters of implants placed in augmented ridges using a 70:30 mixture of autogenous bone and BBM in association with micro-mesh over a 2-year period.

Methods: Sixteen partially edentulous patients requiring bone augmentation were consecutively treated for 19 reconstructive procedures and delayed implant placement (44 implants) after 8 to 9 months of submerged mesh healing. Clinical examinations were performed and radiographs of the implants were taken 6 months after prosthetic loading and once a year during a 2-year follow-up.

Results: Only one (5.3%) of the 19 micro-meshes became exposed after 2 months and was removed. Computed tomography scans of the alveolar ridge pre- and postreconstruction demonstrated mean vertical augmentation of 3.71 +/- 1.24 mm and mean horizontal augmentation of 4.16 +/- 0.59 mm. All of the implants were retained after 2 years, yielding a 100% survival rate. The mean bone resorption around the implants was 1.37 +/- 0.32 mm during the observation period. Only three implants demonstrated bone resorption >2 mm, whereas 41 implants were considered clinically successful, resulting in a success rate of 93.1%.

Conclusion: This 2-year prospective study demonstrated that implants placed into augmented bone using this technique exhibited peri-implant stability with high survival (100%) and success (93.1%) rates.

PURPOSE:

When failing front teeth are replaced by implants, vestibular bone deficiencies frequently require augmentation, even though the amount of missing alveolar volume may vary. The objective of this study was to analyze the horizontal alveolar ridge dimension after implant placement and simultaneous augmentation, and to compare it to the condition at the contralateral natural site.

MATERIALS AND METHODS:

Forty-eight patients with a failing maxillary incisor received an immediate or early implant (Straumann Bone Level), according to a randomized study protocol. The vestibular wall of the implant site was reconstructed and moderately overcontoured with bovine hydroxyapatite and a collagen membrane (BioOss, BioGide, Geistlich). Provisional restoration followed either immediately, or after a 6-week healing period. To investigate the vestibular volume 6 months after surgery, a plaster model of the maxilla was scanned with cone beam computed tomography (CBCT; Morita 3D) and evaluated using coDiagnostiX software (Dental Wings). Statistical analysis comprised one- and two-sample t tests.

RESULTS:

The ridge volume was not significantly influenced by the treatment schedule. The vestibular segments had a mean ± SD volume of 207.9 ± 102.5 mm³ for the implant sites, and 202.1 ± 101.5 mm³ for the corresponding natural sites (P = .28). The difference in vestibular volume between implant sites and natural tooth sites was 10.4 ± 36.2 mm³ for immediate implantation, and 0.00 ± 31.1 mm³ for early implantation (P = .32). Comparing immediate and early restoration, a difference of 0.4 mm³ and 12.5 mm³ between the implant and contralateral site was found (P = .23).

CONCLUSION:

Six months after treatment, no significant differences between the alveolar volumes at augmented implant sites and natural sites were found. Moderate buccal overcontouring may have been beneficial to achieve a symmetrical contour. Long-term follow-up investigation will document if the restored volume remains stable over time.

Alveolar ridge preservation is of great importance for successful implant therapy. This study investigated the effects of a xenogeneic tridimensional collagen matrix (CM) in conjunction with deproteinized bovine bone mineral blended with 10% collagen (DBBM-C) on the healing of 12 intact extraction sockets in the esthetic area. Cone beam computed tomograpy examinations revealed nearly stable alveolar ridge dimensions (> 90% of the ridge horizontal dimension was preserved). New bone formation of approximately 45% and adequate resorption of the grafted material were histologically observed. Thus, application of CM together with DBBM-C using minimally invasive flapless approach can preserve the original ridge volume and support bone formation, contributing to adequate bone volume for implant insertion.

Alveolar ridge preservation is of great importance for successful implant therapy. This study investigated the effects of a xenogeneic tridimensional collagen matrix (CM) in conjunction with deproteinized bovine bone mineral blended with 10% collagen (DBBM-C) on the healing of 12 intact extraction sockets in the esthetic area. Cone beam computed tomograpy examinations revealed nearly stable alveolar ridge dimensions (> 90% of the ridge horizontal dimension was preserved). New bone formation of approximately 45% and adequate resorption of the grafted material were histologically observed. Thus, application of CM together with DBBM-C using minimally invasive flapless approach can preserve the original ridge volume and support bone formation, contributing to adequate bone volume for implant insertion.

Bone substitutes of bovine origin are widely used for treatment of bone defects in dental and orthopedic surgery. Due to the occurrence of BSE and the new variant of Creutzfeldt Jakob Disease risks of transmitting diseases through the use of such materials need to be carefully evaluated. Risk analysis can either be based on theoretical assessments or experimental evidence. Here we present a comparative study on two bovine bone substitutes (Bio-Oss^® and Osteograf/N), which is based on theoretical values. Furthermore, for one of these materials, i.e. Bio-Oss^®, the prion inactivation capacity of one of the production steps was experimentally evaluated. Theoretical and experimental data indicate that the use of these materials does not carry a risk of transmitting BSE to patients.

The surface area and the microporosity of bone regeneration materials influence their chemical and biological properties. Therefore, the size of the specific surface area (see Fig.) and the distribution of the pore diameters (pore<1 µm) of bone regeneration materials were analyzed within this study. The analyzed hydroxyapatites were of synthetic, bovine, and phytotroph origin. The tricalcium phosphates and the bioglasses included only synthetic materials.

The aim of the present study was to immunohistochemically evaluate angiogenesis pattern of native and cross-linked collagen membranes after subcutaneous implantation in rats. Five commercially available and three experimental membranes (VN) were included: (1) BioGide (BG), (2) BioMend (BM), (3) BioMend Extend (BME), (4) Ossix (OS), (5) TutoDent (TD), and (6-8) VN(1-3). Specimens were randomly allocated in unconnected subcutaneous pouches (n=4) separated surgically on the back of 40 wistar rats, which were divided into five groups (2, 4, 8, 16, and 24 weeks), including eight animals each. Pattern of angiogenesis was labelled using primary mouse monoclonal antibody to transglutaminase II. For each membrane, the period of time, needed for a complete and homogeneous transmembraneous vascularization, was assessed immunohistomorhometrically. Differences between the membranes were found regarding the initial pattern of transmembraneous angiogenesis, as evaluated 2 weeks following implantation. Mean cross- and longitudinal-sectional area of blood vessels (%) was highest for VN(3) (5.27+/-2.73), followed by BG (2.45+/-0.88), VN(1) (2.07+/-0.29), VN(2) (1.91+/-0.55), TD (1.44+/-0.53), BME (0.35+/-0.29) and BM (0.25+/-0.4). In contrast to BG and VN(1-3), BM, BME and TD exhibited a homogeneous transmembraneous formation of blood vessels merely 4-8 weeks following implantation. OS, however, exhibited no signs of angiogenesis throughout the whole study period. Within the limits of the present study, it may be concluded that pattern of transmembraneous angiogenesis markedly differs among the membranes investigated.

The purpose of the present study was to evaluate the effect of anorganic porous bovine-derived bone mineral (Bio-Oss) and expanded polytetrafluoroethylene (ePTFE) membrane in the treatment of peri-implantitis. A total of 64 implants with a titanium plasma-sprayed (TPS) surface were inserted in eight cynomolgus monkeys (Macaca fascicularis). After a 3-month healing period with plaque control, experimental peri-implantitis characterized by a bone loss of 4-6 mm was induced during a period of 9-18 months. Surgical treatment involving Bio-Oss+membrane, Bio-Oss, membrane, or a conventional flap procedure (control) only was carried out. The animals were sacrificed six months after treatment. Evaluation by clinical parameters, radiography including quantitative digital subtraction radiography, histology, and stereology demonstrated healthy peri-implant tissue irrespective of the applied surgical procedure. However, the amount of re-osseointegration and the total amount of bone (Bio-Oss and regenerated bone) were significantly higher in defects treated with membrane-covered Bio-Oss as compared with the other three treatment procedures. A mean bone-to-implant contact of 36% was obtained within defects treated with membrane-covered Bio-Oss. The corresponding values for the three other treatment procedures were 13-23%. The Bio-Oss particles were in general highly integrated within the regenerated bone, but the particles in the occlusal part of the defects were entirely surrounded by connective tissue irrespective of membrane coverage. The present study demonstrates that surgical treatment involving Bio-Oss covered by an ePTFE membrane is a useful treatment modality of experimental peri-implantitis around implants with a TPS surface in cynomolgus monkeys. However, the treatment outcome is not as encouraging as seen with membrane-covered autogenous bone graft particles documented in a study with same experimental design.

The aim of the present study was to evaluate whether it is possible to orthodontically move migrated teeth into infrabony defects augmented with a biomaterial. Three adult patients suffering from chronic periodontitis were treated. Each of the patients presented with an infrabony defect adjacent to a migrated maxillary central incisor. After cause-related therapy was completed, a surgical procedure was performed using the papilla preservation technique. The defects were filled with a collagen bovine bone mineral; after 2 weeks, an orthodontic device was activated using light, continuous forces. Orthodontic treatment time varied from 4 to 9 months; during this period, patients were enrolled in an oral hygiene recall program. At baseline and 6 months after the end of therapy, probing pocket depths (PPD) and clinical attachment levels (CAL) were assessed. In addition, the vertical and horizontal dimensions of the defects were measured on standardized radiographs. Residual mean PPD was 3.33 mm, with a mean reduction of 3.67 mm. Mean CAL gain was 4.67 mm. Radiologic vertical and horizontal bone fills were, on average, 3.17 mm and 2.0 mm, respectively. The present case series shows the effectiveness of a combined periodontic-orthodontic approach for the treatment of infrabony defects. Reduction of PPD to physiologic values, CAL gain, and radiologic defect resolution were obtained. No detrimental effects from the orthodontic movement were observed on the augmentation material.

Background: Following tooth extraction and immediate implant installation, the edentulous site of the alveolar process undergoes substantial bone modeling and the ridge dimensions are reduced. Objective: The objective of the present experiment was to determine whether the process of bone modeling following tooth extraction and immediate implant placement was influenced by the placement of a xenogenic graft in the void that occurred between the implant and the walls of the fresh extraction socket.

Material and Methods: Five beagle dogs about 1 year old were used. The 4th premolar in both quadrants of the mandible ((4) P(4)) were selected and used as experimental sites. The premolars were hemi-sected and the distal roots removed and, subsequently, implants were inserted in the distal sockets. In one side of the jaw, the marginal buccal-approximal void that consistently occurred between the implant and the socket walls was grafted with Bio-Oss Collagen® while no grafting was performed in the contra-lateral sites. After 6 months of healing, biopsies from each experimental site were obtained and prepared for histological analyses.      Results: The outline of the marginal hard tissue of the control sites was markedly different from that of the grafted sites. Thus, while the buccal bonecrest in the grafted sites was comparatively thick and located at or close to the SLA border, the corresponding crest at the control sites was thinner and located a varying distance below SLA border.

Conclusion: It was demonstrated that the placement of Bio-Oss Collagen® in the void between the implant and the buccal-approximal bone walls of fresh extraction sockets modified the process of hard tissue healing, provided additional amounts of hard tissue at the entrance of the previous socket and improved the level of marginal bone-to-implant contact. 

The aim of the present study was to evaluate the biocompatibility of differently cross-linked collagen membranes in cultures of human PDL fibroblasts and human osteoblast-like cells. Four collagen membranes (Bio-Gide (BG), BioMend (BM), Ossix (OS) and TutoDent (TD)] were tested. Cells plated on culture dishes served as positive controls. Six specimens of each membrane were incubated with (1) human PDL fibroblasts (2x10⁴ cells) (n=24), and (2) human osteoblast-like cells) (SaOs-2) (2x10⁴ cells) (n=24) under standardized conditions. After 7 days, adherent cells were stained with hematoxylin and counted using a reflected light microscope and the cell density per square millimeter was calculated. Additionally, cell morphology was investigated using scanning electron microscopy (SEM). Cell counts were presented as means and standard deviations (cell/mm²) and analyzed for statistical difference using the Wilcoxon test: (1) CD (434 ± 76)>BG (64 ± 19)=OS (61 ± 8)>TD (44 ± 4)>BM (12 ± 5);  (2) CD (453 ± 92)>BG (94 ± 46)=TD (84 ± 49)>OS (41 ± 23)>BM (0). SEM examination revealed that PDL fibroblasts adherent on BG, TD and OS appeared spindle-shaped and flat, like cells on CD. SaOs-2 osteoblasts adherent on CD were star shaped and flat, but mostly round in shape on BG, OS and TD. BM appeared to be incompatible with the attachment and proliferation of SaOs-2 cells; however, a few PDL fibroblasts were found in a round shape. Within the limits of the present study, it was concluded that (i) BG, TD and OS promoted, and (ii) BM inhibited the attachment and proliferation of human PDL fibroblasts and human SaOs-2 osteoblasts.

The aim of the present study was to compare the biodegradation of differently cross-linked collagen membranes in rats. Five commercially available and three experimental membranes (BN) were included: (1) Bio-Gide® (BG) (non-cross-linked porcine type I and III collagens), (2) BioMend® (BM), (3) BioMendExtend® (BME) (glutaraldehyde cross-linked bovine type I collagen), (4) Ossix® (OS) (enzymatic-cross-linked bovine type I collagen), (5) TutoDent® (TD) (non-cross-linked bovine type I collagen, and (6-8) VN (1-3) (chemical cross-linked porcine type I and III collagens). Specimens were randomly allocated in unconnected subcutaneous pouches separated surgically on the back of 40 wistar rats, which were divided into five groups (2, 4, 8, 16, and 24 weeks), including eight animals each. After 2, 4, 8, 16, and 24 weeks of healing, the rats were sacrificed and explanted specimens were prepared for histologic and histometric analysis. The following parameters were evaluated: biodegradation over time, vascularization, tissue integration, and foreign body reaction. Highest vascularization and tissue integration was noted for BG followed by BM, BME, and VN(1); TD, VN(2), and VN(3) showed prolongated, while OS exhibited no vascularization. Subsequently, biodegradation of BG, BM, BME and VN(1) was faster than TD, VN(2), and VN(3). OS showed only a minute amount of superficial biodegradation 24 weeks following implantation. Biodegradation of TD, BM, BME, VN(2), and VN(3) was associated with the presence of inflammatory cells. Within the limits of the present study, it was concluded that cross-linking of bovine and porcine-derived collagen types I and III was associated with (i) prolonged biodegradation, (ii) decreased tissue integration and vascularization, and (iii) in case of TD, BM, BME, VN(2), and VN(3) foreign body reactions.

The aim of this study was to evaluate histologically the simultaneous placement of endosseous implants into the sinus cavity and the surgical elevation of the sinus floor including filling the cavity with different grafting materials. In 9 sinus areas of 5 beagle dogs, 9 titanium implants (ITI® Dental Implant System) were placed, and the void space of the sinus cavity was filled simultaneously with either demineralized freeze- dried human cortical bone, a resorbable hydroxyapatite or natural cancellous bone mineral (Bio-Oss®). To study bone formation, fluorochrome markers (tetracycline-HCI and calcein green) were used at 2 and 8 weeks.

Clinically, all implants healed uneventfully, and 5 months after implant placement the dogs were killed for histologic evaluation. The implants surrounded by freeze-dried human bone yielded no formation of new bone, whereas the sites with hydroxyapatite or natural bovine bone mineral demonstrated newly formed bone with direct contact at the implant surface. The average extent of bone to implant contact was 25 % (SD = 10.6 %) and 27% (SD = 8.8 %), respectively in relation to the length of the originally denuded implant surface. In addition, the bone markers revealed a rapid bone formation and remodeling, especially around Bio-Oss® particles. This study yields new bone formation with direct contact to the implants surfaces in the sinus cavity into which suitable grafting materials were placed simultaneously.

INTRODUCTION:
Segmental maxillary osteotomy enables correction of anterior open bites. However, the outcome can be somewhat unstable, particularly if pseudarthrosis occurs. Bone grafts can be used to prevent this complication. Among the many biomaterials available for grafting, Bio-oss(®) has been used successfully in a range of modalities, with studies to support several indications. This report describes a case of segmental maxillary osteotomy in which Bio-oss(®) granules were used as bone grafts in the surgical gap.

PRESENTATION OF CASE:
A 24-year-old female presented with anterior open bite, Angle class III posterior occlusion, and Angle class II anterior occlusion. Virtual surgical planning of the procedure predicted a gap of approximately 5mm in the region of the osteotomy, which was bridged with Bio-oss(®) granules. DISCUSSION:

Although autogenous bone grafting is the gold standard due to its osteoconductive, osteoinductive, and osteogenic properties, it involves increased morbidity for the patient, unpredictable resorption rates, increased operative time, and risk of infection at the donor site. Use of the Bio-oss(®) material can provide good bone stability, osteoconduction, and biocompatibility, while reducing operative time and surgical morbidity.

CONCLUSION:
This is the first report of bone grafting with a granular biomaterial in segmental maxillary osteotomy. Successful formation of new bone with density greater than that of the surrounding tissue was achieved, preventing pseudarthrosis and postoperative instability.

Objectives: To assess whether the use of a graft and/or membrane post-tooth extraction improves healing of the site dimensionally, radiographically, and/or histologically.

Materials and Methods: MEDLINE and EMBASE and the Cochrane Central register of controlled trials (CENTRAL) were searched up until August 2011. Randomized controlled trials that included and compared healing post-tooth extraction between a control (no intervention) and a graft and/or membrane (test) were selected.

Results: Titles and abstracts of 2,861 papers were screened. A total of 42 papers were selected for full text reading. Nine papers met the eligibility criteria and were selected for further analysis. Because of the varying graft materials used and the different methods of investigation, as well as the variation in follow-up times, a meta-analysis was not possible. The present review found that clinically, there was a range in loss of width in the control sites of 2.46 mm (SD 0.4 mm) to 4.56 mm (SD 0.33 mm) compared to 1.14 mm (SD 0.87 mm) to 2.5 mm (SD 1.2 mm) in the test sites. The range in loss of height in control sites was 0.9 mm (SD 1.6 mm) to 3.6 mm (SD 1.5 mm) compared to a gain of 1.3 mm (SD 2 mm) to a loss of 0.62 mm (SD 0.51 mm) in test sites. Radiographically a range of change in bone height of between 0.51 mm (No SD) to 1.17 mm (SD 1.23 mm) was noted in control sites compared to a change of between 0.02 mm (SD 1.2 mm) and 1 mm (SD 1.4 mm) in test sites.

Conclusion: There is limited data regarding the effectiveness of alveolar ridge preservation therapies when compared to the control. Overall the socket intervention therapies did reduce alveolar ridge dimensional changes post-extraction, but were unable to prevent resorption. Histology did demonstrate a large proportion of residual graft material that may account for some of the difference in alveolar ridge dimensions at follow up.

Aims: To compare the reaction of the alveolar bone to the preservation of the extraction socket by Bio-Oss Collagen with and without combination of implant treatment. To evaluate whether early implant insertion 8-10 weeks thereafter could be a suitable time point for long term bone stability around the implant.

Methods: A total of 25 patients were divided into three groups: The first group (seven patients) received Bio-Oss Collagen after extraction and 8-10 weeks later an implant, the second group (eight patients) received only Bio-Oss Collagen without implantation thereafter, while the third group was considered as a control (eleven patients), where the sockets healed without any treatment. The change in the vertical bone level of the alveolar crests were measured from panoramic radiographs and statistically analysed.

Results: Bone level change was significantly less for Group 1 than Group 3 (P<0.001), while was not significantly different for Group 2 and Group 3 (P=0.23). However, the rate of bone level change per year was statistically smaller for Group 1 compared to Group 3 (P=0.019) and as well as for Group 1 than for Group 2 (P=0.003), whereas the change per year was not significantly different for Group 2 vs. Group 3 (P=0.122).

Conclusion: Bone level preservation of extraction sockets using Bio-Oss Collagen with implantation is significantly better compared to using Bio-Oss Collagen only and untreated sockets. Implant insertion 8-10weeks after extraction is a suitable time point after socket augmentation.

The aim of the present study was to conduct a long-term histologic analysis of retrieved specimens in humans where Bio-Oss® was used in sinus augmentation procedures. Specimens were retrieved from 20 patients after varying periods from 6 months to 4 years and were processed to obtain thin ground sections. Bio-Oss® particles were surrounded for the most part by mature, compact bone. In some Haversian canals it was possible to observe small capillaries, mesenchymal cells, and osteoblasts in conjunction with new bone. No gaps were present at the interface between the Bio-Oss® particles and newly formed bone. In specimens retrieved after 18 months and 4 years, it was also possible to observe the presence of osteoclasts in the process of resorbing the Bio-Oss® particles and neighboring newly formed bone. Bio-Oss® appears to be highly biocompatible and osteoconductive, is slowly resorbed in humans, and can be used with success as a bone substitute in maxillary sinus augmentation procedures.

Aim: To compare the influence of autologous or deproteinized bovine bone mineral as grafting material on healing of buccal dehiscence defects at implants installed immediately into the maxillary second incisor extraction socket in dogs. Material and Methods: In the maxillary second incisor sockets of 12 Labrador dogs, implants were installed immediately following tooth extraction. A standardized buccal defect was created and autologous bone particles or deproteinized bovine bone mineral were used to fill the defects. A collagen membrane was placed to cover the graft material, and the flaps were sutured to fully submerge the experimental areas. Six animals were sacrificed after 2 months, and six after 4 months of healing. Ground sections were obtained for histological evaluation.

Results: After 2 months of healing, all implants were osseointegrated. All buccal dehiscence defects were completely filled after 2 months irrespective of the augmentation material (autologous bone or Bio-Oss®) applied. Bone-to-implant contact (BIC) on the denuded implant surfaces was within a normal range of 30-40%. However, the newly formed tissue at 2 months was partially resorbed (>50% of the area measurements) after 4 months.

Conclusion: Applying either autologous bone or deproteinized bovine bone mineral to dehiscences at implants installed immediately into extraction sockets resulted in high degree of regeneration of the defects with satisfactory BIC on the denuded implant surface.

This study examines the effect of sinus lift surgery using Bio-Oss® on the bone anchorage of titanium plasma flame-spray-coated cylindrical implants. A total of 54 implants were placed n the lateral bony antral walls of 27 mountain sheep. Host site augmentation was done simultaneously using Bio-Oss® and autogenous cancellous bone from the iliac crest in 18 sinuses each. The bone walls of the remaining 18 sinuses received no augmentation. Pull-out tests were carried out at 12, 16 and 26 weeks, revealing a significant influence of the implants resident time on pull-out strength (P=0.004). The implants of the non- augmented group and those of the group augmented using cancellous bone showed a linear increase in pull-out strength to 169.8 N and 523.7 N, respectively, until the 26th week. The implants of the group augmented with Bio-Oss® exhibited the highest initial pull-out strength (325.1 N) that further increased to 521.8 N until the 26th week. All in all, this group showed a significantly greater pull-out strength than did the negative control group (P=0.03).

OBJECTIVES:
The aim of this study was to radiographically assess the vertical and horizontal alterations of buccal alveolar bone after the insertion of a post-extractive implant using Bio-Oss(®) Collagen graft.

MATERIAL AND METHODS:
The study was designed as a prospective study. Adult patients were eligible for the study if they needed one or more immediately inserted and immediately restored implant replacing teeth to be extracted within region 15-25. After the insertion, the buccal gap was carefully grafted using Bio-Oss(®) Collagen and the implant immediately restored. Cone-Beam Computed Tomography (CBCT) was performed immediately after surgery and a series of measurements were made to determine the dimension of the buccal bone plate and the void between implant and extraction socket. A second CBCT was taken and the measurements repeated after 12 months.

RESULTS:
Altogether, 69 patients were included in the study; a total of 69 implants were inserted. The study demonstrated that the extraction of a tooth and the immediate insertion of an implant together with an xenograft resulted in alterations of the vertical and horizontal dimension of the buccal bone plate (respectively, 25.6% and 29.3%). Nevertheless, the vertical and horizontal gap reduction was nearly complete (respectively, 99.3% and 99.1%) and the implant was normally in contact with buccal bone.

CONCLUSIONS:
Implant placement into extraction sockets can result in favorable radiological results even in the presence of evident alterations of the buccal bone wall.

"BACKGROUND: There is lack of studies regarding preservation and possible changes in BBT at dental implants.

PURPOSE: To assess, on cone beam computer tomograms, the presence of bone at the time of tooth extraction in the maxillary esthetic region and the mean buccal bone thickness 1 month and 1 year after final restoration placement in patients with large bony defects.

MATERIAL AND METHODS: In a cohort study, patients were selected presenting a failing tooth with a large bony defect (test group [n = 20]: large bony defect, immediate placed implant and delayed provisionalization). Results were compared with a group in which patients presented a failing tooth without or with a small bony defect: (control group [n = 20]: without or small bony defect, immediate placed implant and delayed provisionalization). Cone beam computer tomograms were made preoperatively, and 1 month and 1 year after placement of the restoration, and buccal bone thickness was analyzed.

RESULTS: In both groups approximately 1 mm of buccal bone thickness was present after 1 month and 1 year, without a significant difference between the groups.

CONCLUSION: In patients with large bony defects at a failing tooth it was possible to create a bone layer buccally of the implant and this bone layer remained stable during a 1-year follow-up; there were no significant differences between thickness of buccal bone at 1 month and 1 year in patients with large buccal bony defects and patients without or with small bony defects."

Use of collagen membrane (CM) with deproteinized bovine bone mineral (DBBM) and enamel matrix derivative (EMD) in periodontal regenerative therapy was evaluated. A total of 40 intrabony defects in periodontitis patients were treated. Clinical parameters and filled bone volume (FBV) and rate (FBR) were assessed. Probing pocket depth (PPD) was reduced significantly at 12 months with CM treatment, while clinical attachment level (CAL), FBV, and FBR showed similar improvements. In stratified analyses, CM-treated thick-biotype patients showed significant improvement in PPD and CAL. Regenerative therapy with the use of EMD and DBBM showed similar improvements in periodontal tissue regeneration with or without CM. The combination with CM appeared to influence the healing of soft tissue and was effective in decreasing pocket depth.

This study evaluated an anorganic bovine-derived xenograft (Bio-Oss Collagen) in the treatment of human periodontal defects. Four patients with intrabony defects on teeth that were treatment planned for extraction were enrolled in the study. Presurgical measurements of probing depth, attachment level, and recession were recorded. The surgical procedure consisted of flap reflection, debridement of the osseous defects and root surface, placement of a notch through calculus into the root surface, topical application of a tetracycline paste to the root surface, grafting with Bio-Oss Collagen, and flap closure. Three of the eight defects examined received a resorbable collagen barrier (Bio-Gide) in addition to the bone graft. Patients were seen every 2 weeks for plaque control and review of oral hygiene measures. Six months postsurgery, clinical parameters were rerecorded prior to en bloc resection of teeth and adjacent graft sites. The majority of sites showed a favorable clinical response with respect to probing depth reduction and clinical attachment gain. Histologic analysis demonstrated new bone, cementum, and periodontal ligament coronal to the reference notch in two of the eight specimens. Two sites demonstrated new attachment, and four showed a long junctional epithelium. Periodontal regeneration is possible following a bone-replacement graft of Bio-Oss Collagen.

OBJECTIVES:
This work aimed to investigate the effectiveness and predictability of different treatment modalities for gain of keratinized tissue (KT) in fully edentulous jaws prior to dental implant placement: apically positioned flap (APF), APF plus xenogeneic collagen matrix (XCM), and APF plus free gingival graft (FGG).

MATERIALS AND METHODS:
In fully edentulous patients with insufficient zones of KT at the prospective implant positions, four treatment modalities were performed in the lower jaw: APF, XCM, FGG, and an untreated control group (control). APF and XCM were applied in the first molar positions, FGG and control in the canine positions. Assessed outcomes up to 3 months post-surgery included changes in width of KT (over a 3-month period), histomorphometric analysis of harvested soft-tissue biopsies (at 3 months postoperatively), and patient-reported outcomes measures (PROMs).

RESULTS:
For the primary outcome, changes in KT width demonstrated an increase of 1.93 ± 1.6 mm (APF), whereas XCM and FGG showed an increase of 4.63 ± 1.25 mm and 3.64 ± 2.01, respectively. Histomorphometric analyses revealed a thickness of the epithelium ranging between 375 ± 122 μm (APF), 410 ± 116 μm (XCM), 336 ± 122 μm (FGG), and 413 ± 109 μm (control). All biopsies showed a regular muco-periosteal structure with a keratinized epithelium of comparable thickness in all groups.

CONCLUSION:
All three methods were suitable to increase the width of KT, although APF alone rendered roughly 50% less gain compared to XCM and FGG.

CLINICAL RELEVANCE:
The use of XCM in conjunction with an APF represents a valuable treatment option for the gain of keratinized tissue in edentulous sites."

Objectives: To assess in a randomized-clinical trial the influence of three augmentation techniques (chinbone with or without a Bio-Gide membrane and Bio-Oss with a Bio-Gide membrane) on the clinical and radiographic characteristics of hard and soft tissues around implants and adjacent teeth in the reconstructed maxillary anterior region, up to 1 year after functional loading.

Materials and Methods: Ninety-three patients requesting single-tooth replacement and presenting with a horizontal (bucco-palatinal) bone deficiency were included. After augmentation, 93 ITI-Esthetic(Plus) implants were placed. Clinical variables, standardized photographs and radiographs were analysed to assess the impact on the levels of the marginal gingiva (MGL) and marginal bone (MBL) around implants and adjacent teeth, viz at pre-augmentation, pre-implantation (TPI) and 1 (T(1)) and 12 (T(12)) months after final crown placement. 

Results: Implant survival was 97.8%. No significant differences were observed in the treatment outcomes of the three augmentation modalities. Combining the three modalities, a slight but significant increase in the implants approximal pocket depth was found between T(1) and T(12). Approximal bone loss at the implant between T(1) and T(12) was 0.14 +/- 0.76 mm (mesial) and 0.14 +/- 0.47 mm (distal); the approximal MGL slightly increased (mesial: 0.24 +/- 0.46 mm, distal: 0.25 +/- 0.66 mm), and the buccal MGL decreased (0.11 +/- 0.61 mm). Bone loss at the adjacent teeth, although minor, was significant between TPI and T(1). No correlations were observed in changes of MBL and MGL.

Conclusion: None of the three applied augmentation technique procedures influenced the characteristics of the MGL and MBL or the implant survival of single-tooth replacements. Peri-implant hard and soft tissues were very stable in the first year after loading.

Abstract Purpose: The aim of this study was to test whether or not implants associated with bone regeneration show the same survival and success rates as implants placed in native bone in patients requiring both forms of therapy.

Material and Methods: Thirty-four patients (median age of 60.3 years, range 18-77.7 years) had been treated 5 years before the follow-up examination. Machined screw-type implants were inserted following one of two surgical procedures: (1) simultaneously with a guided bone regeneration (GBR) procedure, which involved grafting with xenogenic bone substitute material, autogenous bone or a mixture of the two and defect covering with a bio-absorbable collagen membrane (test) and (2) standard implantation procedure without bone regeneration (control). For data recording, one test and one control implant from each patient were assessed. Examination included measurements of plaque control record (PCR), probing pocket depth (PPD), bleeding on probing (BOP), width of keratinized mucosa (KM), frequency of situations with supra-mucosal location of the crown margin, implant survival assessment and radiographic examination. Radiographs were digitized to assess the marginal bone level (MBL). Differences between groups were tested using the one-sample t-test. The estimation of survival rate was based on Kaplan-Meier analysis.

Results: The follow-up period of the 34 GBR and 34 control implants ranged from 49 to 70 months (median time 57 months). Cumulative survival rates reached 100% for the GBR group and 94.1% for the control group without statistical significance. No statistically significant differences for clinical and radiographic parameters were found between the two groups regarding PCR, BOP, PPD, KM and MBL.

Conclusion: The present study showed that, clinically, implants placed with concomitant bone regeneration did not performed differently from implants placed into native bone with respect to implant survival, marginal bone height and peri-implant soft tissue parameters.

AIM:

To test whether implants placed with simultaneous guided bone regeneration (GBR) differ from implants placed without GBR regarding survival rate, interproximal marginal bone level (MBL), and dimensions of buccal bone and mucosa.

MATERIAL AND METHODS:

Twenty-three patients treated 15 years earlier were included. Machined implants had been inserted following one of the two procedures: (i) with simultaneous GBR, which involved grafting with particulate deproteinized bovine bone mineral (DBBM), autogenous bone (AB), or a mixture of the two and defect covering with a native collagen membrane (CM) (GBR group) and (ii) standard implant placement without GBR (control group). One GBR and one control implant in each patient were selected for analysis. At 15 years, the dimensions of buccal bone and mucosa were measured with cone beam computed tomography. The interproximal MBL was evaluated at 5 and 15 years on periapical radiographs.

RESULTS:

The 15-year survival rate amounted to 95.6% for GBR implants and to 94.1% for control implants. At 15 years, interproximal MBL measured 1.44 ± 0.84 mm for the GBR group and 1.69 ± 0.84 mm for the control group. From the 5- to the 15-year examination, the loss of interproximal MBL reached 0.23 ± 0.70 mm for the GBR group and 0.28 ± 0.63 mm for the control group. At 15 years, buccal MBL measured 1.98 ± 0.98 mm for GBR implants and 2.19 ± 1.29 mm for control implants. None of these values reached statistical significant differences between the groups. In cases in which GBR involved grafting with DBBM, GBR implants achieved approximately 0.3-0.4 mm higher mean values in buccal bone dimensions and mucosal level in comparison to control implants. In contrast, when GBR was performed by grafting with AB without DBBM, implants rendered less favourable results in buccal bone and mucosa dimensions than the control implants.

CONCLUSIONS: Implants placed with simultaneous GBR using particulate DBBM and/or AB in combination with CM did not significantly differ from implants completely placed into pristine bone with respect to 15-year implant survival, interproximal bone levels, and dimensions of buccal bone and mucosa. The machined-surface implants placed both into native bone and sites augmented by GBR exhibited stable interproximal bone levels.

OBJECTIVE: The aim of this systematic review (SR) was to evaluate the effects of xenogenic collagen matrix (XCM) on the outcomes of clinical treatments of patients with Miller class-I or -II gingival recessions.

MATERIALS AND METHODS: Articles that were published before March 2018 were electronically searched in four databases without any date or language restrictions and manually searched in regular journals and gray literature. The eligibility criteria comprised randomized controlled trials (RCTs) and prospective controlled trials with follow-up periods of 6 months or more that compared the performance of XCM in the treatment of Miller class-I or -II gingival recessions. This SR was registered in PROSPERO under number CRD42018106118.

RESULTS: Nine RCTs published between 2010 and 2018 were included in this SR. The percentage of root coverage (RC) was significantly higher (p = .0003) when gingival recessions were treated with XCM when compared to coronally advanced flap (CAF) alone. In addition, the parameters of keratinized mucosa width (KMW) (p = .006) and gingival thickness (GT) (p = .0003) were also improved when the XCM was used in comparison to the CAF alone. There was not a statistically significant difference (p = .22) between the clinical attachment level (CAL) achieved with the use of XCM and that achieved with CAF alone. RC with the use of XCM, when compared to connective tissue grafts (CTGs) (p = .09) and enamel matrix derivative (EMD) (p = .62), there was no significant difference; however, XCM yielded lower RC than CTG in the treatment of Miller class-I or -II gingival recessions.

CONCLUSIONS: Based on both the individual studies' outcomes and the pooled estimates, it can be concluded that the use of XCM improves the RC, KMW and GT in the treatment of gingival recessions when compared to CAF alone and may be a viable alternative to use of CTG.

AIM:

The aim of this study was to test a new collagen matrix (CM) aimed to increase keratinized gingiva/mucosa when compared with the free connective tissue graft (CTG).

MATERIAL AND METHODS:

This randomized longitudinal parallel controlled clinical trial studied 20 patients with at least one location with minimal keratinized tissue (less than or equal to 1 mm). Main Outcome Measure: The 6-month width of keratinized tissue. As secondary outcomes, the aesthetic outlook, the maintenance of periodontal health and the patient morbidity were assessed pre-operatively at 1, 3 and 6 months.

RESULTS:

At 6 months, the CTG attained a mean width of keratinized tissue of 2.6 (0.9) mm, while the CM was 2.5 (0.9) mm, these differences being insignificant. In both groups, there was a marked contraction (60% and 67%, respectively) although the periodontal parameters were not affected. The CM group had a significantly lower patient morbidity (pain and medication intake) as well as reduced surgery time.

CONCLUSION:

These results prove that this new CM was as effective and predictable as the CTG for attaining a band of keratinized tissue, but its use was associated with a significantly lower patient morbidity.

The purpose of this study was to compare the bovine derived xenograft (BDX) Bio-Oss to demineralized freeze-dried bone allograft (DFDBA) in human intrabony defects. 17 healthy patients with no systemic disease with moderate-severe periodontitis (7 males, 10 females; aged 34-67) were treated. Surgically, defects were included only if the intraosseous defect depth was >3.0 mm. Final selection included 30 defects. The sites were randomly assigned treatment with DFDBA or BDX. Soft tissue and osseous defect measurements were taken the day of surgery and 6 months post-operatively at re-entry. Average baseline PD, CAL, and surgical defect depth for the DFDBA group were not statistically different from the BDX group. No adverse healing response occurred. The results showed a statistically significant improvement in PD and AL for both materials at 6 months in 26 defects (4 defects did not respond to therapy). Soft tissue measurements for the DFDBA group included PD reduction of 2.0+/-1.3 mm, and AL gain of 2.6+/-1.6 mm, while the BDX group showed a PD reduction of 3.0+/-1.7 mm, and AL gain of 3.6+/-1.8 mm. Osseous measurements showed bone fill of 2.4 mm (46.8%) for the DFDBA group and 3.0 mm (55.8%) for the BDX group. Defect resolution was 59.4% for the DFDBA group and 77.6% for the BDX group. Statistical analysis revealed there was no statistical difference between the 2 materials in all measurements.

"PURPOSE: To evaluate the 5-year clinical outcomes for implants placed in a staged sinus floor elevation (SFE) procedure and to compare three patient groups with sinus grafts with three different ratios of bovine bone mineral (BBM) and autogenous bone (AB) mixture.

MATERIALS AND METHODS: A 5-year prospective cohort study was conducted on 81 patients with 119 staged SFEs non-randomly distributed to three groups based on the origin of the AB and the mixture ratio with BBM: group 1 (locally harvested AB [LHB] from osteotomy sites + BBM, ratio: 1:10), 31 patients, 37 SFEs; group 2: (LHB + intraorally harvested peripheral AB [IHPB] from retromolar/chin region + BBM, ratio: 1:4), 22 patients, 29 SFEs; and group 3 (LHB + extraorally harvested peripheral AB [EHPB] from iliac crest/tibia + BBM, ratio 1:1), 28 patients, 53 SFEs. After graft healing (5 to 7 months), 284 dental implants (group 1: 76, group 2: 61, group 3: 147 [overall: 2.3 implants/sinus]) were placed. After an additional healing period (5 to 7 months), all implants placed were functionally loaded and prospectively followed by clinical and radiographic evaluations assessing implant survival/success rate as well as peri-implant marginal bone level (MBL) alteration at 1, 3, and 5 years postloading.

RESULTS: A total of 76/81 patients with 267/284 implants were followed for up to 5 years (dropouts: 5 patients/15 implants; implant loss = 2). The 5-year implant survival and implant success rate (group 1: 100%/98.6%; group 2: 98.3%/96.6%; group 3: 99.3%/95.7%) did not differ between the three graft mixture groups. The peri-implant marginal bone alteration (reduction) averaged over all 5 years was 1.40 ± 0.29 mm for group 1, 1.41 ± 0.22 mm for group 2, and 1.46 ± 0.46 mm for group 3 (P = .187). However, over time, a continual and significant MBL reduction (P = .045) was noted for all groups presenting peri-implant MBL changes between 1 year and 5 years of -0.17 mm (group 1), -0.12 mm (group 2), and -0.24 mm (group 3), respectively.

CONCLUSION: According to the clinical results obtained, dental implants inserted in grafted (staged) SFE using a mixture of BBM with a minimal amount of AB harvested from local sites provide for similarly high 5-year implant/augmentation success rates as graft mixtures with AB harvested from peripheral intraoral or extraoral donor sites, confirming no need for additional bone harvesting."

BACKGROUND:
This study aimed to evaluate, longitudinally, the outcome of periodontal regenerative therapy using a deproteinized bovine bone mineral (DBBM) in combination with a collagen barrier (CB) for the treatment of intrabony defects.

RESULTS:
Patients with chronic periodontitis who have completed initial periodontal therapy participated in this study. They had at least one 2- or 3-wall intrabony periodontal defect of ≥3 mm in depth. During surgery, defects were filled with DBBM and covered with CB. Ten patients completed 2.5-year reevaluation. At baseline, mean clinical attachment level (CAL) of the treated site was 8.0 mm and mean probing depth (PD) was 7.5 mm. Mean depth of intrabony component was 4.6 mm. Mean gains in CAL at 6 months and 2.5 years were 2.8 ± 1.0 and 1.4 ± 1.5 mm, respectively, both showing a significant improvement from baseline. CAL gains at 1 and 2.5 years were significantly reduced from that at 6 months. A significant improvement in PD was also noted: mean reductions in PD at 6 months and 2.5 years were 4.0 ± 0.8 and 3.2 ± 0.8 mm, respectively.

CONCLUSIONS:
The combination therapy using DBBM and CB yielded statistically significant effects such as CAL gain and PD reduction, up to 2.5 years in the treatment of intrabony defects. However, the trend for decrease in CAL gain over time calls for the need for careful maintenance care.

Aim: This prospective multicenter randomized controlled clinical trial was designed to compare the clinical outcomes of papilla preservation flap surgery with or without the application of a guided tissue regeneration (GTR)/bone replacement material.

Materials and Methods: One hundred and twenty-four patients with advanced chronic periodontitis were recruited in 10 centers in seven countries. All patients had at least one intrabony defect of >/=3 mm. The surgical procedures included access for root instrumentation using either the simplified or the modified papilla preservation flap in order to obtain optimal tissue adaptation and primary closure. After debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CALs), probing pocket depths (PPDs), recession, full-mouth plaque scores and full-mouth bleeding scores (FMBS) were assessed.

Results: One year after treatment, the test defects gained 3.3+/-1.7 mm of CAL, while the control defects yielded a significantly lower CAL gain of 2.5+/-1.5 mm. Pocket reduction was also significantly higher in the test group (3.7+/-1.8 mm) when compared with the controls (3.2+/-1.5 mm). A multivariate analysis indicated that the treatment, the clinical centers, baseline PPD and baseline FMBS significantly influenced CAL gains. Odds ratios (ORs) of achieving above-median CAL gains were significantly improved by the test procedure (OR=2.6, 95% CI 1.2-5.4) and by starting with deeper PPD (OR=1.7, 1.3-2.2) but were decreased by receiving treatment at the worst performing clinical center (OR=0.9, 0.76-0.99).

Conclusion: The results of this trial indicated that regenerative periodontal surgery with a GTR/bone replacement material offers an additional benefit in terms of CAL gains, PPD reductions and predictability of outcomes with respect to papilla preservation flaps alone.

The aim of this study was to evaluate the clinical remodeling of the alveolar socket following the application of bovine-derived xenograft collagen and collagen membrane compared to natural spontaneous healing during the first 6 months following tooth extraction. A total of 20 patients with 20 fresh alveolar sockets were randomly allocated into a test or control group. After a 6-month follow-up period, surgical reentry was performed and implants were placed. Significant statistical differences were recorded in terms of vertical and horizontal bone changes between the test and control groups. Within the limitations of this study, socket preservation procedures may provide more favorable conditions for subsequent implant placement.

This study evaluated the clinical, radiographic, and histologic response to Bio-Oss® porous bone mineral when used alone or in combination with Bio-Gide® bilayer collagen membrane in human periodontal defects were treated: two received Bio-Oss® alone and two were treated with a combination of Bio-Oss® and Bio-Gide®. Radiographs, clinical probing depths, and attachment levels were obtained preoperatively and 6 to 9 months postoperative, and teeth and surrounding tissues were biopsied. Both treatments significantly improved clinical probing depths and attachment levels, and the radiographic appearance suggested osseous fill. Histologic evaluation revealed that both treatments produced new cementum with inserting collagen fibers and new bone formation on the surface of the graft particle; this regenerative effect was more pronounced using the Bio-Oss®/Bio-Gide® combination, which resulted in 7 mm of new cementum and periodontal ligament and extensive new bone incorporating the graft (see Fig.). The membrane was intact at 7 months and partially degraded by 9 months after treatment. This human histologic study demonstrates that the porous bone mineral matrix used has the capacity to stimulate substantial new bone and cementum formation and that this capacity is further increased when the graft is used with a slowly resorbing collagen membrane.

