Soft and hard tissue evaluation of guided socket shield implant cases.

BACKGROUND: The socket-shield (SS) technique results in long-term functional osseo- and dento-integration, preserving the dimensional stability of hard and soft tissues over time. This study aimed to describe the successful implementation of a surgical technique to facilitate "SS" cases. METHODS: The cases included males and females aged 32-81 years consecutively treated between 2020 and 2023 (longest follow-up, 3.5 years). For each case, pre- and post-operative cone-beam computed tomography (Digital Imaging and Communications in Medicine files) and intraoral optical scans (IOS; STL files) were performed. Digital immediate implant placement and simultaneous tooth extraction and SS production were planned using an implant planning software. Implants were planned considering sagittal-ridge and tooth-root angular-configuration. Surgical guides were used to perform the digitally-supported SS technique. All cases were planned and surgically performed by one operator (Pedro M. Trejo). Preoperative digital IOS-models were superimposed to post-operative models to assess soft-tissue changes. Pre and post sagittal views were used to assess the radiographic buccal-plate thickness at various healing times. An investigator not involved with case planning or treatment performed measurements. RESULTS: Results reflected soft-tissue stability with minimal mean thickness change at 0-, 1-, 2-, and 3-mm measurement levels of 0.03, -0.2, 0.14, -0.07, and 0.04 mm, respectively, with a mean gingival-margin change of 0.04 mm. The free gingival-margin change ranged from a 0.58-mm gain in height to a -0.57-mm loss. The mean radiographic buccal-plate thickness post-operatively was 2.04 mm (range, 0.7-2.9 mm). CONCLUSION: The digitally-supported guided SS technique enables predictable immediate implant-placement positions and stable buccal peri-implant soft and hard tissues over time. KEY POINTS: Why are these cases new information? The uniqueness of the surgical technique described herein is that it results in favorable positions of immediate, socket-shielded (SSed), implant placements, with soft- and hard-tissue stability as the byproduct. What are the keys to successful management of these cases? Digitally, plan for the best possible implant position within the alveolar housing to satisfy prosthetic requirements, and then adjust this position to accommodate the socket shield dimensions. Digitally, provide a space/gap between the future dentinal shield and the implant. Clinically, allow for time to carve the final position and dimensions of the shield. Plan ahead the extent of the apical third of the SS, and the removal of the apex, if dealing with a long root. What are the primary limitations to success in these cases? Inadequate use of digital technology; case-sensitive technique requires proper execution of each digital and technical clinical step.

Resorbable bilayer membrane made of L-lactide-ε-caprolactone in guided bone regeneration: an in vivo experimental study.

PURPOSE: Guided bone regeneration (GBR) is an accepted method in dental practice that can successfully increase the bone volume of the host at sites chosen for implant placement; however, existing GBR membranes exhibit rapid absorption and lack of adequate space maintenance capabilities. We aimed to compare the effectiveness of a newly developed resorbable bilayer membrane composed of poly (L-lactic acid) and poly (-caprolactone) (PLACL) with that of a collagen membrane in a rat GBR model. METHODS: The rat calvaria was used as an experimental model, in which a plastic cylinder was placed. We operated on 40 male Fisher rats and subsequently performed micro-computed tomography and histomorphometric analyses to assess bone regeneration. RESULTS: Significant bone regeneration was observed, which was and similar across all the experimental groups. However, after 24 weeks, the PLACL membrane demonstrated significant resilience, and sporadic partial degradation. This extended preservation of the barrier effect has great potential to facilitate optimal bone regeneration. CONCLUSIONS: The PLACL membrane is a promising alternative to GBR. By providing a durable barrier and supporting bone regeneration over an extended period, this resorbable bilayer membrane could address the limitations of the current membranes. Nevertheless, further studies and clinical trials are warranted to validate the efficacy and safety of The PLACL membrane in humans.

Semilunar Lingualized Apically Positioned Flap (SLAP) for Peri-Implant Soft Tissue Phenotype Modification Therapy Around Mandibular Implants: A Case Report.

Mucogingival deformities around implants are frequent findings in clinical practice and often present as inadequate keratinized tissue and insufficient mucosal thickness. Phenotype modification therapy can increase peri-implant mucosal thickness and the amount of keratinized mucosa, improving the long-term clinical outcomes of implants. Free gingival graft (FGG) is considered the gold standard to increase keratinized mucosa; however, FGGs on lingual aspects of implants are less predictable due to technique sensitivity and often present with insufficient gain in tissue thickness ue to limited blood supply. The Semilunar Lingualized Apically Positioned Flap (SLAP) with subperiosteal tunnel connective tissue graft (CTG) can increase both peri-implant mucosal thickness and keratinized mucosal width circumferentially. SLAP consists of one full-thickness, semilunar incision within keratinized mucosa on the buccal, and two vertical releasing incisions mesial and distal of the implant, extending lingually into the alveolar mucosa. The tissue is apically positioned lingual to the implant, and sutured in place creating buccal space for CTG via buccal subperiosteal tunneling. SLAP is a minimally invasive and predictable approach in improving peri-implant mucosal phenotype. This case reports demonstrates gain in peri-implant mucosal thickness and the amount of keratinized mucosa over a 10-month period utilizing SLAP with subepithelial CTG.

Ridge preservation with the socket-shield technique and immediate provisionalization for delayed implant placement.

