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.

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.

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.

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.

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.

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.

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.

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. 

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.

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.

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.

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.

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.

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.

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.

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.

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 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.

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.

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.

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.

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 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: 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:
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.

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.

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.

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:
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.

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.

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.

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.

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.

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 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.

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:
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.

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.

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.

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

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. "