PURPOSE:
As dental implants have become routine therapy, clinicians are more frequently being faced with treating peri-implantitis. To date, no single treatment protocol has been shown to be the preferred means to treat peri-implantitis. The aim of this retrospective case series is to present a novel approach utilizing porcine collagen-coated bovine bone (CBB) to treat peri-implantitis.

MATERIALS AND METHODS:
Eleven patients, with no history of periodontitis, presenting with peri-implantitis around a single restored dental implant, were included in the study. At initial and follow-up examinations, bleeding on probing (BOP), probing depth (PD), and gingival margin location (GM) were recorded. Following surgical debridement of the peri-implant defect and treatment of the implant surface with a 0.12% chlorhexidine gluconate solution, bony defects were grafted with CBB. All patients had 12 months of follow-up.

RESULTS:
Upon presentation, average PD at the deepest site (DS) was 7.6 ± 1.9 mm. At the time of surgery, excess cement was found around nine implants (81%). All patients healed uneventfully without postoperative complications. At 6 and 12 months, all implants showed favorable results with average DS PD reduction of 3.9 ± 1.5 mm and 4.1 ± 1.6 mm, respectively. All implants showed radiographic signs of bone fill, while GM showed no changes from preoperative measurements at either 6 (0.1 ± 0.5 mm) or 12 (0.0 ± 0.6 mm) months.

CONCLUSION:
The use of a porcine collagen-coated bovine bone graft to treat peri-implantitis represents a potentially predictable therapeutic modality. Randomized controlled trials are necessary to substantiate the treatment outcomes.

Background: Combined periodontal regenerative technique (CPRT) is a surgical procedure that combines the use of barrier membranes with a filling material in the treatment of periodontal defects. The effectiveness of CPRT has been evaluated in many studies in comparison to GTR with membranes alone, but conflicting results have been obtained by different clinicians, particularly in the treatment of intrabony defects. The aim of the present study was to compare CPRT to GTR with collagen membranes in the treatment of human intrabony defects characterized by a relevant 1-wall component.

Methods: Thirty-four (34) healthy, non-smoking patients affected by moderate to severe chronic periodontitis participated in this study. Each patient had good oral hygiene and at least 1 radiographically detectable intrabony defect > or = 4 mm, with a 1-wall component of at least 50% of the defect, involving 2 tooth surfaces or more with a probing depth (PD) > or = 6 mm. Seventeen (17) subjects were randomly assigned to the test group and underwent CPRT by anorganic bovine bone and a collagen membrane, and 17 randomly assigned to the control group who received GTR with a collagen membrane alone. Pre- and post-therapy clinical parameters (probing depth [PD]; clinical attachment level [CAL]; gingival recession [GR]) and intrasurgical parameters (depth of intraosseous component [IOC]; level of the alveolar crest [ACL]) were compared between test and control groups 1 year after treatment. Vertical bone gain (VBG) from the base of the defect to the cemento-enamel junction was also evaluated in both groups.

Results: At the 1-year examination, clinical and intrasurgical parameters showed statistically significant changes within each experimental group from baseline. A statistically greater CAL gain was reported in the test group (P<0.05), whereas the control group exhibited more GR [recessions] and alveolar crest resorption at a statistically significant level (P<0.01). VBG was significantly greater (P<0.01) at test sites (5.23 +/- 1.30 mm) compared to controls (3.82 +/- 1.28 mm).

Conclusion: The results suggest that the use of CPRT may be preferred when bioabsorbable membranes are used to treat intrabony defects characterized by unfavorable architecture.

This case report presents a 3-year follow-up of the clinical outcomes of a combined surgical therapy for advanced peri-implantitis with concomitant soft tissue volume augmentation using a collagen matrix. One patient suffering from advanced peri-implantitis and a thin mucosal biotype underwent access flap surgery, implantoplasty at buccally and supracrestally exposed implant parts, and augmentation of the intrabony components using a natural bone mineral and a native collagen membrane after surface decontamination. A collagen matrix was applied to the wound area to increase soft tissue volume and support transmucosal healing. The following clinical parameters were recorded over a period of 3 years: bleeding on probing (BOP), probing depth (PD), mucosal recession (MR), clinical attachment level (CAL), and width of keratinized mucosa (KM). At 36 months, the combined surgical procedure was associated with a clinically important reduction in mean BOP (100%), PD (4.3 ± 0.5 mm), and CAL (4.4 ± 0.4 mm). Site-level analysis of the buccal aspects pointed to an increase in MR (-1.0 ± 0.4 mm) and a decrease in KM (-1.3 ± 0.5 mm) values at 12 months. However, a regain in mucosal height and KM was noted at 24 months, even reaching respective baseline values after 36 months of healing. The presented combined surgical procedure was effective in controlling an advanced peri-implantitis lesion without compromising the overall esthetic outcome in the long term.

AIM: The aim of this split-mouth randomized controlled study was to evaluate radiographic dimensional changes after tooth extraction in posterior sites treated with a ridge preservation technique or left for spontaneous healing.

MATERIALS AND METHODS: In a total of 18 patients, tooth extraction in posterior sites of the upper and lower jaw was performed in a split-mouth design. The post-extraction sockets were randomly assigned to the following two treatment modalities: deproteinized bovine bone mineral (DBBM) with 10% collagen (DBBM-C) covered with a native bilayer collagen membrane (NBCM) (test group) and spontaneous healing (control group). Cone beam computed tomography (CBCT) scans were performed after extractions, 3 and 6 months later. The following parameters were measured: the height of the buccal bone plate (BH), height of the palatal bone plate (PH), horizontal width of the extraction socket at 1 mm, 3 mm, and 5 mm (HW-1, HW-3, HW-5), and the horizontal width (thickness) of the buccal bone plate at 1 mm, 3 mm, and 5 mm (BHP-1, BHP-3, BHP-5). Statistical analysis was performed applying a nonparametric Wilcoxon signed-rank test.

RESULTS: The CBCT analysis showed a bone loss compared to baseline in test and control group. The measurements which have reached statistically significant differences at 6 months were BH (test: -2.31% vs control: -13.11%), PH (test: -2.07% vs control: -15.32%), HW-1 (test: -17.14% vs control: -32.47%), and HW-3 (test: -11.65% vs control: -28.47%).

CONCLUSIONS: The posterior ridge preservation technique using DBBM-C covered with a NBCM is a valid approach reducing the amount of the radiographic loss in alveolar ridge dimensions.

The authors review patient-reported outcome (PRO) metrics for dentistry, and in particular, periodontics. The PRO commentary for periodontics includes a review of split-mouth, randomized, controlled clinical trial results that specifically tracked pain at different sites over time after intervention and provided guidelines for peak pain time points and evidence for referred pain assessment when studying soft tissue augmentation procedures. Both the questions that are asked of patients and the timing of those questions are important study design considerations. The authors suggest PRO methodology for periodontal clinical trials that can be used to identify information important to patients and clinicians.

Purpose: Bovine-derived bone xenograft and mineralized cancellous bone allograft have been successfully used as bone substitutes in dental surgery, but few clinical studies in humans have been reported. The objective of this study was to compare the osteoconductive effects of deproteinized bovine bone mineral (DBBM), irradiated cancellous allograft (ICA), and solvent-dehydrated allograft (SDA) when used to preserve extraction sockets.

Materials and methods: Twenty patients received bone grafting in extraction sockets with DBBM (n = 7), ICA (n = 8), or SDA (n = 5). Core biopsies were taken from each graft site 4 to 6 months after grafting and were evaluated histomorphometrically. One-way analysis of variance was used to compare each variable. P values less than .05 were considered significant.

Results: DBBM induced more new bone deposition in the periphery of the native bone particles than ICA or SDA, whereas ICA and SDA were more frequently surrounded by fibrous tissue than DBBM. In addition, DBBM retained more residual graft bony particles than ICA or SDA.

Conclusion: Based on these findings, the DBBM showed more of an osteoconductive effect than ICA or SDA, producing a more rigid bony structure. It is therefore suggested that DBBM may be more favorable for the preservation of extraction sockets than allogeneic graft materials.

AIM: To test the non-inferiority of demineralized bovine bone mineral (DBBM) compared to DBBM with 10% collagen (DBBM-C) for maintenance of bone volume after tooth extraction in the anterior maxilla.

MATERIALS AND METHODS: Sixty-six patients were randomly treated with DBBM or DBBM-C, both of which were covered with a collagen matrix for ridge preservation in the anterior maxilla. Cone-beam computed tomographic analysis was performed immediately and 4 months after treatment. The primary outcome, for which non-inferiority of DBBM was tested, was change in the horizontal ridge width 1 mm below the buccal alveolar crest (HW-1) 4 months after extraction.

RESULTS: Four months after extraction, HW-1 measured -1.60 mm ± 0.82 mm for DBBM-C, while the DBBM group showed a mean loss of -1.37 mm ± 0.84 mm (p = 0.28, 0.23 [95% CI: -0.19; 0.64]). The horizontal ridge width at 3 mm (HW-3) showed -0.98 mm (±0.67 mm) for DBBM-C and -0.84 mm (±0.62 mm) for DBBM (p = 0.40, 0.12 [95% CI: -0.19; 0.45]), and the horizontal ridge width at 5 mm (HW-5) showed -0.67 mm (±0.47 mm) for DBBM-C and -0.56 mm (±0.48 mm) for DBBM (p = 0.36, 0.11 [95% CI: -0.13; 0.34]).

CONCLUSIONS: The present clinical trial demonstrated non-inferiority of DBBM compared to DBBM-C for maintenance of alveolar bone volume 4 months after tooth extraction in the anterior maxilla.

This prospective, randomized, controlled clinical trial compared the clinical outcomes for a polylactic acid barrier versus a collagen membrane in conjunction with guided tissue regeneration (GTR). Thirty patients with chronic periodontitis and at least one intrabony defect of a minimum 4 mm were enrolled. Following full-mouth scaling, GTR using a collagen membrane or a polylactic acid barrier was performed at one site in each patient. At 1 week before and 6 months after surgery, probing pocket depth (PPD), clinical attachment level (CAL), marginal tissue recession, and bone fill were assessed. A significant reduction in PPD (2.50 +/- 1.35 mm for the polylactic acid barrier and 2.60 +/- 1.08 mm for the collagen membrane) was obtained, in addition to gains in CAL (2.40 +/- 1.17 mm for the polylactic acid barrier and 2.60 +/- 1.26 mm for the collagen membrane) and bone fill (0.33 +/- 1.89 mm for polylactic acid barrier and 2.57 +/- 1.64 mm for collagen membrane), for each group compared to baseline. Significantly, the results from 6 months after surgery showed that there was greater bone fill when the collagen membrane was used compared to the polylactic acid barrier.

"PURPOSE: To evaluate the effectiveness of collagen matrix (CM) grafts as an alternative to free gingival grafts (FGGs) in increasing the zone of keratinized tissue (KT) around dental implants.

METHODS: Thirty subjects with 2 contralateral implants were recruited. The test group (n = 30) received CM grafts. The control group (n = 30) received FGGs. Clinical variables were plaque index, gingival index, probing depths, bleeding on probing (BOP), and mucosal recession (MR). Subjects were followed at 1 and 2 weeks and 1, 3, and 6 months.

RESULTS: FGGs resulted in mean gains (3.73 ± 1.93 mm) in KT for 28 of 30 implants (93% success rate). CM grafts resulted in mean gains (3.23 ± 1.52 mm) in KT for 29 of the 30 implants (97% success rate). Mean change in pocket depth around implants grafted with FGG was -0.24 ± 1.02 mm and with CM was -0.25 ± 0.80 mm. Mean change in BOP around implants grafted with FGG was 0.03 ± 0.49 and with CM was 0.13 ± 0.57.

CONCLUSION: CM grafts achieved results comparable to those of FGGs in augmented tissue. They do not negatively affect probing depths, MR, or bleeding on probing."

The purpose of this study was (a) to evaluate the cytocompatibility of three resorbable and nonresorbable membranes in fibroblast and osteoblast-like cell cultures and (b) to observe the growth of those cells on the various barriers by scanning electron microscopy (SEM). Primary human periodontal ligament fibroblasts (HPLF) and human osteoblast-like cells (SAOS-2) were incubated with nonresorbable polytetrafluoroethylene (ePTFE) barriers and resorbable polylactic acid as well as collagen membranes. Cytotoxic effects were determined by XTT (mitochondrial metabolic activity) and sulforhodamine B assays (cellular protein content). In addition, HPLF and SAOS-2 grown for 21 days on the investigated barriers were evaluated by SEM. Data were analyzed statistically by ANOVA using the Wilcoxon-Mann-Whitney test (P<0.05). No changes were established in the periodontal fibroblasts and human osteoblast-like cells after incubation with collagen membrane. Cytotoxic effects, however, were induced by the polylactic acid barrier, which slightly inhibited cell metabolism of the periodontal fibroblasts (XTT: 90.1%_+ 3.6of control value). Moderate cytotoxic reactions were caused by the nonresorbable ePTFE membrane in HPLF-cultures (XTT: 82.7%±3.5) and osteoblast-like cell monolayers (XTT: 80.0%±0.6%). Mitochondrial activity in both cell cultures was significantly reduced by ePTFE barriers in comparison to non-incubated control cells (P = 0.028). SEM analysis of cell behavior on barriers demonstrated the differences between these materials: collagen barriers were densely populated with HPLF and SAOS-2, whereas only few or no cells were seen to adhere to the ePTFE and polylactic acid membranes. Our findings indicate that the collagen barrier investigated is very cytocompatible and may be integrated into connective tissue well. On the contrary, the ePTFE and polylactic acid membranes induced slight to moderate cytotoxic reactions which may reduce cellular adhesion. Thus, gap formation between the barrier surface and the connective tissue may be promoted which may facilitate epithelial downgrowth and microbial accumulation. Consequently, these effects may reduce the potential gain in periodontal attachment.

Multiple adjacent recession defects were treated in 32 patients using a coronally advanced flap (CAF) with or without a collagen matrix (CM). The percentage of root coverage was 81.49% ± 10.01% root coverage (72% complete root coverage) for CM plus CAF sites (test). The results achieved in the test group were significantly greater than in the control group, indicating that CM plus CAF is a suitable option for the treatment of multiple adjacent gingival recessions.

Background: Early barrier membrane degradation may result in decreased bone formation in guided bone regeneration (GBR) procedures. The aim of this study was to evaluate the bio-degradation of cross-linked (CLM) and non-cross-linked (NCLM) collagen membranes experimentally exposed to the oral environment of study animals.

Methods: In eight cats, 48 surgical procedures were performed, three along each side of the palate: 24 full-thickness soft tissue perforations were made and 24 full-thickness mini-flaps were raised. CLM or NCLM discs were placed either under the perforations and peripheral mucosa and left exposed (experimental) or covered by the flaps (controls). The four treatment modalities were equally distributed among the eight animals. Block sections were retrieved at 7 and 28 days post-operatively, providing histological specimens (6 each) at 7 and 28 days for each treatment modality.

Results: Histological observation revealed that CLM and NCLM remained intact in the control sites during the 28 days. At 7 and 28 days, CLM appeared interrupted in three and two experimental sites, respectively, and were undetected in the remaining sites. NCLM were interrupted in two sites each at 7 and 28 days, and were undetected in the other sites. There was no statistical difference between control specimens and between CLM and NCLM of the different treatment modalities at 7 or 28 days. Conclusion: Both cross-linked and non-cross-linked membranes were resistant to tissue degradation and maintained continuity throughout the study. However, none of the membranes was resistant to degradation when exposed to the oral environment.

OBJECTIVES: To present the clinical, radiographic, and patient-related outcomes of patients presenting with severely resorbed ridges reconstructed with autogenous calvarial bone blocks and rehabilitated with implant-supported prostheses. MATERIAL AND METHODS: From 1998 to 2014, 72 patients presenting with severe bone defects were reconstructed with autogenous calvarial bone blocks covered with bovine bone mineral granules and collagen membranes. Four to 9 months later, 330 implants were placed and loaded 3-9 months later. The follow-up ranged from 3 to 19 years (mean: 8.1 years). The following parameters were recorded: (a) complication rate of the reconstructive procedure; (b) bone resorption before implant placement; (c) implant survival rate and implant-related complications; (d) peri-implant bone resorption; and (e) patient's satisfaction inquired with a dedicated questionnaire. RESULTS: No patients developed severe complications, such as complete loss or resorption of the grafts. A dehiscence occurred in six patients, which developed a mild graft resorption. The mean peri-implant bone resorption before implant placement was 0.13 mm (SD ± 0.71). All patients received the planned number of implants. Three patients were lost during the follow-up. The survival rate of implants at the end of the observation period was 98.5%. The mean peri-implant bone resorption ranged from 0.00 to 4.87 mm (mean: 1.11 mm). At last, 90% of the patients were very satisfied as regards the treatment received. CONCLUSIONS: Results from this study suggested that: (a) bone volume in the areas reconstructed with calvarial grafts was stable over time; (b) survival rates of implants were consistent with those reported for implants placed in native bone; (c) patient's satisfaction was high.

This 6-month clinical study evaluated the use of a porous bone mineral matrix xenograft (Bio-Oss) as an adjunct to a biodegradable barrier membrane (Bio-Gide) to support healing following the immediate placement of transmucosal implants into extraction sockets. Twenty adult patients scheduled for tooth replacement with dental implants were accepted for participation. Following implant placement into the extraction site, subjects were assigned to one of two treatment alternatives for the remaining bone defect around the implant: (1) Bio-Oss + Bio-Gide membrane (test); or (2) Bio-Gide membrane (control). The treatment outcome was evaluated ­­­­after 6 months by the use of clinical and radiographic variables. The null hypothesis of no treatment group differences was tested by ANOVA. At 6 months, the radiographic bone level remained unchanged compared to baseline in the test and control groups. No differences were observed between test and control groups in terms of mean probing attachment level. At proximal sites, the soft tissue margin was located 2.6 mm more coronal than the shoulder of the implant in the test group, compared to 1.3 mm in the control group.

The corresponding figures for the lingual aspect were 2.3 mm and 1.1 mm, respectively, and at buccal sites 2.1 mm and 0.9 mm, respectively. The use of deproteinized bovine bone mineral as a membrane support at immediately placed transmucosal implants may offer an advantage in areas with high esthetic demands in terms of soft tissue support.

OBJECTIVES: This study aimed at evaluating soft and hard tissue dimensions after immediate implant placement and immediate temporization with or without alveolar preservation at the maxillary anterior region.

MATERIALS AND METHODS: Twenty-two patients needing maxillary incisor extraction and with the possibility of immediate implant placement were randomly assigned to the following groups: test (n = 11): immediate implant placement + deproteinized bovine bone derived with collagen inserted into the alveolus or control (n = 11): immediate implant placement without biomaterial. All soft tissue measurements were evaluated at baseline, 3 months, and 6 months after implant therapy. Cone beam tomography was performed at baseline and at 6 months after implant placement to evaluate hard tissue dimension.

RESULTS: The test group presented higher height of soft tissue at mesiobuccal and distobuccal sites at 3 months and 6 months when compared to the control group (p  < 0.05). Regarding the bone tissue, the test group showed higher buccolingual ridge dimension at 6 months when compared to the control group (p < 0.05).

CONCLUSIONS: It can be concluded that the use of deproteinized bovine bone derived with collagen together with immediate dental implants results in better soft and bone tissue outcomes than immediate implants alone.

CLINICAL RELEVANCE: The use of deproteinized bovine bone derived with collagen may enhance the results regarding soft and bone tissue in combination with immediate implant and temporization.

Aim: To evaluate the influence of deproteinized bovine bone mineral (DBBM) particles concomitant with the placement of a collagen membrane on alveolar ridge preservation and on osseointegration of implants placed into alveolar sockets immediately after tooth extraction.

Material and Methods: The pulp tissue of the mesial roots of (3) P(3) was removed in six Labrador dogs and the root canals were filled. Flaps were elevated in the right side of the mandible, and the buccal and lingual alveolar bony plates were exposed. The third premolar was hemi-sectioned and the distal root was removed. A recipient site was prepared and an implant was placed lingually. After implant installation, defects of about 0.6 mm wide and 3.1 mm depth resulted at the buccal aspects of the implant, both at the test and at the control sites. The same surgical procedures and measurements were performed on the left side of the mandible. However, DBBM particles with a size of 0.25-1 mm were placed into the remaining defect concomitant with the placement of a collagen membrane.

Results: All implants were integrated into mature bone. No residual DBBM particles were detected at the test sites after 4 months of healing. Both the test and the control sites showed buccal alveolar bone resorption, 1.8 +/- 1.1 and 2.1 +/- 1 mm, respectively. The most coronal bone-to-implant contact at the buccal aspect was 2 +/- 1.1 and 2.8 +/- 1.3 mm, at the test and the control sites, respectively. This difference in the distance was statistically significant.

Conclusion: The application of DBBM concomitant with a collagen membrane to fill the marginal defects around implants placed into the alveolus immediately after tooth extraction contributed to improved bone regeneration in the defects. However, with regard to buccal bony crest preservation, a limited contribution of DBBM particles was achieved.

Objectives: The aim of the following study was to assess contour changes after socket preservation techniques.

Material and Methods: In five beagle dogs, the distal root of the third and fourth mandibular premolars was extracted. The following treatments (Tx) were randomly assigned for the extraction socket. Tx 1: BioOss Collagen. Tx 2: BioOss Collagen and a free soft tissue graft. Tx 3: No treatment. Tx 4: The internal buccal aspect was covered with an experimental collagen membrane, the extraction socket was filled with BioOss Collagen and the membrane folded on top of the graft. Impressions were obtained at baseline, 2 and 4 months after surgery. Bucco-lingual measurements were performed using digital imaging analysis.

Results: All groups displayed contour shrinkage at the buccal aspect. Only the differences between the two test groups (Tx 1, Tx 2) and the control group (Tx 3) were significant at the buccal aspect (p< or =0.001). No measurements of the Tx 4 group could be performed. Conclusion: Socket preservation techniques, used in the present experiment, were not able to entirely compensate for the alterations after tooth extraction. Yet, incorporation of BioOss Collagen seems to have the potential to limit but not avoid the post-operative contour shrinkage.

Aim: To assess dimensional ridge alterations following immediate implant placement in molar extraction sites.

Material and Methods: Twelve subjects received 12 immediate transmucosal implants in molar extraction sites. Peri-implant defects were treated according to the principles of Guided Bone Regeneration by means of a deproteinized bone substitute and a bioresorbable collagen membrane. Changes in vertical (IS-BD, CREST-BD) and horizontal distances (EC-I, IC-I) of alveolar bony walls to the bottom of the defects (BD) and to the implant surfaces (I) were compared between implant placement and surgical re-entry at 6 months.

Results: The implant survival rate at 6 months was 100%. Statistically significant differences (P<0.01) were observed in the mean changes in vertical distances IS-BD and CREST-BD between baseline and re-entry. At re-entry, all peri-implant marginal defects assessed from the internal socket wall to the implant surface (IC-I) were healed. The residual combined thickness of the buccal wall with the newly formed peri-implant bone at sites with an initial thickness of 1 mm was statistically significantly smaller (P<0.05) compared with that of sites with an initial buccal thickness of 2 mm (2.50 +/- 0.76 vs. 4+/-0 mm).

Conclusion: The marginal defects around immediate implants placed in molar extraction sites were completely filled after 6 months of healing through de novo bone formation. Bone resorption was observed from the external aspects of the buccal and oral socket walls. Dimensional changes of the external socket walls were mostly pronounced at the buccal aspects.

Purpose: This study was designed to evaluate the use of xenograft plus a membrane as grafting material for periodontal osseous defects distal to the mandibular second molar compared with nongrafted extraction sites after removal of impacted mandibular third molars.

Materials and methods: We performed a single-blind, randomized, controlled clinical trial, and the sample comprised of subjects at high risk for the development of periodontal osseous defects distal to the second molar after third molar extraction (aged 30-35 years), pre-existing osseous defects distal to the second molar, and horizontal third molar impaction. The predictor variable was the treatment status of the second molar osseous defects. The third molar extraction sites were grafted with an anorganic xenograft plus a membrane. The other sites received a full-thickness flap and extraction of the third molar without placement of the grafting materials. The outcome variables were the change in gingival index, pocket probing depth, and clinical attachment level on the distobuccal aspect of the second molar preoperatively and at 3, 6, 9, and 12 months after surgery. Data were statistically analyzed by multivariate analysis of variance, and the statistical significance was set at P < .05.

Results: The study was composed of 28 sites that were selected by use of a split-mouth design for each patient, and this was randomly determined through a biased coin randomization. Twelve months after third molar removal, there was a statistically significant gain in the clinical attachment level and a reduction in the probing pocket depth in the grafted sites compared with the nongrafted sites (P < .001). Moreover, there was a significant difference in the alveolar bone height during the monitoring periods for the grafted sites compared with the nongrafted sites (P < .001).

Conclusion: Grafting of osseous defects distal to mandibular second molars with an anorganic xenograft plus a membrane predictably resulted in a significant reduction in the probing pocket depth, clinical attachment level gain, and bone fill, which suggests that grafting the extraction sites with an anorganic xenograft plus a membrane could prevent periodontal disease in the future.

Aim: To evaluate the soft tissue response to immediately placed implants using the platform-switching concept.

Material and Methods: In 22 patients, 22 implants of 5.5 mm platform diameter were placed immediately into fresh extraction sockets in maxillae without compromised bone tissue. Eventual post-extraction bone defects were filled using bovine bone matrix mixed with collagen. Immediately after insertion, implants were randomly divided: 11 implants were connected with a 3.8 mm diameter abutment (test group) and 11 with a 5.5 mm diameter abutment (control group). A provisional crown was adapted and adjusted for non-functional immediate positioning. Two months later, definitive prosthetic rehabilitation was performed. Periodontal parameter, buccal peri-implant mucosal changes (REC), mesial and distal papilla height (PH) and vertical height of jumping distance (VHG) were measured at the time of implant placement, of definitive prosthesis insertion and every 6 months thereafter.

Results: The mean follow-up was 25 months. All implants were clinically osseointegrated. The test group showed a +0.18 mm REC gain. PH gain was +0.045 mm on average. The mean values were statistically significant (P< or =0.005) compared with the control group (PH=-0.88 mm; REC=-0.45 mm). No difference between the two groups in periodontal parameters was found. The mean value of bone filling was 7.51 mm in the test group (97.4% of VHG) and 8.57 mm in the control group (95.2% of VHG). No statistically significant difference was found between the two groups.

Conclusion: This study suggests that, in a limited time period of 2 years, immediately placed implants with subsequent platform switching can provide peri-implant tissue stability.

Aim: The objective of this experiment was to analyze processes involved in the incorporation of Bio-Oss Collagen in host tissue during healing following tooth extraction and grafting.

Methods: Five beagle dogs were used. Four premolars in the mandible ((3)P(3), (4)P(4)) were hemi-sected, the distal roots were removed and the fresh extraction socket filled with Bio-Oss Collagen. The mucosa was mobilized and the extraction site was closed with interrupted sutures. The tooth extraction and grafting procedures were scheduled in such a way that biopsies representing 1 and 3 days, as well as 1, 2 and 4 weeks of healing could be obtained. The dogs were euthanized and perfused with a fixative. Each experimental site, including the distal socket area, was dissected. The sites were decalcified in EDTA, and serial sections representing the central part of the socket were prepared in the mesio-distal plane and parallel with the long axis of the extraction socket. Sections were stained in hematoxylin and eosin and were used for the overall characteristics of the tissues in the extraction socket. In specimens representing 1, 2 and 4 weeks of healing the various tissue elements were assessed using a morphometric point counting procedure. Tissue elements such as cells, fibers, vessels, leukocytes and mineralized bone were determined. In deparaffinized sections structures and cells positive for tartrate-resistant acid phosphatase activity (TRAP), alkaline phosphatase and osteopontin were identified.

Results: The biomaterial was first trapped in the fibrin network of the coagulum. Neutrophilic leukocytes [polymorphonuclear (PMN) cells] migrated to the surface of the foreign particles. In a second phase the PMN cells were replaced by multinuclear TRAP-positive cells (osteoclasts). The osteoclasts apparently removed material from the surface of the xenogeneic graft. When after 1-2 weeks the osteoclasts disappeared from the Bio-Oss granules they were followed by osteoblasts that laid down bone mineral in the collagen bundles of the provisional matrix. In this third phase the Bio-Oss particles became osseointegrated.

Conclusion: It was demonstrated that the incorporation of Bio-Oss in the tissue that formed in an extraction wound involved a series of different processes.

Background: Early implant placement is one of the treatment options in postextraction sites in the anterior maxilla. Implant placement is performed after a soft tissue healing period of 4 to 8 weeks. Implant placement is combined with a simultaneous guided bone regeneration (GBR) procedure to rebuild esthetic facial hard and soft tissue contours.

Methods: In this prospective case-series study, 20 consecutive patients treated with an implant-borne single crown were prospectively followed for 12 months. Clinical, radiologic, and esthetic parameters were recorded to assess treatment outcomes. Results: At the 12- month examination, all 20 implants were successfully integrated, demonstrating ankylotic stability and healthy peri-implant soft tissues as documented by standard parameters. The esthetic outcomes assessed by a pink esthetic score (PES) and a white esthetic score (WES) demonstrated pleasing results overall. The WES values were slightly superior to the PES values. The periapical radiographs showed minimal crestal bone loss around the used bone level implants, with mean bone loss of 0.18 mm at 12 months. Only one implant showed >0.5 mm bone loss, combined with minor mucosal recession of 0.5 to 1.0 mm.

Conclusion: This prospective case series study evaluating the concept of early implant placement demonstrated successful tissue integration for all 20 implants. The short-term follow-up of 12 months revealed pleasing esthetic outcomes overall, as assessed by objective parameters. The risk for mucosal recession was low; only one patient showed minor recession of the facial mucosa. These encouraging results need to be confirmed with 3- and 5-year follow-up examinations.

Introduction: Maxillary sinus augmentation is a predictable implant site development technique, although several local and systemic factors may influence outcomes. The aim of this study was to evaluate healing patterns and bone remodeling activity following the use of two different graft mixtures for maxillary sinus augmentation.

Materials and Methods: Patients in need of maxillary sinus augmentation were randomly assigned to two different groups. A graft mixture using a 50% autologous bone (AB) to 50% anorganic bovine bone (ABB) ratio was used in-group 1, while a 20% AB to 80% ABB ratio was utilized for group 2. After a 6-month healing period, bone core biopsies were harvested for histological, histomorphometrical, and immunohistochemical analyses.

Results: Twenty-eight subjects participated in this study. No statistically significant differences were found between groups in regards to vital bone and non-mineralized tissue proportions. Higher number of osteoid lines (18.05 +/- 10.06 in group 1 vs. 9.01 +/- 7.53 in group 2; P=0.023) and higher cellularity, particularly regarding the number of osteocytes (631.85 +/- 607.98 in group 1 vs. 219.08 +/- 103.26 in group 2; P=0.002), were observed in specimens from group 1. Differences in expression patterns of osteopontin and tartrate-resistant acid phosphatase were also detected between groups.

Conclusion: AB to ABB ratio appears to influence bone remodeling patterns and cell content following maxillary sinus augmentation procedures. Similar proportion of vital bone was found in specimens obtained from both groups. More cellular presence was observed in samples containing higher proportions of AB.

Background: The purpose of this investigation was to evaluate the regenerative response to deproteinized porous bovine bone mineral (BM) when used alone or in combination with a bioresorbable porcine-derived bilayer collagen membrane (CM) for alveolar ridge augmentation in dogs.

Materials and Methods: The mandibular premolars were extracted unilaterally and three ridge defects were induced in six mongrel dogs. Each defect site was randomly assigned to one of the following treatment groups: BM alone (group A), BM in combination with CM (group B), or neither membrane nor bone graft, which served as a control (group C). No adverse events occurred during the experimental period. Dental computed tomography (CT) scans were taken after postoperative periods of 8 and 16 weeks.

Results: The percentage of CT-derived bone density in groups A and B was significantly different from that of group C (p < 0.01) at 8 and 16 weeks. The percentage of CT-derived bone density of the dogs in Group B was significantly higher than that of those in group A at 8 and 16 weeks (p < 0.01). Gross evaluation of the 3-dimensional CT reconstruction image of the canine mandibles after 16 weeks of implantation showed that group B had the greatest amount of bone augmentation and excellent thickness of the buccal aspect of the alveolar ridge.

Conclusion: These results suggest that BM leads to more successful bone regeneration for guided bone regeneration procedures, especially in conjunction with the use of a CM as a barrier in order to promote the regeneration of canine alveolar ridge defects.

Aim: The aim of the present study was to evaluate if the use of deprotenized bovine bone mineral (DBBM) and collagen barrier membranes (CM) in combination with mandibular bone block grafts could reduce bone block graft resorption during healing.

Methods: A prospective randomized controlled study has been designed. Twenty-two ridges presenting horizontal alveolar deficiency (crest width <4 mm) and at least two adjacent missing teeth were included in the study. In the control group, one or multiple mandibular blocks were used to gain horizontal augmentation of the ridge. In the test group, DBBM granules were added at the periphery and over the graft. The reconstructions were covered by two layers of CM. Implants were placed 4 months after grafting. Direct measurements of crest width were performed before and immediately after bone augmentation, and immediately before implant placement.

Results: Statistical analysis showed no significant differences in crest width between test and control groups at baseline and immediately after grafting. Mean augmentation at first surgery in the test group was 4.18 vs. 4.57 mm in the control group. Final gain obtained at the time of implant placement was 3.93 mm in the test and 3.67 mm in the control groups. The difference in mean graft resorption between test and control sites was statistically significant (0.25 mm in the test group vs. 0.89 mm in the control group, P=0.03). Complications seem to occur more often in the test group (complications recorded in three cases in the test group vs. one complication recorded in the control group). In all cases, implants could be placed in the planned sites and a total of 55 implants were placed (28 in the test group and 27 in the control group). All implants could be considered successfully integrated at the 24-month follow-up visit.

Conclusion: The results from this study showed that the addition of bovine bone mineral and a CM around and over a mandibular bone block graft could minimize graft resorption during healing. On the other hand, the use of bone substitutes and barrier membranes in combination with block grafts increased the frequency of complications and the difficulty of their management.

OBJECTIVES:
The augmentation of the alveolar ridge using iliac cortico-spongeous bone grafts is routinely used. However, bone grafts show a substantial degree of resorption, which may negatively affect the long-term success of dental implants in the augmented area. The aim of this study was to evaluate the effect of a deproteinized bovine bone matrix coverage on the resorption of iliac bone grafts.

MATERIAL AND METHODS:
Two cohorts consisting of 40 patients who received a vertical augmentation of the alveolar ridge with onlay grafts from the iliac crest were prospectively investigated over a period of 2 years. In half of the patients (n = 40), the grafts were covered by a thin layer of deproteinized bovine bone matrix (DBBM cohort). The other 40 patients received the identical surgical procedure without a DBBM coverage (non-DBBM cohort). The graft height/resorption was radiographically determined immediately after surgery, 6 months, 1 year, and 2 years postoperatively.

RESULTS:
The height of the bone graft 6 months after surgery accounted 92.15% of the initial value in the DBBM cohort and 87.76% in the non-DBBM cohort. One year after augmentation, the height reduced to 83.95% in the DBBM cohort and 72.92% in the non-DBBM cohort. Two years after surgery, the resorption slowed down and the height of the grafts accounted 81.27% in the DBBM cohort and 71.43% in the non-DBBM cohort. The difference was statistically significant.

CONCLUSION:
Deproteinized bovine bone matrix reduces the postoperative resorption of iliac bone block grafts and may therefore enhance the long-term implant prognosis in the augmented area.

Background: Grafting the floor of the maxillary sinus has become the most common surgical intervention for increasing alveolar bone height prior to the placement of endosseous dental implants in the posterior maxilla. Outcomes of this procedure may be affected by specific surgical techniques, simultaneous versus delayed implant placement, use of barrier membranes over the lateral window, selection of graft material, and the surface characteristics and the length and width of the implants.

Rationale: The primary objective of this systematic review was to determine the efficacy of the sinus augmentation procedure and compare the results achieved with various surgical techniques, grafting materials, and implants.

Focused Question: In patients requiring dental implant placement, what is the effect on implant survival of maxillary sinus augmentation versus implant placement in the non-grafted posterior maxilla?

Search Protocol: MEDLINE, the Cochrane Oral Health Group Specialized Trials Register, and the Database of Abstracts and Reviews of Effectiveness were searched for articles published through April 2003. Hand searches were performed on Clinical Oral Implants Research, International Journal of Oral and Maxillofacial Implants, and the International Journal of Periodontics & Restorative Dentistry and the bibliographies of all relevant papers and review articles. In addition, researchers, journal editors, and industry sources were contacted to see if pertinent unpublished data that had been accepted for publication were available.

Selection Criteria/Inclusion Criteria: Human studies with a minimum of 20 interventions, a minimum follow-up period of 1-year loading, an outcome measurement of implant survival, and published in English, regardless of the evidence level, were considered.

Exclusion Criteria: Studies involving multiple simultaneous interventions (e.g., simultaneous ridge augmentation) and studies with missing data that could not be supplied by the study authors were excluded. Data Collection and Analysis: Where adequate data were available, subgroups of dissimilar interventions (e.g., surgical techniques, graft materials, implant surfaces, membranes) were isolated and subjected to meta-regression, a form of meta-analysis.

Main Results: 1. Forty-three studies, 3 randomized controlled clinical trials (RCTs), 5 controlled trials (CTs), 12 case series (CS), and 23 retrospective analyses (RA) were identified. Thirty-four were lateral window interventions, 5 were osteotome interventions, 2 were localized management of the sinus floor, and 2 involved the crestal core technique. 2. Meta-regression was performed to determine the effect of the variables of block versus particulate grafting techniques, implant surface, graft material, and the use of a membrane over the lateral window. 3. The survival rate of implants placed in sinuses augmented with the lateral window technique varied between 61.7% and 100%, with an average survival rate of 91.8%. For lateral window technique: 4. Implant survival rates reported in this systematic review compare favorably to reported survival rates for implants placed in the non-grafted posterior maxilla. 5. Rough-surfaced implants have a higher survival rate than machine-surfaced implants when placed in grafted sinuses. 6. Implants placed in sinuses augmented with particulate grafts show a higher survival rate than those placed in sinuses augmented with block grafts. 7. Implant survival rates were higher when a membrane was placed over the lateral window. 8. The utilization of grafts consisting of 100% autogenous bone or the inclusion of autogenous bone as a component of a composite graft did not affect implant survival. 9. There was no statistical difference between the covariates of simultaneous versus delayed implant placement, types of rough-surfaced implants, length of follow-up, year of publication, and the evidence level of the study.

Reviewers' Conclusion: Insufficient data were present to statistically evaluate the effects of smoking, residual crestal bone height, screw versus press-fit implant design, or the effect of implant surface micromorphology other than machined versus rough surfaces. There are insufficient data to recommend the use of platelet-rich plasma in sinus graft surgery.

The purpose of this study was to investigate the effect of porous xenographic bone graft (Bio-Oss) with a collagen barrier membrane (Bio-Gide) on formation of new cementum and new bone in experimental intrabony defects of dogs. The intrabony defects were treated by either guided tissue regeneration with the collagen membrane (control group) or the collagen membrane with the porous bone mineral graft (experimental group). After 8 weeks, the animals were sacrificed and the tissues were histologically examined. New cementum with inserting collagen fibers was observed on the exposed surfaces in both groups. The amount of new bone was significantly greater in the group using the bone graft with the membrane than in the control group. The use of the collagen barrier membrane in combination with the porous bone graft material may enhance new bone and cementum formation.

Background: The effect of two different bioabsorbable collagen membranes on bone regeneration was assessed in standardized, membrane-protected calvarial defects in pigs.

Methods: Two standardized defect types (6 x 6 x 6 mm and 9 x 9 x 9 mm) were produced in the calvaria of pigs: empty defects without a membrane (group 1; eight defects per size); defects filled with deproteinized bovine bone mineral (DBBM) without a membrane (group 2; eight defects per size); defects filled with DBBM and covered by a collagen membrane (group 3; eight defects per size); and defects filled with DBBM and covered by a cross-linked collagen membrane (CCM) (group 4; eight defects per size). Sacrifice took place 16 weeks after surgery, and the following parameters were analyzed: descriptive histology; semiquantitative histology (SQH), assessing bone regeneration in the whole defect area; and histomorphometric analysis of the percentage of bone and DBBM in the regenerated area at three different depth levels of the defect.

Results: Using SQH, both membrane types resulted in significantly better bone regeneration compared to groups 1 and 2, irrespective of the defect size (P <0.005), with no difference between the two membranes. In the histomorphometric analysis, the layer immediately below the surface exhibited a significantly higher percentage of bone in groups 3 (27%) and 4 (36%) versus the two other groups for the 9 x 9 x 9-mm defects. No such differences were apparent for the 6 x 6 x 6-mm defects or the other two depth levels (bottom and middle layer) for either defect size.

Conclusion: The two collagen membranes tested significantly enhanced bone regeneration, especially in the superficial level of the calvarial bone defects. The prototype CCM did not provide any further advantage in the present animal model.

ABSTRACT:

The purpose of this study was a histomorphometric comparison of vital bone formation following maxillary sinus augmentation with two different particle sizes of anorganic bovine bone matrix (ABBM). Bilateral sinus floor augmentations were performed in 13 patients. Trephine bone cores were taken from the lateral window areas of 11 patients 6 to 8 months after augmentation for histologic and histomorphometric analysis. Bone samples from both the large and small particle size groups showed evidence of vital bone formation similar to that seen in previous studies, confirming the osteoconductivity of ABBM. Significant bone bridging was seen creating new trabeculae composed of the newly formed bone and residual ABBM particles. Histologic evaluation revealed the newly formed bone to be mostly woven bone with some remodeling to lamellar bone. Osteocytes were seen within the newly formed bone as well as osteoblast seams with recently formed osteoid. Isolated osteoclasts were observed on the ABBM surfaces. Vital bone formation (primary outcome measure) was more extensive in the large particle grafts compared with the small particle grafts (26.77% ± 9.63% vs 18.77% ± 4.74%, respectively). The histologic results reaffirm the osteoconductive ability of ABBM when used as the sole grafting material in maxillary sinus augmentation. The histomorphometric results at 6 to 8 months revealed a statistically significant increase (P = .02) in vital bone formation when the larger particle size was used. Additional studies should be performed to confirm these results.

In aesthetic sites, the integrity of the facial bone wall dimension in the anterior maxilla is jeopardized by physiologic and structural changes postextraction. An effective regenerative protocol is key to reestablish and maintain the hard and soft tissue dimensions over time. The present prospective case series study examined the effectiveness of early implant placement with simultaneous contour augmentation through guided bone regeneration with a 2-layer composite graft in postextraction single-tooth sites over an observation period of 10 y among 20 patients. The median peri-implant bone loss was 0.35 mm between the 1- and 10-y examination. A success rate of 95% was obtained, with pleasing aesthetic outcomes and a high median Pink Esthetic Score (8). Implant crowns (ICs) revealed significant median facial recession between IC10y and IC1y (0.17 mm). The facial bone wall dimensions were assessed by preoperative cone beam computed tomography and 2 subsequent scans taken at 6 and 10 y. The median facial bone wall thickness increased significantly from 0 mm at surgery to 1.67 mm at the 10-y examination. The facial vertical bone wall peak (DIC) was located at a median distance of 0.16 mm coronal to the implant shoulder. The facial vertical bone loss of DIC amounted to 0.02 mm between 6 and 10 y. Equivalence testing was performed for the null hypothesis of a difference of >0.2 mm per year between 2 respective time points, showing stable bone conditions. Modulating factors influencing the regenerative outcomes at 10 y were the preoperative proximal crest width and soft tissue thickness. In conclusion, the present study confirmed the long-term effectiveness of early implant placement with simultaneous contour augmentation through guided bone regeneration with a 2-layer composite graft in postextraction single-tooth sites offering stable bone conditions with low risks of mucosal recessions over an observation period of 10 y ( ClinicalTrials.gov NCT03252106).

The aim of this study was to investigate the effects of a combination of porous bovine inorganic bone graft (Bio-Oss) and bilayer porcine collagen membrane (Bio-Gide) on refractory one-wall intrabony defects in dogs. Bio-Oss and Bio-Gide were applied into the refractory one-wall intrabony defect. The contralateral sites were used as controls (without the application of Bio-Oss and Bio-Gide). At 24 weeks after surgery, similar pocket depths were found in both groups. However, histologic observation revealed an infiltration of inflammatory cells in the control group caused by poor gingival architecture, whereas only a few of the experimental sites showed inflammatory infiltration. In addition to the healthy gingival tissue, periodontal tissue regeneration was observed in the experimental group. The combination of Bio-Oss and Bio-Gide was an effective treatment for refractory one-wall intrabony defects in dogs.

BACKGROUND: Few studies have looked at professional assessment or patient perception of aesthetics after root coverage procedures. The addition of connective tissue grafts (CTG) seems to improve aesthetic outcomes. The objective of this a priori analysis was to compare aesthetics after addition of CTG or a collagen matrix (CMX) to coronally advanced flap (CAF).

METHODS: Two independent, trained and calibrated assessors analysed baseline and 6-month post-operative Images from 183 subjects with 475 recessions from a previously reported multicentre multinational randomized clinical trial. The root coverage aesthetic score (RES) was assessed in its five constituent components after assessing the suitability of images blindly with regard to treatment assignment and centre. Data were analysed at the tooth and subject level.

RESULTS: One hundred and fifty-five subjects (81 CTG) and 393 teeth (207 CTG) were included in the analysis. CTG control subjects had higher total RES scores (mean adjusted difference of 1.3 ± 0.8 RES units, p = 0.002). Analyses of RES subcomponents showed that the CTG group had higher scores in terms of gingival margin position but that better marginal tissue contour (OR 3.0, 95% CI 1.2-7.7) and soft tissue texture (OR 3.3, 95% CI 1.9-5.8) was observed for the CMX group. No significant differences were observed for mucogingival alignment and gingival colour.

CONCLUSION: Better overall RES scores were observed for the CTG group. Better marginal tissue texture and marginal contour were observed in the CMX group. More research and development is needed to optimize materials to be used in conjunction with CAF to improve root coverage without negatively affecting tissue texture and marginal contour.

PURPOSE: To investigate periimplant soft tissue response following flapless extraction and immediate implant placement and provisionalization (IIPP) associated with bovine hydroxyapatite bone and connective tissue grafting in the anterior maxilla. The study evaluated the effectiveness of this technique in terms of soft tissue contours in esthetic areas with the use of the pink esthetic score (PES). MATERIALS AND METHODS: In this retrospective study, 39 consecutive patients were treated and followed by two experienced clinicians for single-tooth implant treatment in the esthetic zone. Treatment consisted of flapless extraction, immediate implant placement, inorganic bovine bone filling of the periimplant gap, and connective tissue grafting. A provisional crown was placed at the time of implant placement. The final crown was positioned 5 to 8 months after surgery. To assess the esthetic outcome of the technique, the soft tissue around the tooth to be extracted was scored according to the PES by seven evaluators before the surgery at visit 1 (v1), and at least 1 year after the final prosthesis placement at visit 2 (v2). RESULTS: After a mean follow-up of 4 years, the mean total PES score on a scale from 1 to 10 was 5.64 and 7.07 at v1 and v2, respectively. Statistical analysis revealed a significant difference between the PES scores before surgery and at the follow-up examination of the anterior single implants (P = 0.0008). CONCLUSION: Within the limitations of this study, postextraction with immediate implant loading associated with bovine hydroxyapatite and connective tissue grafting is a predictable technique. The esthetic outcome is that soft tissue seems to be maintained or improved significantly according to PES assessment compared with baseline.

Implant-supported prostheses often present with mucogingival deficiencies that may cause esthetic or hygienic issues. These issues may present as limited or no keratinized tissue, irregular soft tissue contour or concavity, and gray "showthrough" of the implant abutment and root forms. An interpositional soft tissue graft substitute that generates keratinized tissue and increases soft tissue thickness would be beneficial, as it would reduce donor site morbidity and be available in unlimited, off-the-shelf supply. Thirty patients were assessed as part of a multicenter, practice-based evaluation of the material. A xenogeneic collagen matrix was placed as an interpositional graft on the buccal aspect of implant sites; sites were reassessed at 6 months posttreatment. Results indicated that the collagen matrix increased tissue thickness and keratinized tissue around existing dental implants.

Forty-eight single dental implants were inserted 4 months after tooth extraction following ridge preservation (RP; n = 24) or spontaneous healing (EXT; n = 24). During surgery, 1 (7%) of 24 implants in the RP group and 14 (58%) of 24 in the EXT group required additional bone grafting, and the implant stability quotient value was similar in the two groups. The survival rate of the implants in both groups was 100% at the 1-year follow-up. The success rate was 95.83% in the RP group and 91.66% in the EXT group. No statistically significant differences in the marginal bone level were detected between the two groups. Similar outcomes of implants inserted in preserved or spontaneously healed ridges can be anticipated, but the use of an RP procedure reduces the need for further bone augmentation.

"Predictable and effective surgical techniques that aim to increase the width of keratinized gingiva, relocate the mucogingival junction, and deepen the vestibule often involve soft tissue autografts; however, soft tissue autograft supply is limited and its harvesting is associated with patient morbidity. With a strip autograft and xenogeneic collagen matrix (XCM) technique combination, autograft harvest requirements and patient morbidity are reduced. In this histologic evaluation, 12 strip autograft/XCM biopsy samples were compared with 3 reference samples of palatal strip autografts. Tissue morphology, keratin, and collagen expression appear identical, indicating that the combined grafting technique provides desired and physiologically normal keratinized gingiva."

BACKGROUND:
Alveolar ridge volume loss may be minimized when postextraction sockets are filled by bone substitutes.

PURPOSE:
The aim of the study was to measure the effect of alveolar ridge preservation (ARP) in maintaining the external contour of the ridge after fresh socket grafting with or without particulate anorganic bovine bone mineral (BBM) and resorbable barrier covering.

MATERIALS AND METHODS:
In the present controlled study, patients subjected to single-tooth extraction were allocated to 2 groups: postextraction sockets grafted with bovine bone mineral (bbm), and naturally healing sockets (nat). Before and at 5 months following tooth extraction, plaster cast contours of the sockets were acquired by means of an optical scanner; the 2 contours of each patient underwent voxelization and fusion using a matrix elaborator. Outcome variables at 5 months (volumetric, surface, and linear changes) were measured in digital fused plaster casts with a dental scan software analyzing a volume of interest ranging from residual papilla to 10 mm toward the apical point. Intra- and inter-group pair-wise variables' comparisons were conducted. Level of significance was set at 0.05.

RESULTS:
Twenty-four sites were enrolled: 12 ARP and 12 naturally healed. Five-month percentage of volume loss of the bbm-group (21.7% ± 7.4%) was significantly lower (Ps < .0003) than that of the naturally healing group (38.8% ± 7.9%). When tooth position was investigated, volume loss in percentage registered a significantly better (P values ≤ .0485) behavior in molars (ΔV% = -19.1% ± 6.5% and ΔV% = -35.6% ± 7.6%, respectively, for bbm and nat) than that in premolars (ΔV% = -26.9% ± 7.2% and ΔV% = -45.1% ± 4.2%, respectively, for bbm and nat), in both the preserved and naturally healing groups.

CONCLUSION:
The dimensional loss in postextraction sockets grafted with anorganic bovine bone substitute and covered by a resorbable collagen barrier was lower than that of the naturally healing sites. However, ridge preservation was able to maintain almost 80% of the pristine bone.

Although the use of autogenous harvested tissues has proven to be the gold standard for soft tissue augmentation procedures involving root coverage or generation of keratinized tissue, harvest site morbidity and limited supply have prompted clinicians to seek graft alternatives. Using a hierarchy of evidence, the author reviews both clinical and patient-reported results for harvest graft substitutes and, considering his own research experience, reviews autogenous graft substitute outcomes, attachment, and stability over time. Overall, when the goal is keratinized-tissue generation, living cellular constructs and xenogeneic collagen matrices have provided acceptable clinical results, but with better esthetics and patient preference than autogenous free gingival grafts. For root coverage therapy, enamel matrix derivatives, platelet-derived growth factors, and xenogeneic collagen matrices have provided acceptable results with equivalent esthetics to autogenous connective tissue grafts, while also being preferred by patients. Longterm results for enamel matrix derivatives, platelet-derived growth factors, and xenogeneic collagen matrices indicate root coverage can be maintained over time. In the author's hands, xenogeneic collagen matrices have been the only harvest graft alternatives that can be used either covered or uncovered by soft tissue.

Objectives: The fresh extraction socket in the alveolar ridge represents a special challenge in everyday clinical practice. Maintenance of the hard and soft tissue envelope and a stable ridge volume were considered important aims to allow simplifying subsequent treatments and optimizing their outcomes in particular, when implants are planned to be placed.

Material and Methods: Prior to the consensus meeting four comprehensive systematic reviews were written on two topics regarding ridge alteration and ridge preservation following tooth extraction and implant placement following tooth extraction. During the conference these manuscripts were discussed and accepted thereafter. Finally, consensus statements and recommendations were formulated.

Results: The systematic reviews demonstrated that the alveolar ridge undergoes a mean horizontal reduction in width of 3.8 mm and a mean vertical reduction in height of 1.24 mm within 6 months after tooth extraction. The techniques aimed at ridge preservation encompassed two different approaches: i) maintaining the ridge profile, ii) enlarging the ridge profile. Regarding timing of implant placement the literature showed that immediate implant placement leads to high implant survival rates. This procedure is primarily recommended in premolar sites with low esthetic importance and favorable anatomy. In the esthetic zone, however, a high risk for mucosal recession was reported. Hence, it should only be used in stringently selected situations with lower risks and only by experienced clinicians. In molar sites a high need for soft and hard tissue augmentation was identified.

Conclusion: Future research should clearly identify the clinical and patient benefits resulting from ridge preservation compared with traditional procedures. In addition, future research should also aim at better identifying parameters critical for positive treatment outcomes with immediate implants. The result of this procedure should be compared to early and late implant placement.

OBJECTIVES:

Attached peri-implant gingiva has proven to have an influence on the long-term stability of dental implants. In patients with head and neck cancer, a functional peri-implant gingiva is even more of critical importance. The aim of the presented prospective study was to investigate a three-dimensional xenogeneic collagen matrix for augmentation around dental implants in patients with former head and neck cancer.

MATERIAL AND METHODS:

Eight patients presenting with insufficient peri-implant gingiva underwent vestibuloplasty on 51 implants using a xenogeneic collagen matrix. The clinical performance and the shrinking tendency of the matrix were analyzed in a cohort study. Furthermore, eight biopsies from the augmented regions were examined histologically to determine the biomaterial-related tissue reaction.

RESULTS:

Initially after vestibuloplasty, a mean width of attached gingiva of 4.4 ± 0.94 mm could be achieved. At clinical follow up investigation 6 months after vestibuloplasty, a mean width of 3.9 ± 0.65 mm attached peri-implant gingiva with a mean shrinking tendency of 14 % could be detected. Histological analysis of the biopsies revealed a well integrated collagen22 matrix covered with epithelium. Within the compact layer, mononuclear cells were observed only, while the spongious layer was infiltrated with a cell-rich connective tissue.

CONCLUSION: Within its limits, the presented study revealed that the investigated collagen matrix is suitable to enlarge the peri-implant attached gingiva in head and neck cancer patients without adverse reactions or a multinucleated giant cell-triggered tissue reaction.

CLINICAL RELEVANCE: The application of the investigated three-dimensional collagen matrix in vestibuloplasty achieved a sufficient amount of peri-implant attached gingiva in head and neck cancer patients. The favorable tissue reaction and the low shrinking tendency make the collagen matrix a promising alternative to autologous tissue grafts.

This study compared the osteoconductive capability of deproteinized bone particles of two different sizes (300-500 and 850-1000 microm) in rabbits undergoing maxillary sinus lift. Histologically, deproteinized bone particles of both sizes induced osteoconduction 1 week after implantation. Bone initially formed at the sinus wall and proliferated into the center of the augmented sinus cavity. In the small-particle group, newly formed bone showed many interconnections and appeared in most areas of the cavity 8 weeks after implantation. In the large-particle group, newly formed bone showed limited intercommunications, and the center of the sinus cavity contained fibrous connective tissue with no evidence of ossification 8 weeks after implantation. Histomorphometric analysis revealed a significantly higher density of newly formed bone in the small-particle group than in the large-particle group both 4 and 8 weeks after implantation. The total newly formed bone-particle contact length was also significantly higher in the small-particle group. The total surface length of the small particles was larger than that of the large particles, but the ratio of the newly formed bone-particle contact length to the total particle surface length did not differ significantly between the groups at any time. The interparticular spaces of the small particles were larger than those of the large particles. The bone area ratio in the interparticular spaces of the small particles was significantly higher than that of the large particles both 4 and 8 weeks after implantation. We conclude that graft bone particle size and interparticular space are important determinants of osteoconduction.

Socket or ridge preservation is performed to maintain the contour of the alveolar ridge prior to conventional or implant-based prosthetic therapy. In this retrospective analysis of consecutive subjects, a natural bone mineral containing collagen was grafted into 110 sockets in 62 patients. The sites were left open to heal. Based on external measurements with a periodontal probe, the soft tissue volume and contour were largely preserved at all sites, irrespective of the initial defect morphology. Clinical advantages of this protocol include predictable preservation of the soft tissues, favorable healing characteristics, and easy handling of the material.

Objective: The aim of this study was to compare the radiographic dimensional changes of sinus graft height above and between placed implants, and evaluate the factors effecting these changes with 2 different grafting materials and both combination.

Study Design: The study group comprised 42 patients (50 sinus augmentation procedures). Four consecutive panoramic radiographs were evaluated for changes in sinus graft height between and above the placed implants. Factors that may influence graft height reduction were evaluated.

Results: The mean percentage of autogenous bone height reduction was 23% between implants and 13% above the implants. Bovine xenograft showed a mean of 6.5% graft height reduction between implants and 0% above implants. The only 2 parameters that correlated with reduction of graft height above and between the implants were time elapsed from surgery and the type of bone graft. Autogenous bone graft presented significantly more reduction (P = .022), whereas anorganic bovine bone graft had only minor or no changes in height.

Conclusion: The most important factor influencing reduction in vertical bone height on the time axis, following sinus augmentation is the grafting material, followed by the presence of a functional implant. Anorganic bovine bone was found superior in graft height maintenance in an up to 10 years of follow-up.

The aim of this retrospective clinical study was to evaluate the influence of different factors on the outcome of GBR treatment. 75 patients, who were not randomly assigned to the investigated parameters for clinical reasons, were included in the study. They presented with defect sites around implants and were treated with a xenogenic grafting material and a resorbable collagen membrane. The defect morphology was described, its dimension was measured and calculated at the time of implant installation and at re-entry. The success of GBR treatment was related to several clinical variables and possible correlations were evaluated. Defect sites around maxillary implants showed significantly more bone fill (96%) compared to those in the mandible (78%). The insertion of a provisional restoration during the healing period was also associated with significantly better results than when no provisional was inserted. Immediate and short-term delayed implant placements showed the best results both with 92% bone fill, when compared with long-term delayed placements with 80% bone fill (n.s.). In sites with type I bone quality (compact bone), a reduced bone fill was observed (64%). The results indicate that successful bone fill can be achieved with GBR; this is more feasible in the maxilla, when a provisional restoration is used. Early implant placement timings seem to be preferable due to the alveolar ridge preservation, more favorable defect morphologies and a higher regenerative capacity.

Background: Treatment with a natural bone mineral (NBM) and a guided tissue regeneration (GTR) has been shown to promote periodontal regeneration. However, until now there are only very limited data on the long-term clinical results following this regenerative technique.

Aim: To present the 5-year results of a prospective, randomized, controlled clinical study evaluating the treatment of deep intra-bony defects either with open flap debridement (OFD) and a combination of an NBM and GTR (test) or OFD alone (control).

Methods: Nineteen patients diagnosed with advanced chronic periodontitis, and each of whom displayed one intra-bony defect, received randomly the test or the control treatment. Results were evaluated at baseline, at 1 and at 5 years following therapy.

Results: No statistically significant differences in any of the investigated prameters were observed at baseline between the two groups. At 1 year after therapy, the test group showed a reduction in mean probing depth (PD) from 9.1± 1.1 to 3.7 ± 0.8 mm (P<0.001) and a change in mean clinical attachment level (CAL) from 10.4 ± 1.3 to 6.4 ± 1.2 mm (p<0.001). At 5 years, mean PD and CAL measured 4.3 ± 0.8 and 6.7 ± 1.6 mm, respectively. At 5 years, both PD and CAL were statistically significantly improved compared with baseline (p<0.001) without statistically significant differences between the 1- and 5-year results. In the control group, mean PD was reduced from 8.9 ± 1.3 to 4.9 ± 1.2 (p<0.001 and mean CAL changed from 10.6 ± 1.4 to 8.8 ± 1.5 mm (p<0.01). At 5 years, mean PD and CAL measured 5.6 ± 1.1 and 9.1 ± 1.3 mm, respectively, and were still statistically significantly improved compared with baseline (p<0.01). No statistically significant differences were found between the 1- and 5- year results. The test treatment, at both 1 and 5 years, yielded statistically significantly higher CAL gains than the control one (p<0.01). Compared with baseline, at 5 years a CAL gain of 3>mm was found in nine defects (90%) of the test group but in none of the defects treated with OFD alone.

Conclusion: It was concluded that (i) treatment of intra-bony defects with OFD + NBM + GTR may result in significantly higher CAL gains than treatment with OFD, and (ii) the clinical results obtained after both treatments can be maintained over a period of 5 years.

The basic aspects of bone tissue engineering include chemical composition and geometry of the scaffold design, because it is very important to improve not only cell attachment and growth but especially osteodifferentiation, bone tissue formation, and vascularization. Geistlich Bio-Oss^® (GBO) is a xenograft consisting of deproteinized, sterilized bovine bone, chemically and physically identical to the mineral phase of human bone. In this study, we investigated the growth behaviour and the ability to form focal adhesions on the substrate, using vinculin, a cytoskeletal protein, as a marker. Moreover, the expression of bone specific proteins and growth factors such as type I collagen, osteopontin, bone sialoprotein, bone morphogenetic protein-2 (BMP-2), BMP-7 and de novo synthesis of osteocalcin in normal human osteoblasts (NHOst) seeded on xenogenic GBO were evaluated. Our observations suggest that after four weeks of culture in differentiation medium, the NHOst showed a high affinity for the three dimensional biomaterial; in fact, cellular proliferation, migration and colonization were clearly evident. The osteogenic differentiation process, as demonstrated by morphological, histochemical, energy dispersive X-ray microanalysis and biochemical analysis was mostly obvious in the NHOst grown on three-dimensional inorganic bovine bone biomaterial. Functional studies displayed a clear and significant response to calcitonin when the cells were differentiated. In addition, the presence of the biomaterial improved the response, suggesting that it could drive the differentiation of these cells towards a more differentiated osteogenic phenotype. These results encourage us to consider GBO an adequate biocompatible three-dimensional biomaterial, indicating its potential use for the development of tissue-engineering techniques.

PURPOSE:
Bio-Oss and demineralized freeze-dried bone allograft (DFDBA) are two commercial bone grafts that have been associated with clinical success for many years. However, there are few in vivo studies regarding their healing mechanism. The purpose of this study was to investigate the level of bone formation using microcomputed tomography (micro-CT) and gene expression in mouse calvaria at 1 and 3 months after bone grafting with deproteinized bovine bone and freeze-dried human bone, and compare them to natural bone healing.

MATERIALS AND METHODS:
Thirty-six mice were divided into three groups (n = 6 per group) according to the type of bone graft used: group 1 (control)-an empty defect without bone graft; group 2-treatment with deproteinized bovine xenograft (Bio-Oss); group 3-treatment with DFDBA. The bone graft was inserted into two 3-mm calvarial defects created on both sides of the parietal bone. At 1 and 3 months, the mice were sacrificed and bone volume was evaluated using micro-CT and gene expression analysis using reverse transcription polymerase chain reaction (RT-PCR).

RESULTS:
Micro-CT analysis demonstrated that the parietal bone of mice grafted with Bio-Oss had significantly greater bone volume than both the DFDBA and control groups at both 1 and 3 months. The expression of bone marker genes (Runx2, Osterix [Osx], alkaline phosphatase [ALP], osteopontin [OPN], and osteocalcin [OCN]) were significantly increased from 1 month in both Bio-Oss and DFDBA groups at 3 months. Runx2 and Osx had significantly higher expression in the Bio-Oss and DFDBA groups compared to the control group at 3 months. No statistically significant difference was observed among groups after 1 month.

CONCLUSION:
These results showed that both bone graft materials promoted bone regeneration. Bio-Oss demonstrated high osteoconductive properties.

Bio-Oss® (Geistlich, Wolhusen, Switzerland) is composed by anorganic bovine bone and is widely used in several bone regeneration procedures in oral surgery. How this biomaterial alters osteoblast gene expression to promote bone formation is poorly understood. We therefore attempted to address this question by using microarray techniques to identify genes that are differentially regulated in osteoblasts exposed to Bio-Oss. By using DNA microarrays containing 20,000 genes, we identified in osteoblast-like cells line (MG-63) cultured with Bio-Oss® several genes which expression was significantly up- and down-regulated. The differentially expressed genes cover a broad range of functional activities: (a) signaling transduction, (b) transcription, (c) cell cycle regulation, (d) vesicular transport, (e) apoptosis, and (f) immunity. These results could explain the reported bioaffinity of Bio-Oss® to host animals, its biological affinity to osteogenic cells and its capability to stimulate osteoblastic differentiation. The data reported are, to our knowledge, the first genetic portrait of Bio-Oss effects. They can be relevant to our improved understanding of the molecular mechanism underlying bone regenerative procedures and as a model for comparing other materials with similar clinical effects.

Our aim was to compare the outcome of implants inserted in maxillary sinuses augmented with anorganic bovine bone grafts compared with those augmented with mixed 50:50 bovine and autologous bone grafts. Twenty sinuses with 1-4mm of residual crestal height below the maxillary sinuses were randomised into two groups according to a parallel group design (n=10 in each). Sinuses were grafted using a lateral approach. In one group the grafts were 50:50 anorganic bovine bone and autologous bone and in the other anorganic bovine bone alone. After 7 months, 32 implants had been inserted. Outcome measures were survival of implants, complications, marginal changes in the height of the bone, and soft tissue variables (pocket probing depth and bleeding on probing). Probabilities of less than 0.05 were accepted as significant. No patient failed to complete the trial and no implant had failed at 1 year. There were some minor complications. After 12 months, the mean (SD) marginal bone loss (mm) was 1.06 (0.61) in the 50:50 group and 1.19 (0.53) in the anorganic bovine group. The mean (SD) values for pocket probing depth (mm) and bleeding on probing (score) were 2.49 (0.38) and 1.59 (0.82) in the 50:50 group and 2.31 (0.64) and 1.36 (0.87) in the anorganic bovine group (neither difference was significant). The present data are consistent with the hypothesis that the outcome of implants inserted in sinuses grafted with either material is comparable.

Objectives: To evaluate the value of deproteinized bone particles on bone resorption in the augmented space after maxillary sinus floor elevation in rabbits.

Material and Methods: A total of 20 rabbits underwent bilateral grafting, using blood clots (control group) and deproteinized bone particles (experimental group), and followed with histologic and histomorphometric analysis.

Results: Two weeks after grafting, the augmented space was almost completely obliterated by both newly formed bone and fibrous connective tissue in the control group. Some osteoclasts were found on the surface of newly formed bone, especially near the elevated sinus membrane. In the experimental group, newly formed bone was found along the elevated sinus membrane, the cortical wall of the augmented space, and the surface of deproteinized bone particles near the cortical wall. Some osteoclasts were found along the deproteinized bone particles and a few adhered to the surface of the newly formed bone. Eight to 10 weeks after implantation in the control group, most of the newly formed bone had been resorbed. In the experimental group, newly formed bone was found in most parts of the convex augmented space. Histomorphometrical analysis showed that the augmented height was significantly higher in the experimental group than in the control group at all evaluation times. Bone area was significantly higher in the experimental group than in the control group at 6, 8, and 10 weeks after implantation. The area of grafted deproteinized bone particles did not change significantly from 2 to 10 weeks.

Conclusion: Slowly resorbed deproteinized bone particles contribute to stable augmentation of the maxillary sinus floor by inhibiting bone resorption.

AIM:
To test whether implant placement with simultaneous guided bone regeneration (GBR) differs from implant placement without GBR regarding the change in marginal mucosal contour.

MATERIALS AND METHODS:
In 28 patients, single implants were placed >4 months after tooth extraction. Eighteen implants were completely surrounded by native bone, and no bone augmentation was performed. At 10 implant sites, bone defects and thin bone plates were grafted with deproteinized bovine-derived bone mineral and covered with collagen membrane. Impressions were taken prior to implant placement (baseline), at 3 months before abutment connection, at 6 months immediately after crown insertion, at 1 year, and at 3 years. Models were optically scanned and 3D images were superimposed for the evaluation of mucosal contour changes at the mid-buccal aspect. The nonparametric Mann-Whitney U-test was applied to detect differences.

RESULTS:
From baseline to 6 months, horizontal contour change at the level 1 and 2 mm apical to the mucosal margin measured 0.65 ± 0.74 mm and 0.55 ± 0.56 mm at sites without GBR, and 1.92 ± 0.87 mm and 1.76 ± 0.70 mm at sites with GBR (P < 0.05). In the period from baseline to 1 year, the corresponding values amounted to 0.81 ± 0.67 mm and 0.60 ± 0.55 mm in the group without GBR, and to 1.81 ± 0.86 mm and 1.37 ± 0.62 mm in the group with GBR (P < 0.05). From baseline to 6 months, mucosal margin moved 0.16 ± 0.49 mm in the coronal direction in the group without GBR and 0.82 ± 0.65 mm in the group with GBR (P < 0.05). In the period from baseline to 1 year, vertical change of mucosal margin amounted to 0.64 ± 0.54 mm in the group without GBR and to 1.17 ± 0.53 mm in the GBR group (P < 0.05). From 1 to 3 years, the mucosal contours remained stable.

CONCLUSIONS:
Implant placement with simultaneous GBR resulted in more gain of buccal soft tissue contour in comparison with implant placement without GBR. Abutment connection increased the contour of the marginal mucosa at the augmented and the nonaugmented sites. GBR procedure contributed more to the contour gain than did the abutment connection. The augmented and the nonaugmented ridges exhibited stable peri-implant mucosal contour over a 3-year period.

BACKGROUND:

Guided bone regeneration (GBR) is a viable treatment for osseous defects surrounding dental implants. Controversy exists regarding the choice of barrier membrane used and the method of membrane fixation to achieve GBR.

METHODS:

This study compared the efficacy of a porcine-derived bioabsorbable collagen membrane and an expanded polytetrafluoroethylene (ePTFE) membrane (non-resorbable) for GBR using a bovine bone xenograft/autograft bone composite in defects surrounding dental implants. The study also examined the effect of primary barrier fixation on GBR. Defect size was recorded at Stage 1 and 2 surgeries (performed 6 months apart). Forty-eight subjects (41% males, 59% females) requiring GBR were treated with either collagen (23) or ePTFE (25) barriers, respectively. Implants were titanium self-tapping screw-type. In 34 GBR sites, barrier fixation was achieved with polylactic acid resorbable pins. The remaining barriers were secured with the implant cover screw and/or embedded beneath the flaps.

RESULTS:

At 6 months, a decrease in defect width (collagen barrier 1.95 +/- 0.60 mm, ePTFE barrier 2.65 +/- 0.56 mm), length (collagen barrier 2.65 +/- 0.61 mm, ePTFE barrier 2.26 +/- 0.66 mm), and circumference (degrees) (collagen barrier 57.7 +/- 18.7, ePTFE barrier 80.2 +/- 19.9) was observed for both membranes. A significant number (chi2, P = 0.041) of postoperative complications occurred when barrier fixation was lacking at initial surgery. Furthermore, a significant difference (P <0.05) in the success of GBR with respect to defect size was observed when barrier fixation was taken into account.

CONCLUSIONS:

In conclusion, both collagen and ePTFE barriers proved suitable for achieving GBR of osseous defects surrounding dental implants. The results of this study stress the importance of barrier fixation at the time of initial surgery.

Lateral periodontal cysts (LPCs) are rare odontogenic cysts of developmental origin. A 52-year-old man presented with an asymptomatic gingival swelling located between the mandibular left canine and first premolar, both of which were vital. Radiography showed a well-circumscribed radiolucent area and loss of the lamina dura around the tooth socket in contact with the lesion and of the interproximal buccal bone. The lesion was enucleated. The defect was immediately grafted with a 1:1 mixed autologous and heterologous bone graft covered with a collagen membrane. Histology confirmed the diagnosis of LPC. At 12- and 24-month clinical and radiologic follow-up, complete bone and periodontal healing was found, with no sign of recurrence.

PURPOSE:
The aim of this meta-analysis was to evaluate different methods for guided bone regeneration using collagen membranes and particulate grafting materials in implant dentistry.

MATERIALS AND METHODS:
An electronic database search and hand search were performed for all relevant articles dealing with guided bone regeneration in implant dentistry published between 1980 and 2014. Only randomized clinical trials and prospective controlled studies were included. The primary outcomes of interest were survival rates, membrane exposure rates, bone gain/defect reduction, and vertical bone loss at follow-up. A meta-analysis was performed to determine the effects of presence of membrane cross-linking, timing of implant placement, membrane fixation, and decortication.

RESULTS:
Twenty studies met the inclusion criteria. Implant survival rates were similar between simultaneous and subsequent implant placement. The membrane exposure rate of cross-linked membranes was approximately 30% higher than that of non-cross-linked membranes. The use of anorganic bovine bone mineral led to sufficient newly regenerated bone and high implant survival rates. Membrane fixation was weakly associated with increased vertical bone gain, and decortication led to higher horizontal bone gain (defect depth).

CONCLUSION:
Guided bone regeneration with particulate graft materials and resorbable collagen membranes is an effective technique for lateral alveolar ridge augmentation. Because implant survival rates for simultaneous and subsequent implant placement were similar, simultaneous implant placement is recommended when possible. Additional techniques like membrane fixation and decortication may represent beneficial implications for the practice.

Objectives: The aim of the following experimental study was to assess bone changes in the horizontal and vertical dimension when using different socket preservation procedures.

Material and Methods: In five beagle dogs the distal roots of the 3rd and 4th premolar were extracted without elevation of a mucoperiosteal flap and the following treatments were assigned: Tx 1: The extraction socket was filled with Bio-Oss Collagen (Geistlich Biomaterials, Wolhusen, Switzerland) and interrupted sutures were applied.: Tx 2: The extraction socket was filled with Bio-Oss Collagen (Geistlich Biomaterials, Wolhusen, Switzerland) and a free gingival graft was sutured to cover the socket.: Tx 3: The extraction socket was left with its blood clot and interrupted sutures were applied.: Four months after surgery the dogs were sacrificed and from each extraction site two histological sections were selected for histometric analysis. The following parameters were evaluated: (1) the vertical dimension was determined by placing a horizontal line on the lingual bone wall. Then, the distance from this line to the buccal bone wall was measured. (2) The horizontal dimension was assessed at three different areas measured from the top of the lingual crest: 1 mm (Value 1), 3 mm (Value 3) and 5 mm (Value 5).

Results: the mean vertical loss of the buccal bone plate for the Tx 1 group was 2.8+/-0.2 mm. The Tx 2 group showed vertical loss of 3.3+/-0.2 mm. The Tx 3 group demonstrated 3.2+/-0.2 mm of mean vertical loss. The horizontal dimension of the alveolar process was 4.4+/-0.3/6.1+/-0.2/7.2+/-0.1 mm at the three different levels for the Tx 1 group. The Tx 2 group depicted bone dimensions of 4.8+/-0.2/6.0+/-0.2/7.1+/-0.1 mm. The horizontal dimension of the Tx 3 group was 3.7+/-0.3/6.2+/- 0.2/7.0+/-0.1 mm. When the results from the horizontal measurements were tested with the analysis of variance (ANOVA), a clear significance could be found in particular for Value 1 mm between the test groups Tx 1 and Tx 2 and the control group (Tx 3) (P<0.001). Furthermore the mean of treatment 1 (Tx 1) was slightly significantly lower than of treatment 2 (Tx 2) (P<0.05).

Conclusion: The findings from the present study disclose that incorporation of Bio-Oss Collagen into the extraction socket has only limited impact on the subsequent biologic process with particular respect to the buccal bone plate. The horizontal measurement of the alveolar ridge depicted that the loss of the buccal bone plate was replaced to a certain amount by newly generated bone guided by the Bio-Oss Collagen scaffold. It seems that the mechanical stability provided by Bio-Oss Collagen and furthermore by a free gingival graft could act as a placeholder preventing the soft tissue from collapsing.

The aim of the present experiment was to study the healing after 3 and 7 months of bone defects filled with cancellous bovine bone mineral and compare the healing around implants placed in normal bone and in defects filled with bovine bone mineral. 5 beagle dogs, about 1-year-old, were used. At baseline, extractions of all mandibular left and right premolars were performed. Bone defects were prepared in the left mandibular quadrant. The defects were immediately filled with natural bovine cancellous bone mineral particles (Bio-Oss®). No resective surgery was performed in the right jaw quadrant. In both quadrants the flaps were adjusted to allow full coverage of the edentulous ridge and sutured. 3 months later, 2 dogs (group I) were euthanized and biopsies from the premolar regions obtained and prepared for histologic analysis. The 3 remaining dogs (group II) were at this time interval (3 months) subjected to implant installation in the premolar region of both the right and left mandibular jaw quadrants. 2 fixtures of the ITI Dental Implant System (solid-screw) were installed in each side. The fixtures in the test side were placed within the previously grafted defect area, while the fixtures in the control side were placed in normally healed extraction sites. A 4-month period of plaque control was initiated. At the end of this period, a clinical examination including assessment of plaque and soft tissue inflammation was performed and radiographs obtained from the implant sites. Biopsies were harvested and 4 tissue samples were yielded per dog, each including the implant and the surrounding soft and hard peri-implant tissues. The biopsies were processed for ground sectioning or “fracture technique” and the sections produced were subjected to histological examination. The volume of the hard tissue that was occupied by clearly identified Bio-Oss® particles was reduced between the 3- and 7-month intervals. This indicates that with time, Bio-Oss® becomes integrated and subsequently replaced by newly formed bone. In other words, this xenograft fulfills the criteria of an osteoconductive material. It was also observed that 4 months after implant installation, the titanium/hard tissue interface at test and control sites exhibited, from both a quantitative and qualitative aspect, a similar degree of “implant osseointegration”.

Objectives: The current experiments had three aims (i) to determine whether the absence of the periodontal ligament (PDL) may alter features of the healing of an extraction socket, (ii) to examine if there were differences in the proportion of different tissues in resolved extraction sockets and surgically produced defects after 3 months of healing, (iii) to study the influence of different biomaterials on the healing of surgically produced bone defects.

Material and Methods: Extraction sites: In five dogs, the 4th mandibular pre-molars were hemi-sected and the distal roots were removed. The extraction socket of one of the pre-molars was instrumented to eliminate all remnants of the PDL tissue. The socket of the contra-lateral pre-molar was left without instrumentation. The dogs were sacrificed after 3 months of healing. Defect sites: In five dogs, the pre-molars and 1st molars on both sides of the mandible were first removed and 3 months of healing allowed. After this interval three standardized cylindrical defects were prepared in each side of the mandible. The defects were 3.5 mm in diameter and 8 mm deep. In each quadrant one defect was grafted with Bio-Oss Collagen, one with Collagen Sponge and one defect was left non-grafted. The dogs were sacrificed 3 months after the grafting procedure.

Results: Extraction sites: The two categories of extraction sockets did not differ with respect to gross morphological features. The tissue of the extraction sites, apical of a newly formed bone bridge, was dominated by bone marrow. Few trabeculae of lamellar bone were also present. Defect sites: The non-augmented defect was sealed by a hard-tissue bridge. In the central and apical portions of the defect bone marrow made up about 61%, and mineralized bone 39% of the tissues. The invagination of the surface of this crestal bone was 0.8+/-0.3 mm. The defect augmented with Collagen Sponge was covered by a hard-tissue bridge, 38% of the tissue within the defect was made up of bone marrow while the remaining 62% was occupied by mineralized bone. The invagination of the hard-tissue bridge was on the average 0.6+/-0.1 mm. In defects augmented with Bio-Oss Collagen the biomaterial occupied a substantial portion of the tissue volume. Eighty-five percent of the periphery of the Bio-Oss particles was found to be in direct contact with newly formed mineralized bone. Woven bone and bone marrow made up 47% and 26% of the newly formed tissue. The invagination of the most coronal part of the bone defect was 0.1+/-0.1 mm.

Conclusion: Sockets that following tooth removal had their PDL tissue removed exhibited similar features of healing after 3 months as sockets which had the PDL retained. The tissues present in an extraction site appeared to be more mature than those present in a surgically produced defect of similar dimension. The Bio-Oss Collagen augmented defect exhibited less wound shrinkage than the non-augmented defect.

Abstract Aim: The purpose of the present study was to compare clinically the treatment of deep intra-bony defects with a combination of a composite bovine-derived xenograft (BDX Coll) and a bioresorbable collagen membrane [guided tissue regeneration (GTR)] to access flap surgery only.

Methods: Thirty-two patients, each of whom displayed one intra-bony defect, were treated either with BDX Coll+GTR (test) or with access flap surgery (control). The results were evaluated at 1 year following therapy.

Results: No differences in any of the investigated parameters were observed at baseline between the two groups. Healing was uneventful in all patients. At 1 year after therapy, the test group showed a reduction in the mean probing depth (PD) from 8.3+/-1.5 to 2.9+/-1.3 mm (p<0.001) and a change in the mean clinical attachment level (CAL) from 9.4+/-1.3 to 5.3+/-1.5 mm (p<0.0001). In the control group, the mean PD was reduced from 8.0+/-1.2 to 4.4+/-1.7 mm (p<0.001) and the mean CAL changed from 9.6+/-1.3 to 7.9+/-1.6 mm (p<0.01). The test treatment resulted in statistically higher PD reductions (p

Conclusion: Within the limits of the present study, it can be concluded that the combination of BDX Coll+GTR resulted in significantly higher CAL gains than treatment with access flap surgery alone, and thus appears to be a suitable alternative for treating intra-bony periodontal defects.

The purpose of the present study was to explore the regenerative potential of natural bone mineral plus collagen (Bio-Oss Collagen®) in experimental intrabony defects. Eight healthy female beagle dogs were used. After extraction of the mandibular third premolars (P3), surgical defects were created and inflammation induced by placement of cotton and steel braids. Eight weeks later, the braids were removed. The experimental lesions thus obtained were either treated by plain flap curettage (group 1: control) or implanted with Bio-Oss Collagen® (group 2: experimental). The results show that the surface of the implanted particles has the characteristics of a bone tissue. These particles are gathered together with a fibrillar network. 6, 18, and 36 weeks postoperative (PO), non-decalcified specimens from both groups were examined histologically by contact microradiography. In the control group, no significant bone regeneration was observed at 6, 18, or 36 weeks PO. In group 2, trabeculae undergoing mineralization and circumscribing dense particles above the reference notch were seen at 6 weeks PO; 18 and 36 week specimens showed significant bone regeneration with more or less dense remaining particles. The periodontal ligament space was always clear and the only signs of ankylosis noticed were deep in the notch on one 18 week test specimen and on one 36 week control specimen.

Background: Histologic data regarding the use of anorganic bovine bone (ABB) in humans are scarce. This study was a histologic evaluation and an examination of the elemental composition of ABB particles and adjacent bone in humans.

Methods: Ten biopsies were retrieved 20 months after maxillary sinus augmentation in five patients. The investigation was carried out using light microscopy in brightfield, fluorescence, and circularly polarized light and scanning electron microscopy (SEM) with energy-dispersive x-ray spectroscopy.

Results: The regenerated tissue consisted of 38% +/- 2.1% newly formed bone, 36% +/- 1.3% marrow spaces, and 29% +/- 1.8% residual ABB particles. Under polarized light, the newly formed bone was characterized by randomly oriented collagen fibers. Under fluorescence, the biomaterial showed close apposition to bone; under SEM, several projections of newly formed bone were seen penetrating the ABB particles. ABB and bone were distinguished by the lighter gray color of the biomaterial in back-scattered electron images; ABB particles were surrounded and linked by newly formed bone. Elemental analysis gave average calcium/phosphorus ratios (atomic %) approximately 1.9 for ABB and 1.4 for bone. Relatively high concentrations of calcium and phosphorus in the biomaterial decreased gradually toward the interface with bone.

Conclusion: The persistence of ABB in the human tissue after 20 months might have been related to the relatively high calcium content of the biomaterial as well as the absence of proteins.

A variety of biomaterials are used when performing sinus augmentation techniques. Bovine hydroxyapatite (BH) has already been demonstrated to present osteoconductive properties. The aim of this article is to provide a histologic and histomorphometric analysis, at 26 months, of a bone specimen extracted from a BH maxillary sinus graft. Histomorphometric results showed 64.4% bone density and 24.4% biomaterial density. Histologic analysis revealed marked bone formation and high osteoconductive properties in the BH particles, with no associated signs of inflammation. Resorption appeared minimal. BH seems to present high biocompatibility and osteoconductive properties.

A variety of biomaterials are used when performing sinus augmentation techniques. Bovine hydroxyapatite (BH) has already been demonstrated to present osteoconductive properties. The aim of this article is to provide a histologic and histomorphometric analysis, at 26 months, of a bone specimen extracted from a BH maxillary sinus graft. Histomorphometric results showed 64.4% bone density and 24.4% biomaterial density. Histologic analysis revealed marked bone formation and high osteoconductive properties in the BH particles, with no associated signs of inflammation. Resorption appeared minimal. BH seems to present high biocompatibility and osteoconductive properties.

Healing of extraction sockets may sometimes result in formation of fibrous tissue instead of bone, even after 4 months, an occurrence that may hinder implant placement. The aim of this preliminary observational study was to histologically evaluate quality and amount of bone regeneration after treating nonhealing sockets with a bovine-derived xenograft enriched with porcine collagen (Bio-Oss Collagen, Geistlich) without barrier membranes. Biopsy specimens were collected during implant placement, 4 months after grafting. A total of 10 cases were treated and evaluated. In all cases, correct implant placement was possible and no implant failure occurred up to 6 months after loading. The histologic analysis demonstrated new bone formation in all specimens. The percentage of newly formed bone was 29.1% (SD 20.71%; range 5% to 48%). Xenograft particles in direct contact with newly formed bone were visible, and mature lamellar bone was observed in 8 cases.

The purpose of this study was to histologically evaluate new bone formation and dimensional soft tissue changes of two different healing protocols (16 weeks and 32 weeks) using deproteinized bovine bone mineral (DBBM) covered with collagen matrix (CM) for alveolar ridge preservation in the anterior esthetic zone prior to dental implant placement. Compared to baseline, both treatments yielded statistically significant differences in several clinical parameters and in the microarchitecture of the native bone and in the newly formed bone in the augmented sites. However, the protocol at 32 weeks determined greater new vital bone formation and fewer dimensional tissue changes.

The purpose of this study was to histologically evaluate new bone formation and dimensional soft tissue changes of two different healing protocols (16 weeks and 32 weeks) using deproteinized bovine bone mineral (DBBM) covered with collagen matrix (CM) for alveolar ridge preservation in the anterior esthetic zone prior to dental implant placement. Compared to baseline, both treatments yielded statistically significant differences in several clinical parameters and in the microarchitecture of the native bone and in the newly formed bone in the augmented sites. However, the protocol at 32 weeks determined greater new vital bone formation and fewer dimensional tissue changes.

Purpose: The aim of this study was to compare a bovine bone substitute (Bio-Oss) to autogenous bone with respect to its value as a material for sinus augmentation.

Materials and Methods: In 10 beagle dogs 12 months of age; the 3 maxillary premolars were extracted on both sides. Six weeks later, 2 cavities of predefined size were produced in the region of the nasal cavity. The antral window was 25 mm long and had a vertical extension of 7 mm. Two Frialit-2 implants (3 x 8 mm) were placed in each bone defect (n = 20). Every implant was primarily stable because of fixation in native bone. In each maxilla, 1 bone defect was filled with autogenous bone harvested from the mandible and 1 was filled with Bio-Oss (material selected at random). The animals were sacrificed at 90 and 180 days, and histologic specimens were examined and the results subjected to statistical analysis by the Wilcoxon test for paired observations.

Results: No healing problems were observed. Histologically, after 90 days the volume of the augmentation showed a reduction of 14.6 +/- 4.4% within the Bio-Oss group and 3.8 +/- 2.5% in the group with autogenous bone. Bone-implant contact of 52.16 +/- 13.15% in the Bio-Oss group and 60.21 +/- 11.46% in the autogenous bone group was observed. At 180 days, the Bio-Oss group showed bony ingrowth of the substitute, whereas in the autogenous group a differentiation from original bone could no longer be made. The volume reduction was 16.5 +/- 8.67% in the Bio-Oss group and 39.8 +/- 16.14% in the autogenous group. Bone-implant contact of 63.43 +/- 19.56% in the Bio-Oss group and 42.22 +/- 12.80% in the autogenous bone group was measured. Discussion and Conclusion: The results indicated that because of the nonresorptive properties of the bone substitute Bio-Oss, regeneration of the defects is achievable. It was demonstrated that the bone substitute seemed to behave as a permanent implant. The volume of the area augmented by autogenous bone decreased over the observation period.

Background: The reconstruction of edentulous patients with adequate bone volume and density by using dental implants has become a viable treatment option with high predictability. However, initial stabilization is difficult to achieve in the posterior maxillary regions where cortical bone is thin or absent due to severely resorbed alveolar ridges. Maxillary sinus lift procedures applied with various grafting materials enable clinicians to place implant-supported prostheses even in cases with increased pneumatization of the maxillary sinus. Methods: The purpose of this study was to evaluate histologically and clinically different grafting materials used in maxillary sinus floor augmentation. Deproteinized bovine bone granules (DBBG), demineralized freeze-dried bone powder (DFBP), and porous hydroxyapatite (PHA) were used as grafting materials. A total of 19 implants in 8 patients were placed into grafted sites. In 3 patients, a 2-stage approach was used wherein implants were inserted after a 6-month healing period following a sinus lift procedure. Specimens were taken with a trephine drill, and the site of the specimen was enlarged to accept an implant. For the remaining cases, a 1-stage approach, which included sinus lifting and implant placement, was used and bone biopsies were taken during the uncovering stage. After 6 months of healing, fixed prosthetic restorations were fabricated.

Results: The healing period progressed without any complications, and all implants were loaded. The mean functioning time was 12 months, varying from 9 to 24 months.

Conclusion: The results indicate that DFBP resorbs earlier than PHA and DBBG in sinus lift procedures.

Objective: The purpose of the present study was to histologically and histomorphometrically evaluate the long-term tissue response to deproteinized bovine bone (DPBB) particles used in association with autogenous bone and to compare particle size after 6 months and 11 years, in the same patients, in order to determine possible resorption.

Material and Methods: Twenty consecutive patients (14 women and six men) with a mean age of 62 years (range 48-69 years) with severe atrophy of the posterior maxilla were included in this study. Thirty maxillary sinuses with <5 mm subantral alveolar bone were augmented with a mixture of 80% DPBB and 20% autogenous bone. Eleven years (mean 11.5 years) after augmentation, biopsies were taken from the grafted areas of the 11 patients who volunteered to participate in this new surgical intervention. The following histomorphometrical measurements were performed in these specimens: total bone area in percentage, total area of the DPBB, total area of marrow space, the degree of DPBB-bone contact (percentage of the total surface length for each particle), the length of all DPBB particles and the area of all DPBB particles. The length and the area of the particles were compared with samples harvested from the same patients at 6 months (nine samples) and pristine particles from the manufacturer.

Results: The biopsies consisted of 44.7+/-16.9% lamellar bone, 38+/-16.9% marrow space and 17.3+/-13.2% DPBB. The degree of DPBB to bone contact was 61.5+/-34%. There were no statistically significant differences between the length and area of the particles after 11 years compared with those measured after 6 months in the same patients or to pristine particles from the manufacturer.

Conclusion: DPBB particles were found to be well integrated in lamellar bone, after sinus floor augmentation in humans, showing no significant changes in particle size after 11 years.

Purpose: Lack of bone height in the posterior maxilla often necessitates augmentation prior to or simultaneously with dental implant placement. The purpose of this clinical study was to evaluate the use of the natural bone mineral Bio-Oss alone or in combination with autogenous bone in sinus floor elevations performed as 1- or 2-step procedures.

Materials and Methods: Thirty-eight patients required sinus augmentation. Natural bone mineral alone was used in sinus floor augmentation in 21 patients. In 13 patients, a mixture of the bone substitute and autogenous bone was used, and in 4 patients autogenous bone alone was used. In all of the patients, samples were taken for biopsy 3 to 8 months postoperatively, and bone regeneration was evaluated histologically and histomorphometrically.

Results: In all patients, the amount of new bone significantly increased over the observation time, while marrow areas decreased. There was no statistically significant difference in the amount of new bone formation between the Bio-Oss group (new bone 29.52% +/- 7.43%) and the Bio-Oss/autogenous bone group (new bone 32.23% +/- 6.86%). In the 4 patients treated with autogenous bone alone, a greater amount of newly formed bone was found; however, in these cases the area volume filled was smaller than in the other 2 groups. DISCUSSION: The data showed that new bone formation takes place up to 8 months after sinus floor elevation and that there is no difference in the amount of bone formation between procedures done with the bone substitute alone or with the mixture of the substitute and autogenous bone.

Conclusion: These data suggest that predictable bone formation can be achieved with the use of Bio-Oss.

Objective: The purpose of this study was to compare the effects of two different resorbable collagen membranes on new bone formation after sinus grafts with anorganic bovine bone mineral (BBM).

Materials and Methods: For 64 patients presenting with an initial residual bone height

Results: The core biopsy specimens of Bio-Arm (n = 37 sites) and Bio-Gide group (n = 22 sites) were compared. The results showed that the BBM particles were in direct contact with the newly formed bone in all cases. In histomorphometric analysis, the Bio-Gide group showed significantly higher new bone formation (33.3 +/- 12%) compared with the Bio-Arm group (26.3 +/- 8.1%) (P < 0.05). All the implants survived successfully after a mean follow-up of 35.3 months (range 22-63 months) in the Bio-Arm group and 55.5 months (range 35-66 months) in the Bio-Gide group. The amount of new bone in the specimens did not significantly correlate with the residual bone height at the time of surgery or the length of the healing period.

Conclusion: The type of resorbable membrane did not readily affect the long-term survival of the implants at the grafted sinus. On the other hand, Bio-Gide group showed more new bone formation than the Bio-Arm group, which implied that the function of the membrane can influence the remodeling of the grafted sinus. As the amount of residual bone substitute particle had not decreased significantly over time, the results suggest that the BBM was rarely resorbable for at least 15 months after the surgery.

Introduction: Sinus grafting is a technique oriented to facilitate implant placement in posterior atrophic maxillae. Several modifications of the original technique and a wide variety of materials have been proposed; most of them associated with implant survival rates. However, the quality of the bone obtained after the application of certain grafting materials has not been fully elucidated yet. The aims of this multicenter study were to analyse histomorphometrical samples obtained 6 months after sinus grafting using a composite graft consisting of anorganic bovine bone (ABB)+ autologous bone (AB), and to compare these samples with maxillary pristine bone biopsies.

Material and Methods: Ninety maxillary sinus augmentations were performed for delayed implant placement (N=90) in 45 consecutive patients (test group). Bone cores were harvested 6 months after grafting for histomorphometric and ultrastructural study. Control pristine bone biopsies were taken from the posterior maxilla of 10 patients (control). Bone radiographic changes were assessed up to 24 months after implant loading.

Results: The total mean values after analysis of test cores revealed a proportion of 46.08+/-16.6% of vital bone, 42.27+/-15.1% of non-mineralized connective tissue, and 37.02+/-25.1% of the remaining ABB particles. Significant bone remodeling activities were noticed in sinus grafting samples when compared with pristine bone. A statistically significant difference was observed in the number of osteoid lines between two groups, with higher values in the test one (15.1+/-11.48% vs. 2.5+/-2.2%, P=0.0005). Ultrastructural study showed that vital trabecular bone was in intimal contact with ABB particles. Radiographic analysis revealed that the higher the proportion of remaining ABB, the lower the total vertical resorption of the graft.

Conclusion: Sinus grafting constitutes an excellent model for the study of de novo bone formation patterns and graft consolidation, when a combination of different bone substitutes is applied. The combination of ABB+AB yields highly satisfactory outcomes from both a clinical and a histologic perspective. 

OBJECTIVE:
To compare the clinical and histologic outcomes of two different grafting materials (allograft and xenograft) when combined with autogenous bone and covered with a collagen membrane for sinus augmentation.

MATERIAL AND METHODS:
A parallel case series of fourteen patients in need of a unilateral sinus augmentation was evaluated in this study. Seven patients received a graft composed by autologous cortical bone (ACB) and anorganic bovine bone in a ratio of 1:1; the other seven patients received ACB mixed with an allograft in the same ratio. Bone biopsies were obtained 6 months after sinus augmentation at the time of implant placement. Comparative histomorphometrical, histopathological, and immunohistochemical analyses were conducted and statistically analyzed.

RESULTS:
After 12 months of functional loading, all implants in both groups were clinical and radiographically successful. Histomorphometrically, although the initial bone formation was not significantly different between groups (new mineralized tissue: 41.03(12.87)% vs. 34.50(13.18)%, p = .620; allograft vs. xenograft groups), the graft resorbed faster in the allograft group (remnant graft particles: 9.83[7.77]% vs. 21.71[17.88]%; p = .026; allograft vs. xenograft groups). Non-mineralized tissue did not statistically differ either (49.00[14.32]% vs. 43.79[19.90]%; p = .710; allograft vs. xenograft groups). The histologic analyses revealed higher cellular content, four times more osteoid lines, and higher vascularization in the xenograft group. Musashi-1 (mesenchymal stromal cell marker) was also more intensively expressed in the xenograft group (p = .019).

CONCLUSIONS:
Both composite grafts generate adequate substratum to receive dental implants after healing. Compared with the xenograft composite, allograft composite shows faster turnover and a quicker decrease in biological action after 6 months."

To analyze the clinical outcome of horizontal ridge augmentation using autogenous block grafts covered with anorganic bovine bone mineral (ABBM) and a bioabsorbable collagen membrane. In 42 patients a clinical series] with severe horizontal bone atrophy, a staged approach was chosen for implant placement following horizontal ridge augmentation. A block graft was harvested from the symphysis or retromolar area, and secured to the recipient site with fixation screws. The width of the ridge was measured before and after horizontal ridge augmentation. The block graft was subsequently covered with ABBM and a collagen membrane. Following a tension-free primary wound closure and a mean healing period of 5.8 months, the sites were re-entered, and the crest width was re-assessed prior to implant placement. Fifty-eight sites were augmented, including 41 sites located in the anterior maxilla. The mean initial crest width measured 3.06 mm. At re-entry, the mean width of the ridge was 7.66 mm, with a calculated mean gain of horizontal bone thickness of 4.6 mm (range 2-7 mm). Only minor surface resorption of 0.36 mm was observed from augmentation to re-entry. The presented technique of ridge augmentation using autogenous block grafts with ABBM filler and collagen membrane coverage demonstrated successful horizontal ridge augmentation with high predictability. The surgical method has been further simplified by using a resorbable membrane. The hydrophilic membrane was easy to apply, and did not cause wound infection in the rare instance of membrane exposure.

AIM:
To clinically and radiographically evaluate bone regeneration of severe horizontal bone defects.

MATERIALS AND METHODS:
This study was designed as a single cohort, prospective clinical trial. Partially or fully edentulous patients, having less then 4 mm of residual horizontal bone width were selected and consecutively treated with resorbable collagen membranes and a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, 7 months before implant placement. Tapered body implants were inserted and loaded 3 to 6 months later with a screw retained crown or bridge. Outcomes were: implant survival rate, any biological and prosthetic complications, horizontal alveolar bone dimensional changes measured on cone beam computed tomography (CBCT) taken at baseline and at implant insertion, peri-implant marginal bone level changes measured on periapical radiographs, plaque index (PI), and bleeding on probing index (BoP).

RESULTS:
Eighteen consecutive patients (11 females, 7 males) with a mean age of 56.8 years (range 24-78) and 22 treated sites received 55 regular platform implants. No patient dropped-out and no implants failed during the entire follow-up, resulting in a cumulative implant survival rate of 100%. No prosthetic or biological complications were recorded. Supraimposition of pre- and 7-month post-operative CBCT scans revealed an average horizontal bone gain of 5.03 ± 2.15 mm (95% CI: 4.13-5.92 mm). One year after final prosthesis delivery, mean marginal bone loss was 1.03 ± 0.21 mm (95% CI 0.83-1.17 mm). PI was 11.1% and BoP was 5.6%.

CONCLUSION:
Within the limitation of the present study, high implant survival rate and high average bone augmentation seem to validate the use of collagen resorbable membranes with a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, for the reconstruction of severe horizontal ridge defects.

BACKGROUND: To evaluate dimensional bone alterations following horizontal ridge augmentation using guided bone regeneration (GBR) with or without autogenous block graft (ABG) for the rehabilitation of atrophic jaws with dental implants.

MATERIALS AND METHODS: Forty-two patients, with 42 severe horizontal bone atrophy sites in the maxilla or mandible were randomly assigned to two groups: ABG or GBR. The ABG group received a combination of ABG with particulate xenograft, covered by a collagen membrane, while the GBR group received particulate xenograft alone, covered by a collagen membrane. After 6-9 months of healing, implants were inserted. All implants were definitively restored 6 months after implant placement. Radiographic examination (cone-beam computed tomograms) was performed immediately after bone grafting procedure (T0), at 6 months (T6), and at 18 months (T18), to evaluate the amount of horizontal bone width (HBW) gain. Patient demographic information, amount of ridge width augmentation, implant survival, complications, and contributing factors were gathered and analyzed.

RESULTS: Thirty-nine patients completed the study. Both groups developed enough bone ridge width for implant placement. A total of 65 implants were placed. Implant survival rate was 100% in both groups at T18. Mean increases in HBW amounted to 5.6 ± 1.35 mm in GBR sites and 4.8 ± 0.79 mm in ABG sites at T18. There was no statistically significant difference in HBW gain obtained in the GBR group when compared to the ABG group at 6 months (P = 0.26) or 18 months (P = 0.26). However, the ABG group had a statistically significant higher prevalence of sensory disturbances (P = 0.02) and hematomas (P = 0.002) compared to the GBR group.

CONCLUSION: These findings indicated that either GBR with or without ABG is an effective approach in augmenting resorbed horizontal deficient ridges prior to implant placement. However, more complications may be seen with the use of ABG related to the donor sites.

This report presents a histologic assessment of guided bone regeneration for dehiscence defects treated with bovine bone mineral or a combination of autogenous and synthetic bone. The samples were obtained from an autopsy specimen donated by a patient, which is a rare opportunity to evaluate long-term results of guided bone regeneration and osseointegration. The values for bone-to-implant contact were similar in both sites. The augmentation with bovine bone mineral demonstrated bone reconstruction after 1 year, whereas the augmentation with autogenous and synthetic bone failed to maintain the augmented volume, eventually leading to mucosal recession after 5.5 years.

To date, the majority of studies on bone substitute materials have investigated their regenerative properties; however, little is known about their resorption processes, forasmuch as it is believed that the ideal biomaterial for bone regeneration must be completely resorbable. This study is aimed at defining the in vitro resorption potential of human osteoclasts (OCLs) on a xenogenous bone mineral (XBM). Peripheral blood mononuclear cells from healthy volunteers were used to generate OCLs in vitro in the presence of macrophage colony stimulating factor and receptor activator of NF-kappaB ligand on bovine bone slices and XBM. By using morphologic and biochemical methods, we observed that OCL formation occurred on XBM and these cells were positive for the major OCL markers. Regarding OCL activity, resorption pits were detected on XBM by reflection and confocal microscopy. However, biochemical analysis revealed that collagen degradation at day 14 and 21 was significantly lower in XBM supernatants when compared to bovine bone, suggesting that XBM underwent a much slower resorption over time. These findings demonstrate that OCLs are generated on, attach to, and resorb XBM though more slowly than native bone, and suggest that cultured human OCLs could be used as a model for comparing resorption rates of bone substitute materials.

The present case series evaluated three-dimensional volumetric bone tissue changes and new bone formation in severely resorbed extraction sockets augmented with Bio-Oss collagen and a covering collagen membrane in nine chronic periodontitis patients. Healing was by secondary intention. After 12 months of healing, the augmentation procedure appeared not only to compensate for bone remodeling but also appeared to repair a significant portion of the buccal wall. The mineralized tissue filled the 91.49% ± 6.77% of the maximum volume for regeneration. Overall, a mean of 49.6% new bone, 27.1% residual graft material, and 23.3% connective tissue were detected.

OBJECTIVES:
To evaluate bone reconstruction and soft tissue reactions at immediate implants placed into intact sockets and those with buccal bone dehiscence defects.

METHODS:
Fifty-nine internal connection implants from four different manufacturers were immediately placed in intact sockets(non-dehiscence group, n=40), and in alveoli with buccal bone dehiscence defects: 1) Group 1(n= N10), the defect depth measured 3-5 mm from the gingival margin. 2) Group 2(n=9), the depth ranged from 5mm to 7mm. The surrounding bony voids were grafted with deproteinized bovine bone mineral (DBBM) particles. Cone beam computed tomography(CBCT) was performed immediately after surgery (T1), and at 6 months later(T2). Radiographs were taken at prosthesis placement and one year postloading(T3). Soft tissue parameters were measured at baseline (T0), prosthesis placement and T3.

RESULTS:
No implants were lost during the observation period. For the dehiscence groups, the buccal bone plates were radiographically reconstructed to comparable horizontal and vertical bone volumes compared with the non-dehiscence group. Marginal bone loss occurred between the time of final restoration and 1-year postloading was not statistically different(P=0.732) between groups. Soft tissue parameters did not reveal inferior results for the dehiscence groups.

CONCLUSIONS:
Within the limitations of this study, flapless implant placement into compromised sockets in combination with DBBM grafting may be a viable technique to reconstitute the defected buccal bone plates due to space maintenance and primary socket closure provided by healing abutments and bone grafts.

CLINICAL SIGNIFICANCE:
Immediate implants and DBBM grafting without using membranes may be indicated for sockets with buccal bone defects.

AIM:
To associate the dimension of the facial bone wall with clinical, radiological, and patient-centered outcomes at least 10 years after immediate implant placement with simultaneous guided bone regeneration in a retrospective study.

MATERIAL AND METHODS:
Primary endpoint was the distance from the implant shoulder (IS) to the first bone-to-implant contact (IS-BIC10y ). Secondary endpoints included the facial bone thickness (BT10y ) 2, 4, and 6 mm apical to the IS, and the implant position. At baseline, the horizontal defect width (HDWBL ) from the implant surface to the alveolar wall was recorded. At recall, distance from the IS to the mucosal margin (IS-MM10y ), degree of soft tissue coverage of the mesial and distal aspects of the implants (PISm10y , PISd10y ; Papilla Index), pocket probing depth (PPD10y ), and patient-centered outcomes were determined. Width of the keratinized mucosa (KM), Full-Mouth Plaque and Bleeding Score (FMPS, FMBS) were available for both time points.

RESULTS:
Of the 20 patients who underwent immediate implant placement with simultaneous guided bone regeneration and transmucosal healing, nine males and eight females with a median age of 62 years (42 min, 84 max) were followed up for a median period of 10.5 y (min 10.1 max 11.5). The 10-year implant survival rate was 100%. Multivariate regression analysis revealed a correlation of the IS-BIC10y , controlled for age and gender, with four parameters: HDWBL (P = 0.03), KMBL -10 (P = 0.02), BT10 4 mm (P = 0.01), and BT10 6 mm (P = 0.01).

CONCLUSION:
Within the conditions of the present study, the horizontal defect width was the main indicator for the vertical dimension of the facial bone. The facial bone dimension was further associated with a reduction in the width of the keratinized mucosa and the dimension of the buccal bone.

This retrospective study aimed to analyse the fate of the buccal crest after immediate implant placement (IIP) through the use of cone beam computed tomography (CBCT). In 16 consecutive patients, an implant was placed in a more palatal position after extraction, thereby creating a gap of at least 2mm between the implant and the buccal crest. Subsequently, this gap was filled with a bone substitute. Preoperatively, immediate postoperatively, and late postoperatively, a CBCT was made to measure the thickness of the buccal crest. After application of the bone substitute, the buccal crest increased in thickness from 0.9mm to 2.4mm (mean). At a mean of 103 weeks after IIP, late postoperative CBCT scans showed that the thickness of the buccal crest was compacted to 1.8mm. In the same period, the height of the buccal crest increased by 1.6mm (mean) to, on average, 1.2mm above the implant shoulder. The aesthetic outcome was analysed using the White and Pink Esthetic Score (WES and PES). Both scored high: 8.4 and 11.8, respectively. Within the limitations of this study, the results of this IIP protocol are promising. Long-term prospective research on this topic on a large number of patients is necessary.

This clinical study assessed at 5 years both implant survival and peri-implant tissue architecture of immediately provisionalized implants placed 4 to 6 months following augmentation with demineralized bovine bone allograft and collagen membrane. Of 23 implants in 19 patients, one implant failed prior to loading (95.6% survival). Implant tissue relationships were stable following implant placement; marginal bone level changes from implant placement to 5 years (mean ± SD: -0.18 ± 0.79mm, range: -1.6 to 1.4mm, P = .51), the mesial and distal papilla length changes (mesial mean ± SD: 1.14 ± 0.92mm, P<.001; distal mean ± SD: 0.74 ± 1.46mm, P = .04), and the unchanged mucosal zenith location (mean ± SD: 0.24 ± 0.93mm, P = .15) were recorded. There were no major surgical complications during the 5-year period. When augmentation is required, subsequent dental implant placement in the anterior maxilla may be achieved using immediate placement and provisionalization protocol to attain osseointegration success and stable peri-implant tissue responses.

Aim: The study was designed to evaluate the clinical treatment outcome of placing transmucosal implants into extraction. The purpose of the present clinical study was to test whether peri-implant bone defects can successfully be filled by applying both the bone and the bioresorbable materials for the guided tissue regeneration.

Methods: Twelve patients who required extraction of a single molar were treated with immediate placement of an ITI implant (Dental Implant System). Guided bone regeneration (GBR) technique was always applied simultaneously using deproteinized bovine bone mineral. Implants and bone were covered with a resorbable collagen membrane. Clinical measurements were taken at 6 sites around each implant. Radiological and clinical parameters were measured at the time of implant placement and at follow-up after 1, 3, 6, 12 and 24 months. Prosthetic rehabilitation was performed 3 months after surgery using a porcelain fused to metal crown.

Results: Soft tissue healing, at all sites, was free of complications, independently on the width of bone defect. Radiographs showed strength contact between peri-implant bone and the fixture without any defect between bone and implant. Clinical examination showed absolute implant stability complying with Albrektsson's requirements.

Conclusion: The use of GBR with resorbable membrane to cover Bio-Oss, in association with immediate implant insertion at posterior sites when there is a wide bone defect, also allows early defect filling and good stability, already in the first month, with the possibility of prosthetic loading after only 3 months.

Objectives: The aim of the present study was to evaluate immunohistochemically the pattern of guided bone regeneration (GBR) using different types of barrier membranes.

Material and Methods: Standardized buccal dehiscence defects were surgically created following implant bed preparation in 12 beagle dogs. Defects were randomly assigned to six different GBR procedures: a collagen-coated bone grafting material (BOC) in combination with either a native, three cross-linked, a titanium-reinforced collagen membrane, or expanded polytetrafluorethylene (ePTFE), or BOC alone. After 1, 2, 4, 6, 9, and 12 weeks of submerged healing, dissected blocks were processed for immunohistochemical (osteocalcin - OC, transglutaminase II - angiogenesis) and histomorphometrical analysis [e.g., bone-to-implant contact (BIC), area of new bone fill (BF)].

Results: In general, angiogenesis, OC antigen reactivity, and new bone formation mainly arose from open bone marrow spaces at the bottom of the defect and invaded the dehiscence areas along the implant surface and BOC. At 4 weeks, membranes supporting an early transmembraneous angiogenesis also exhibited some localized peripheral areas of new bone formation. However, significantly increasing BIC and BF values over time were observed in all groups. Membrane exposure after 10-12 weeks was associated with a loss of the supporting alveolar bone in the ePTFE group. Conclusion: Within the limits of the present study, it was concluded that (i) angiogenesis plays a crucial role in GBR and (ii) all membranes investigated supported bone regeneration on an equivalent level.

Aim:
To test whether a collagen matrix (CM) can improve early wound healing and aesthetics, and decrease wound sensitivity compared with spontaneous healing.

Methods:
In 15 volunteers, 6-mm punch biopsies were harvested at both palatal sites. A CM was sutured in one site; the other one was left untreated (control). Measurements included the remaining defect area, the colour match to surrounding tissue and somatosensory parameters at various time-points (pre-operative, post-operative, 4, 8, 15, 29 days).

Results:
The defect area decreased over time for both treatments. Re-epithelization was completed in all subjects by day 15. The defect area was significantly smaller for CM (mean ± SD: 19.3 ± 3.4 mm2) compared with control (21.3 ± 3.3 mm2) at day 4 (p < 0.05), and at day 8 (CM: 11.7 ± 2.5 mm2); control 13.6 ± 2.9 mm2; p < 0.01). The colour match was more favourable for CM at day 4, 8 and 29 (p > 0.05). Somatosensory measurements revealed slightly lower wound sensitivity at day 4 for CM compared with control.

Conclusion:
The use of CM can enhance wound healing compared with spontaneous healing during the first week. This was mainly documented by a faster re-epithelization. Colour match and wound sensitivity measurements did not reach statistical significance between CM and control sites.

AIMS:
The primary objective of this study was to compare the in vivo performance, namely in terms of quantity of newly formed bone and bone-to-material contact (osteoconductivity), of three hydroxyapatite-based biomaterials (HA) of different origins (natural or synthetic) or manufacturing process in a sinus lift model in rabbits. The secondary objective was to correlate the findings with the physical and topographical characteristics of the biomaterials.

MATERIALS AND METHODS:
Two bovine HA manufactured with different processes (bovine hydroxyapatites [BHA] and cuttlebone hydroxyapatite [CBHA]) and a synthetic hydroxyapatite (SHA) sintered at high temperature were characterised with scanning electronic microscopy (SEM) and the measurement of specific surface area (BET). The materials were implanted in a sinus lift model in rabbits; histological and histomorphometric evaluation using non-decalcified sections was performed at 1, 5 and 12 weeks after implantation.

RESULTS:
The studied biomaterials displayed a different surface topography. The two natural HA displayed significantly higher bone quantities (P = 0.0017; BHA vs. SHA, P = 0.0018 and CBHA vs. SHA, P = 0.033) at 5 and 12 weeks compared to the synthetic one (SHA). Moreover, the osteoconductivity (bone-to-material contact) was significantly higher in the BHA group compared to the two other groups (P = 0.014; BHA vs. SHA, P = 0.023 and BHA vs. CBHA, P = 0.033).

CONCLUSION:
HA-based biomaterials from diverse origins and manufacturing processes displayed different topographical characteristics. This may have influenced different regenerated bone architecture observed; more bone was found with natural HA compared to the synthetic one, and significantly higher bone-to-material contacts were found with BHA.

Purpose: The objectives of this study were to (1) evaluate the survival of implants placed in maxillary sinuses augmented with a 70:30 mixture of autogenous bone and anorganic bovine hydroxyapatite (Bio-Oss) at 1 and 5 years, (2) observe the difference in survival rate between 1-stage and 2-stage procedures, and (3) compare the survival rate of rough-surfaced implants with that of machined implants.

Materials and Methods: A total of 30 consecutively patients (48 sinuses) with Cawood and Howell Class V and VI atrophy were evaluated. Lateral osteotomy techniques were used in all cases. Implants were placed either simultaneous with grafting (1-stage procedure) or after a delay (2-stage procedure), depending on the amount of residual bone. A 70:30 mixture of autogenous bone and anorganic bovine hydroxyapatite was used as the graft material. All patients were followed up at 1 year after prosthetic loading, while a limited group of these patients was followed up to 5 years.

Results: In 8 patients where the residual crestal bone under the sinus floor assessed by computed tomography was at least 4.5 mm (mean, 5.3 mm), the 1-stage procedure was used for 11 sinus elevations and 32 implants. In 22 patients where the residual crestal bone was less than 4.5 mm (mean, 2.5 mm), the 2-stage procedure was used for 37 sinus elevations and 108 implants. For the 140 implants placed, the overall survival rate was 95.7% at the healing abutment surgery, and the cumulative survival rate was 94.9% at 1 and 5 years. The type of surgical technique was significantly associated with implant failure (P < .05); implants placed using the 1-stage procedure showed a failure rate of 12.5%, while implants placed with the 2-stage procedure had a failure rate of 2.8%. No significant difference in survival rate was observed with respect to implant surface.

Conclusion: A high survival rate was achieved when sinus elevation was performed with a combination of autogenous bone and anorganic bovine hydroxyapatite, even where a minimal amount of residual crestal bone was present. The survival rate was improved when implants were placed after a healing period.

Purpose: The aims of this clinical study were to evaluate the occurrence of sinus graft infection and the results of a planned surgical and pharmacologic treatment regimen to eliminate infections and preserve the graft. Materials and Methods: Patients were consecutively treated with sinus floor elevations using the lateral window technique. If a clinical diagnosis of sinus graft infection was made for a patient, a postoperative computed tomographic scan was performed to diagnose involvement of the sinus cavity.

Results: Of 198 patients treated with 274 sinus grafts, 8 (2.3%) developed a sinus graft infection. These patients were treated with the same surgical and pharmacologic regimen. Symptoms of infection were recognized, the infected graft was removed, and the remaining graft material was cleansed. The remaining defect was not filled with new graft material; instead, it was left to heal for an extended healing period (average of 10.6 months), and residual bone defects were corrected during implant placement. Acute symptoms of infection disappeared within 48 hours of treatment and all patients healed uneventfully thereafter. All 24 implants placed have survived to date (with implant loading times ranging from 1 to 9 years), resulting in a 100% implant survival rate for these sites with postoperative infection.

Conclusion: The overall clinical outcome, including patient satisfaction, achievement of optimal graft volume without subsequent sinus elevation, and long-term implant survival, confirmed the success of this treatment protocol.

OBJECTIVE: To evaluate the influence of the posterior residual bone height and sinus width on the outcome of maxillary sinus bone augmentation using anorganic bovine bone.

MATERIAL AND METHODS: Bilateral sinus bone augmentation was performed using anorganic bovine bone in 20 patients with residual bone height <2 mm in at least one site on each side. Trephine samples were removed at the implant insertion site 8 months after the grafting procedure, and histological and histomorphometric analyses were performed to examine the relative amount (%) of new bone, anorganic bovine bone, and soft tissue in the grafted area. Based on cone beam computed tomography evaluation, the sites of implant insertion were classified according to sinus width into narrow, average, and wide, and according to residual bone height into ≤2 and >2 mm.

RESULTS: A total of 146 implants were installed and 103 biopsies were evaluated. New bone formation in sites classified as narrow (69 sites), average (19 sites), and wide (15 sites) was 28.5% ± 9.24, 28.9% ± 8.61, and 30.3% ± 7.80, respectively. The mean posterior maxillary residual bone height was 4.0 ± 2.43 mm, and 26 and 77 sites were classified as ≤2 and >2 mm, respectively. New bone formation was 26.2% ± 9.10 and 29.8% ± 8.67 for residual bone height ≤2 and >2 mm, respectively. The differences were non-significant.

CONCLUSIONS: Within the limitations of the present study, posterior residual bone height and sinus width were not factors with influence on new bone formation in sinuses grafted exclusively with anorganic bovine bone after 8 months of healing.

Background: Dental implants require sufficient bone to be adequately stabilised. For some patients implant treatment would not be an option without bone augmentation. A variety of materials and surgical techniques are available for bone augmentation.

Objectives: General objectives: To test the null hypothesis of no difference in the success, function, morbidity and patient satisfaction between different bone augmentation techniques for dental implant treatment. Specific objectives: (A) to test whether and when augmentation procedures are necessary; (B) to test which is the most effective augmentation technique for specific clinical indications. Trials were divided into three broad categories according to different indications for the bone augmentation techniques: (1) major vertical or horizontal bone augmentation or both; (2) implants placed in extraction sockets; (3) fenestrated implants.

Search Strategy: The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched. Several dental journals were handsearched. The bibliographies of review articles were checked, and personal references were searched. More than 55 implant manufacturing companies were also contacted. Last electronic search was conducted on 1 October 2005.

Selection Criteria: Randomised controlled trials (RCTs) of different techniques and materials for augmenting bone for implant treatment reporting the outcome of implant therapy at least to abutment connection.

Data Collection and Analysis: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted independently and in duplicate. Authors were contacted for any missing information. Results were expressed as random-effects models using weighted mean differences for continuous outcomes and odd ratios for dichotomous outcomes with 95% confidence intervals. The statistical unit of the analysis was the patient.

Main Results: Thirteen RCTs out of 29 potentially eligible trials reporting the outcome of 330 patients were suitable for inclusion. Since different techniques were evaluated in different trials, no meta-analysis could be performed.  Six trials evaluated different techniques for vertical or horizontal bone augmentation or both. Four trials evaluated different techniques of bone grafting for implants placed in extraction sockets and three trials evaluated different techniques to treat bone dehiscence or fenestrations around implants.

Authors' Conclusion: Major bone grafting procedures of extremely resorbed mandibles may not be justified. Bone substitutes (Bio-Oss or Cerasorb) may replace autogenous bone for sinus lift procedures of extremely atrophic sinuses. Both guided bone regeneration (GBR) procedures and distraction osteogenesis can augment bone vertically, but it is unclear which is the most efficient technique. It is unclear whether augmentation procedures at immediate single implants placed in fresh extraction sockets are needed, and which is the most effective augmentation procedure, however, sites treated with barrier + Bio-Oss showed a higher position of the gingival margin, when compared to sites treated with barriers alone. Non-resorbable barriers at fenestrated implants regenerated more bone than no barriers; however it remains unclear whether such bone is of benefit to the patient. It is unclear which is the most effective technique for augmenting bone around fenestrated implants. No bone promoting molecule has been shown to be effective or necessary in conjunction with dental implant treatment. The use of particulated autogenous bone from intraoral locations, also taken with dedicated aspirators, might be associated with an increased risk of infective complications. These findings are based on few trials including few patients, having sometimes short follow up, and being often judged to be at high risk of bias.

BACKGROUND:
The use of autogenous block grafts harvested from intraoral donor sites has proven to be effective for the reconstruction of horizontal bone defects.

PURPOSE:
The objective of this study was to analyze implant success and the rate of block graft resorption 10 years after ridge augmentation to elucidate contributing factors influencing graft maintenance.

MATERIALS AND METHODS:
A staged horizontal block graft augmentation was performed in 52 implant sites exhibiting severe horizontal bone atrophy using autogenous block grafts protected by DBBM and collagen membranes. The crest width was assessed intraoperatively at surgery and at re-entry after 6 months. At the 10 year reexamination clinical and radiographic parameters were assessed using cone beam computed tomography.

RESULTS:
The 10-year implant success rate amounted to 98.1%, with minimal peri-implant bone loss (-0.17 mm for the maxilla, -0.09 mm for the mandible). The surface resorption rate after 10 years was 7.7% (0.38 mm). Grafts originating from the chin demonstrated significantly better graft maintenance at 10 years compared to retromolar grafts. Recipient site and age had no significant impact on graft resorption, whereas females showed more bone loss at the 10-year examination.

CONCLUSIONS:
Lateral ridge augmentation using autogenous block grafts and guided bone regeneration demonstrated a favorable success rate of 98.1% with minimal block graft resorption of 7.7% after 10 years. Modulating factors were origin of the graft and gender.

The objective of this systematic review was to test the hypothesis of no difference in implant treatment outcomes when using Bio-Oss alone or Bio-Oss mixed with particulate autogenous bone grafts for lateral ridge augmentation. A search of the MEDLINE, Cochrane Library, and Embase databases in combination with a hand-search of relevant journals was conducted. Human studies published in English from 1 January 1990 to 1 May 2016 were included. The search provided 337 titles and six studies fulfilled the inclusion criteria. Considerable variation prevented a meta-analysis from being performed. The two treatment modalities have never been compared within the same study. Non-comparative studies demonstrated a 3-year implant survival of 96% with 50% Bio-Oss mixed with 50% autogenous bone graft. Moreover, Bio-Oss alone or Bio-Oss mixed with autogenous bone graft seems to increase the amount of newly formed bone as well as the width of the alveolar process. Within the limitations of this systematic review, lateral ridge augmentation with Bio-Oss alone or in combination with autogenous bone graft seems to induce newly formed bone and increase the width of the alveolar process, with high short-term implant survival. However, long-term studies comparing the two treatment modalities are needed before final conclusions can be drawn.

BACKGROUND:
The optimal ratio of deproteinized bovine bone (DPBB) and autogenous bone (AB) for lateral augmentation is presently unknown.

PURPOSE:
To evaluate implant treatment outcome and radiological graft changes after lateral ridge augmentation with 2 different mixtures of DPBB and AB, 2 years after functional loading.

MATERIALS AND METHODS:
Thirteen patients were included in a split mouth, randomized, controlled trial. Four partially edentulous and 10 totally edentulous jaws with an alveolar ridge width of <4 mm were augmented with a graft mixture of 90:10 (DPBB:AB) on one side and 60:40 (DPBB:AB) on the contra lateral side. Graft width changes were measured on CBCT scans at different time points. Implant survival and success rates were calculated. Resonance frequency analysis and marginal bone measurements were performed after 2 years of loading.

RESULTS:
The survival rate was 94.4% for implants installed in the 90:10 and 100% for implants installed in the 60:40. There were no statistically significant differences in survival rate or success rate between the mixtures. The width was 5.7 mm and 6.2 mm, respectively for the 2 groups without any significant difference between the groups after 2 years of loading. There was a significant difference in graft reduction between the groups, 54.4% (90:10) and 37.5% (60:40), respectively. There were no statistically significant differences in implant stability or marginal bone levels at any time points.

CONCLUSIONS:
The 2 treatment modalities may be successfully used for lateral ridge augmentation and presented good clinical results after 2 years of loading. However, long-term RCTs are required before final conclusions can be provided on this specific topic.

The present retrospective study evaluates the long-term results of reconstructive periodontal surgery using a bovine-derived bone mineral with or without a bio-resorbable collagen membrane. Teeth (241) in 54 patients were treated. Treatment was performed regardless of the patients' genetic predisposition, medical status or social habits. The patients had to follow a strict oral hygiene program prior to periodontal surgery. One year after treatment, an overall reduction of the mean pocket probing depth (PPD) of 2.69 mm on average (from 6.88 ± 1.89 mm to 4.19 ± 1.40 mm) and an increase in clinical attachment level (CAL) of 3.14 mm on average (from 8.56 ± 2.39 mm to 5.42 ± 1.50 mm) could be shown. At two years from baseline, no statistical differences in PPD reduction were found compared to the one year's data. Within the limits of the present study, it can be concluded that periodontal surgical therapy by the use of bovine-derived bone mineral with or without a bio-resorbable collagen membrane in combination with a strict oral hygiene program results in significantly high PPD reduction and CAL gain. Thus this treatment appears to be a suitable treatment for severe periodontal defects, leading to predictable and stable results.

BACKGROUND:
To the best of the authors' knowledge, there is very limited clinical data on the outcomes of simultaneous guided bone regeneration (GBR) for horizontal and/or vertical bone gain for the reconstruction of severely atrophic edentulous maxilla. Therefore, the purpose of the clinical series presented herein was to clinically evaluate long-term horizontal and vertical bone gain, as well as implant survival rate after reconstruction of severely atrophic edentulous maxillary ridges.

MATERIAL AND METHODS:
Sixteen patients (mean age: 64.6 ± 14.6 years of age) were consecutively treated for vertical and/or horizontal bone augmentation via GBR in combination with bilateral sinus augmentation utilizing a mixture of autologous and anorganic bovine bone. Implant survival, bone gain, intraoperative/postoperative complications and peri-implant bone loss were calculated up to the last follow-up exam.

RESULTS:
Overall, 122 dental implants were placed into augmented sites and have been followed from 12 to 180 months (mean: 76.5 months). Implant survival was 100% (satisfactory survival rate of 97.5%). Mean bone gain was 5.6 mm (max: 9 mm; min: 3 mm) While vertical bone gain was 5.1 ± 1.8 mm; horizontal bone gain was 7.0 ± 1.5 mm. No intraoperative/postoperative complications were noted. Mean peri-implant bone loss values were consistent within the standards for implant success (1.4 ± 1.0 mm). At patient-level, only one patient who had three implants presented with severe peri-implant bone loss.

CONCLUSION:
Complete reconstruction of an atrophied maxilla can be successfully achieved by means of guided bone regeneration for horizontal and/or vertical bone gain including bilateral sinus augmentation using a mixture of anorganic bovine bone and autologous bone.

OBJECTIVES:
Porcine collagen matrices are proclaimed being a sufficient alternative to autologous free gingival grafts (FGG) in terms of augmenting the keratinized mucosa. The collagen matrix Mucograft® (CM) already showed a comparable clinical performance in the early healing phase, similar histological appearance, and even a more natural appearance of augmented regions. Predictability for long-term stability does not yet exist due to missing studies reporting of a follow-up >6 months.

MATERIAL AND METHODS:
The study included 48 patients with atrophic edentulous or partially edentulous lower jaw situations that had undergone an implant treatment. In the context of implant exposure, a vestibuloplasty was either performed with two FGGs from the palate (n = 21 patients) or with the CM (n = 27 patients). Surgery time was recorded from the first incision to the last suture. Follow-up examinations were performed at the following time points: 10, 30, 90, and 180 days and 1, 2, 3, 4, and 5 years after surgery. The width of keratinized mucosa was measured at the buccal aspect of each implant, and augmented sites were evaluated in terms of their clinical appearances (texture and color).

RESULTS:
The groups showed similar healing with increased peri-implant keratinized mucosa after surgery (FGG: 13.06 mm ± 2.26 mm and CM: 12.96 mm ± 2.86 mm). The maximum follow-up was 5 years (5 patients per group). After 180 days, the width of keratinized mucosa had decreased to 67.08 ± 13.85% in the FGG group and 58.88 ± 14.62% in the CM group with no statistically significant difference. The total loss of the width of keratinized mucosa after 5 years was significant between the FGG (40.65%) and the CM group (52.89%). The CM group had significantly shorter operation times than the FGG group. Augmented soft tissues had a comparable clinical appearance to adjacent native gingiva in the CM group. FGGs could still be defined after 5 years.

CONCLUSIONS:
The FGG and the CM are both suitable for the regeneration of the peri-implant keratinized mucosa with a sufficient long-term stability. With the CM, tissue harvesting procedures are invalid, surgery time can be reduced, and regenerated tissues have a more esthetic appearance.

BACKGROUND:
Although connective tissue grafts with coronally advanced flaps (CTG + CAF) have been deemed the gold standard for recession defect treatment, to provide adequate recession coverage, the periodontal profession continues to pursue lower-morbidity, patient-preferred substitutes that are more convenient and of unlimited supply.

METHODS:
Using a randomized, controlled, and masked contralateral comparison of matched-pair, within-patient recession defects, collagen matrix (CMX) + CAF therapy was compared with CTG + CAF at 6 months and 5 years. The primary efficacy endpoint was percentage of root coverage (RC). Secondary efficacy parameters included width of keratinized tissue (KTw), probing depth (PD), clinical attachment level (CAL), clinician rating of color and texture compared with surrounding tissues, and patient esthetic satisfaction.

RESULTS:
Seventeen patients were available for the 5-year recall. Mean RC between 6 months and 5 years changed from 89.5% to 77.6% for CMX + CAF test sites and 97.5% to 95.5% for CTG + CAF control sites. KTw averaged >3 mm for both test and control sites at 5 years. PD was equivalent at all time points. The 6-month to 5-year changes for RC, KTw, and PD were not significantly different between therapies. CAL change from 6 months to 5 years was greater for CTG + CAF (0.26 mm) than CMX + CAF (-0.21 mm). Tissue color match to surrounding tissues remained similar for both therapies throughout the study. There was a difference in tissue texture at both 6 months and 5 years, with CMX + CAF sites tending to be ""equally firm"" and CTG + CAF sites ""more firm."" Patient satisfaction was high, with no statistical difference in satisfaction between therapies at any time point.

CONCLUSION:
When balanced with patient-reported satisfaction, clinical rankings of esthetics, and control and historical RC results reported by other investigators, CMX + CAF appears to present a viable and long-term alternative to traditional CTG + CAF therapy.

AIM:
Evaluation of the long-term effectiveness of regenerative treatment of intra-bony defects in periodontal practice.

MATERIAL AND METHODS:
A total of 1,008 intra-bony defects in 176 patients were analysed after using collagen-added deproteinized bovine bone mineral (DBBMc) with or without collagen membrane (CM) or enamel matrix derivative (EMD). Defects were classified as one- and two-wall and as shallow (≤6 mm), moderate (>6 and <11 mm) and deep (≥11 mm). Radiographic bone level changes were evaluated after 1 year, 2 to 4 years and 5 to 10 years.

RESULTS:
Mean radiographic defect fill was 3.8 mm after 1 year and remained stable up to 10 years. Deep and moderate defects showed a higher degree of fill than shallow defects (53.3%, 49.2%, 42.9%). Tooth loss amounted to 2.6%, was dependent on initial defect size (1.2% shallow, 1.4% moderate, 5.7% deep defects) and occurred mainly due to endodontic reasons.

CONCLUSIONS:
Within the limits of the retrospective study design, the findings indicate that periodontal treatment using DBBMc with or without CM or EMD can lead to long-term defect reduction and tooth survival for up to 10 years in the setting of a periodontal practice.

BACKGROUND:
Contour augmentation around early-placed implants (Type 2 placement) using autogenous bone chips combined with deproteinized bovine bone mineral (DBBM) and a collagen barrier membrane has been documented to predictably provide esthetically satisfactory clinical outcomes. In addition, recent data from cone beam computed tomography studies have shown the augmented volume to be stable long-term. However, no human histologic data are available to document the tissue reactions to this bone augmentation procedure.

METHODS:
Over an 8-year period, 12 biopsies were harvested 14 to 80 months after implant placement with simultaneous contour augmentation in 10 patients. The biopsies were subjected to histologic and histomorphometric analysis.

RESULTS:
The biopsies consisted of 32.0% ± 9.6% DBBM particles and 40.6% ± 14.6% mature bone. 70.3% ± 14.5% of the DBBM particle surfaces were covered with bone. On the remaining surface, multinucleated giant cells with varying intensity of tartrate-resistant acid phosphatase staining were regularly present. No signs of inflammation were visible, and no tendency toward a decreasing volume fraction of DBBM over time was observed.

CONCLUSIONS:
The present study confirms previous findings that osseointegrated DBBM particles do not tend to undergo substitution over time. This low substitution rate may be the reason behind the clinically and radiographically documented long-term stability of contour augmentation using a combination of autogenous bone chips, DBBM particles, and a collagen membrane.

BACKGROUND:
Contour augmentation around early-placed implants (Type 2 placement) using autogenous bone chips combined with deproteinized bovine bone mineral (DBBM) and a collagen barrier membrane has been documented to predictably provide esthetically satisfactory clinical outcomes. In addition, recent data from cone beam computed tomography studies have shown the augmented volume to be stable long-term. However, no human histologic data are available to document the tissue reactions to this bone augmentation procedure.

METHODS:
Over an 8-year period, 12 biopsies were harvested 14 to 80 months after implant placement with simultaneous contour augmentation in 10 patients. The biopsies were subjected to histologic and histomorphometric analysis.

RESULTS:
The biopsies consisted of 32.0% ± 9.6% DBBM particles and 40.6% ± 14.6% mature bone. 70.3% ± 14.5% of the DBBM particle surfaces were covered with bone. On the remaining surface, multinucleated giant cells with varying intensity of tartrate-resistant acid phosphatase staining were regularly present. No signs of inflammation were visible, and no tendency toward a decreasing volume fraction of DBBM over time was observed.

CONCLUSIONS:
The present study confirms previous findings that osseointegrated DBBM particles do not tend to undergo substitution over time. This low substitution rate may be the reason behind the clinically and radiographically documented long-term stability of contour augmentation using a combination of autogenous bone chips, DBBM particles, and a collagen membrane.

BACKGROUND:

Early implant placement with simultaneous contour augmentation is documented with short- and medium-term studies. The long-term stability of contour augmentation is uncertain.

METHODS:

In this prospective, cross-sectional study, 41 patients with an implant-borne single crown were examined twice, in 2006 and 2010. Clinical, radiologic, and esthetic parameters were assessed at both examinations. In addition, a cone beam computed tomography (CBCT) image was obtained during the second examination to assess the dimensions of the facial bone wall.

RESULTS:

All 41 implants demonstrated ankylotic stability without signs of peri-implant infection at both examinations. The clinical parameters remained stable over time. Satisfactory esthetic outcomes were noted, as assessed by the pink and white esthetic score (PES/WES) indices. Overall, the PES scores were slightly higher than the WES scores. None of the implants developed mucosal recession over time, as confirmed by facial DIM values and cast measurements. The periapical radiographs yielded stable peri-implant bone levels, with a mean DIB of 2.22 mm. The CBCT analysis demonstrated a mean thickness of the facial bone wall around 2.2 mm. In two implants (4.9%) no facial bone wall was detectable radiographically.

CONCLUSIONS:

This prospective cross-sectional study demonstrated stable peri-implant hard and soft tissues for all 41 implants examined, and satisfactory esthetic outcomes overall. The follow-up of 5 to 9 years confirmed again that the risk for mucosal recession is low with early implant placement. In addition, contour augmentation with guided bone regeneration (GBR) was able to establish and maintain a facial bone wall in 95% of patients.

BACKGROUND:
Sinus elevation is a reliable and often-used technique. Success of implants placed in such situations, even with bone substitutes alone, prompted the authors of this study to strive for bone loss close to zero and research variables that cause higher or lower rates of resorption. The objective of this study is to evaluate survival rates and marginal bone loss (MBL) around implants placed in sites treated with maxillary sinus augmentation using anorganic bovine bone (ABB), and identify surgical and prosthetic prognostic variables.

METHODS:
Fifty-five implants were placed in 30 grafted maxillary sinuses in 24 patients. Periapical radiographs were evaluated immediately after implant placement (baseline), 6 months, and at the most recent follow-up. MBL was calculated from the difference between initial and final measurements, taking into account a distortion rate for each radiograph compared with original implant measurements.

RESULTS:
Survival rate was 98.2%, with only one implant lost (100% survival rate after loading) over a mean follow-up time of 2.0 ± 0.9 years. MBL ranged from 0 to 2.85 mm: 75.9% of mesial sites and 83.4% of distal sites showed <1 mm of MBL, whereas 35.2% of mesial sites and 37% of distal sites exhibited no bone loss. MBL was significantly (P <0.05) greater in open-flap compared with flapless surgery.

CONCLUSIONS:
Within the limitations of the present study, it was concluded that maxillary sinus elevation with 100% ABB gives predictable results, and that flapless surgery results in less MBL compared with traditional open-flap surgery.

The aim of this study was to evaluate clinically, histologically and histometrically the use of natural bovine bone matrix (i.e. Bio-Oss®) as a grafting material for maxillary sinus augmentation procedures. In 4 adult male rhesus monkeys (i.e. Macaca mulatta) the 1st, 2nd and 3rd maxillary molars on one side of the jaws were extracted. The remaining bone between the alveolar crest and the bottom of the sinus was then reduced to 3-4 mm. After 3 months, maxillary sinus augmentation procedures were performed on one side of the jaws in each monkey and the sinuses were grafted with the bovine bone matrix. At that time, 2 IMZ pure titanium plasma coated implants were immediately placed into the augmented sinuses (i.e. simultaneous implants-loaded group). After 4 months, 2 additional similar implants were placed into these previously augmented sinuses (i.e. delayed implants-loaded group). Four months later, the abutment connection was performed and all 4 implants were loaded with a gold-alloy bridge for 6 months (i.e. until sacrifice of the animals). The contralateral side of each monkey received the same treatment with the exception that the extractions were performed 7 months after those in the opposite side and that the implants in this side were not loaded. Thus, 2 additional study groups (i.e. simultaneous implants-unloaded group and delayed implants-unloaded group) were obtained. Clinically, all loaded implants were stable at the day of sacrifice. Histologically, the grafted sinuses exhibited significant bone formation with integration of the bovine bone matrix particles to the new bone. Direct mineralized bone-to-implant contact was greater for the delayed implant placement groups than for the implants installed simultaneously with the sinus augmentation. Furthermore, the percentage of direct mineralized bone-to-implant contact was greater in the residual bone than in the augmented area. It was concluded that the natural bovine bone matrix facilitated bone formation and implant osseointegration in the augmented sinuses and that the delayed implant placement in combination with the sinus augmentation procedure seemed to be preferable.

Abstract Objective: The aim of this study was to determine the clinical efficacy of a mixture of autologous bone harvested from the lateral wall of the maxilla using bone shavers and bovine-derived hydroxyapatite (HA) placed as a graft to elevate the maxillary sinus floor. The histological picture of tissue found in the sinus, the survival rate and the success of the implants were all evaluated.

Material and Methods: A total of 90 titanium implants were placed in 34 patients. In all of them, the lateral maxillary wall was harvested as a particulate bone graft, subsequently mixed with bovine-derived HA and packed in the sinus cavity. The lateral access window was then covered with a bioresorbable porcine-derived collagen membrane. In 32 sinuses, a two-stage surgery was performed, while in the remaining 10 cases a one-stage surgery was carried out. In the two-stage approach, 14 randomly selected biopsies were obtained at the time of implant insertion after a healing period of 9 months. The histological specimens were histologically and histomorphometrically evaluated.

Results: One implant was lost, leading to a survival rate of 98.9%. The new bone consisted of lamellae of living bone contained osteocytes and in close contact with bovine bone particles that were partly infiltrated by newly formed bone. Bovine bone particle resorption could not be found. The histomorphometric analysis showed the following averages: 29% of newly formed bone and 21% of anorganic bovine bone. The marrow spaces made up the remaining 50% of the specimens.

Conclusion: Sinus lift graft with autologous bone harvested from the maxillary lateral wall combined with demineralized bovine bone leads to a predictable outcome regarding the amount of bone formation in sinus floor augmentation.

Abstract: Biological interactions occurring at the bone–biomaterial interface are critical for long-term clinical success. Bio-Oss is a deproteinized, sterilized bovine bone that has been extensively used in bone regeneration procedures. The aim of the present study was a comparative light, scanning, and electron microscopy evaluation of the interface between Bio-Oss and bone in specimens retrieved after sinus augmentation procedures. Under light microscopy, most of the particles were surrounded by newly formed bone, while in a few cases, at the interface of some particles it was possible to observe marrow spaces and biological fluids. Under scanning electron microscopy, in most cases, the particle perimeter appeared lined by bone that was tightly adherent to the biomaterial surface. Transmission electron microscopy showed that the bone tissue around the biomaterial showed all the phases of the bone healing process. In some areas, randomly organized collagen fibers were present, while in other areas, newly formed compact bone was present. In the first bone lamella collagen fibers contacting the Bio-Oss surface were oriented at 243.73 ± 7.12° (mean ± SD), while in the rest of the lamella they were oriented at 288.05 ± 4.86° (mean ± SD) with a statistically significant difference of 44.32° (p < 0.001). In the same areas the intensity of gray value was 172.56 ± 18.15 (mean ± SD) near the biomaterial surface and 158.71 ± 21.95 (mean ± SD) in the other part of the lamella with an unstatistically significant difference of 13.79 (p ±0.071). At the bone–biomaterial interface there was also an electron-dense layer similar to cement lines. This layer had a variable morphology being, in some areas, a thin line, and in other areas, a thick irregular band. The analyses showed that Bio-Oss particles do not interfere with the normal osseous healing process after sinus lift procedures and promote new bone formation. In conclusion, this study serves as a better understanding of the morphologic characteristics of Bio-Oss and its interaction with the surrounding tissues.

Aims: The objective of the present systematic review was to test the hypothesis of no differences in the implant treatment outcome when Bio-Oss® or Bio-Oss® mixed with autogenous bone is used as graft for the maxillary sinus floor augmentation (MSFA) applying the lateral window technique.

Material and Methods: A MEDLINE (PubMed) search in combination with a hand search of relevant journals was conducted by including human studies published in English from January 1, 1990 to June 1, 2010. The search provided 879 titles and 35 studies fulfilled the inclusion criteria. Considerable variation in the included studies prevented meta-analysis from being performed and no long-term study comparing MSFA with the two treatment modalities was identified. Also, the survival of suprastructures after the two augmentation procedures was not compared within the same study.

Results: The 1-year implant survival was compared in one study demonstrating no statistically significant difference. The implant survival was 96% with Bio-Oss® and 94% with a mixture of 80% Bio-Oss® and 20% autogenous mandibular bone. Addition of a limited amount of autogenous bone to Bio-Oss® seemed not to increase the amount of new bone formation and bone-to-implant contact compared with Bio-Oss®.

Conclusion: Therefore, the hypothesis of no differences between the use of Bio-Oss® or Bio-Oss® mixed with autogenous bone as graft for MSFA could neither be confirmed nor rejected.

The objective of this study was to determine the predictability of endosseous implants placed in a maxillary sinus grafted with a mixture of porous bone mineral (Bio-Oss®) and demineralized freeze-dried bone. Sixty implants were placed in 20 patients representing 28 sinuses using either a one- or two-stage technique. After an implant loading period of more than 2 years, the survival rate (eg. a clinically functioning implant without signs of mobility or infection) varied from 90% to 96%. No infections or other complications were encountered. The data suggest that this treatment regimen can result in a high rate of survival. Conclusion: The results of this human study suggest that composite grafts represent an important alternative to autografts in sinus floor lift procedures, especially when cylindrical implants are used. Autogenous bone still remains the most predictable material for the sinus lift procedure, especially in cases of large sinuses with only a thin cortical layer of bone bordering the inferior aspect of the sinus cavity. On the other hand, the porous natural bone mineral (Bio-Oss®) showed excellent osseoconductive properties and could be indicated alone in case of sufficient remaining bone around the sinus. The histologic findings suggest that the osseoinductive effect of DFDBA is insufficient and that promotion of new bone is a result of the osseoconductive properties of the bone mineral matrix (Bio-Oss®).

Purpose: The aim of the present retrospective study was to evaluate the survival rate of titanium plasma spray-coated cylindric and machined screw-type implants placed in sinuses grafted with Bio-Oss® mixed with demineralized freeze-dried bone allograft (DFDBA) or with Bio-Oss® alone.

Materials and Methods: The patients included in this study were treated with a 1- or 2-stage technique, according to the volume of residual bone. This determined the possibility of primary stabilization and the duration of the treatment, which was 9 or 12 months, respectively.

Results: The overall implant survival rate was 94.5% after a mean functioning period of 6.5 +/- 1.9 years. The Implant survival rate was better in sinuses grafted with Bio-Oss® alone than with a mixture of Bio-Oss® with DFDBA (96.8% versus 90%). The implant survival rate was similar for cylindric and screw-type implants in sinuses grafted with Bio-Oss® alone.

Discussion: Because of the good bone quality, the implant survival rate was similar for cylindric and screw-type implants in sinuses grafted with Bio-Oss®.

Conclusion: Bio-Oss® used alone appears to be a suitable material for sinus floor augmentation.

Literature regarding the outcome of maxillary sinus floor elevation to create sufficient bone fraction to enable implant placement was systematically reviewed. Bone fraction and implant survival rate were assessed to determine whether grafting material or applied growth factor affected bone fraction. Trials where sinus floor elevations with autogenous bone (controls) were compared with autogenous bone combined with growth factors or bone substitutes, or solely with bone substitutes (test groups) were identified; 12 of 1124 fulfilled all inclusion criteria. Meta-analyses comparing the bone fraction after applying: autogenous bone; autologous bone with growth factors (platelet rich plasma); or autogenous bone and bone substitutes (bovine hydroxyapatite, bioactive glass, corticocancellous pig bone) revealed no significant differences in bone formation after 5 months. A significantly higher bone fraction was found in the autogenous bone group compared to the sole use of beta-tricalciumphosphate (P=0.036). The one-year overall implant survival rate showed no significant difference between implants. Bone substitutes combined with autogenous bone provide a reliable alternative for autogenous bone as sole grafting material to reconstruct maxillary sinus bony deficiencies, for supporting dental implants after 5 months. Adding growth factors (platelet rich plasma) to grafting material and the sole use of beta-tricalciumphosphate did not promote bone formation.

Purpose: The objective of the present study was to histologically evaluate barrier durability and host tissue response of new prototype collagen membranes in comparison to clinically available collagen and synthetic polymer membranes.

Materials and Methods: The experimental study was conducted in 20 rabbits with 4 different healing periods of 2, 6, 12, and 28 weeks. Following surgical exposure of the calvarium, 6 circular bone defects (diameter 4 mm, depth 1.5 mm) were drilled into the outer cortex. After the bone had been removed, each defect was covered with 1 of 6 different membranes: 3 collagen prototype membranes, a Bio-Gide collagen membrane (BG), a glycolide-lactide-trimethylene carbonate Osseoquest membrane (OQ), and a polylactide Atrisorb membrane (AS). Histological analysis was performed following staining with toluidine blue and transversal sectioning of the calvarial bone. Results: All collagen membranes showed similar tissue integration characterized by fibrous encapsulation with differentiation of a periosteumlike tissue upon the external bony surface. One prototype collagen membrane displayed clearly longer membrane integrity. The evaluated synthetic membranes demonstrated extended barrier durability but also exhibited inflammatory foreign-body reactions.

Discussion: Recent experimental investigations have shown that degradation of collagen membranes may begin within days to weeks of membrane placement. This was confirmed in the present study. However, 1 of the chemically modified collagen prototype membranes exhibited prolonged membrane integrity in the absence of an inflammatory tissue response.

Conclusion: Further investigation of the prototype membrane that showed prolonged membrane integrity to evaluate its potential in GBR procedures is needed.

The aim of this study was to evaluate microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression in sinus augmentation with Bio-Oss®. Twenty patients participated in this study. The sinuses were filled with 100% Bio-Oss®.  Implants were inserted after 3 months in group A, and 6 months in group B. A trephine was used to harvest bone cores. As control, the pre-existing subantral bone was used. The mean MVD in control bone was 23.6 +/- 1.8. In the sites augmented with Bio-Oss®, at 3 months, the MVD was 23.3 +/- 2.1, while in the sites retrieved at 6 months the MVD was 29.5 +/- 2.4. The difference in MVD between the control bone and group A was not statistically significant. The difference between the control bone and group B was statistically significant (P < 0.05). The statistical analysis showed that the difference in MVD between group A and group B was statistically significant (P < 0.05). Bio-Oss®seemed to induce an increase in MVD that reached a higher value after 6 months. The percentage of vessels positive to VEGF was higher in group A than in group B. Our data also showed a higher percentage of vessel and stromal cells positive to VEGF and higher MVD values in areas where there was newly formed bone compared with areas where maturation processes were occuring, and this fact could point to a close spatial relationship between angiogenesis and osteogenesis.

OBJECTIVES:

Our objectives were to examine vascular and cellular colonization in anorganic bovine bone (ABB) after 6 months of healing in human maxillary sinus augmentation grafts.

MATERIAL AND METHODS:

Fifty unilateral maxillary sinus augmentation procedures were performed on 50 consecutive patients. Bone cores were obtained through the implant receptor sites 6 months later and evaluated with morphological image analysis and immunohistochemical techniques.

RESULTS:

Image analysis revealed a mean of 35.44 ± 16% vital bone, 31.66 ± 15% non-mineralized tissue, and 32.72 ± 25% remnant ABB particles. In our patients, neovascularization in 46.3% of cases was demonstrated within ABB particles 6 months after sinus floor augmentation surgery. Neovascularization of ABB particles was inversely related to age, directly to osteoclast number per mm², and not influenced by habits or disease. CD44-positive cells colonization was found in 74% of cases. An important correlation was found regarding CD44 expression and number of vessel in ABB particles (r = 0.624 P < 0.001, Pearson). Osteopontin expression was detected on the interstitial boundary of bone with ABB particles and within the osteocyte lacunae and bone canaliculi and was relationship with presence of CD44-positive cells inside ABB particles (r = 0.388, P = 0.046, Pearson).

CONCLUSION:

In conclusion, images compatible with osteone colonized by osteocytes CD44 positive and neovascularization in ABB particles were observed after 6 months of graft maturation. These biologic events have not previously been morphologically and immunohistochemically documented

AIM:
To assess peri-implant soft tissue dimensions at implant sites, previously augmented with a collagen matrix (VCMX) or an autogenous subepithelial connective tissue graft (SCTG), between crown insertion and 1 year.

METHODS:
Twenty patients with single-tooth implants received soft tissue augmentation prior to abutment connection randomly using VCMX or SCTG. Following abutment connection 3 months later, final reconstructions were fabricated and inserted (baseline). Patients were recalled at 6 months (6M) and at 1 year (FU-1). Measurements included clinical data, soft tissue thickness, volumetric outcomes and patient-reported outcome measures (PROMs).

RESULTS:
The buccal soft tissue thickness showed a median decrease of -0.5 mm (-1.0;0.3) (VCMX) and 0.0 mm (-0.5;1.0) (SCTG) (p = .243) up to FU-1. The soft tissue volume demonstrated a median decrease between BL and FU-1 of -0.1 mm (-0.2;0.0) (p = .301) for VCMX and a significant decrease of -0.2 mm (-0.4; -0.1) (p = .002) for SCTG, respectively. Intergroup comparisons did not reveal any significant differences between the groups for peri-implant soft tissue dimensions and changes up to FU-1 (p > .05). PROMs did not show any significant changes over time nor differences between the groups.

CONCLUSION:
Between crown insertion and 1 year, the buccal peri-implant soft tissue dimensions remained stable without relevant differences between sites that had previously been grafted with VCMX or SCTG.

The purpose of this case series was to assess safety and feasibility of a novel resorbable collagen matrix (CMX) to enhance tissue thickness simultaneous with implant placement and guided bone regeneration (GBR) in esthetic sites over an 8-week healing period. Soft tissue thickness at implant sites and adjacent teeth was monitored with an ultrasonic device. Overall tissue contour changes were assessed by sequential digital surface model superimpositions. Periodontal parameters and patient-related outcomes revealed no significant changes. Combining a novel CMX and GBR revealed a significant soft tissue thickness increase of 1.56 mm at implant sites after 8 weeks, with no significant decrease between 4 and 8 weeks. The overall tissue contour increase was most significant at a distance of 5 mm from the mucosal margin, corresponding to a tissue increase at the implant shoulder area. No effect was observed at adjacent teeth after 8 weeks.

PURPOSE: To present the medium-term results of one-stage guided bone regeneration (GBR) using autologous bone and anorganic bovine bone, placed in layers, in association with resorbable collagen membranes, for the reconstruction of horizontal bony defects.

MATERIALS AND METHODS: This study was designed as an uncontrolled prospective study. Partially edentulous patients, having less than 6.0 mm and more than 4.0 mm of residual horizontal bone width were selected and consecutively treated with simultaneously implant installation and bone regeneration by using 2.0 mm of autologous bone and 2.0 mm of anorganic bovine bone that was placed in layers and then covered with a resorbable collagen membrane. Outcome measures were: implant and prosthesis failures, any complications, peri-implant marginal bone level changes, probing pocket depth (PPD) and bleeding on probing (BOP).

RESULTS: In total, 45 consecutive patients (20 male, 25 female) with a mean age of 52.1 years each received at least one GBR procedure, with contemporary placement of 63 implants. At the 3-year follow-up examination, no patient had dropped out and no deviation from the original protocol had occurred. No implant or prosthesis failed. In six patients (13.3%) the collagen membrane was slightly exposed 1 to 2 weeks after bone reconstruction. Four of these patients were moderate smokers. Post-hoc analysis using Fisher's exact test found significant association (P = 0.0139) between a smoking habit and early membrane exposure. Mean marginal bone loss experienced between initial loading and 30 months afterwards was 0.60 ± 0.20 mm (95% CI 0.54 - 0.66). The mean BOP values measured at the definitive restoration delivery were 1.23 ± 0.93, while 2 years later they were 1.17 ± 0.78. The difference was not statistically significant (-0.06 ± 0.76; P = 0.569). The mean PPD values measured at the definitive restoration delivery were 2.62 ± 0.59 mm, while 2 years later they were 2.60 ± 0.54 mm. The difference was not statistically significant (-0.03 ± 0.62; P = 0.765).

CONCLUSIONS: Within the limitations of the present study, the use of a 2.0 mm layer of particulated autologous bone on the implant threads, and a 2.0 mm layer of anorganic bovine to cover the resorbed ridge, in combination with the resorbable collagen membrane, seems to be a viable treatment option for the reconstruction of horizontal bony defects. Conflict of interest statement: This study was not supported by any company, and there are no conflicts of interest."

PURPOSE:
To present the medium-term results of one-stage guided bone regeneration (GBR) using autologous bone and anorganic bovine bone, placed in layers, in association with resorbable collagen membranes, for the reconstruction of horizontal bony defects.

MATERIALS AND METHODS:
This study was designed as an uncontrolled prospective study. Partially edentulous patients, having less than 6.0 mm and more than 4.0 mm of residual horizontal bone width were selected and consecutively treated with simultaneously implant installation and bone regeneration by using 2.0 mm of autologous bone and 2.0 mm of anorganic bovine bone that was placed in layers and then covered with a resorbable collagen membrane. Outcome measures were: implant and prosthesis failures, any complications, peri-implant marginal bone level changes, probing pocket depth (PPD) and bleeding on probing (BOP).

RESULTS:
In total, 45 consecutive patients (20 male, 25 female) with a mean age of 52.1 years each received at least one GBR procedure, with contemporary placement of 63 implants. At the 3-year follow-up examination, no patient had dropped out and no deviation from the original protocol had occurred. No implant or prosthesis failed. In six patients (13.3%) the collagen membrane was slightly exposed 1 to 2 weeks after bone reconstruction. Four of these patients were moderate smokers. Post-hoc analysis using Fisher's exact test found significant association (P = 0.0139) between a smoking habit and early membrane exposure. Mean marginal bone loss experienced between initial loading and 30 months afterwards was 0.60 ± 0.20 mm (95% CI 0.54 - 0.66). The mean BOP values measured at the definitive restoration delivery were 1.23 ± 0.93, while 2 years later they were 1.17 ± 0.78. The difference was not statistically significant (-0.06 ± 0.76; P = 0.569). The mean PPD values measured at the definitive restoration delivery were 2.62 ± 0.59 mm, while 2 years later they were 2.60 ± 0.54 mm. The difference was not statistically significant (-0.03 ± 0.62; P = 0.765).

CONCLUSIONS:
Within the limitations of the present study, the use of a 2.0 mm layer of particulated autologous bone on the implant threads, and a 2.0 mm layer of anorganic bovine to cover the resorbed ridge, in combination with the resorbable collagen membrane, seems to be a viable treatment option for the reconstruction of horizontal bony defects. Conflict of interest statement: This study was not supported by any company, and there are no conflicts of interest.

Objectives: The objectives of this study were to assess the microvessel density (MVD) of intra-sinus grafts after 6 months of wound healing and to study the relationship between revascularization processes and patient clinical variables and habits.

Material and Methods: We performed 45 maxillary sinus augmentations with different implant placements in 25 consecutive patients, obtaining bone cores of the grafted area for histological, histomorphometric and immunohistochemical study. Biopsies were also taken from pristine bone in the posterior maxilla (control).

Results: All implants survived at 24 months. Biopsies of sinus augmentation areas showed significantly greater remodeling activity vs. pristine bone, with significantly more osteoid lines. The morphometry study revealed 34.88+/-15.2% vital bone, 32.02+/-15.1% non-mineralized tissue and 33.08+/-25.4% remnant anorganic bovine bone particles. The number of CD34- positive vessels was 86.28+/-55.52/mm(2) in graft tissue vs. 31.52+/-13.69/mm(2) in native tissue (P=0.002, Mann-Whitney U=46). The larger amount of non-mineralized tissue in grafts was directly correlated with a higher MVD (r=0.482, P=0.0001, Pearson's test). MVD was affected by the presence of periodontitis or tobacco and alcohol consumption.

Conclusion: The angiogenesis and revascularization obtained by this type of graft achieve adequate tissue remodeling for osseointegration and are influenced by periodontal disease and tobacco or alcohol consumption.

Objective: To study if it was possible to move, by orthodontic means, a tooth into an area of the jaw that had been augmented with Bio-Oss^®.

Material and Methods: 5 beagle dogs were used. The 1^st, 2^nd, and 4^th mandibular premolars on each side were removed. The defect at the left 4^th premolar site was filled with a biomaterial (Bio-Oss^®) while the corresponding defect in the right side was left for spontaneous healing. 3 months later, an orthodontic device was inserted in each side of the mandible. The device was designed to allow distal, bodily movement of the 3^rd premolars. When the experimental teeth had been moved into the extraction sites of the 4^th premolars, the animals were sacrificed and biopsies of the premolar-molar regions of the mandible sampled. The tissues were prepared for histological analysis using standard procedure. In the sections, 3 zone were identified: zone A=the bone tissue within the distal portion of the previous extraction site (4^th premolar), zone B=the pressure side of the 3^rd premolar, zone C=the tension side of the 3^rd premolar. The area occupied by mineralized bone, Bio-Oss^® particles and bone marrow was determined by a point counting procedure. The width of the periodontal ligament as well as the percentage of the root surface (in zone B) that exhibited resorption was determined.

Results: The findings demonstrated that it was possible to move a tooth into an area of an alveolar ridge that 3 months previously had been augmented with a biomaterial. It was also demonstrated that 12 months after grafting, Bio-Oss^® particles remained as inactive filler material in the not utilized part of zone A. The biomaterial was not present in zone C but present in small amounts in zone B.

Conclusion: During the orthodontic tooth movement the graft material (Bio-Oss^®) was degraded and eliminated from the part of the alveolar ridge that was utilized for the experiment. In the non-utilized part of the ridge the biomaterial, however, remained as a seemingly inactive filler material.

AIM:
The aim of this study was to test whether or not a collagen matrix can improve early wound healing compared to spontaneous healing based on histological and immunohistologic analyses.

METHODS:
In 20 volunteers, 6 mm punch biopsies were harvested at the palate. A xenogeneic collagen matrix (XCM) was sutured in one site; the other one was left untreated (control). Biopsies with a diameter of 8 mm were subsequently obtained at 4, 8, 15 and 29 days and histological and immunohistologic analyses were performed.

RESULTS:
At day 4, wound bed keratinization amounted to 12.4 ± 7.5% (control) and 18.0 ± 10.2% (XCM). This increased up to day 8 (19.7 ± 25.5% control; 29.1 ± 8.0% XCM) and reached complete keratinization at day 15 in both groups. The quantitative analyses of the superficial compartment measured an increase in the amount of granulation tissue (32-88% control; 14-41% XCM) from day 4 to day 8. Angiogenesis was first detected at 8 days. At day 29, the amount of connective tissue in all compartments reached values similar to the native tissue at baseline.

CONCLUSIONS:
The application of a XCM as a wound dressing on palatal wounds might be beneficial in the early stages of wound healing. Further research with a larger sample size is needed to confirm these results.

Objectives: The aim of this prospective study was to evaluate the 5-year performance and success rate of titanium screw-type implants with the titanium plasma spray (TPS) or the sandblasted, large grit, acid-etched (SLA) surface inserted in a two-stage sinus floor elevation (SFE) procedure in the posterior maxilla.

Material and Methods: A total of 59 delayed SFEs were performed in 56 patients between January 1997 and December 2001, using a composite graft with autogenous bone chips combined with deproteinized bovine bone mineral (DBBM) or synthetic porous beta-tricalcium phosphate (beta-TCP). After a healing period averaging 7.75 months, 111 dental implants were inserted. After an additional 8-14-week healing period, all implants were functionally loaded with cemented crowns or fixed partial dentures. The patients were recalled at 12 and 60 months for clinical and radiographic examination.

Results: One patient developed an acute infection in the right maxillary sinus after SFE and did not undergo implant therapy. Two of the 111 inserted implants had to be removed because of a developing atypical facial pain, and 11 implants were lost to follow-up and were considered drop-outs. The remaining 98 implants showed favorable clinical and radiographic findings at the 5-year examination. The peri-implant soft tissues were stable over time; the mean probing depths and mean attachment levels did not change during the follow-up period. The measurement of the bone crest levels (DIB values) indicated stability as well. Based on strict success criteria, all 98 implants were considered successfully integrated, resulting in a 5-year success rate of 98% (for TPS implants 89%, for SLA implants 100%).

Conclusion: This prospective study assessing the performance of dental implants inserted after SFE demonstrated that titanium implants can achieve and maintain successful tissue integration with high predictability for at least 5 years of follow-up in carefully selected patients.

This study evaluated the clinical, radiographic, and histologic response to the composite use of Bio-Oss® porous bone mineral and autogenous bone in combination with a Bio- Gide® bilayer collagen membrane to achieve regeneration when treating human periodontal bone defects. Preoperative recordings for four treatment areas included radiographs, clinical probing depths, and attachment levels; cementum with inserting collagen fibers and new bone formation on the surface of both types of grafts materials. This grafting combination not only compared favorably with the previous use of Bio Oss® and Bio-Gide®, but exceeded that result with almost complete periodontal regeneration. This human histologic study demonstrated that autogenous bone in combination with porous bone mineral matrix, together with the Bio-Gide® collagen membrane, has the capacity to stimulate substantial new bone and cementum formation with Sharpey’s fiber attachment.

This multicenter prospective case series study aimed to evaluate the outcome of periodontal regenerative therapy using a deproteinized bovine bone mineral (DBBM) in combination with a collagen barrier (CB) in the treatment of intrabony defects. A total of 36 nonsmoking patients with chronic periodontitis were recruited in five centers in Japan. All patients had at least one intrabony defect of ≥ 3 mm. The surgical procedures included access for debridement using a papilla preservation technique. Defects were filled with DBBM and covered with CB. Clinical evidence after 6 months supported the effectiveness of the combination therapy in the treatment of intrabony defects.

Background: Porous bovine bone mineral (PBBM) has been used in ridge preservation procedures following tooth extractions. The aim of this study was to investigate histochemically tissue sockets grafted with PBBM at 9 months post-extraction. By using different histochemical stainings, characteristics of the newly formed bone; i.e., lamellar/woven ratio at different socket depths, were investigated and the arrangement of bone around the grafted material, as well as the nature of the amorphous organic material found in all specimens, were examined.

Methods: After extraction of 15 single-rooted maxillary teeth from 15 patients, socket sites were grafted with PBBM particles (250 to 1,000 mu). Primary soft tissue closure of the grafted site was established using the rotated split palatal pedicle flap technique. At 9 months, a cylindrical tissue specimen, 2.5 mm in diameter, was trephined from each previously grafted site followed by placement of a screw-shaped implant. Horizontal tissue section cuts, 5 mu wide, were prepared for histological examination. Histochemical staining included alcian blue, periodic-acid Schiff, Mallory trichrome, reticulin, Van Gieson, and picrosirius red (PSR). PSR stained slides were further evaluated morphometrically, using polarized microscopy to determine the amount of lamellar versus woven bone in superficial, mid and deep specimen section cut areas.

Results: All staining methods revealed that newly formed bone encircled and adhered to the grafted material in most specimens. Mallory trichrome staining showed osteoblasts present within an osteoid layer, lining the interface zone of PBBM particles and the new osseous tissue. Morphometric evaluation of the PSR stained slides disclosed a constant pattern of increased osseous tissue in a coronal-apical direction. An average of 17.1% osseous tissue with 1:12.9 lamellar/woven bone ratio was calculated in the superficial area. The average bone tissue fraction was 48.3% with a lamellar/woven ratio of 1:3.8 in the mid section area and in the deep area, it increased to 63.9%, with a lamellar/woven ratio average of 1:1.7. Differences between ratios at these sites were statistically significant (P<0.001). An amorphous organic substance was noted in most grafted particles. This material usually attached cell striae and harbored glycoproteins as revealed by periodic-acid Schiff and alcian blue stainings. Mallory trichrome staining showed denatured protein within the decalcified mineral particles; reticulin, Van Gieson stainings, and polarization of PSR stained sections refuted the existence of collagen in the grafted particles.

Conclusion: Cancellous PBBM is a biocompatible filler agent in extraction socket sites and an acceptable graft for edentulous ridge preservation at sites prepared to receive endosseous implants. The osteoconductivity of PBBM was determined based on promoting osseous ingrowth and close integration with the newly generated bone. Grafted particles were not significantly resorbed at 9 months. Further studies are needed to determine the resorbable capability, as well as the nature and significance of the amorphous organic substance of PBBM observed in the grafted particles.

Purpose:
To compare epithelial connective tissue graft vs porcine collagen matrix for sealing postextraction sockets grafted with deproteinised bovine bone.

Materials and methods:
A total of 30 patients, who needed a maxillary tooth to be extracted between their premolars and required a delayed, fixed, single implant-supported restoration, had their teeth atraumatically extracted and their sockets grafted with deproteinised bovine bone. Patients were randomized according to a parallel group design into two arms: socket sealing with epithelial connective tissue graft (group A) vs porcine collagen matrix (group B). Outcome measures were: implant success and survival rate, complications, horizontal and vertical alveolar bone dimensional changes measured on Cone Beam computed tomography (CBCT) scans at three levels localized 1, 3, and 5 mm below the most coronal aspect of the bone crest (levels A, B, and C); and between the palatal and buccal wall peaks (level D); and peri-implant marginal bone level changes measured on periapical radiographs.

Results:
15 patients were randomized to group A and 15 to group B. No patients dropped out. No failed implants or complications were reported 1 year after implant placement. Five months after tooth extraction there were no statistically significant differences between the 2 groups for both horizontal and vertical alveolar bone dimensional changes. At level A the difference was 0.13 ± 0.18; 95% CI 0.04 to 0.26 mm (P = 0.34), at level B it was 0.08 ± 0.23; 95% CI –0.14 to 0.14 (P = 0.61), at level C it was 0.05 ± 0.25; 95% CI -0.01 to 0.31 mm (P = 0.55) and at level D it was 0.13 ± 0.27; 95% CI -0.02 to 0.32 mm (P = 0.67). One year after implant placement there were no statistically significant differences between the 2 groups for peri-implant marginal bone level changes (difference 0.07 ± 0.11 mm; 95% CI -0.02 to 0.16; P = 0.41).

Conclusions:
When teeth extractions were performed atraumatically and sockets filled with deproteinised bovine bone, sealing the socket with a porcine collagen matrix or a epithelial connective tissue graft showed similar outcomes. The use of porcine collagen matrix allowed simplification of treatment because no palatal donor site was involved.

Conflict of interest statement: This study was not supported by any company and there are no conflicts of interest.

PURPOSE:
To compare epithelial connective tissue graft vs porcine collagen matrix for sealing postextraction sockets grafted with deproteinised bovine bone.

MATERIALS AND METHODS:
A total of 30 patients, who needed a maxillary tooth to be extracted between their premolars and required a delayed, fixed, single implant-supported restoration, had their teeth atraumatically extracted and their sockets grafted with deproteinised bovine bone. Patients were randomised according to a parallel group design into two arms: socket sealing with epithelial connective tissue graft (group A) vs porcine collagen matrix (group B). Outcome measures were: implant success and survival rate, complications, horizontal and vertical alveolar bone dimensional changes measured on Cone Beam computed tomography (CBCT) scans at three levels localised 1, 3, and 5 mm below the most coronal aspect of the bone crest (levels A, B, and C); and between the palatal and buccal wall peaks (level D); and peri-implant marginal bone level changes measured on periapical radiographs.

RESULTS:
15 patients were randomised to group A and 15 to group B. No patients dropped out. No failed implants or complications were reported 1 year after implant placement. Five months after tooth extraction there were no statistically significant differences between the 2 groups for both horizontal and vertical alveolar bone dimensional changes. At level A the difference was 0.13 ± 0.18; 95% CI 0.04 to 0.26 mm (P = 0.34), at level B it was 0.08 ± 0.23; 95% CI -0.14 to 0.14 (P = 0.61), at level C it was 0.05 ± 0.25; 95% CI -0.01 to 0.31 mm (P = 0.55) and at level D it was 0.13 ± 0.27; 95% CI -0.02 to 0.32 mm (P = 0.67). One year after implant placement there were no statistically significant differences between the 2 groups for peri-implant marginal bone level changes (difference: 0.07 ± 0.11 mm; 95% CI -0.02 to 0.16; P = 0.41).

CONCLUSIONS:
When teeth extractions were performed atraumatically and sockets were filled with deproteinised bovine bone, sealing the socket with a porcine collagen matrix or a epithelial connective tissue graft showed similar outcomes. The use of porcine collagen matrix allowed simplification of treatment because no palatal donor site was involved.

The aim of this prospective clinical study was to analyze graft-enhanced soft tissue healing during the initial phases after tooth extraction. Twenty patients in need of tooth extraction (incisors, canines, and premolars) and implant replacement were included. In patients with multiple extractions, one tooth was randomly selected for treatment. After administration of antibiotics, the selected tooth was gently removed. The socket was completely filled with deproteinized bovine bone mineral integrated in a 10% collagen matrix to fill out the space of the alveolus and support the soft tissue. A biopsy punch with a diameter corresponding to the socket orifice was chosen to harvest a free gingival graft of 2- to 3-mm thickness from the palate. The punched graft was carefully sutured to the deepithelialized soft tissue margins of the socket. One week after graft insertion, 64.3% of the mean graft area was fully integrated, 35.6% was fibrinoid, and 0.1% showed necrotic parts. Three and 6 weeks postsurgery, the mean integrated graft surface increased to 92.3% and 99.7%, respectively. After 6 weeks, a mean of 0.3% of the surface in four grafts showed incomplete wound closure, and no fibrin or necrosis was present. Colorimetry of the graft and adjacent tissue revealed a mean color match of deltaE = 2.91, lower than the critical threshold of 3.7 for intraoral visibility of different colors. This soft tissue punch technique led to successful biologic and esthetic integration of the transplanted graft into the local host tissues.

Background: Extraction of deep-impacted mandibular third molars may lead to periodontal defects at the distal surface of the adjacent second molar. The purpose of this study was to compare the ability of three regenerative approaches to prevent third molar extraction-related periodontal defects.

Methods: Forty-five patients with bilateral osseous or soft tissue-impacted lower third molars were selected to participate in the study. Inclusion criteria were the presence of a pocket that was located distally to the mandibular second molar with a probing depth (PD) >/=7 mm and with a probing clinical attachment level (CAL) >/=6 mm. Ninety three molar impactions were used and were randomly assigned to three equal treatment groups (30 each): bovine porous bone mineral (BPBM) alone, BPBM plus collagen membrane (CM), and an untreated control group. Clinical and radiographic measurements were recorded at 3, 6, 9, 12, 18, 24, 36, 48, 60, and 72 months after the surgery.

Results: BPBM or BPBM + CM resulted in a significant reduction in PD and gain in CAL compared to the control group at all time points. BPBM + CM had the best outcome for the prevention of a second-molar periodontal defect.

Conclusion: The application of BPBM, with or without a collagen membrane, can be a viable and stable treatment to alleviate the periodontal defects that are often associated with impacted mandibular third molar extractions.

Objectives: The aim of this study was to follow 41 intraoperative perforations of the Schneiderian membrane during sinus floor elevation and to identify potential differences from patients without perforations.

Material and Methods: Two hundred and one sinus floor elevations were performed at the department of oral and maxillofacial surgery of the University Hospital of Schleswig-Holstein in the years 2005 and 2006. Forty-one intraoperative perforations (20.4%) were documented and treated according to the following scheme: defects smaller than 5 mm were covered with a collagen membrane. Larger defects were additionally sutured. Particulated jawbone mixed 50:50 with bone substitute (25 cases) and a 50:50 mix of particulated iliac crest bone and BioOss (six cases) mainly served as graft material in the perforation group. In 12 cases, implants were installed at the time of sinus grafting, and in 27 cases, a second operation was performed.

Results: Four sinus lift procedures had to be discontinued intraoperatively. Over a mean control interval of 162 days, one implant of the 93 inserted had to be replaced in the perforation group. After 1 year, the implant survival rate was 14 out of 14 in the perforation group vs. 81/92 in the control group.

Conclusion: With appropriate treatment, intraoperative sinus membrane perforations did not represent an elevated risk for implant loss, infectious complications or displacement of graft material in the investigated population.

BACKGROUND:

Various sinus-lift techniques have been described in the literature. The aim of this retrospective study is to evaluate the efficacy of a transalveolar sinus-lift technique in terms of implant survival, marginal bone loss, and complications.

METHODS:

A total of 538 patient records were examined, and after applying exclusion and inclusion criteria, a sample of patients was included with a mean follow-up of 5 years. Implants with a smooth or tapered surface were considered. Therefore, only sinus lifts with inorganic bovine bone matrix or demineralized bone matrix were included, and 1,536 periapical radiographs were analyzed. Outcome measures were implant success, implant failure (peri-implantitis and loss of osseointegration), marginal bone resorption, and biologic complications (membrane perforations, sinusitis, and intraoperative and/or postoperative hemorrhage). Periapical radiographs were evaluated before surgery, post-surgery, and after 6 months and 1, 3, and 5 years. We analyzed the residual crestal bone height under the sinus, the amount (mm) of height increase after surgery, and values of implant marginal bone resorption for considered follow-ups.

RESULTS:

Two hundred eighty-two (282) patients were excluded. Therefore, 256 patients treated with the transalveolar sinus-lift technique were included. A total of 376 dental implants and 323 sinus lifts were analyzed. The overall rates of implant success and failure were 94.9% and 5.1%, respectively. The mean bone loss around implants was 1.98 mm (mean follow-up of 5 years). Patients treated with inorganic bovine bone matrix showed a better implant success rate (P = 0.03) than did patients treated with demineralized human matrix. Three Schneiderian membrane perforations occurred in the 323 sinus lifts. In these cases, the surgeon performed another surgical operation after 3 months. Postoperative complications were peri-implantitis (six cases) and osseointegration losses (13 cases).

CONCLUSION:

The transalveolar sinus-lift technique was a safe, minimally invasive technique with an implant success rate comparable to traditional implantology. The implant success rate was positively affected by the low-resorption graft material, and a low bone-resorption rate around implants was found.

OBJECTIVES:
The aims of this randomized clinical trial were to compare the dimensional changes and the histological composition after using deproteinized bovine bone mineral (DBBM) or deproteinized bovine bone mineral with 10% collagen (DBBM-C) and a collagen membrane in ridge preservation procedures.

MATERIAL AND METHODS:
Patients who required an extraction and a subsequent implant-supported rehabilitation at a non-molar site were recruited. After extraction, a cone beam computed tomography (CBCT) was performed and sites were randomly treated either with DBBM or DBBM-C plus a collagen membrane. At 5 months, before implant placement, a second CBCT was performed and a biopsy of the area was obtained. A blinded investigator superimposed the CBCTs and performed measurements to determine bone volume changes between the two time points. Additionally, a histomorphometric analysis of the biopsies was performed in a blinded manner.

RESULTS:
Eleven sites belonged to the DBBM group and eleven to the DBBM-C group. All together, a significant reduction in height and width was observed at 5 months of healing, but no statistically significant differences were observed between the DBBM and the DBBM-C group. The histomorphometric analysis revealed a similar composition in terms of newly formed bone, connective tissue and residual graft particles in both groups.

CONCLUSIONS:
Deproteinized bovine bone mineral with 10% collagen showed a similar behaviour as DBBM not only in its capacity to minimize ridge contraction but also from a histological point of view. Thus, both graft materials seem to be suitable for ridge preservation procedures.

OBJECTIVE:

To evaluate the radiographic changes of the alveolar ridge following application of different ridge preservation techniques 6 months after tooth extraction.

MATERIALS AND METHODS:

Four treatment modalities were randomly assigned in 40 patients: β-tricalcium-phosphate-particles with polylactid coating (β-TCP), demineralized bovine bone mineral with 10% collagen covered with a collagen matrix (DBBM-C/CM), DBBM-C covered with an autogenous soft-tissue graft (DBBM-C/PG) and spontaneous healing (control). Cone-beam computed tomography scans were performed after treatment and 6 months later.

RESULTS:

After 6 months, the vertical changes ranged between -0.6 mm (-10.2%) for control and a gain of 0.3 mm (5.6%) for DBBM-C/PG on the lingual side, and between -2.0 mm (-20.9%) for β-TCP and a gain of 1.2 mm (8.1%) for DBBM-C/PG on the buccal side. The most accentuated ridge width changes were recorded 1 mm below the crest: -3.3 mm (-43.3%, C), -6.1 mm (-77.5%, β-TCP), -1.2 mm (-17.4%, DBBM-C/CM) and -1.4 mm (-18.1%, DBBM-C/PG). At all three levels, DBBM-C with either CM or PG was not significantly differing (p > 0.05), while most other differences between the groups reached statistical significance (p < 0.05).

CONCLUSION:

Application of DBBM-C, covered with CM or PG, resulted in less vertical and horizontal changes of the alveolar ridge as compared with controls 6 months after extraction.

OBJECTIVES:
To assess two- and three-dimensional changes of the peri-implant tissues as well as clinical, biological, and radiological outcomes of implants having been treated with resorbable or nonresorbable membranes at 3 years.

MATERIALS AND METHODS:
Twenty-three patients were re-examined after having received a single-tooth implant in the esthetic zone in conjunction with guided bone regeneration (GBR) using either a resorbable (RES) or a titanium-reinforced nonresorbable membrane (N-RES) and demineralized bovine bone mineral. Volumetric and linear as well as clinical and radiographic measurements were performed at crown insertion (baseline), at 1 year (FU-1) and 3 years (FU-3). Statistics were performed by means of parametric and nonparametric tests.

RESULTS:
Minor, but ongoing buccal volume loss was observed in both groups during the 3-year follow-up. A slightly higher volume loss was observed in group RES (-0.22 mm) compared to N-RES (-0.14 mm) at 1 year (FU-1), but aligned at 3 years (FU-3) RES (-0.30 mm) N-RES (-0.32 mm). All changes over time were statistically significantly different within (p < .05), but not between the groups (p > .05). Stable median interproximal bone levels after 3 years (FU-3); 0.26 mm (0.04; 0.36) (RES) and 0.14 mm (0.08; 0.20) (N-RES) and healthy tissues (BOP, PD) were obtained with both membranes.

CONCLUSIONS:
Both treatment modalities resulted in minor, but ongoing contour changes of the peri-implant tissues. Stable interproximal bone levels and healthy tissues can be obtained with membranes up to 3 years.

AIM:
To test whether or not the use of a volume-stable collagen matrix (VCMX) results in soft tissue volume increase at implant sites non-inferior to an autogenous subepithelial connective tissue graft (SCTG).

METHODS:
In 20 patients, soft tissue augmentation at implant sites was performed using VCMX or SCTG. Casts obtained prior to augmentation (BL), at 30 (FU-30) and 90 days (FU-90) were digitized and transferred to stereolithography (STL) files. BL, FU-30 and FU-90 STL files were superimposed and linear volumetric changes evaluated in crestal and buccal regions of interest (ROI). Descriptive analysis was computed for both groups and a test for non-inferiority was performed.

RESULTS:
The median linear changes from BL to FU-90 in the crestal ROI amounted to 0.175 mm (0.06; 0.51) for VCMX (p = 0.002 over time) and to 0.51 mm (0.23; 0.94) for SCTG (p = 0.129). The differences between the two groups were not significant (p = 0.287). The respective values in the buccal ROI were 0.59 mm (0.26; 1.06) for VCMX (p = 0.002) and 0.94 mm (0.66; 1.13) for SCTG (p = 0.004). The differences between the two groups were not significant (crestal: p = 0.287; buccal: p = 0.534). Non-inferiority could be concluded for VCMX compared to SCTG for both ROI.

CONCLUSION:
VCMX and SCTG can be used for soft tissue augmentation at implant sites resulting in an at least short-term increase in volume.

AIM:
To test whether or not the use of a collagen matrix (VCMX) results in short-term soft tissue volume increase at implant sites non-inferior to an autogenous subepithelial connective tissue graft (SCTG), and to evaluate safety and tissue integration of VCMX and SCTG.

METHODS:
In 20 patients with a volume deficiency at single-tooth implant sites, soft tissue volume augmentation was performed randomly allocating VCMX or SCTG. Soft tissue thickness, patient-reported outcome measures (PROMs), and safety were assessed up to 90 days (FU-90). At FU-90 (abutment connection), tissue samples were obtained for histological analysis. Descriptive analysis was computed for both groups. Non-parametric tests were applied to test non-inferiority for the gain in soft tissue thickness at the occlusal site.

RESULTS:
Median soft tissue thickness increased between BL and FU-90 by 1.8 mm (Q1:0.5; Q3:2.0) (VCMX) (p = 0.018) and 0.5 mm (-1.0; 2.0) (SCTG) (p = 0.395) (occlusal) and by 1.0 mm (0.5; 2.0) (VCMX) (p = 0.074) and 1.5 mm (-2.0; 2.0) (SCTG) (p = 0.563) (buccal). Non-inferiority with a non-inferiority margin of 1 mm could be demonstrated (p = 0.020); the difference between the two group medians (1.3 mm) for occlusal sites indicated no relevant, but not significant superiority of VCMX versus SCTG (primary endpoint). Pain medication consumption and pain perceived were non-significantly higher in group SCTG up to day 3. Median physical pain (OHIP-14) at day 7 was 100% higher for SCTG than for VCMX. The histological analysis revealed well-integrated grafts.

CONCLUSIONS:
Soft tissue augmentation at implant sites resulted in a similar or higher soft tissue volume increase after 90 days for VCMX versus SCTG. PROMs did not reveal relevant differences between the two groups.

BACKGROUND:
The standard of care for increasing keratinized tissue (KT) and vestibular area is an autogenous free gingival graft (FGG) and vestibuloplasty; however, there is morbidity associated with the harvest of autogenous tissue, and supply is limited. The purpose of this study is to determine if a xenogeneic collagen matrix (CM) might be as effective as FGG.

METHODS:
This study is a single-masked, randomized, controlled, split-mouth study of 30 patients with insufficient zones of KT (<2 mm). It uses a within-patient treatment-comparison design to establish non-inferiority of the test (CM) versus control (FGG) therapy. The primary efficacy endpoint was change in KT width (∆KT) from surgery to 6 months post-surgery. Secondary endpoints included traditional periodontal measures, such as clinical attachment level, recession, and bleeding on probing. Patient-reported pain, discomfort, and esthetic satisfaction were also recorded. Biopsies were obtained at 6 months.

RESULTS:
Surgery and postoperative sequelae were uneventful, with normal healing observed at both test and control sites. The primary outcome, ∆KT width at 6 months, did not establish non-inferiority of CM compared to FGG (P = 0.9992), with the FGG sites averaging 1.5 mm more KT width than CM sites. However, the amount of new KT generated for both therapies averaged ≥2 mm. Secondary outcomes were not significantly different between test and control sites. All site biopsies appeared as normal mucoperiosteum with keratinized epithelium. CM sites achieved better texture and color matches, and more than two-thirds of patients preferred the appearance of their CM sites.

CONCLUSION:
With the proviso of sufficient KT (≈2 mm in width) and study goals of lower morbidity, unlimited supply, and patient satisfaction, CM appears to be a suitable substitute for FGG in vestibuloplasty procedures designed to increase KT around teeth.

Six anatomically complicated periodontal intrabony defects in 6 patients were surgically reconstructed using a bioresorbable GTR barrier supported by cancellous bovine bone mineral. Following cause-related periodontal treatment open-flap surgery was performed to expose the defects. After debridement, the defects were filled with the bone mineral and covered with the barrier. All patients were advised to rinse 2x daily with a 0.2% chlorhexidine digluconate solution and to avoid brushing in the operated area for 6 weeks. The treatment results were evaluated clinically and radiographically 6 months after surgery. All defects healed uneventfully and all patients maintained a high standard of plaque control throughout the study. Probing assessments during surgery showed a bone defect depth and width of an average 7.2 and 2.8 mm. The corresponding measures on presurgical intra-oral radiographs were 7.9 and 2.6 mm respectively. Clinical attachment level (CAL) gain averaged 5.3 mm, corresponding to 73% of the original bone defect depth. Radiographically, the defect fill averaged 6.2 mm or 80% of the original radiographic bone defect. It was concluded that the placement of bovine bone mineral beneath bioresorbable GTR barriers facilitates the clinical handling of the barrier and chances the space for potential periodontal reconstruction of anatomically complicated defects. It remains, however, to be ascertained to what degree the achieved clinical and radiographic results reflect a gain in new connective tissue attachment and alveolar bone.

Bone grafting may be required prior to implant placement, at the time of implant placement, or subsequent to it. The aim of this study was to compare the healing of onlay block grafts when deproteinized bovine bone coverage was used with the healing of the grafts without such coverage. The purpose was a clinical evaluation of deproteinized bovine bone's ability to reduce grafted bone resorption. The results indicated that bovine bone can be placed over grafted areas, taking advantage of its osteoconductive properties and compensating for the natural bone resorption caused by remodeling.

Background: Regenerative periodontal therapy aims to predictably restore the tooth's supporting periodontal tissues and should result in formation of a new connective tissue attachment (i.e. new cementum with inserting periodontal ligament fibres) and new alveolar bone. Histologic evidence from preclinical models has demonstrated periodontal regeneration following treatment with barrier membranes, various types of grafting materials or a combination thereof. However, it is still not clear to what extent a combination of barrier membranes and grafting materials may additionally enhance the regeneration process compared with barrier membranes alone, grafting materials alone or open flap debridement. Objectives: To review with a systematic approach all preclinical (i.e. animal) studies presenting histologic support for periodontal regeneration using the combination of barrier membranes and grafting materials.

Material and Methods: Based on a focused question, an electronic and manual search was conducted for animal studies presenting histological data for the effect of the combined use of barrier membranes and grafting materials on the treatment of periodontal defects. A systematic approach was followed by two independent reviewers including eligibility criotateria for study inclusion, outcome measures determination, screening method, data extraction, data synthesis and drawing of Conclusion.

Results: Ten papers completely fulfilling the inclusion criteria were selected. All relevant data from the selected papers were extracted and recorded in separate tables according to the types of periodontal defects treated (i.e. supra-alveolar defects, intrabony defects, furcation defects and fenestration defects) with the combination of barrier membranes and grafting materials. Most studies have demonstrated periodontal regeneration following the combination approach. Most studies demonstrated superior histologic healing following the combination of barrier membranes and grafting materials than following open flap debridement. Histologically superior healing following the combination of barrier membranes and grafting materials when compared with barrier membranes alone or grafting materials alone were only obtained in non-contained two wall intrabony and supraalveolar defects.

Conclusion: Within its limits the present analysis indicates that: (a) The combination of barrier membranes and grafting materials may result in histological evidence of periodontal regeneration, predominantly bone repair. (b) No additional benefits of combination treatments were detected in models of three wall intrabony, Class II furcation or fenestration defects. (c) In supra-alveolar and two wall intrabony (missing buccal wall) defect models of periodontal regeneration, the additional use of a grafting material gave superior histological results of bone repair to barrier membranes alone. (d) In one study using a supra-alveolar model, combined graft and barrier membrane gave a superior result to graft alone.

OBJECTIVES:
There is limited evidence regarding the long-term efficacy of regenerative treatment for peri-implantitis. The aim of this study was to evaluate a combination therapy of deproteinized bovine bone mineral with 10% collagen (DBBMC), enamel matrix derivative (EMD) and Doxycycline in the regeneration of bone defects associated with peri-implantitis.

METHODS:
Thirty patients diagnosed with peri-implantitis (BoP/suppuration, probing depth greater than 4 mm, minimum radiographic bone loss of 20%, at least 2 years in function) were enrolled in the study. Clinical measurements included probing depths, recession, radiographic bone fill, gingival inflammation and bleeding on probing/suppuration. Following surgical access and debridement, the implant surfaces were decontaminated with 24% EDTA for 2 min, and the bone defects were filled with a combined mixture of DBBMC, EMD and Doxycycline powder. The defects were covered with connective tissue grafts where necessary. Clinical measurements were recorded after 12, 24 and 36 months.

RESULTS:
The mean probing depth and bone loss at the initial visit was 8.9 mm (±1.9) and 6.92 mm (±1.26), respectively. Both mean probing depth and bone loss reduced significantly from baseline to 3.55 mm (±0.50) and 2.85 mm (±0.73) at 12 months, 3.50 (±0.50) and 2.62 mm (±0.80) at 24 months and 3.50 mm (±0.50) and 2.60 mm (±0.73) at 36 months. 56.6% of the implants were considered successfully treated (according to Successful Treatment Outcome Criterion: PD < 5 mm, no further bone loss >10%, no BoP/suppuration, no recession >0.5 mm for anterior implants and >1.5 mm for posterior implants) after 36 months.

CONCLUSION:
Regenerative treatment of peri-implantitis using a combined mixture of DBBMC, EMD and Doxycycline achieved promising results. The benefits of this protocol incorporating EMD should be tested in randomized clinical trials.

BACKGROUND: Platelet concentration based membranes, as well as collagen membranes in combination with bone substitutes, have demonstrated successful outcomes in regeneration of peri-implant bone defects (PBD).

 

PURPOSE: The aim of this study was to evaluate the clinical and radiographic outcomes of regenerative surgical treatment (RST) of peri-implantitis using a bone substitute combined with two different bioresorbable barrier membranes, either collagen membrane (CM) or concentrated growth factor (CGF), during 12-month follow-up.

 

MATERIALS AND METHODS: Fifty two patients, who had at least one peri-implantitis lesion was treated by using a bone substitute in combination with CGF or CM. After surgical procedures, implants were allowed for submerged healing. Clinical assessments were conducted at baseline, 6 and 12 months postoperatively, while radiographic evaluation was performed at baseline and 12 months.

 

RESULTS: Significant reductions were obtained in the mean gingival index (GI), bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL) and mucosal recession (MR) values at both 6 and 12 months postoperatively compared to baseline for both treatment procedures (P< 0.05). At 6 months, no statistically significant difference was observed for all clinical parameters between the groups, whereas the mean PD, CAL and vertical defect depth (VDD) values were statistically significant in favor of the CM group at 12 months (P < 0.05). The mean defect fill (DF) in the CM group (1.99 ±0.76) was not statistically significantly different from that observed in the CCF group (1.63 ±1.00) (P = 0.154).

 

CONCLUSIONS: The outcomes of the present study suggest that both regenerative approaches yielded significant improvements in both clinical and radiographic assessments. The procedure using a collagen membrane in combination with a bone substitute showed better results at 12  months in RST of peri-implantitis.

BACKGROUND: Platelet concentration based membranes, as well as collagen membranes in combination with bone substitutes, have demonstrated successful outcomes in regeneration of peri-implant bone defects (PBD). PURPOSE: The aim of this study was to evaluate the clinical and radiographic outcomes of regenerative surgical treatment (RST) of peri-implantitis using a bone substitute combined with two different bioresorbable barrier membranes, either collagen membrane (CM) or concentrated growth factor (CGF), during 12-month follow-up. MATERIALS AND METHODS: Fifty two patients, who had at least one peri-implantitis lesion was treated by using a bone substitute in combination with CGF or CM. After surgical procedures, implants were allowed for submerged healing. Clinical assessments were conducted at baseline, 6 and 12 months postoperatively, while radiographic evaluation was performed at baseline and 12 months. RESULTS: Significant reductions were obtained in the mean gingival index (GI), bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL) and mucosal recession (MR) values at both 6 and 12 months postoperatively compared to baseline for both treatment procedures (P < 0.05). At 6 months, no statistically significant difference was observed for all clinical parameters between the groups, whereas the mean PD, CAL and vertical defect depth (VDD) values were statistically significant in favor of the CM group at 12 months (P < 0.05). The mean defect fill (DF) in the CM group (1.99 ±0.76) was not statistically significantly different from that observed in the CCF group (1.63 ±1.00) (P = 0.154). CONCLUSIONS: The outcomes of the present study suggest that both regenerative approaches yielded significant improvements in both clinical and radiographic assessments. The procedure using a collagen membrane in combination with a bone substitute showed better results at 12 months in RST of peri-implantitis.

The treatment of a peri-implant infrabony defect is difficult because of contamination of the implant surface and adjacent tissues. This case series addresses the ability of a carbon dioxide (CO2) laser to decontaminate failing implants in 15 patients. Clinical and radiologic data are presented with regard to using the laser in combination with bone grafting and a barrier. Augmentation with autogenous bone grafting material (n = 10) or a xenogenic bone grafting material (BioOss) (n = 9) was used, and bone grafts were covered with a collagen membrane. Clinical and radiologic parameters were evaluated postoperatively. After an observation period of 27 months (+/- 17.83), almost complete bone fill in the peri-implant defect was accomplished. These preliminary clinical and radiologic findings suggest that decontamination of the implant surfaces with the CO₂ laser in combination with augmentative techniques can be an effective treatment method for peri-implantitis.

The most frequent intraoperative complication with sinus elevation is perforation of the schneiderian membrane. In most instances, the repair of this perforation is necessary to contain particulate grafting material and complete the procedure. New techniques are presented here for the management of large perforations of the schneiderian membrane. A bioabsorbable collagen membrane is stabilized outside the antrostomy and then folded inward to create either a new superior wall that can obliterate a large perforation or a "pouch" that can completely contain the particulate material. This can make it possible to complete a procedure that otherwise may have had to be aborted by preventing dispersion of the particulate graft within the sinus cavity. Clinical cases are shown, along with follow-up at 6 to 9 months, demonstrating histologic and/or radiographic evidence of success, continued sinus health, and superior vital bone formation. The authors have used this technique on 20 consecutive patients without experiencing any procedural failures.

"The objective of this study was to investigate marginal bone level (MBL) changes as the primary outcome of implants placed following healing of extraction sockets treated with ridge preservation, compared to implants placed following unassisted healing. A total of 268 patients (contributing 572 implants) treated from April 2005 to March 2013 were included in this retrospective study. Following estimation of the overall success rate of implants placed in the practice, 129 patients (contributing 222 implants) met the inclusion and exclusion criteria to be further evaluated. Of these, 78 patients (contributing 105 implants) received ridge preservation procedures, which entailed placement of anorganic bovine bone mineral covered with polytetrafluoroethylene membrane. The other 51 patients (contributing 117 implants), with healed sites without history of bone grafting, served as controls. Digital radiographs were taken at the time of implant placement and during follow-up visits. The mean follow-up period for ridge preservation sites was 33.6 months (range: 7.5 to 61.5 months) and for healed sites was 36.3 months (range: 6 to 91.2 months). The survival rate of implants in sites following healing of ridge preservation was 97.3%, compared to 98.5% in the nongrafted healed sites. The mean MBL changes during the observation period were 0.11 and 0.07 mm on the mesial and 0.06 and 0.06 mm on the distal aspects of the ridge preservation and healed sites, respectively (P > .05). The mean crestal bone remodeling during the observation period was 0.63 and 0.45 mm on the mesial and 0.48 and 0.12 mm on the distal aspects in the ridge preservation and healed sites, respectively (P < .05). The results of this study demonstrated stable MBL and survival of implants placed in sites following ridge preservation with xenograft as well as nongrafted healed sites. "

A total of 68 extraction sockets were grafted with anorganic bovine bone mineral and covered by dense polytetrafluoroethylene membrane. Quantitative analysis of three-dimensional microcomputed tomography imaging of core samples retrieved after a mean of 21.0 ± 14.2 weeks revealed 40.1% bone volume fraction (bone volume [BV]/total volume [TV]) and 12% residual graft. Evidence of de novo bone formation was observed in the form of discrete islands of newly formed bone in direct apposition to graft particles, separated from parent bone. Anterior sockets exhibited a significantly higher percentage of residual graft compared to premolar sockets (P = .05). The BV/TV and percentage of residual graft correlated well with histomorphometric analysis of the same sites, but not with implant outcomes.

OBJECTIVE:
To evaluate dimensional alterations of the alveolar ridge that occurred following tooth extraction at sites grafted with Bio-Oss(®) Collagen.

MATERIAL AND METHODS:
Twenty-eight subjects with maxillary incisors, canines, and premolars scheduled for extraction were included. The tooth was carefully removed. The patients were randomly assigned to a test or a control group. In the test group patients, Bio-Oss(®) Collagen was placed in the fresh extraction socket while in the controls no grafting was performed. Radiographic examination (cone beam computed tomograms, CBCT) was performed immediately after tooth extraction and socket treatment. Four months later, a new CBCT was obtained. In the radiographs, (i) the distance (mm) between base of the alveolar process (apex) and the buccal and palatal crests was determined, (ii) the outer profile of alveolar process of the experimental sites was outlined, and the cross section of the area (mm(2) ) determined.

RESULTS:
After 4 months of healing, the buccal and to a less extent also the palatal bone plate had become markedly reduced in height. The placement of a biomaterial in the socket failed to prevent resorption of the buccal and palatal bone walls. The cross-sectional area of the control ridge was reduced about 25% and of the test ridge with 3%.

CONCLUSION:
The placement of a xenograft in fresh extraction sockets markedly counteracted the reduction in the hard tissue component of the edentulous sites.

Objective: Lateral ridge augmentations are traditionally performed using autogenous bone grafts to support membranes for guided bone regeneration (GBR). The bone-harvesting procedure, however, is accompanied by considerable patient morbidity. AIM: The aim of the present study was to test whether or not resorbable membranes and bone substitutes will lead to successful horizontal ridge augmentation allowing implant installation under standard conditions.

Material and Methods: Twelve patients in need of implant therapy participated in this study. They revealed bone deficits in the areas intended for implant placement. Soft tissue flaps were carefully raised and blocks or particles of deproteinized bovine bone mineral (DBBM) (Bio-Oss) were placed in the defect area. A collagenous membrane (Bio-Gide) was applied to cover the DBBM and was fixed to the surrounding bone using poly-lactic acid pins. The flaps were sutured to allow for healing by primary intention.

Results: All sites in the 12 patients healed uneventfully. No flap dehiscences and no exposures of membranes were observed. Nine to 10 months following augmentation surgery, flaps were raised in order to visualize the outcomes of the augmentation. An integration of the DBBM particles into the newly formed bone was consistently observed. Merely on the surface of the new bone, some pieces of the grafting material were only partly integrated into bone. However, these were not encapsulated by connective tissue but rather anchored into the newly regenerated bone. In all of the cases, but one, the bone volume following regeneration was adequate to place implants in a prosthetically ideal position and according to the standard protocol with complete bone coverage of the surface intended for osseointegration. Before the regenerative procedure, the average crestal bone width was 3.2 mm and to 6.9 mm at the time of implant placement. This difference was statistically significant (P<0.05, Wilcoxon's matched pairs signed-rank test).

Conclusion: After a healing period of 9-10 months, the combination of DBBM and a collagen membrane is an effective treatment option for horizontal bone augmentation before implant placement.

Background: In previous short-term studies, it was observed that while the placement of biomaterial in alveolar sockets may promote bone formation and ridge preservation, the graft may in fact also delay healing.

Aim: The objective of the present experiment was to evaluate the more long-term effect on hard tissue formation and the amount of ridge augmentation that can occur by the placement of a xenogeneic graft in extraction sockets of dogs.

Material and Methods: Five beagle dogs were used. The third mandibular premolars were hemi-sected. The distal roots were carefully removed. A graft consisting of Bio-Oss Collagen was placed in one socket while the contra-lateral site was left without grafting. After 6 months of healing, the dogs were euthanized and biopsies were sampled. From each experimental site, four ground sections – two from the mesial root and two from the healed socket – were prepared, stained and examined under a microscope.

Results: The placement of Bio-Oss Collagen in the fresh extraction socket served as a scaffold for tissue modeling but did not enhance new bone formation. In comparison with the non-grafted sites, the dimension of the alveolar process as well as the profile of the ridge was better preserved in Bio-Oss-grafted sites.

Conclusion: The placement of a biomaterial in an extraction socket may modify modeling and counteract marginal ridge contraction that occur following tooth removal.

OBJECTIVE:

The aim was to examine the tissue composition of extraction sockets that had been grafted with deproteinized bovine bone mineral and allowed to heal for 6 months.

MATERIAL AND METHODS:

Twenty-five subjects with one tooth each scheduled for extraction and replacement with dental implants were recruited. The assigned teeth were carefully removed. The site/patient was thereafter allocated to a test or a control group. In the test group patients, Bio-Oss® Collagen was placed to fill the fresh extraction socket while in the controls no grafting was performed. After about 6 months of healing, a biopsy was sampled from the center of the extraction site. The specimens were decalcified, embedded in paraffin, sectioned, and stained in HTX. The proportions occupied by mineralized bone, osteoid, bone marrow, fibrous tissue, and Bio-Oss® particles were determined by morphometric point counting.

RESULTS:

Mineralized bone made up 57.4 ± 12.4% of the control sites (C) and 48.9 ± 8.5% of the T1 sites (graft material not included). The amount of bone marrow (C: 7.1 ± 6.1%, T1: 2.1 ± 3.1%) and osteoid (C: 7.3 ± 4.9%, T1: 1.9 ± 2.1%) was about five times greater in the control than in the test sites. Fibrous tissue comprised 23.1 ± 16.3% (C) and 40.0 ± 11.9% (T1). I n the T2 sites (graft material included), the percentage mineralized bone was 39.9 ± 8.6 while the proportions of bone marrow and osteoid were 1.8 ± 2.5% and 1.6 ± 1.8%. Fibrous tissue occupied 32.4 ± 9.2% and Bio-Oss® particles 19.0 ± 6.5% of the T2 sites.

CONCLUSION:

Placement of the biomaterial in the fresh extraction socket retarded healing. The Bio-Oss® particles were not resorbed but became surrounded by new bone. This may explain why grafted extraction sites may fail to undergo dimensional change.

The aim of this retrospective case control study was to compare a porcine collagen matrix (Mucograft Seal, Geistlich) with a free gingival punch graft with respect to size, invagination, and color of resulting soft tissue scar formation. Following definition of inclusion and exclusion criteria, 22 patients were retrospectively included in this study. The patients were divided into two groups. In group A, the extraction socket was filled with bovine bone mineral (Bio-Oss, Geistlich) and covered with a free gingival punch graft. In group B, the extraction socket was filled with bovine bone mineral (Bio-Oss) and covered with porcine collagen matrix. After final prosthetic reconstruction (18 implant-retained crowns and 4 fixed partial dentures), two independent examiners evaluated the size, invagination, and color of the soft tissue scar using a modified scar-evaluation scale originally developed for dermal wounds (lower values correspond to less scarring). Patient satisfaction was recorded using a questionnaire. Patient records were screened for frequency and costs of scar removal treatment. The average scar score for groups A and B was 1.33 and 4.3, respectively, revealing significantly less scarring in group B (P = .000295). Frequency and costs of scar removal treatment were statistically significantly higher in Group A (P = .000234). Patient satisfaction was not statistically significantly different between the treatment groups (P = .711 for group A and P = .809 for group B. The results suggest that alveolar ridge preservation using bovine bone mineral and porcine collagen matrix leads to less scar tissue formation when compared with bovine bone mineral and free gingival punch grafts from the palate.

Purpose: To test our null hypothesis stating that the mixture of autogenous cortical bone scrapings and bovine bone mineral (BBM) in a ratio of 1:4, compared with BBM alone, would have no significant effect on new bone formation 4 months after maxillary sinus floor augmentation.

Patients and Methods: Twenty-four patients presenting with alveolar bone height of less than 5 mm in the narrowest zone between the sinus floor and alveolar crest were randomly assigned to 2 treatment groups in this randomized controlled trial. We augmented 12 maxillary sinuses with a mixture of BBM and cortical autogenous bone graft, which was collected from the lateral wall of the maxillary sinus by a bone scraper, and 12 maxillary sinuses with BBM alone. Four months postoperatively, new bone formation in the augmented sinus sites was evaluated through bone scintigraphy, as well as histologic and histomorphometric analyses of the biopsy specimens obtained during implant placement. Data were statistically analyzed by independent-samples t test.

Results: Scintigraphically detectable new bone formation did not differ significantly between the groups (P > .05). Histologic findings showed that the new bone bridged between BBM particles and BBM underwent resorption by osteoclasts with or without the addition of autogenous bone graft. According to histomorphometric findings, the difference between the percentages of newly formed bone in the sinuses augmented with graft mixture (25.73%) and BBM alone (24.19%) was statistically nonsignificant (P > .05). Conclusion: The addition of autogenous cortical bone scrapings to BBM in a ratio of 1:4, compared with BBM alone, does not markedly increase new bone formation 4 months after maxillary sinus lifting.

OBJECTIVES:
The aim of this randomized controlled trial was to assess the 10-year effects of three different augmentation techniques (augmentation with chin bone, augmentation with chin bone plus a membrane and augmentation with a bone substitute plus a membrane) for implant-supported restorations in the maxillary aesthetic region regarding clinical and radiographic parameters, and patient-centred outcomes.

MATERIALS AND METHODS:
Ninety-three patients requesting single tooth replacement and presenting with a horizontal bone deficiency were included. After augmentation, 93 implants were placed. Clinical variables, standardized radiographs and photographs and patient questionnaires were analysed to assess the impact of the various augmentation techniques 1 month (T1 ), 12 months (T12 ) and 120 months (T120 ) after final crown placement.

RESULTS:
10-years implant survival was 95.7% and did not differ between the groups neither were significant differences observed in the other treatment outcomes assessed. Peri-implant bone loss was low, viz. 0.48 ± 1.19 mm (mesial) and 0.30 ± 1.24 mm (distal) at T120 . Loss of midbuccal marginal gingival level at T120 was 0.32 ± 0.83 mm. Mean overall satisfaction at T120 was 8.6 with 98.6% of the patients satisfied.

CONCLUSIONS:
Clinical, radiographic, aesthetic and patient centred outcomes were very favourable after 10 years and did not differ between the groups with different bone augmentation techniques.

The purpose of the present study, which used anorganic bovine bone (Bio-Oss) with and without autogenous bone as the augmentation material, was to compare the results of sinus elevation performed without a membrane (control) with the results of sinus elevation performed with either a short-term bioabsorbable membrane (Bio-Gide) or a nonabsorbable membrane (Gore-Tex) with regard to both vital bone formation and implant survival. Sinus lifts were performed on 51 patients (38 unilateral, 13 bilateral) with the delayed placement of 135 implants. Histomorphometric data were obtained at the time of implant placement, 6 to 10 months following the grafting procedure. Vital bone formation was 17.6%, 16.9%, and 12.1%, respectively, for the Bio-Gide, Gore-Tex, and no membrane groups. Of the 135 implants placed there were 3 failures (2 Bio-Gide, 1 Gore-Tex). There was no significant difference between the membrane groups as to vital bone formation and implant survival.

Objectives: To compare the amount of newly formed bone after sinus floor augmentation with two different particle sizes of bovine bone mineral (BBM) using clinical, micro-computerized tomography (CT) and histological techniques.

Methods: Bilateral sinus floor augmentations were performed in 10 patients. Six to 9 months later, bone samples were retrieved and analyzed.

Results: Results: Both groups were not different in vertical bone height achieved after augmentation, post-operative complications and maximal torque for the insertion of implants. Micro-CT measurements could not detect a statistically significant difference in bone volume between the groups (with a tendency for new more bone in the small granules group). Histomorphometric analysis revealed that both granule sizes produced the same pattern of bone formation, surrounding the graft granules, and producing a shape of a network, "bridging" between the BBM particles. Multi-nucleated giant cells, probably osteoclasts, were observed directly on the BBM particle surface in both groups. The osteoclast-like cells preferred the small- size BBM particles and not the large particles both in the small-size and the large-size granules group.

Conclusion: Both sizes of BBM granules preformed equally and achieved the aim of the sinus floor augmentation procedure clinically and histologically.

Xenografts have been used extensively, either alone or in combination with autogenous bone, in sinus floor elevation techniques. However, controversy exists regarding the need to cover the lateral osteotomy site with a membrane. Also, the healing period before loading remains undefined when machined-surface implants are placed. Twenty-nine patients showing reduced bone volume in the posterior maxilla had 61 Brånemark System implants placed in 30 sinuses augmented with a lateral osteotomy approach. Sinuses grafted with Bio-Oss® and covered with a collagen membrane Bio-Gide® (M+) received 29 implants, while grafted but uncovered sites

(M-) received 32 implants. An immediate procedure was followed to place 41 implants and a staged procedure was used for 20 implants. Abutment connection was made in 2 distinct postoperative periods: 6 to 9 months and over 9 months. The patients were followed for an average of 22.4 months. The survival rate of the implants was dependent on the postoperative healing time and membrane presence. In case of the immediate procedure and in M- sites, when residual bone height was less than 5 mm, more failures occurred when the loading was done at 6 to 9 months than after 9 months. No failures occurred in the M- series when a staged approach was followed. The overall survival rate was 78.1% for the M- sites and 93.1% for the M+ sites. No failures occurred (0/35) in the control implants placed in adjacent native bone. Implant survival rate was related to the quality of the reconstructed cortical plate and to implant length. The concomitant use of a collagen barrier to cover the osteotomy site, when machined-surface implants were used in sinus grafting, seemed to improve the quality of the graft healing and survival rate of the implants loaded between 6 and 9 months after placement.

PURPOSE:
To compare the outcome of implants inserted in maxillary sinuses augmented with anorganic bovine bone (ABB) grafts vs mixed 50% ABB and 50% autologous bone graft, using a lateral window approach.

MATERIALS AND METHODS:
This study was designed as a randomised controlled trial of parallel groups. Patients in need of an implant-supported prosthesis in a maxillary posterior area with a residual alveolar bone height no greater than 4 mm (range 0-4 mm) were recruited for lateral sinus grafting. Patients were randomly allocated to receive 50% ABB and 50% autogenous bone (group A) or 100% ABB (group B). After 7 months, tapered implants were inserted with an insertion torque between 20 and 45 Ncm. After 3 months, implants were loaded with screw-retained temporary crowns. Definitive crowns were delivered 3 months later. Outcome measures were implant survival, complications, radiographic marginal bone-level changes, probing pocket depths (PPD) and bleeding on probing (BOP). Clinical data were collected at definitive prosthesis delivery, 1 and 2 years after loading.

RESULTS:
Thirty-two consecutive patients were treated with 32 sinus lift procedures (16 group A, 16 group B). A total of 46 implants were installed. No patient dropped out. No crown/implant failed by the end of the study. Three complications (one sinus membrane perforation and two chipping of the ceramic) were observed in three patients in group A, vs none in group B (RR 0.81; 95% CI 0.64 - 1.03 mm; P = 0.225). At the 2-year after final loading follow-up, the mean marginal bone loss was 1.18 ± 0.50 mm (95% CI 0.95 - 1.45 mm) in group A and 1.28 ± 0.48 mm (95% CI 0.97 - 1.43 mm) in group B, with no statistically significant differences between the two groups (difference 0.11 ± 0.22 mm; 95% CI -0.06 - 0.16 mm; P = 0.586). At the same follow-up, the mean PPD value was 2.70 ± 0.39 for group A and 2.54 ± 0.66 for group B, with no statistically significant difference between groups (difference 0.17 ± 0.39 mm; 95% CI 0.06 - 0.32 mm; P = 0.456), while the mean BOP value was 1.21 ± 0.79 for group A and 1.28 ± 0.68 for group B, (difference: 0.06 ± 0.49 mm; 95% CI -0.23 - 0.25 mm; P = 0.297).

CONCLUSIONS:
Within the limitations of this study, the present data seem to confirm the hypothesis that the clinical outcome of implants inserted in sinuses grafted with ABB vs implants inserted in sinuses grafted with mixed 50% ABB and 50% autologous bone are comparable. Conflict-of-interest statement: This study was not supported by any company. All the authors declare no conflict of interest.

This study compared the dimensional alterations; the need for sinus floor elevation, and the histologic wound healing of augmented and nonaugmented alveolar sockets. Sixteen human extraction sockets were either grafted or left untreated. At baseline and 3 and 6 months postextraction, alveolar ridge alterations were evaluated; at 3, 6, and 9 months, histologic analyses were conducted. Implant placement with or without sinus floor augmentation was decided at 6 months. Three of eight patients in the control group underwent sinus floor augmentation compared to one of six in the experimental group. The alveolar ridge augmentation procedure presented here increases the possibility of inserting implants without the need for a sinus augmentation procedure.

Background: Studies in humans and animals have shown that following tooth removal (loss), the alveolar ridge becomes markedly reduced. Attempts made to counteract such ridge diminution by installing implants in the fresh extraction sockets were not successful, while socket grafting with anorganic bovine bone mineral prevented ridge contraction.

Aim: To examine whether grafting of the alveolar socket with the use of chips of autologous bone may allow ridge preservation following tooth extraction.

Methods: In five beagle dogs, the distal roots of the third and fourth mandibular premolars were removed. The sockets in the right or the left jaw quadrant were grafted with either anorganic bovine bone or with chips of autologous bone harvested from the buccal bone plate. After 3 months of healing, biopsies of the experimental sites were sampled, prepared for buccal-lingual ground sections and examined with respect to size and composition.

Results: It was observed that the majority of the autologous bone chips during healing had been resorbed and that the graft apparently did not interfere with socket healing or processes that resulted in ridge resorption.

Conclusion: Autologous bone chips placed in the fresh extraction socket will (i) neither stimulate nor retard new bone formation and (ii) not prevent ridge resorption that occurs during healing following tooth extraction. To cite this article: Araujo MG, Lindhe J. Socket grafting with the use of autologous bone: an experimental study in the dog.  Clin. Oral Impl. Res. 22, 2011; 9-13.doi: 10.1111/j.1600-0501.2010.01937.x.

After tooth extraction, varying amounts of bone resorption occur because of qualitative and quantitative changes at the edentulous site of the alveolar process. The aims of this randomized controlled clinical trial were (1) to compare the post extraction changes in residual ridge dimensions during spontaneous healing with those during socket preservation, (2) to analyze the histologic and histomorphometric aspects of the grafted sockets, and (3) to compare probing pocket depth (PPD) and clinical attachment level (CAL) changes at teeth adjacent to extraction sites. Forty-eight teeth were extracted from 41 patients referred for extraction of 1 or more maxillary or mandibular premolars or molars. The edentulous sites were randomly assigned to the control (EXT, extraction alone) or experimental groups (SP, extraction and socket preservation). In the SP group, the sockets were filled with bovine bone mineral and covered with porcine collagen membrane. At baseline and after 4 months, PPD, gingival recession (REC), and CAL were measured at teeth adjacent to the edentulous sites. The changes in ridge dimensions from baseline to 4 months were assessed on dental casts. At 4 months, bone was harvested from the grafted areas in the SP group and the edentulous areas in the EXT group. PPD, REC, and CAL were comparable between groups. However, from baseline to 4 months, the SP group showed significantly less reduction in ridge width (1.04 ± 1.08 mm vs 4.48 ± 0.65 mm, P < .001) and height (0.46 ± 0.46 mm vs 1.54 ± 0.33 mm, P < .001). Histologically, the grafted sockets exhibited various stages of bone maturation and formation without inflammatory responses. No significant difference in the mineralized and non-mineralized fractions was noted between the groups. Socket preservation using bovine bone mineral and porcine collagen membrane considerably limits the amount of horizontal and vertical bone resorption when compared with extraction alone.

In 52 patients, single anterior teeth were extracted and replaced by immediate implants. The peri-implant gap was left either untreated (control) or was grafted and covered with a membrane (test group). After 12 months the horizontal bone resorption was significantly lower in the test group (test sites: 0.69 ± 0.68 mm, 8.13%; control sites: 1.92 ± 1.02 mm, 21.62%; P = .001), and there was less reduction in ridge height (test sites: 0.58 ± 0.77 mm; control sites: 1.69 ± 1.74 mm;P = .004). Ridge preservation considerably limited the amount of horizontal and vertical soft tissue alterations when compared with implant placement alone.

AIM:
The aim of this study was to test whether or not soft tissue augmentation with a collagen matrix (VCMX) leads to a similar increase in ridge width around dental implants compared to the use of an autogenous subepithelial connective tissue graft (SCTG).

MATERIALS AND METHODS:
In 12 dogs, immediate dental implants were placed with simultaneous guided bone regeneration. Three months later, soft tissue volume augmentation was performed by randomly allocating three treatment modalities to these sites [VCMX, SCTG, sham-operated group (control)]. Dogs were sacrificed at 1 (n = 4), 2 (n = 4) or 6 months (n = 4). Descriptive histology and histomorphometric measurements for soft tissue thickness were performed on non-decalcified sections.

RESULTS:
The horizontal soft tissue thickness was maximal at the most coronal level (alveolar crest) at 1 month (VCMX: 2.1 ± 1.6 mm; SCTG: 2.5 ± 1.7 mm; p = 0.877) and decreased until 6 months. At 6 months, the greatest mucosal thickness was at a level 3.5 mm below the crest (VCMX: 0.8 ± 0.3 mm; SCTG: 0.7 ± 0.2 mm) (p = 0.754). Control sites revealed no relevant soft tissue augmentation at any level and any time-point. Tissue integration for VCMX and SCTG were favourable with minimal inflammatory reactions.

CONCLUSIONS:
Soft tissue volume augmentation at implant sites was obtained to a similar extent using VCMX and SCTG up to 2 months. Thereafter, degradation and remodelling processes were enhanced leading to a minimal increase in soft tissue thickness at 6 months for VCMX and SCTG.

OBJECTIVES:
The aim was to test, whether or not soft tissue volume augmentation with a specifically designed collagen matrix (CM), leads to ridge width gain in chronic ridge defects similar to those obtained by an autogenous subepithelial connective tissue graft (SCTG).

MATERIAL AND METHODS:
In six dogs, soft tissue volume augmentation was performed by randomly allocating three treatment modalities to chronic ridge defects [CM, SCTG and sham-operated control (Control)]. Dogs were sacrificed at 28 (n = 3) and 84 days (n = 3). Descriptive histology and histomorphometric measurements were performed on non-decalcified sections.

RESULTS:
SCTG and CM demonstrated favourable tissue integration, and subsequent re-modelling over 84 days. The overall mean amount of newly formed soft tissue (NMT) plus bone (NB) amounted to 3.8 ± 1.2 mm (Control), 6.4 ± 0.9 mm (CM) and 7.2 ± 1.2 mm (SCTG) at 28 days. At 84 days, the mean NMT plus NB reached 2.4 ± 0.9 mm (Control), 5.6 ± 1.5 mm (CM) and 6.0 ± 2.1 mm (SCTG). Statistically significant differences were observed between CM/SCTG and Control at both time-points (p < 0.05).

CONCLUSION:
Within the limits of this animal model, the CM performed similar to the SCTG, based on histomorphometric outcomes combining NB and NMT.

OBJECTIVES:
The aim was to test whether or not soft tissue augmentation with a newly developed collagen matrix (CM) leads to volume gain in chronic ridge defects similar to those obtained by an autogenous subepithelial connective tissue graft (SCTG).

MATERIAL AND METHODS:
In six dogs, soft tissue volume augmentation was performed by randomly allocating three treatment modalities to chronic ridge defects (CM, SCTG, sham-operated control). Impressions were taken before augmentation (baseline), at 28, and 84 days. The obtained casts were optically scanned and the images were digitally analysed. A defined region of interest was measured in all sites and the volume differences between the time points were calculated.

RESULTS:
The mean volume differences per area between baseline and 28 days amounted to a gain of 1.6 mm (CM; SD+/-0.9), 1.5 mm (SCTG; +/-0.1), and a loss of 0.003 mm (control; +/-0.3). At 84 days, the mean volume differences per area to baseline measured a gain of 1.4 mm (CM; +/-1.1), 1.4 mm (SCTG; +/-0.4), and a loss of 0.3 mm (control; +/-0.3). The differences between CM and SCTG were statistically significant compared with control at 28 and 84 days (p<0.001).

CONCLUSION:
Within the limits of this animal study, the CM may serve as a replacement for autogenous connective tissue."

The results of a case series of 51 consecutively treated, peri-implantitis-affected implants in 38 patients with follow-up measurements from 3 to7.5 years are presented. Each implant displayed bleeding on probing, probing depths ≥ 6 mm, and bone loss ≥ 4 mm prior to surgery. A successful regenerative approach including surface decontamination, use of enamel matrix derivative, a combination of platelet-derived growth factor with anorganic bovine bone or mineralized freeze-dried bone, and coverage with a collagen membrane or a subepithelial connective tissue graft was employed in all cases. Patients were divided into two groups. Group 1 included patients in which the greatest defect depth was visible on radiographs; group 2 included patients in which the greatest loss of bone was on the facial or oral aspect of the implant. Bone level changes in patients in group 2 were determined by probe sounding under local anesthesia. Probing depth reductions at 3 to 7.5 years of follow-up were 5.4 and 5.1 mm in groups 1 and 2, respectively. Concomitant bone level gain was 3.75 mm in group 1 and 3.0 mm in group 2. No implant in either group lost bone throughout the duration of the study. The results to date with this regenerative approach for the treatment of peri-implantitis appear to be encouraging.

The results of a case series of 51 consecutively treated, peri-implantitis-affected implants in 38 patients with follow-up measurements from 3 to 7.5 years are presented. Each implant displayed bleeding on probing, probing depths ≥ 6 mm, and bone loss ≥ 4 mm prior to surgery. A successful regenerative approach including surface decontamination, use of enamel matrix derivative, a combination of platelet-derived growth factor with anorganic bovine bone or mineralized freeze-dried bone, and coverage with a collagen membrane or a subepithelial connective tissue graft was employed in all cases. Patients were divided into two groups. Group 1 included patients in which the greatest defect depth was visible on radiographs; group 2 included patients in which the greatest loss of bone was on the facial or oral aspect of the implant. Bone level changes in patients in group 2 were determined by probe sounding under local anesthesia. Probing depth reductions at 3 to 7.5 years of follow-up were 5.4 and 5.1 mm in groups 1 and 2, respectively. Concomitant bone level gain was 3.75 mm in group 1 and 3.0 mm in group 2. No implant in either group lost bone throughout the duration of the study. The results to date with this regenerative approach for the treatment of peri-implantitis appear to be encouraging.

Objective: This systematic review aims to evaluate the scientific evidence on the efficacy in the surgical protocols designed for preserving the alveolar ridge after tooth extraction and to evaluate how these techniques affect the placement of dental implants and the final implant supported restoration.

Material and Methods: A thorough search in MEDLINE-PubMed, Embase and the Cochrane Central Register of controlled trials (CENTRAL) was conducted up to February 2011. Randomized clinical trials and prospective cohort studies with a follow-up of at least 3 months reporting changes on both the hard and soft tissues (height and/or width) of the alveolar process (mm or %) after tooth extraction were considered for inclusion.

Results: The screening of titles and abstracts resulted in 14 publications meeting the eligibility criteria. Data from nine of these 14 studies could be grouped in the meta-analyses. Results from the meta-analyses showed a statistically significant greater ridge reduction in bone height for control groups as compared to test groups (weighted mean differences, WMD = -1.47 mm; 95% CI [-1.982, -0.953]; P < 0.001; heterogeneity: I(2) = 13.1%; chi(2) P-value = 0.314) and a significant greater reduction in bone width for control groups compared to the test groups (WMD = -1.830 mm; 95% CI [-2.947, -0.732]; P = 0.001; heterogeneity: I(2) = 0%; chi(2) P-value = 0.837). Subgroup analysis was based on the surgical protocol used for the socket preservation (flapless/flapped, barrier membrane/no membrane, primary intention healing/no primary healing) and on the measurement method utilized to evaluate morphological changes. Meta-regression analyses demonstrated a statistically significant difference favoring the flapped subgroup in terms of bone width (meta-regression; slope = 2.26; 95% IC [1.01; 3.51]; P = 0.003).

Conclusion: The potential benefit of socket preservation therapies was demonstrated resulting in significantly less vertical and horizontal contraction of the alveolar bone crest. The scientific evidence does not provide clear guidelines in regards to the type of biomaterial, or surgical procedure, although a significant positive effect of the flapped surgery was observed. There are no data available to draw conclusions on the consequences of such benefits on the long-term outcomes of implant therapy.

Objectives: The present case series aimed at investigating the 4-year clinical outcomes following surgical regenerative therapy of peri-implantitis lesions using either a nanocrystalline hydroxyapatite (NHA) or a natural bone mineral in combination with a collagen membrane (NBM+CM).

Materials and Methods: Twenty patients suffering from moderate peri-implantitis (n=20 intrabony defects) were randomly treated with (1) access flap surgery (AFS) and the application of NHA (n=9), or with AFS and the application of NBM+CM (n=11). Clinical and radiographic (R) parameters were recorded at baseline (R) and after 36 and 48 (R) months of non-submerged healing.

Results: One patient from the NBM+CM group was discontinued from the study due to severe pus formation at 36 months. Compared with NHA, the application of NBM+CM resulted in higher mean PD reductions (NBM+CM: 2.5 +/- 0.9 mm versus NHA: 1.1 +/- 0.3 mm) and clinical attachment-level gains (NBM+CM: 2.0 +/- 1.0 mm versus NHA: 0.6 +/- 0.5 mm) at 48 months. A radiographic bone fill was observed for five sites in the NHA group, and eight sites in the NBM+CM group.

Conclusion: While the application of NBM+CM resulted in clinical improvements over a period of 4 years, the long-term outcome obtained with NHA without barrier membrane must be considered as poor.

AIM:
To evaluate the efficacy of a reconstructive surgical procedure in single peri-implantitis infrabony defects.

METHODS:
Seventy-five patients with one peri-implantitis crater-like lesion with pocket depth (PD) ≥ 6 mm, were included. Each defect was assigned to one characteristic class, by an independent examiner. After implant decontamination, defects were filled with deproteinized bovine bone mineral with 10% collagen.

RESULTS:
At 1-year follow-up, four patients were lost and six implants removed. Treatment success, PD ≤ 5 mm and absence of suppuration/bleeding on probing (BOP), was obtained in 37 (52.1%) of the 71 implants examined. PD was significantly reduced by 2.92 ± 1.73 mm (p < 0.0001). BOP decreased from 71.5 ± 34.4% to 18.3 ± 28.6% (p < 0.0001). The mean number of deep pockets (≥ 6 mm) decreased from 3.00 ± 0.93 to 0.85 ± 1.35 (p < 0.0001).

CONCLUSIONS:
These results confirm the possibility to successfully treat peri-implantitis lesions. There is lack of evidence of whether or not the resolution of the peri-implant disease is associated with the defect configuration. Due to the fact that complete resolution does not seem a predictable outcome, the clinical decision on whether implants should be treated should be based on several patient related elements.

OBJECTIVES:
The aim of this prospective study was to evaluate a regenerative surgical treatment modality for peri-implantitis lesions on two different implant surfaces.

MATERIALS AND METHODS:
Twenty-six patients with one crater-like defect, around either TPS (Control) or SLA (Test) dental implants, with a probing depth (PD) ≥6 mm and no implant mobility, were included. The implant surface was mechanically debrided and treated using a 24% EDTA gel and a 1% chlorhexidine gel. The bone defect was filled with a bovine-derived xenograft (BDX) and the flap was sutured around the non-submerged implant.

RESULTS:
One-year follow-up demonstrated clinical and radiographic improvements. PDs were significantly reduced by 2.1±1.2 mm in the Control implants and by 3.4±1.7 mm in the Test implants. Complete defect fill was never found around Controls, while it occurred in three out of 12 Test implants. Bleeding on probing decreased from 91.1±12.4% (Control) and 75.0±30.2% (Test) to 57.1±38.5% (p=0.004) and 14.6±16.7% (p=0.003), respectively. Several deep pockets (≥6 mm) were still present after surgical therapy around Controls.

CONCLUSIONS:
Surface characteristics may have an impact on the clinical outcome following surgical debridement, disinfection of the contaminated surfaces and grafting with BDX. Complete fill of the bony defect seems not to be a predictable result.

OBJECTIVES:

The aim of this study was to evaluate the long-term results of the surgical treatment of single peri-implantitis intrabony defects, by means of deproteinized bovine bone mineral with 10% collagen (DBBMC).

MATERIAL AND METHODS:

The original population consisted of 26 patients with one crater-like defect, around either sandblasted and acid-etched (SLA) or titanium plasma-sprayed (TPS) dental implants, with a probing depth (PD) ≥6 mm and no implant mobility (Roccuzzo et al. J Clin Periodontol. 2011; 38: 738). Implants were mechanically debrided and treated using EDTA gel and chlorhexidine gel. The bone defects were filled with DBBMC, and the flap was sutured around the non-submerged implant. Patients were placed on an individually tailored supportive periodontal therapy (SPT).

RESULTS:

Two patients were lost to follow-up. During SPT, additional antibiotic and/or surgical therapy was necessary in eight implants, and four of these were removed for biologic complications. At 7-year, the survival rate was 83.3% for SLA implants and 71.4% for TPS. PD was significantly reduced from 6.6 ± 1.3 to 3.2 ± 0.7 mm in SLA and 7.2 ± 1.5 to 3.4 ± 0.6 mm in TPS. Bleeding on probing decreased from 75.0 ± 31.2% to 7.5 ± 12.1% (SLA) and from 90.0 ± 12.9% to 30.0 ± 19.7% (TPS). When successful therapy was defined as PD ≤5 mm, absence of bleeding/suppuration on probing, and no further bone loss, treatment success was obtained in 2 of 14 (14.3%) of the TPS and in 7 of 12 (58.3%) of the SLA implants.

CONCLUSIONS:

Seven years after surgical treatment with DBBMC, patients, in an adequate SPT, maintained sufficient peri-implant conditions in many cases, particularly around SLA implants. Nevertheless, some patients required further treatment and some lost implants. The clinical decision on whether implants should be treated or removed should be based on several factors, including implant surface characteristics.

Based on a systematic review of the literature from 1986 to 2002, this study sought to determine the survival rate of root-form dental implants placed in the grafted maxillary sinus. Secondary goals were to determine the effects of graft material, implant surface characteristics, and simultaneous versus delayed placement on survival rate. A search of the main electronic databases was performed in addition to a hand search of the most relevant journals. All relevant articles were screened according to specific inclusion criteria. Selected papers were reviewed for data extraction. The search yielded 252 articles applicable to sinus grafts associated with implant treatment. Of these, 39 met the inclusion criteria for qualitative data analysis. Only 3 of the articles were randomized controlled trials. The overall implant survival rate for the 39 included studies was 91.49%. The database included 6,913 implants placed in 2,046 subjects with loaded follow-up time ranging from 12 to 75 months. Implant survival was 87.70% with grafts of 100% autogenous bone, 94.88% when combining autogenous bone with various bone substitutes, and 95.98% with bone grafts consisting of bone substitutes alone. The survival rate for implants having smooth and rough surfaces was 85.64% and 95.98%, respectively. Simultaneous and delayed procedures displayed similar survival rates of 92.17% and 92.93%, respectively. When implants are placed in grafted maxillary sinuses, the performance of rough implants is superior to that of smooth implants. Bone-substitute materials are as effective as autogenous bone when used alone or in combination with autogenous bone. Studies using a split-mouth design with one variable are needed to further validate the findings.

Several bone grafting materials have been used in sinus augmentation procedures. Bio-Oss (deproteinized and sterilized bovine bone) has shown to have osteoconductive properties and no inflammatory or adverse responses have been published. In spite of these successful results, histologic data regarding bone augmentation using Bio-Oss in humans is scarce. The purpose of this study was to analyse the amount of Bio-Oss ossification in a case of maxillary sinus augmentation, recording and comparing histomorphometric data 8 months, 2 and 10 years after surgery. This long-term histologic evaluation of retrieved specimens has been performed, comparing histomorfometric measures at different times. Eight months after surgery we observed in 20 different thin sections of the specimen a mean amount of bone tissue (including medullar spaces) of 29.8% (and 70.2% of Bio-Oss) +/- 2.6. At 2 years the bone tissue increased to 69.7% + 2.7 and 10 years after surgery it was 86.7% +/- 2.8. The comparison of the means for each time has shown a highly significant increasing trend in bone formation associated with Bio-oss resorption: at 8 months, 2 and 10 years.

The purpose of this article is to present a surgical and restorative protocol for the replacement of missing teeth in the esthetic zone. The ABC protocol consists of digitally guided implantation, autogenous bone graft (A), followed by bovine bone xenograft (B) and connective tissue graft (C). Autogenous bone is placed in contact with the implant surface to induce osseointegration; bovine bone xenograft is then applied to augment the ridge dimension and provide long-term stability. Connective tissue is used to provide additional volume. The ABC biomaterial sequence offers favorable hard and soft tissue dimensions and immediate provisional restoration predictably leads to an esthetically pleasing definitive prosthesis.

Objectives: Bone replacement substitutes are almost unavoidable in augmentation procedures such as sinus grafting. The objective of the present study was to evaluate the osteoconductive capability of two different scaffold fillers in inducing newly formed bone in this procedure.

Material and Methods: Sinus floor augmentation and implant placement were carried out bilaterally in 12 patients. Bovine bone mineral (BBM) was grafted on one side and beta-tricalcium phosphate (beta-TCP) on the contralateral side. Both were mixed (1:1 ratio) with autogenous cortical bone chips harvested from the mandible by a scraper. Hard tissue specimen cores were retrieved from the augmented sites (at the previous window area) at 12 months. Decalcified sections were stained with haematoxylin-eosin and the fraction area of new bone and filler particles was measured. In addition to the effect of the filler on new bone formation, the latter was tested to determine whether it correlated with the tissue depth and residual amount of the grafted material.

Results: Bone area fraction increased significantly from peripheral to deeper areas at both grafted sites in all cores: from 26.0% to 37.7% at the beta-TCP sites and from 33.5% to 53.7% at the BBM-grafted sites. At each depth the amount of new bone in BBM sites was significantly greater than that in TCP sites. However, the average area fraction of grafted material particles was similar in both fillers and all depth levels (beta-TCP=27.9-23.2% and BBM=29.2-22.6%, NS). A significant negative correlation was found between bone area fraction and particle area fraction at the middle (p=0.009) and deep (p=0.014) depths in the beta-TCP sites, but not at the BBM sites.

Conclusion: At 12 months post-augmentation, the two examined bone fillers, beta-TCP and BBM, promoted new bone formation in sinus grafting but the amount of newly formed bone was significantly greater in BBM-grafted sites. However, both exhibited similar residual grafted material area fraction at this healing period. This could imply that BBM possesses better osteoconductive properties.

BACKGROUND: Evidence exists on the clinical efficacy and safety of periodontally accelerated osteogenic orthodontics (PAOO) with ""Piezocision""-a minimally invasive, flapless alternative to corticotomy for alveolar bone augmentation. Allograft has been extensively studied for alveolar bone augmentation in Piezocision; however, the use of deproteinized bovine bone mineral with 10% collagen (DBBM-C) in Piezocision for PAOO has not been investigated.

METHODS: This study is a prospective, observational, cohort study of 19 patients of Angle Class I malocclusion with a total of 692 teeth assessed for maintenance of health of the periodontal attachment apparatus. Patient-centered pain, sensitivity, and satisfaction outcomes, digital photographs and radiographs, and changes in probing depth, clinical attachment level, width of keratinized tissue, percussion sensitivity, pulp vitality tests, radiographic pathology, and root-crown-ratio were all recorded.

RESULTS: Overall treatment was significantly faster (5 to 7 days between clear aligner tray changes), periodontal parameters remained stable, and alveolar bone loss was not observed. Visual analog score for healing, sensitivity/duration, bleeding/duration, swelling/duration, appearance, and inflammation, demonstrated no significant differences between DBBM-C and control (no bone graft) groups. Patient-centered outcomes revealed high levels of satisfaction with Piezocision. Piezocision-treated teeth with DBBM-C tended to exhibit less root resorption, although it was not statistically significant (P = 0.074).

CONCLUSIONS: Within the limits of the study, our results show that the use of DBBM-C with piezosurgically enhanced orthodontics is effective and safe. This study was not designed to demonstrate equivalence with other materials that might be used in Piezocision. To understand whether there is an advantage to using DBBM-C, additional studies may be required.

The purpose of this study was to assess the clinical efficacy of the periodontal surgery with porous bone graft material (Bio-Oss®) and collagen membrane (Bio-Gide®). Sixty-seven adult periodontitis patients each having a Class II furcation defect or vertical defects, participated in the study. Mucoperiosteal flaps were elevated and granulation tissue in the defects were debrided with hand instruments. After each defect was filled with

Bio-Oss®, Bio-Gide® was positioned over graft material and the defects. The flaps were replaced coronary to cover the membrane ensuring primary closure. The clinical examinations were taken before surgery at 1, 3 weeks, 3 and 6 months after surgery. Postoperatively, clinical healing generally progressed uneventfully in all patients. The significant differences were found in probing depth and clinical attachment level between pre-surgery and 6 months post-surgery measurements. Mean probing depth was reduced from 6.74±1.17 mm to 3.08±1.17 mm with a mean reduction of 3.67±1.21 mm. Mean clinical attachment level was reduced from 8.39±1.99 mm to 5.60±2.11 mm with a mean clinical attachment gain of 2.79±1.38 mm. The improvement of radioluency at defect area was noted in 48 of 66 patients. The side effect was not observed in any cases. This study revealed that the periodontal surgery with Bio-Oss® and Bio-Gide® is safety and clinical usefulness.

Twenty-one c.p. titanium screw-shaped implants were immediately installed after extraction and thorough curettage of the alveoli in 15 patients. Granules of natural bovine bone of 0.25-1.0 mm diameter were used to fill the remaining defect when the distance of the defect wall to the implant surface was >3 mm. Dimensional measurements of the defect height and width were made with a pocket probe. Fourteen sites in the upper jaw and 7 sites in the lower jaw were thus treated. The mean defect depth varied between 7 mm vestibularly and 10 mm mesially. The mucoperiosteal flaps were hermetically closed. At re-entry, the particles were packed and firmly attached but still distinguishable from the surrounding bone. Of the 21 sites treated, 5 sites had an exposure of the implant cover screw during the healing period. An exposure of the granular material occurred in 4 sites, but loss of granules in only 3. Even in these sites no signs of infection or inflammation of the soft tissues were observed. At re-entry after 6 months, 10 sites were completely and 9 partially filled. For the partial fills, the mean remaining defect height was 1.6 mm (range: 0.6-3.0 mm). Two sites showed an increased defect of respectively 2.4 and 4.8 mm. No fixtures were lost. The present results indicate that natural bovine bone is a safe filling material to fill remaining defects around implants installed in fresh extraction sockets.

OBJECTIVES:
This study evaluated buccal bone crest remodeling, socket composition after healing, and dimensional ridge preservation after flapless tooth extraction procedures with or without a xenograft comparing histomorphometric and microcomputed tomographic (micro-CT) data.

MATERIAL AND METHODS:
The mandibular premolars of eight dogs were extracted without flaps. One socket on each side received a grafting material (test group), and the other remained only with a blood clot (control group). Twelve weeks after treatment, buccal bone crest, alveolar ridge dimensions, and composition were analyzed by histomorphometry and micro-CT.

RESULTS:
Two- and three-dimensional evaluations showed better results for the grafted group when compared to the non-grafted group.

CONCLUSION:
The flapless alveolar ridge preservation procedure with deproteinized bovine bone material enhanced buccal bone crest, alveolar ridge dimensions and bone formation when compared to sockets with the blood clot only, as observed by histomorphometric and micro-CT analysis.

Objective: To test the ability of Bio-Oss in inducing growth factors and proinflammatory cytokines that may have a role in inflammation after grafting, bone resorption, remodeling and in the homeostasis of osteoblasts.

Material and Methods: Normal human osteoblasts were seeded in Petri dishes containing granules of Bio-Oss, cells were harvested after confluency and RNA was extracted. Reverse transcriptase polymerase chain reaction was performed using specific primers for osteonectin, bone sialoprotein (BSP), bone morphogenetic protein (BMP)-2 and BMP-7, platelet-derived growth factor (PDGF), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha) and integrin beta1. Glycerol-3-phosphate dehydrogenase was used as the housekeeping gene and normal human osteoblasts grown on Petri dishes without Bio-Oss granules were used as negative controls.

Results: Osteoblast grown on Bio-Oss showed a normal RNA expression of osteonectin, integrin beta1 and PDGF. However, compared with control osteoblasts it showed a reduced expression of BSP, BMP-2 and BMP-7, IL-6 and TNF-alpha.

Conclusion: Our findings further support the evidence that Bio-Oss is an excellent biomaterial that does not enhance the production of proinflammatory cytokines.

OBJECTIVE:
To assess the added value of using a bone replacement graft in combination with immediate implants in reducing the bone dimensional changes occurring in the residual ridge.

MATERIAL AND METHODS:
Randomized parallel controlled clinical trial to study the efficacy of grafting with demineralized bovine bone mineral with 10% collagen (DBBM-C) in the gap between the implant surface and the inner bone walls when the implants were immediately placed in the anterior maxilla. The changes between implant placement and 16 weeks later in the horizontal and vertical crestal bone changes in relation to the implant were evaluated through direct bone measurements using a periodontal probe. Mean changes were compared between the experimental and control sites using parametric statistics.

RESULTS:
A total of 86 implant sites in 86 subjects were included in the analysis (43 in the test group and 43 in the control group). The horizontal crest dimension underwent marked changes during healing mainly at the buccal aspect of the alveolar crest where this reduction amounted to 1.1 (29%) in the test group and 1.6 mm (38%) in the control group, being these statistically significant (P = 0.02). This outcome was even more pronounced at sites in the anterior maxilla and with thinner buccal bone plates.

CONCLUSIONS:
In conclusion, the results from this clinical trial demonstrated that placing a DBBM-C bone replacement graft significantly reduced the horizontal bone resorptive changes occurring in the buccal bone after the immediate implantation in fresh extraction sockets.

Objectives: This study was designed to evaluate the effect of bone graft materials and collagen membranes in ridge splitting procedures with immediate implant placement using a dog model.

Materials and Methods: Mandibular premolars were extracted in five beagle dogs. After 3 months, ridge splitting and placement of three OsseoSpeed™ implants were performed bilaterally. The gaps between the implants were allocated according to the following eight treatment modalities; Group 1(no graft), Group 2 (autogenous bone), Group 3 (Bio-Oss Collagen®), Group 4 (Bio-Oss®), Group 5 (no graft+BioGide®), Group 6 (autogenous bone+BioGide®), Group 7 (Bio-Oss Collagen®+BioGide®), and Group 8 (Bio-Oss®+BioGide®). The dogs were sacrificed after 8 or 12 weeks and the specimens were analyzed histologically and histometrically.

Results: The gaps between the implants were filled with the newly formed bone, irrespective of which of the eight grafting techniques was used. Group 1 revealed a significantly lower percentage of bone-to-implant contact (BIC) than Group 5 at 8 and 12 weeks (P<0.05). Group 1 showed the most prominent marginal bone loss (MBL) at 12 weeks (P<0.05). Regarding the use of membranes, Groups 1 and 2 showed significantly more MBL than Groups 5 and 6 at 12 weeks (P<0.05).

Conclusion: After ridge splitting, if the gaps between implants were grafted or covered with collagen membranes, a higher percentage of BIC was obtained. Based on our results, we suggest that the use of bone graft materials and/or collagen membranes is better for the prevention of MBL after ridge splitting procedures.

Purpose: To investigate the effects of resorbable membrane on new bone formation in human maxillary sinus graft using anorganic bovine bone material histomorphometrically in a split-mouth study design.

Materials and methods: This prospective pilot study included six patients who required bilateral sinus augmentations prior to implant treatment. Each patient was grafted with anorganic bovine bone (Bio-Oss). The experimental side was covered with resorbable membrane (Bio-Gide) over the grafted sinus, and the control side was left uncovered. After 8 months of healing (range, 7 to 9 months), implants were placed. Biopsy samples were obtained from each side through the previously grafted sinus window and evaluated. Statistical analysis was performed using the Mann-Whitney U test at a significance level of alpha = .05.

Results: The control side appeared to have a significantly greater amount of soft tissue than the experimental side (P = .026), whereas no significant differences in the amount of new bone were observed (P = .937). Conclusion: Resorbable membranes significantly reduced the amount of soft tissue formed in the sinus grafted with anorganic bovine bone material but had no effect on new bone formation.

BACKGROUND: When keratinized tissue width around dental implants is poorly represented, the clinician could resort to autogenous soft tissue grafting. Autogenous soft tissue grafting procedures are usually associated with a certain degree of morbidity. Collagen matrices could be used as an alternative to reduce morbidity and intra-operatory times. The aim of this study was to assess the efficacy of a xenogeneic collagen matrix as a substitute for soft tissue grafting around dental implants.

METHODS: Fifteen consecutive patients underwent a vestibuloplasty and keratinized tissue reconstruction around dental implants, both in the mandible and the maxilla, with a porcine collagen matrix. The so obtained keratinized tissues were measured and evaluated after 6 months and 1, 4, and 5 years.

RESULTS: The average gain of keratinized tissue was 5.7 mm. After 6 months, it was observed a resorption of 37%, after 1 year 48%, and after 5 years 59%. The mean gain of keratinized tissue after 5 years was 2.4 mm. Hemostatic effect and post-operative pain were evaluated too. All subjects referred minimal pain with no bleeding. No adverse reaction nor infection was noted.

CONCLUSIONS: The present study showed the efficacy of a porcine collagen matrix in keratinized tissue augmentation. The possibility to use a soft tissue substitute is a great achievement as morbidity decreases and bigger areas can be treated in a single surgery.

BACKGROUND: When keratinized tissue width around dental implants is poorly represented, the clinician could resort to autogenous soft tissue grafting. Autogenous soft tissue grafting procedures are usually associated with a certain degree of morbidity. Collagen matrices could be used as an alternative to reduce morbidity and intra-operatory times. The aim of this study was to assess the efficacy of a xenogeneic collagen matrix as a substitute for soft tissue grafting around dental implants.

METHODS: Fifteen consecutive patients underwent a vestibuloplasty and keratinized tissue reconstruction around dental implants, both in the mandible and the maxilla, with a porcine collagen matrix. The so obtained keratinized tissues were measured and evaluated after 6 months and 1, 4, and 5 years.

RESULTS: The average gain of keratinized tissue was 5.7 mm. After 6 months, it was observed a resorption of 37%, after 1 year 48%, and after 5 years 59%. The mean gain of keratinized tissue after 5 years was 2.4 mm. Hemostatic effect and post-operative pain were evaluated too. All subjects referred minimal pain with no bleeding. No adverse reaction nor infection was noted.

CONCLUSIONS: The present study showed the efficacy of a porcine collagen matrix in keratinized tissue augmentation. The possibility to use a soft tissue substitute is a great achievement as morbidity decreases and bigger areas can be treated in a single surgery.

Objectives: To identify the most effective interventions for treating peri-implantitis around osseointegrated dental implants. Data sources: The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched and several journals were handsearched with no language restriction up to January 2008.

Review Methods: Randomised controlled trials (RCTs) comparing interventions for treating peri- implantitis were eligible. Screening of studies, quality assessment and data extraction were conducted in duplicate. Missing information was requested. Outcome measures were: implant failure; complications; changes in radiographic marginal bone level, probing ‘attachment' level (PAL), probing pocket depth (PPD), and recession; aesthetics evaluated by patients and dentists; cost and treatment time.

Results: Ten eligible trials were identified, and seven were included (148 patients). They tested: (1) local antibiotics vs ultrasonic debridement; (2) adjunctive local antibiotics to debridement; (3) different techniques of subgingival debridement; (4) laser vs manual debridement and chlorhexidine irrigation/ gel; (5) systemic antibiotics plus resective surgery plus two local antibiotics with and without implant surface smoothening; and (6) nanocrystalline hydroxyapatite vs Bio-Oss and resorbable barriers. Follow up ranged from 3 months to 2 years. After 4 months, adjunctive local antibiotics to manual debridement in patients who lost at least 50% of peri-implant bone showed improved PAL and PPD (0.6 mm). After 6 months, peri-implant infrabony defects > 3 mm treated with Bio-Oss and barriers gained 0.5 mm more PAL and PPD than those treated with hydroxyapatite. In four trials subgingival mechanical debridement seemed to achieve results similar to more complex therapies.

Conclusion: There is very little reliable evidence suggesting which could be the most effective interventions for peri-implantitis. Sample sizes were too small and follow up too short. This is not to say that currently used interventions are ineffective. Larger well-designed RCTs are needed.

Purpose: To test (a) whether and when bone augmentation procedures are necessary and (b) which is the most effective augmentation technique for specific clinical indications. Trials were divided into 3 categories: (1) major vertical or horizontal bone augmentation (or both); (2) implants placed in extraction sockets; (3) fenestrated implants.

Materials and Methods: An exhaustive search was conducted for all randomized controlled clinical trials (RCTs) comparing different techniques and materials for augmenting bone for implant treatment reporting the outcome of implant therapy at least to abutment connection. No language restriction was applied. The last electronic search was conducted on October 1, 2005. Results: Thirteen RCTs of 30 potentially eligible trials reporting the outcome of 332 patients were suitable for inclusion. Six trials evaluated techniques for vertical and/or horizontal bone augmentation. Four trials evaluated techniques of bone grafting for implants placed in extraction sockets, and 3 trials evaluated techniques to treat fenestrated implants.

Conclusion: Major bone grafting procedures of extremely resorbed mandibles may not be justified. Bone substitutes may replace autogenous bone for sinus lift procedures of extremely atrophic sinuses. Both guided bone regeneration procedures and distraction osteogenesis can be used to augment bone vertically, but it is unclear which is the most efficient. It is unclear whether augmentation procedures are needed at immediate single implants placed in fresh extraction sockets; however, sites treated with barrier + Bio-Oss showed a higher position of the gingival margin than sites treated with barriers alone. More bone was regenerated around fenestrated implants with nonresorbable barriers than without barriers; however, it remains unclear whether such bone is of benefit to the patient. Bone morphogenetic proteins may enhance bone formation around implants grafted with Bio-Oss, but there was no reliable evidence supporting the efficacy of other active agents, such as platelet-rich plasma, in conjunction with implants treatment.

The objective of the present experiment was to evaluate the effect on hard tissue modeling and remodeling of the placement of a xenograft in fresh extraction sockets in dogs. Five mongrel dogs were used. Two mandibular premolars (4P4) were hemisected in each dog, and the distal roots were carefully removed. In one socket, a graft consisting of Bio-Oss Collagen (Geistlich) was placed, whereas the contralateral site was left without grafting. After 3 months of healing, the dogs were euthanized and biopsies sampled. From each experimental site, four ground sections (two from the mesial root and two from the healed socket) were prepared, stained, and examined under the microscope. The presence of Bio-Oss Collagen failed to inhibit the processes of modeling and remodeling that took place in the socket walls following tooth extraction. However, it apparently promoted de novo hard tissue formation, particularly in the cortical region of the extraction site. Thus, the dimension of the hard tissue was maintained and the profile of the ridge was better preserved. The placement of a biomaterial in an extraction socket may promote bone modeling and compensate, at least temporarily, for marginal ridge contraction.

OBJECTIVES:
To evaluate the effect of a resorbable collagen membrane and autogenous bone chips combined with deproteinized bovine bone mineral (DBBM) on the healing of buccal dehiscence-type defects.

MATERIAL AND METHODS:
The second incisors and the first premolars were extracted in the maxilla of eight mongrels. Reduced diameter, bone-level implants were placed 5 weeks later. Standardized buccal dehiscence-type defects were created and grafted at implant surgery. According to an allocation algorithm, the graft composition of each of the four maxillary sites was DBBM + membrane (group D + M), autogenous bone chips + DBBM + membrane (group A + D + M), DBBM alone (group D) or autogenous bone chips + DBBM (group A + D). Four animals were sacrificed after 3 weeks of healing and four animals after 12 weeks. Histological and histomorphometric analyses were performed on oro-facial sections.

RESULTS:
The pattern of bone formation and resorption within the grafted area showed high variability among the same group and healing time. The histomorphometric analysis of the 3-week specimens showed a positive effect of autogenous bone chips on both implant osseointegration and bone formation into the grafted region (P < 0.05). The presence of the collagen membrane correlated with greater bone formation around the DBBM particles and greater bone formation in the grafted region after 12 weeks of healing (P < 0.05). The oro-facial width of the augmented region at the level of the implant shoulder was significantly reduced in cases where damage of the protection splints occurred in the first week of healing (P < 0.05).

CONCLUSIONS:
The addition of autogenous bone chips and the presence of the collagen membrane increased bone formation around DBBM particles. Wound protection from mechanical noxa during early healing may be critical for bone formation within the grafted area.

OBJECTIVES: The aim of this preclinical study was to analyze and compare different grafting techniques with respect to volume stability after wound closure.

MATERIALS AND METHODS: Four different grafting techniques were evaluated in vitro for volume stability in a one-wall horizontal defect configuration. Group 1: guided bone regeneration (GBR) with collagen membrane, particulated xenograft; group 2: GBR with collagen membrane, particulated xenograft, pins; group 3: GBR with titanium-reinforced membrane, particulated xenograft, pins; group 4: autogenous block graft, particulated xenograft, collagen membrane. Cone beam computed tomography scans were performed before and after wound closure, and the horizontal bone dimensions were analyzed for stability at 0-5 mm apical to the implant shoulder (H0-H5).

RESULTS: At H0-H2, wound closure induced a statistically significant change in bone dimensions in groups 1 and 2. In group 3, only the change in H0 was significant, and for group 4, only H2 was significant.

CONCLUSION: Wound closure has a significant impact on graft stability in a one-wall horizontal defect configuration. GBR with additional membrane fixation showed better results than without. Titanium-reinforced membranes and autogenous blocks showed significantly greater volume stability than GBR with collagen membrane, especially in the coronal portion.

Bone grafts and bone substitute biomaterial implemented in guided tissue regeneration should undergo the process of biological decomposition in the recipient's system. The aim of this work is the presentation of current views concerning the issue of Bio-Oss bovine bone bioresorption and their juxtaposition with the results of the author's own research. The work presents histopathological and immunohistochemical tests of the xenogeneic Bio-Oss preparation from biopsies carried out 30 months after implantation. It was observed that the preparations contained correct bone neighbouring remnant particles of Bio-Oss, intratrabecular fibromatosis around the implant, abundant vascularisation, absence of osteoid and of active inflammatory process. A small number of T and B-lymphocytes was detected. The results obtained in the above-described case testify to the descending character of the inflammatory infiltration 30 months after the implementation of Bio-Oss and efficient restoration of the bone. The prevalent view in literature is that Bio-Oss is resorbable biomaterial. However, there are also reports questioning this view, as remnants of Bio-Oss have been detected even 44 months after implantation into the bone defect. In the author's own cases, Bio-Oss remnants could be observed 30 months after implanting. It seems that although the creation of new bone structure is indisputable, the process of biological decomposition of Bio-Oss should be described as slow bioresorption.

The objective of this study was to investigate the morphology and organization of apatite crystallites in mature mammalian bone. Anorganic bovine bone was studied in this investigation to allow for the examination of the mineral crystallites after removal of the organic phase. Field-emission low-voltage scanning electron microscopy (FE-LVSEM) was employed to obtain images at nanometer resolution without the application of a conductive coating. Transmission electron microscopy (TEM) of the samples was also performed to confirm the identification of features observed in the SEM and to allow for comparison with earlier studies of bone mineral architecture. For comparison, in order to demonstrate how the interaction of collagen and apatite results in the architecture and crystal structure of bone mineral, two synthetic hydroxyapatite materials were also analyzed: OsteoGen and OsteoGraf/LD300. FE-LVSEM revealed distinctive features of bone mineral: a fibrillar organization of crystallites, a periodic spacing of crystallites along the fibrils consistent with the banding pattern of collagen, inter-fibrillar bridging crystallites, and a plate-like habit of the crystallites. These findings supported the hypothesis, derived from the earlier TEM data of others, that the mineralization of collagen comprising osteoid proceeds by the formation of apatite crystallites within the fibers at selected periodic sites along their length. Moreover, the very presence in this anorganic material of distinct fibers comprised of the crystallites is demonstration of inter-crystallite bonding. The crystallites of the synthetic hydroxyapatite materials did not display any of these ultrastructural features.

BACKGROUND:

ABSTRACT:

This prospective split-mouth pilot case series compared the use of a bilayer collagen matrix (CM) to an autogenous gingival graft (AGG) in the ability to increase the zone of keratinized attached gingiva. Five patients with inadequate amounts of keratinized attached gingiva bilaterally in the posterior mandible were enrolled using a split-mouth design. There were statistically significant increases in attached gingiva at all test (CM) and control (AGG) sites. The CM sites at 12 months blended well with surrounding tissues, while the AGG sites were morphologically dissimilar to the adjacent areas. Biopsy results showed intra-patient histologic similarity between CM and AGG treatments, with all sites exhibiting mature connective tissue covered by keratinized epithelium. Thus, the obtained data support further investigations in evaluating the role of CM as a viable alternative to AGG in augmenting areas deficient in keratinized gingiva.

OBJECTIVES:
The aim of this study was to analyze linear and volumetric hard tissue changes in severely resorbed alveolar sockets after ridge augmentation procedure and to compare them with spontaneous healing using three-dimensional cone beam computed tomography (CBCT).

MATERIAL AND METHODS:
Thirty patients (mean age 53.2 ± 6.3 years) requiring tooth extraction for advanced periodontitis were randomly allocated to test and control groups. The test sites were grafted using a collagenated bovine-derived bone (DBBM-C) covered with a collagen membrane, while control sites had spontaneous healing. Both groups healed by secondary intention. Linear and volumetric measurements were taken on superimposed CBCT images obtained after tooth extraction and 12 months later.

RESULTS:
Greater horizontal shrinkage, localized mainly in the crestal zone, was observed in the control group (4.92 ± 2.45 mm) compared to the test group (2.60 ± 1.24 mm). While both groups presented a rebuilding of the buccal wall, it was most pronounced in the grafted sockets (2.50 ± 2.12 mm vs. 0.51 ± 1.02 mm). A significant difference was also registered in the percentage of volume loss between grafted and non-grafted sites (9.14% vs. 35.16%, p-value <.0001).

CONCLUSION:
Alveolar sockets with extensive buccal bone deficiencies undergo significant three-dimensional volumetric alterations following natural healing. The immediate application of a slow-resorbing xenograft with a covering collagen membrane seems to be effective in improving alveolar ridge shape and dimensions, thus potentially reducing the need for adjunctive regenerative procedures at the time of implant placement.

In this study was investigated the growth and extracellular matrix synthesis of human osteoblast-like cells on highly porous natural bone mineral. Human bone cells were isolated from trabecular bone during routine iliac cresh biopsies. Under conventional culture conditions, trabecular bone cells were able to assume the organization of a three-dimensional structure on a porous natural bone mineral (Bio-Oss^® Block). Scanning electron microscopy examination after 6 weeks revealed multiple cell layers on the trabecular block. Transmission electron microscopy examination after 6 weeks revealed the accumulation of mature collagen fibrils in the intracellular and extracellular spaces, and showed multilayered, rough endoplasmic reticulum as well as mitochondria-rich cells surrounded by dense extracellular matrix. These morphological observations suggest that the cell layer may resemble the natural three-dimensional structure. Biochemical analysis revealed that the hydroxylysylpyridinoline, lysylpyridinoline, and hydroxyproline content of the cell layer increased in a time-dependent manner, whereas in monolayer culture without natural bone mineral, no measurable amounts of hydroxylysylpyridinoline or lysylpyridinoline, and a barely measurable amount of hydrosyproline, were noted. Mature collagen extracted by ethylenediaminetetraacelic acid-demineralization from the cell layer on natural bone mineral showed an identical electrophoretic pattern to that observed in human bone, as evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The present study demonstrated an excellent biocompatibility of the highly porous natural bone mineral in a three-dimensional bone cell culture system, and thus its potential for tissue-engineered growth of human bone.

This study utilized three-dimensional micro-computed tomography (micro-CT) to evaluate the regenerative response to Bio-Oss Collagen when used alone or in combination with a Bio-Gide bilayer collagen membrane for the treatment of four intrabony defects (5 to 7 mm) around single-rooted teeth. The micro-CT observations are compared to the clinical, radiographic, and histologic results, which have been previously reported. After reflecting a full-thickness flap, thorough degranulation and root planing were accomplished. Bio-Oss Collagen was then used to fill the defects, and in two cases a Bio-Gide membrane was placed over the filled defect. Radiographs, clinical probing depths, and attachment levels were obtained before treatment and immediately preceding en bloc resection of teeth and surrounding tissues 9 months later. A mean pocket depth reduction of 5.75 mm and mean clinical attachment level gain of 5.25 mm were recorded. The histologic evaluation demonstrated the formation of a complete new attachment apparatus with new cementum, periodontal ligament, and alveolar bone at the level of and coronal to the calculus reference notch. Micro-CT evaluation confirmed the histologic results and demonstrated the absence of ankylosis or root resorption for all specimens. This human histologic study demonstrated that Bio-Oss Collagen has the capacity to facilitate regeneration of the periodontal attachment apparatus when placed in intrabony defects. Micro-CT observations confirmed the histologic results and enhanced the three-dimensional understanding of periodontal wound healing. The results indicate that micro-CT may be useful for three-dimensional evaluation of periodontal regenerative procedures.

PURPOSE:
The primary aim of the study was to describe a novel technique to evaluate volumetric hard tissue dimensional changes after ridge augmentation procedures. The secondary aim was to apply this newly developed measuring method to compromised alveolar sockets grafted with a slowly resorbing biomaterial covered with a collagen membrane.

MATERIALS AND METHODS:
Eleven patients (6 men and 5 women, mean age 52.7 ± 8.3 years) requiring extraction of one hopeless tooth for severe periodontitis in the maxillary anterior area were consecutively treated with a ridge augmentation procedure. All experimental sockets showed advanced buccal bone plate deficiency and were grafted with deproteinized bovine bone mineral with 10% collagen covered with a collagen membrane. Sockets healed by secondary intention. Three-dimensional volumetric alveolar bone changes were calculated by superimposing cone beam computed tomography scans obtained before and 12 months after the augmentation procedure.

RESULTS:
After 12 months, the alveolar mineralized tissue filled 91.20% ± 7.96% of the maximum volume for regeneration. The augmentation procedure appeared not only to compensate for bone remodeling in most alveolar regions but also to repair a significant portion of the buccal wall. The most significant ridge width changes occurred 1 mm apical to the bone crest (2.33 ± 1.46 mm, P < .001).

CONCLUSION:
Within present limitations, this radiographic measuring methodology can be a useful tool to evaluate changes in socket volume. A ridge preservation technique performed with collagenated bovine bone and a collagen membrane was able to improve ridge shape and dimensions in compromised alveolar sockets.

INTRODUCTION:
The aim of this study was to evaluate retrospectively the 3-year outcome of implants placed in augmented maxillary sinuses with minimal residual alveolar bone heights (≤3 mm).

MATERIALS AND METHOD:
A total of 28 sinus floors were augmented with xenograft, and 58 implants were placed. The outcome measures were implant success based on implant stability and the absence of periimplantitis, and marginal and apical bone resorption on periapical radiograph and prosthesis survival.

RESULTS:
Fifty-seven of 58 implants with their prostheses remained functional with a success rate of 98.28%. None of the implants showed any signs of mobility or periimplantitis. Both apical and cervical bone resorption around the implants were highest by the end of the first year.

CONCLUSIONS:
The success rate of the implants placed with staged approach in augmented maxillary sinuses with the residual alveolar bone height of ≤3 mm was high in a 3-year term. Bio-Oss is an acceptable substitute autogenous bone and can be used as an augmentation material during the maxillary sinus lift procedure.

Objectives: The aim of this study is to evaluate whether tooth extraction without the elevation of a muco-periosteal flap has advantageous effects on the resorption rate after tooth extraction.

Material and Methods: In five beagle dogs polyether impressions were taken before the surgery. The roots of the first and second pre-molars (P(1) and P(2)) were extracted and the sites were assigned to one of the following treatments: treatment group (Tx) 1, no treatment; Tx 2, surgical trauma (flap elevation and repositioning); Tx 3, the extraction socket was filled with BioOss Collagen and closed with a free soft-tissue graft; Tx 4, after flap elevation and repositioning, the extraction socket was treated with BioOss Collagen and a free soft-tissue graft. Impressions were taken 2 and 4 months after surgery. The casts were scanned, matched together with baseline casts and evaluated with digital image analysis.

Results: The "flapless groups" demonstrated significant lower resorption rates both when using socket-preservation techniques and without. Furthermore, socket-preservation techniques yielded better results compared with not treating the socket.

Conclusion: The results demonstrate that leaving the periosteum in place decreases the resorption rate of the extraction socket. Furthermore, the treatment of the extraction socket with BioOss Collagen and a free gingival graft seems beneficial in limiting the resorption process after tooth extraction.

Reducing the need for a connective tissue graft by using an efficacious biomaterial is an important task for dental professionals and patients. This experimental study aimed to test the soft tissue response to a volume-stable new collagen matrix. The device demonstrated good stability during six different time points ranging from 0 to 90 days of healing with no alteration of the wound-healing processes. The 90-day histologic specimen demonstrates eventual replacement of most of the matrix with new connective tissue fibers.

OBJECTIVES:
To test whether or not tissue integration, biodegradation, and new blood vessel formation in two collagen-based matrices depend on the level of chemical cross-linking.

MATERIAL AND METHODS:
Two collagen matrices with high (CM1) and low (CM2) levels of chemical cross-linking were randomly implanted in two pouches in 14 athymic nude mice. Three and 6 weeks later, the animals were euthanized. Histologic and histomorphometric measurements were performed on paraffin-embedded sections.

RESULTS:
Both collagen matrices integrated well into the surrounding soft tissues. The level of cross-linking and duration of implantation had an effect on the formation of new blood vessels. More blood vessels (n = in absolute numbers) were found in outer compartments compared to the central compartments of the matrices, reaching 5.6 (CM2) vs. 4.3 (CM1) at 3 weeks, and 5.3 (CM2) vs. 7.3 (CM1) at 6 weeks. Similarly, connective tissue formation increased for both matrices between 3 and 6 weeks, whereas the amount of remaining collagen network gradually decreased over time being more pronounced for CM1 (-50%) compared to CM2 (-15%).

CONCLUSIONS:
The degree of cross-linking was negatively correlated for all outcome measures resulting in improved tissue integration, superior matrix stability and enhanced angiogenic patterns for the less cross-linked collagen matrix (CM2) in this experimental study in mice.

The aim of the present study was qualitatively and quantitatively to compare the tissue reaction around four different bone substitutes used in orthopedic and craniofacial surgery. Cylinders of two bovine bone substitutes (Endobon^® and Bio-Oss^®) and two coral derived bone substitutes (Pro Osteon 500^® and Interpore 500 HA/CC^®) were implanted into 5 mm burr holes in rabbit tibia. Interpore 500 HA/CC^® resorbed completely, whereas the other three biomaterials did not undergo any detectable biodegradation. Pro Osteon 500^® and Endobon^® showed no signs of resorption Bio-Oss^® was osseointegrated to a high degree and became included in the natural remodeling process of bone.

Background: The purpose of this study was to evaluate the effect of a bioabsorbable collagen barrier (CB) in combination with a composite bone substitute (deproteinized bovine bone mineral with collagen, DBBM + C) in periodontal regeneration of angular bone defects in humans using a new application technique.

Methods: Twelve patients participated, each contributing at least 1 defect site, which exhibited a probing depth (PD) of > or = 5 mm, a clinical attachment level (CAL) of > or = 6 mm, and was positive for bleeding on probing (BOP) following initial therapy. Twenty-two angular bone defects were filled with DBBM + C. A hole was placed in the membrane, which was then pulled over the tooth. The observation period was 2 years and included measurements of plaque, gingivitis, tooth mobility, PD, CAL, soft tissue recession, and bone level as assessed from standardized radiographs.

Results: The residual PD and CAL were reduced to 3.3 mm (PD) and 5.6 mm (CAL) with a CAL gain of 3.2 mm at 24 months. The radiographic defect reduction (bone fill) was 4.0 mm after surgery and 2.2 mm at 24 months. The changes measured clinically and radiographically were more pronounced in sites with a deep intrabony defect component than in sites with shallow ones.

Conclusion: These findings indicate that angular bone defects can be successfully treated with DBBM + C in combination with CB. A degradation of the filler material seems to occur particularly during the first 6 months, but without affecting the clinical parameters, which improved consistently

Background: Predictable regeneration of lost periodontal tissues in furcations is difficult to achieve. This paper investigates the efficacy of different treatment modalities for Class II molar furcations.

Methods: Publications in English were searched using PubMed, Medline, and Cochrane Library databases combined with hand searching from January 1, 1966 to October 1, 2007. The search included randomized controlled human trials in molar Class II furcations with over 6 months of surgical reentry follow-up. Changes in vertical probing depths, vertical attachment levels, and vertical and horizontal bone levels were compared. Results: The search identified 801 articles of which 34 of 108 randomized clinical trials met the criteria. Thirteen trials had test and control arms allowing three meta-analyses: 1) five comparing non-resorbable versus resorbable membranes, 2) five comparing non-resorbable membranes versus open flap debridement and 3) three comparing resorbable membranes versus open flap debridement. There was significant improvement for resorbable versus non-resorbable membranes mainly in vertical bone fill (0.77 ± 0.33 mm; [95% CI; 0.13, 1.41]). Non-resorbable membranes showed significant improvement in vertical probing reduction (0.75 ± 0.31 mm; [95% CI; 0.14, 1.35]), attachment gain (1.41 ± 0.46 mm; [95% CI; 0.50, 2.31]), horizontal bone fill (1.16 ± 0.29 mm; [95% CI; 0.59, 1.73]), and vertical bone fill (0.58 ± 0.11 mm; [95% CI; 0.35, 0.80]) over open flap debridement. Resorbable membranes showed significant improvement in vertical probing reduction (0.73 ± 0.16 mm; [95% CI; 0.42, 1.05]), attachment gain (0.88 ± 0.16 mm; [95% CI; 0.55, 1.20]), horizontal bone fill (0.98 ± 0.12 mm; [95% CI; 0.74, 1.21]) and vertical bone fill (0.78 ± 0.19 mm; [95% CI; 0.42, 1.15]) over open flap debridement.

Conclusion: Guided tissue regeneration with the use of resorbable membranes was superior to non-resorbable membranes in vertical bone fill. Both types of membranes were more effective than open flap debridement in reducing vertical probing depths and gaining vertical attachment levels and in gaining vertical and horizontal bone.

BACKGROUND:

Connective tissue graft (CTG) plus coronally advanced flap (CAF) is the reference therapy for root coverage. The aim of the present study is to evaluate the use of a porcine collagen matrix (PCM) plus CAF as an alternative to CTG+CAF for the treatment of gingival recessions (REC), in a prospective randomized, controlled clinical trial.

METHODS:

Eighteen adult patients participated in this study. The patients presented 22 single Miller's class I or II gingival recessions, randomly assigned to the test (PCM+CAF) or control (CTG+CAF) group. Recession depth (REC), pocket depth, clinical attachment level (CAL) and width of keratinized tissue (KG) were evaluated at 12 months. In addition, the gingival thickness (GT) was measured 1 mm apical to the bottom of the sulcus.

RESULTS:

At 12 months, mean REC was 0.23 mm for test sites and 0.09 mm for control sites (P <0.01), whereas percentage of root coverage was 94.32% and 96.97%, respectively. CAL gain was 2.41 mm in test sites and 2.95 mm in control sites (P <0.01). KG gain was 1.23 mm in the test group and 1.27 mm in the control group (P <0.01). In test sites, GT changed from 0.82 to 1.82 mm, and in control sites, from 0.86 to 2.09 mm (P <0.01).

CONCLUSION:

Within the limits of the study, both treatment procedures resulted in significant reduction in REC at 12 months. No statistically significant differences were found between PCM+CAF and CTG+CAF with regard to any clinical parameter. The collagen matrix represents a possible alternative to CTG.

OBJECTIVE: The aim of this study was to compare the clinical and radiographic efficacy of guided tissue regeneration with a modified perforated collagen membrane (MPM) or standard collagen membrane (CM) in the treatment of intrabony defects in patients with aggressive periodontitis (AgP).

MATERIALS AND METHODS: Fifteen AgP patients were included in the study. Two single intrabony defects of at least 3 mm depth with ≥ 6 mm probing pocket depth (PPD) from each patient were randomly assigned to either xenogenic graft plus MPM (test group) or xenogenic graft plus CM (control group). PPD, clinical attachment level (CAL), and gingival recession (GR) were recorded at baseline and at 12 months. The radiographic assessments included the measurements of defect depth (DD), change in alveolar crest position (ACP), linear defect fill (LDF), and percentage defect fill (%DF).

RESULTS: After treatment, PPD, CAL, DD, and ACP values improved significantly in both groups, without statistical differences between them. However, with respect to LDF and %DF, the 12-month radiographic analysis at MPM-treated sites showed a significant improvement compared to the 6-month outcomes, that was not observed at control sites (additional LDF of 0.4 ± 0.5 mm, p = 0.010 and %DF of 6.4 ± 7.6%, p = 0.025).

CONCLUSIONS: Both strategies proved effective in the treatment of intrabony defects in patients with AgP. Nonetheless, enhanced LDF and %DF 12 months postoperatively at MPM-treated sites may stem from cellular and molecular migration from the periosteum and overlying gingival connective tissue through barrier's pores. CLINICAL

RELEVANCE: Modification of CM may have positive ramifications on periodontal regeneration.

In this clinical study, a 1:1 mix of particulate cancellous bone and marrow (PCBM) and bovine deproteinized bone (Bio-Oss) was used to fill cavities after elevating the sinus mucosa for major sinus dehiscences. Ten patients with edentulous posterior maxillae were treated with 12 sinus augmentation procedures according to a 2-stage technique, and 30 Frialit-2 endosseous implants were used to complete the implant-prosthetic rehabilitation. Bone cylinders were removed at second-stage surgery immediately prior to implant placement (5 to 7 months after grafting), and histologic evaluation was performed. The results showed that Bio-Oss is a reliable osteoconductive material and its association with PCBM leads to the formation of new bone with an increased overall density. 

This case series evaluated the use of a collagen matrix with a coronally advanced flap procedure for the treatment of multiple recession defects. Fifteen patients with a total of 80 recession defects were included. Root coverage was 85% ± 13% at 6 months and 81% ± 22% at 12 months. Complete root coverage was achieved in 60% of the sites after 6 months and in 56% after 12 months. The percentage of sites with thick gingival morphotype increased significantly. The results indicated that the collagen matrix may be a useful alternative to the connective tissue graft in the treatment of multiple recession defects.

Bio-Oss® is natural bovine bone mineral, which has the property of bone conduction. It is recommended to be used in two- or three-walled bony defects with an ample supply of pleuripotential cells. Two cases are reported. The first was an intentional replantation, because of previous trauma, of a hopeless tooth affected with severe periodontitis. The tooth was replanted after complete elimination of granulation tissue. Bio-Oss®, together with a guided tissue regeneration (GTR) membrane, was used to enhance periodontal regeneration. After 2 years of follow-up, the replanted tooth was quite stable. In the second case, Bio-Oss®, together with bone taken from the retromolar area, was used in a sinus lift grafting procedure after the removal of two supernumerary teeth from the floor of the maxillary sinus. Four months after grafting, an orthodontic treatment was applied to move the two adjacent teeth through the grafted site and align them in the proper position. The clinical results of the two cases were satisfactory.

BACKGROUND:
The presence of keratinized tissue around dental implants is more than desirable either from a functional and aesthetic point of view, making soft tissue grafting a common practice in implant rehabilitation. Autogenous soft tissue grafting procedures are usually associated with high morbidity. Aim of this study was to assess the efficacy of a xenogeneic collagen matrix as a substitute for soft tissue grafting around dental implants.

METHODS:
15 consecutive patients underwent a vestibuloplasty and grafting, both in the mandible and the maxilla, with a collagen matrix.

RESULTS:
The primary endpoint was to evaluate the resorption of the graft along with the re-epithelization grafted area. The percentage of the resorption was 44,4%, with a mean gain in vestibular height of 3 mm. Secondary endpoints evaluated the clinical appearance, the hemostatic effect and the post-operative pain. All subjects referred minimal pain with no bleeding. No adverse reaction nor infection were noted.

CONCLUSION:
This study showed that the used collagen matrix can find major interest in those patients who need a greater aesthetic outcome as the matrix has a perfect integration with the surrounding tissues. Furthermore it is strongly recommended for those patients who can bear little pain.

CLINICAL SIGNIFICANCE:
Post-operative morbidity of autologous grafts is the biggest concern of this type of surgery. The possibility to use a soft tissue substitute is a great achievement as morbidity decreases and bigger areas can be treated in a single surgery. The present study showed the efficacy of a collagen matrix as this kind of substitute.

Purpose: The aim of this randomised controlled double-blinded clinical trial was to determine the efficacy of a new cross-linked membrane (VN) in guided bone regeneration (GBR) around exposed dental implants compared to a native collagen membrane (BG).

Material and Methods: A total of 16 patients in need of implant treatment at two different sites with osseous defects were planned for this split-mouth study. After inserting the dental implants, periimplant defects were treated according to the GBR technique using a VN membrane with prolonged resorption time in the randomised test site and a BG membrane in the control site. After a healing time of 6 months, mucoperiosteal flaps were elevated for the evaluation of the primary (vertical bone fill [ΔDL] and quality of newly formed tissue [QT]) and secondary outcome variables (infrabony defect height [DH], defect width [DW], defect depth [DD] and augmentation depth [AD]) and the sampling of biopsies apical to the implant shoulder.

Results: A total of 16 patients fulfilled the initial non-surgical inclusion and exclusion criteria. However, the study was discontinued early after 9 surgically treated patients because unacceptable safety issues arose and severe infection related to the VN membranes. The VN membrane revealed statistically significantly more soft tissue dehiscence than the BG membrane (56% and 11%, respectively, P = 0.0455). In 3 of these 9 patients the VN membrane had to be removed due to infection early after the first follow-up visit. For the statistical analyses these sites were designated as the value of the baseline. The mean ΔDL values were 1.8 ± 1.6 mm at the VN site and 4.7 ± 3.3 mm at the BG site. The ΔDD values were 0.6 ± 1.0 mm and 1.1 ± 1.2 mm, respectively, and reached statistical significance (P = 0.0208, CI 95% = -2.9 [-5.2;-0.6]). The corresponding linear defect fill (DF) values were 44% and 78%, respectively. The clinical assessment of QT showed comparable median values at sites treated with VN (3, interquartile range: 0; 3.5) and BG (3, interquartile range: 3; 4) without statistical significance. The histomorphometric analysis showed an average area density of 24.4% (SD 10.3, range 8-35%) newly formed bone at the test sites and of 35.0% (SD 20.6, range 8-60%) at the control sites. The histological data showed only some trends and did not reach statistical significance.

Conclusion: In the present study, the VN membranes with prolonged resorption time demonstrated significantly more adverse events and insufficient bone regeneration compared to the native BG membranes and no advantages in favour of the VN membranes were detectable.

PURPOSE: To assess whether the use of a non-crosslinked porcine collagen type I and III bi-layered membrane inter-positioned between the periosteum and a bone defect would interfere with the bone regenerative capacity of the periosteum.

MATERIALS AND METHODS: Sixty rats, each with 1 critical-size calvarial defect (CSD; diameter, 5 mm) in the parietal bone, were randomly allocated to 1 of 3 equal-size groups after CSD creation: 1) the periosteum was excised and the flap was repositioned without interposition of a membrane (no-periosteum [NP] group); 2) the flap including the periosteum was repositioned (periosteum [P] group); and 3) a non-crosslinked collagen membrane was inter-positioned between the flap, including the periosteum, and the bone defect (membrane [M] group). Micro-computed tomography, qualitative histology, immunohistochemistry, and reverse transcription real-time quantitative polymerase chain reaction were performed at 3, 7, 15, and 30 days postoperatively.

RESULTS: A markedly increased radiographic residual defect length was observed in the NP group compared with the P group at 30 days. The NP group also presented a smaller radiographic bone fill area than the P group at 15 and 30 days and then the M group at 30 days. The P and M groups exhibited considerably greater expression of bone morphogenetic protein-2 and osteocalcin than the NP group at 7 days; expression of transforming growth factor-β1 was considerably greater in the NP group at 15 days. Further, the P group presented considerably higher gene expression levels of Runx2 and Jagged1 at 7 days and of alkaline phosphatase at 3 and 15 days compared with the M and NP groups.

CONCLUSION: Interposition of this specific non-crosslinked collagen membrane between the periosteum and the bone defect during guided bone regeneration interferes only slightly, if at all, with the bone regenerative capacity of the periosteum.

PURPOSE:

Soft tissue grafting is often required to correct intraoral mucosal deficiencies. Autogenous grafts have disadvantages including an additional harvest site with its associated pain and morbidity and, sometimes, poor quality and limited amount of the graft. Porcine collagen matrices have the potential to be helpful for grafting of soft tissue defects.

PATIENTS AND METHODS:

Thirty consecutive patients underwent intraoral grafting to re-create missing soft tissue. Defects ranged in size from 50 to 900 mm(2). Porcine collagen matrices were used to reconstruct missing tissue. Indications included preprosthetic (22), followed by tumor removal (5), trauma (2), and release of cheek ankylosis (1).

RESULTS:

The primary efficacy parameters evaluated were the degree of lateral and/or alveolar extension and the evaluation of reepithelialization and shrinkage of the grafted area. Overall, the percentage of shrinkage of the graft was 14% (range, 5%-20%). The amount of soft tissue extension averaged 3.4 mm (range, 2-10 mm). The secondary efficacy parameters included hemostatic effect, pain evaluation, pain and discomfort, and clinical evaluation of the grafted site. All patients reported minimal pain and swelling associated with the grafted area. No infections were noted.

CONCLUSION:

This porcine collagen matrix provides a biocompatible surgical material as an alternative to an autogenous transplant, thus obviating the need to harvest soft tissue autogenous grafts from other areas of the oral cavity.

Purpose: The objective of the present study was to clinically and histologically evaluate the effectiveness of deproteinized bovine bone as the augmentation material in vertical ridge augmentation of the inserted implants.

Materials and Methods: This retrospective study was performed on 10 vertically augmented ridges in which 24 dental implants were inserted. Deproteinized bovine bone (Bio-Oss) was used as the only augmentation material and was covered with a titanium-reinforced expanded polytetrafluoroethylene (e- PTFE) membrane (Gore-Tex). For 3 augmented areas, bone samples were retrieved for histologic and histomorphometric examination.

Results: Clinical evaluations showed bone defects around the implants of 2 to 9 mm (average -5.1 mm; SD = 2.1). Bone height gain at 6 to 8 months after augmentation was 3 to 9 mm (average 5.3 mm; SD = 1.7). Differences between pre- and postaugmentation were statistically significant, for a mean value of > 4 mm (P < .005). The obtained bone biopsy specimens showed significant new bone formation and remodeling of the deproteinized bovine bone material. The radiographic data and the clinical stability showed that all implants were successfully osseointegrated. The radiographic and clinical follow-up indicated that the generated bone crest levels were stable.

Conclusion: This clinical study suggests that vertical ridge augmentation with an e-PTFE membrane and deproteinized bovine bone is predictable and can lead to long-term success.

Objective: To evaluate, from a histological and histomorphometrical perspective, the efficacy of a 1:1
mixture of deproteinized bovine bone mineral (DBBM) and autogenous bone graft associated with an expanded-polytetrafluoroethylene (e-PTFE) membrane for vertical ridge augmentation in the human.

Material and Methods: Seven patients with 10 surgical sites requiring vertical ridge augmentation of partially edentulous lower jaws were included in the study. The vertical augmentation procedure was performed combining a titanium-reinforced e-PTFE Gore-Tex membrane with a composite graft consisting of a 1:1 ratio of DBBM (Bio-Oss) and autogenous bone. Twenty-seven Branemark implants have been inserted. Eleven biopsies from the regenerated area were analyzed histologically and histomorphometrically.

Results: The healing period was uneventful in nine surgical sites. In one site the membrane showed an exposure after 3 months. At the abutment connection, all implants appeared stable and submerged by a hard regenerated tissue clinically similar to bone. The histological analysis showed new bone formation and ongoing remodelling of the autogenous bone and the DBBM particles.

Conclusion: The findings from the present clinical and histological study support the use of a 1:1 combination of DBBM and autogenous bone chips for vertical ridge augmentation by means of guided bone regeneration techniques. The regenerated bone may lead to proper osseointegration of a dental implant inserted at the time of the regenerative procedure or after a healing period of at least 6 months. DBBM undergoes very slow resorption and substitution with new bone. Furthermore, long-term clinical studies are needed to confirm the positive effect of DBBM in enhancing the lasting stability of the vertically augmented bone.

Abstract Objectives: To compare two different techniques for vertical bone augmentation of the posterior mandible: bone blocs from the iliac crest vs. anorganic bovine bone blocs used as inlays.

Materials and Methods: Ten partially edentulous patients having 5-7 mm of residual crestal height above the mandibular canal had their posterior mandibles randomly allocated to both interventions. After 4 months implants were inserted, and after 4 months, provisional prostheses were placed. Definitive prostheses were delivered after 4 months. Histomorphometry of samples trephined at implant placement, prosthesis and implant failures, any complication after loading and peri-implant marginal bone-level changes were assessed by masked assessors. All patients were followed up to 1 year after loading.

Results: Four months after bone augmentation, there was statistically significant more residual graft (between 10% and 13%) in the Bio-Oss group. There were no statistically significant differences in failures and complications. Two implants could not be placed in one patient augmented with autogenous bone because the graft failed whereas one implant and its prosthesis of the Bio-Oss group failed after loading. After implant loading only one complication (peri-implantitis) occurred at one implant of the autogenous bone group. In 16 months (from implant placement to 1 year after loading), both groups lost statistically significant amounts of peri-implant marginal bone: 0.82 mm in the autogenous bone group and 0.59 mm in the Bio-Oss group; however, there were no statistically significant differences between the groups.

Conclusion: Both procedures achieved good results, but the use of bovine blocs was less invasive and may be preferable than harvesting bone from the iliac crest.

Purpose: The aim of this study was to evaluate the capability of a configured titanium mesh (CTM) to serve as a mechanical and biologic device for restoring a vertically defected/resorbed alveolar ridge.

Materials and Methods: The study comprised 10 severely resorbed sites in 10 patients. Pre- and post- operative ridge measurements were taken with reference to the neighboring teeth and supporting screw head base of the CTM. Bio-Oss® served as the augmentation filler material. The metal mesh was removed after 9 months. Subsequently, root-form, screw-type implants were placed. During the implant placement phase, cylindric bone samples were retrieved from the augmented area for histopathologic and histochemical examination.

Results: Upon soft tissue reflection and before augmentation, defect height, as recorded by a periodontal probe along the main threads exposed on the support screw, was between 5 and 8 mm (average 6.4 mm; SD +/- 1.17). At 9 months after augmentation, during the implant placement phase, the defect height was between 0 and 2 mm (average 1.2 mm; SD +/- 0.63). Differences were statistically significant (P < .001). Bone height gain was between 4 and 6 mm (average 5.2 mm, SD +/- 0.79), which gave an average bone fill of 81.2% (SD +/- 7.98). Polarizing microscopic examination of sections stained with Picrosirius red showed a gradual increase in new lamellar bone from coronal to apical cuts, reaching the highest area percentage in the deep apical zone.

Discussion: At 9 months postaugmentation using the CTM surgical technique, the quality and quantity of the newly established hard tissue appeared to be different in the coronal versus apical areas of the restored alveolar ridge.

Conclusion: Although at 9 months postoperatively, the augmented alveolar ridge had different bone content, clinicohistochemical results demonstrated that this surgical technique could be a successful and predictable procedure for rebuilding a resorbed/defected ridge to accommodate endosseous implants.

Purpose: Because vertical ridge augmentation with autogenous bone blocks carries with it a risk of graft resorption and donor site morbidity, the aim of the present study was to compare histologically the healing following vertical ridge augmentation using screwable, xenogenous deproteinized blocks or autologous bone blocks in dogs.

Materials and Methods: Standardized vertical mandibular defects were surgically created in edentulous ridges of six foxhounds. Two bone blocks (6 x 10 x 15 mm) were inserted on each mandibular side and fixed with both a titanium implant and an osteosynthetic screw. Three different therapies were tested: (1) xenogenous block alone; (2) xenogenous block, covered with a chemically cross- linked collagen membrane; and (3) autologous blocks, harvested during defect preparation. After 3 months of submerged healing, the miniscrews were removed and replaced by dental implants. Following an additional healing period of 3 months, the animals were sacrificed, and dissected blocks were prepared for histomorphometric analysis. Results: During the primary healing period, three of 12 hemimandibles (six blocks) had to be removed because of severe inflammatory reactions (two xenogenous block sites with collagen membrane, one autologous block site). In general, histologic analysis revealed that xenogenous blocks, used alone or combined with a collagen membrane, exhibited osteoconductive properties on a level equivalent to that of autologous blocks, resulting in means of 50% to 60% of ossification of the blocks. Some parts of the xenograft were encased in soft tissue, partly surrounded by multinuclear giant cells. However, all groups showed obvious signs of bone/graft resorption.

Conclusion: Within the limits of the present study, it was concluded that the examined screwable xenogenous bone block might be a useful scaffold for ridge augmentation procedures. However, the combination of xenogenous blocks with a cross- linked collagen membrane did not appear to improve outcomes.

Purpose: To compare the efficacy and complications of 2 different techniques for vertical bone augmentation at implant placement: particulated autogenous bone grafts covered either by resorbable collagen barriers supported by osteosynthesis plates (test) or by nonresorbable titanium-reinforced e- polytetrafluoroethylene (e-PTFE) barrier (control).

Materials and Methods: Twenty-two partially edentulous patients requiring vertical bone augmentation were randomly allocated to 2 treatment groups of 11 patients each. Early implant failures, the amount of vertically regenerated bone measured intrasurgically, and biologic complications were recorded by an independent assessor blinded to the group allocation. The implant site requiring the most vertical bone regeneration was selected in each patient for the bone gain assessment. Patients were followed from implant insertion with simultaneous augmentation procedure to insertion of the provisional restoration. Paired and independent t tests and Fisher exact tests were conducted to compare means and proportions at the .05 level of significance.

Results: No patient dropped out or was excluded. Both procedures obtained significant bone gain and achieved the desired results, 2.2 mm (SD 1.5; P < .001) on average for resorbable barriers and 2.5 mm (SD 1.1) for nonresorbable barriers (P < .001). There was no statistically significant difference in bone gain between the 2 procedures (P = .58). Complications occurred in 40% of the patients. There was no difference in occurrence of complications between the procedures (P > .99). Three major complications occurred, 2 in the resorbable group and 1 in the nonresorbable group, which determined the complete failure of the augmentation procedure.

Conclusion: Both techniques were effective in augmenting bone; however, both were associated with complications. Clinicians and patients must carefully weigh risks and benefits when considering the use of vertical guided bone regeneration.

AIM: To assess volumetric and linear changes following ridge preservation (RP) or spontaneous healing plus early implant placement with or without simultaneous guided bone regeneration (GBR).

MATERIALS AND METHODS: In eight adult beagle dogs, the mesial roots of the mandibular P3, P4 and M1 were extracted. Sites were randomized to either ridge preservation (RP) or spontaneous healing (SH). Four weeks later dental implants were placed either with (RP2) or without removing non-integrated DBBM (RP1). In RP2 and SH sites, GBR was applied using a demineralized bovine bone mineral and a resorbable membrane. Impressions were taken postextraction (SH)/postridge preservation (RP1; RP2), before and after implant placement and after healing of 4 and 12 weeks. Casts were digitized to allow for superimposition and measurement of contour alterations.

RESULTS: Median ridge width reduction from postextraction (SH)/postridge preservation (RP1;RP2) to implant placement ranged from -13.9% (SH) to -19.7% (RP) (p > .05), whereas from implant placement to sacrifice, it was statistically significantly lower in group RP1 (-5.5%) compared to group SH (-23.4%; p = .0013) and group RP2 (-22.1%; p = .0026). Encompassing the entire study period, median ridge width changes ranged between -17.8% (SH), -24.8% (RP2) and -32.5% (RP1) (p > .05).

CONCLUSIONS: Irrespective of the treatment modality and the healing period, part of the ridge contour was lost. Early implant placement after ridge preservation without additional GBR resulted in a more stable ridge contour after implant placement compared to controls. "

Objective: The objective of the present study was to learn about the volumetric changes of the graft after maxillary sinus floor augmentation with Bio-Oss and autogenous bone from the iliac crest or the mandible in different ratios in minipigs.

Material and Methods: Bilateral maxillary sinus floor augmentation was performed in 40 minipigs with: (A) 100% autogenous bone, (B) 75% autogenous bone and 25% Bio-Oss, (C) 50% autogenous bone and 50% Bio-Oss, (D) 25% autogenous bone and 75% Bio-Oss, and (E) 100% Bio-Oss. The autogenous bone graft was harvested from the iliac crest or the mandible and the graft composition was selected at random and placed concomitant with implant placement. Computed tomographies of the maxillary sinuses were obtained preoperatively, immediately postoperatively, and at euthanasia after 12 weeks. The volumetric changes of the graft were estimated using the Cavalieri principle and expressed as mean percentage with a 95% confidence interval (CI).

Results: The mean volume of the graft was reduced by (A) 65% (95% CI: 60-70%), (B) 38% (95% CI: 35-41%), (C) 23% (95% CI: 21-25%), (D) 16% (95% CI: 12-21%), and (E) 6% (95% CI: 4-8%). The volumetric reduction was significantly influenced by the ratio of Bio-Oss and autogenous bone (P<0.001), but not by the origin of the autogenous bone graft (P=0.2).

Conclusion: The volume of autogenous bone grafts from the iliac crest and the mandible is reduced significantly after maxillary sinus floor augmentation in minipigs. The graft volume is better preserved after the addition of Bio-Oss and the volumetric reduction is significantly influenced by the ratio of Bio-Oss and autogenous bone. However, further studies are needed addressing the amount of new bone formation and bone-to-implant contact before the final conclusion can be made about the optimal ratio of Bio-Oss and autogenous bone.

Purpose: A variety of techniques and materials have been used to establish the structural base of osseous tissue for supporting dental implants. The aim of this systematic review was to identify the most successful technique(s) to provide the necessary alveolar bone to place a dental implant and support long-term survival. Methods: A systematic online review of a main database and manual search of relevant articles from refereed journals were performed between 1980 and 2005. Updates and additions were made from September 2004 to May 2005. The hard tissue augmentation techniques were separated into 2 anatomic sites, the maxillary sinus and alveolar ridge. Within the alveolar ridge augmentation technique, different surgical approaches were identified and categorized, including guided bone regeneration (GBR), onlay/veneer grafting (OVG), combinations of onlay, veneer, interpositional inlay grafting (COG), distraction osteogenesis (DO), ridge splitting (RS), free and vascularized autografts for discontinuity defects (DD), mandibular interpositional grafting (MI), and socket preservation (SP). All identified articles were evaluated and screened by 2 independent reviewers to meet strict inclusion criteria. Articles meeting the inclusion criteria were further evaluated for data extraction. The initial search identified a total of 526 articles from the electronic database and manual search. Of these, 335 articles met the inclusion criteria after a review of the titles and abstracts. From the 335 articles, further review of the full text of the articles produced 90 articles that provided sufficient data for extraction and analysis.

Results: For the maxillary sinus grafting (SG) technique, the results showed a total of 5,128 implants placed, with follow-up times ranging from 12 to 102 months. Implant survival was 92% for implants placed into autogenous and autogenous/composite grafts, 93.3% for implants placed into allogeneic/nonautogenous composite grafts, 81% for implants placed into alloplast and alloplast/xenograft materials, and 95.6% for implants placed into xenograft materials alone. For alveolar ridge augmentation, a total of 2,620 implants were placed, with follow-up ranging from 5 to 74 months. The implant survival rate was 95.5% for GBR, 90.4% for OVG, 94.7% for DO, and 83.8% for COG. Other techniques, such as DD, RS, SP, and MI, were difficult to analyze because of the small sample size and data heterogeneity within and across studies.

Conclusion: The maxillary sinus augmentation procedure has been well documented, and the long-term clinical success/survival (> 5 years) of implants placed, regardless of graft material(s) used, compares favorably to implants placed conventionally, with no grafting procedure, as reported in other systematic reviews. Alveolar ridge augmentation techniques do not have detailed documentation or long-term follow-up studies, with the exception of GBR. However, studies that met the inclusion criteria seemed to be comparable and yielded favorable results in supporting dental implants. The alveolar ridge augmentation procedures may be more technique- and operator-experience-sensitive, and implant survival may be a function of residual bone supporting the dental implant rather than grafted bone. More in-depth, long-term, multicenter studies are required to provide further insight into augmentation procedures to support dental implant survival.

BACKGROUND:
Peri-implant soft tissue may be critical to prevent inflammation and promote gingival margin stability. The purpose of this randomized clinical trial (RCT) is to compare xenogeneic collagen matrix (XCM) versus connective tissue graft (CTG) to increase buccal soft tissue thickness at implant site.

MATERIALS AND METHODS:
Soft tissue augmentation with XCM (test) or CTG (control) was performed at 60 implants in 60 patients at the time of implant uncovering. Measurements were performed by a blinded examiner at baseline, 3 and 6 months. Outcome measures included buccal soft tissue thickness (GT), apico-coronal keratinized tissue (KT), chair time and post-operative discomfort. Visual Analogue Scale (VAS) was used to evaluate patient satisfaction.

RESULTS:
After 6 months, the final GT increase was 0.9 ± 0.2 in the XCM group and 1.2 ± 0.3 mm in the CTG group, with a significant difference favouring the control group (0.3 mm; p = .0001). Both procedures resulted in similar final KT amount with no significant difference between treatments. XCM was associated with significant less chair-time (p < .0001), less post-operative pain (p < .0001), painkillers intake (p < .0001) and higher final satisfaction than CTG (p = .0195).

CONCLUSION:
CTG was more effective than XCM to increase buccal peri-implant soft tissue thickness.

A xenogeneic collagen matrix recently has been suggested as an alternative to connective tissue graft for the treatment of gingival recession. The matrix avoids the second surgical site, and as a consequence could decrease surgical morbidity. This new matrix was used in various clinical situations and compared to connective tissue graft (CTG) in a split-mouth design case series. A total of 17 recessions were treated with a coronally advanced flap, 9 with CTG, and 8 with the matrix. Mean recession reduction was 2.00 mm with the CTG and 2.00 mm with the matrix. No significant statistical differences between the techniques were observed in this case report.

BACKGROUND:

For root coverage therapy, the connective tissue graft (CTG) plus coronally advanced flap (CAF) is considered the gold standard therapy against which alternative therapies are generally compared. When evaluating these therapies, in addition to traditional measures of root coverage, subject-reported, qualitative measures of esthetics, pain, and overall preferences for alternative procedures should also be considered. This study determines if a xenogeneic collagen matrix (CM) with CAF might be as effective as CTG+CAF in the treatment of recession defects.

METHODS:

This study was a single-blind, randomized, controlled, split-mouth study of dehiscence-type recession defects in contralateral sites - one defect receiving CTG+CAF and the other defect receiving CM+CAF. 25 subjects were evaluated at 6-months and 1-year. The primary efficacy endpoint was recession depth at six months. Secondary endpoints included traditional periodontal measures, such as width of keratinized tissue (KT) and percentage of Root Coverage (%RC). Patient reported values of pain, discomfort and esthetic satisfaction were also recorded.

RESULTS:

At 6-months, recession depth was, on average, 0.52 mm for test sites and 0.10 mm for control sites, Recession depth change from baseline was statistically significant between test and control, with an average of 2.62 mm gained at test sites and 3.10 m gained at control sites for a difference of 0.4 mm (P = 0.0062). At one year, test %RC averaged 88.5%, and controls averaged 99.3%, P = 0.0313. KT width gains were equivalent for both therapies and averaged 1.34 mm for test sites and 1.26 mm for control sites, P = 0.9061. There were no statistically significant differences between patient reported values for esthetic satisfaction and subjects' assessments of pain/ discomfort were also equivalent.

CONCLUSIONS:

When balanced with patient reported esthetic values and compared with historical root coverage outcomes reported by other investigators, CM+CAF presents a viable alternative to CTG+CAF, without the morbidity of soft tissue graft harvest.

BACKGROUND:
Considering xenogeneic collagen matrix (CM) and enamel matrix derivative (EMD) characteristics, it is suggested that their combination could promote superior clinical outcomes in root coverage procedures. Thus, the aim of this parallel, double-masked, dual-center, randomized clinical trial is to evaluate clinical outcomes after treatment of localized gingival recession (GR) by a coronally advanced flap (CAF) combined with CM and/or EMD.

METHODS:
Sixty-eight patients presenting one Miller Class I or II GRs were randomly assigned to receive either CAF (n = 17); CAF + CM (n = 17); CAF + EMD (n = 17), or CAF + CM + EMD (n = 17). Recession height, probing depth, clinical attachment level, and keratinized tissue width and thickness were measured at baseline and 90 days and 6 months after surgery.

RESULTS:
The obtained root coverage was 68.04% ± 24.11% for CAF; 87.20% ± 15.01% for CAF + CM; 88.77% ± 20.66% for CAF + EMD; and 91.59% ± 11.08% for CAF + CM + EMD after 6 months. Groups that received biomaterials showed greater values (P <0.05). Complete root coverage (CRC) for CAF + EMD was 70.59%, significantly superior to CAF alone (23.53%); CAF + CM (52.94%), and CAF + CM + EMD (51.47%) (P <0.05). Keratinized tissue thickness gain was significant only in CM-treated groups (P <0.05).

CONCLUSIONS:
The three approaches are superior to CAF alone for root coverage. EMD provides highest levels of CRC; however, the addition of CM increases gingival thickness. The combination approach does not seem justified.

BACKGROUND:
Gingival recession (GR) might be associated with patient discomfort due to cervical dentin hypersensitivity (CDH) and esthetic dissatisfaction. The aim is to evaluate the effect of root coverage procedure with a xenogenous collagen matrix (CM) and/or enamel matrix derivative (EMD) in combination with a coronally advanced flap (CAF) on CDH, esthetics, and oral health-related quality of life (OHRQoL) of patients with GR.

METHODS:
Sixty-eight participants with single Miller Class I/II GRs were treated with CAF (n = 17), CAF + CM (n = 17), CAF + EMD (n = 17), and CAF + CM + EMD (n = 17). CDH was assessed by evaporative stimuli using a visual analog scale (VAS) and a Schiff scale. Esthetics outcome was assessed with VAS and the Questionnaire of Oral Esthetic Satisfaction. Oral Health Impact Profile-14 (OHIP-14) questionnaire was used to assess OHRQoL. All parameters were evaluated at baseline and after 6 months.

RESULTS:
Intragroup analysis showed statistically significant reduction in CDH and esthetic dissatisfaction with no intergroup significant differences (P >0.05). The impact of oral health on QoL after 6 months was significant for CAF + CM, CAF + EMD, and CAF + CM + EMD (P <0.05). Total OHIP-14 score and psychologic discomfort, psychologic disability, social disability, and handicap dimensions showed negative correlation with esthetics. OHIP-14 physical pain dimension had positive correlation with CDH (P <0.05). OHIP-14 showed no correlation with percentage of root coverage, keratinized tissue width, or keratinized tissue thickness (P >0.05).

CONCLUSION:
Root coverage procedures improve patient OHRQoL by impacting on a wide range of dimensions, perceived after reduction of CDH and esthetic dissatisfaction of patients with GRs treated with CAF + CM, CAF + EMD, and CAF + CM + EMD.