AIM: The present case report with medium-term follow-up aims to report on the successful outcomes of ridge preservation using anorganic bovine bone mineral (ABBM) combined with the socket-shield technique (SST) in conjunction with immediate ovate pontic provisionalization of the extraction site, followed by delayed flapless implant placement and immediate implant provisionalization in the rehabilitation of the maxillary anterior esthetic region. Clinical protocol: Three consecutive patients with failing maxillary anterior teeth were treated with this protocol. The alveolar ridge dimension was preserved utilizing ABBM, combined with the retention of a partial tooth root segment in the buccal portion of the extraction socket, to minimize ridge resorption following tooth extraction. An immediate fixed provisional restoration with an ovate base in direct contact with the extraction site was fabricated and delivered immediately to maintain the soft tissue contour. At 4 months postextraction, flapless implant placement was performed via a computer-generated surgical guide, along with immediate implant provisionalization. Definitive restorations were delivered 4 months following implant placement. RESULTS: At the 2-year follow-up after loading, prosthetic and implant success was demonstrated, with a favorable esthetic outcome and a high level of patient satisfaction. CONCLUSIONS: The immediate ovate pontic provisionalization in conjunction with ridge preservation combining ABBM and the SST, followed by flapless computer-guided implant placement with an immediate implant provisionalization protocol, as proposed in this article, offers a viable method to minimize alveolar ridge resorption as well as optimize esthetic outcomes.

A Novel 3D Volumetric Method of Analyzing Gingival Positional and Dimensional Alterations During Orthodontic Therapy: A Pilot Study.

The aim of the present study was to develop a 3D digital image-analysis method to quantitatively assess gingival changes after clear-aligner orthodontic therapy. Using teeth as fixed reference points, 3D image analysis tools have been used to quantify mucosal level changes after specific therapies. This technology has not been applied to orthodontic therapy, primarily because orthodontic tooth movement precludes using teeth as fixed reference points. Rather than superimposing the pre- and posttherapy volumes for the entire dentition, the methodology presented herein superimposed the pre- and post-therapy volumes for individual teeth. The lingual tooth surfaces, which remained unaltered, were used as fixed references. Intraoral scans taken before and after clear-aligner orthodontic therapy were imported for comparison. Volumes were created for each 3D image and were superimposed in a 3D image-analysis software that allowed quantitative measurements. The results demonstrated this technique's ability to measure very small changes in the apicocoronal position of the gingival zenith, as well as alterations of gingival margin thickness, following clear-aligner orthodontic therapy. The present 3D image-analysis method offers a useful tool for investigating the periodontal dimensional and positional changes that accompany orthodontic therapy.

Clinical efficacy of soft-tissue augmentation on tissue preservation at immediate implant sites: A randomized controlled trial.

AIM: This randomized controlled trial aimed to investigate the efficacy of soft-tissue augmentation (STA) with a subepithelial connective tissue graft (SCTG) or an acellular dermal matrix (ADM) on reducing tissue alterations at an immediate implant site. MATERIALS AND METHODS: This trial had three groups: (i) immediate implant with SCTG (ICT group); (ii) immediate implant with ADM (IAD group); (iii) immediate implant without STA (control group). Forty-six patients were randomly assigned to each group. Implants were placed at the maxillary anterior or premolar areas and restored after the 6-month visit. Clinical outcomes, including buccal soft-tissue contour, peri-implant mucosal level, soft-tissue thickness and keratinized tissue width, were measured at baseline and at 3-, 6- and 12-month follow-up visits. Radiographic bone levels were measured at baseline and at 6- and 12-month follow-up visits. Patient-reported outcomes were also collected. RESULTS: STA procedures increased peri-implant mucosal thickness and maintained buccal soft-tissue contours. Compared to the control group, STA groups did not prevent peri-implant mucosal recession or interproximal bone resorption. Generally, no significant differences in clinical outcomes were detected between the ICT and IAD groups. Most patients were highly satisfied with the immediate implant procedure and outcomes without significant differences between groups. CONCLUSIONS: STA at immediate implant sites enhanced soft-tissue thickness and maintained soft-tissue contours but did not prevent peri-implant mucosal recession or interproximal bone resorption. Long-term follow-up should be performed since these results were reported for only up to 1 year.

Kinetics of Phenotype Modification Therapy with VISTA: A Retrospective Case Series Using 3D Digital Analysis

Phenotype modification therapy has emerged as one of the main treatment objectives of periodontal plastic surgery. However, long-term data on the stability of gingival thickness gains are not available. This study examined the kinetics of mucosal thickness gain as a measure of phenotype modification therapy following treatment of multiple gingival recession defects with vestibular incision subperiosteal tunnel access (VISTA). Six patients with 14 recession type (RT) II teeth were treated using VISTA and subepithelial connective tissue grafts (SCTG). Scanned images of study casts at pre- and postoperative periods (6 to 66 months) were digitally superimposed for quantitative evaluation of soft tissue dimensional changes. Mucosal thickness gains ranged from 1.0 ± 0.7 mm (1 mm apical to cement-enamel junction [CEJ]) to 1.4 ± 0.4 mm (5 mm apical to CEJ). The gingival thickness gains remained relatively stable, with thickness gains at 66 months of 0.5 ± 0.8, 0.9 ± 0.6, 1.1 ± 0.6, 1.0 ± 0.4, and 1.2 ± 0.6 mm at 1, 2, 3, 4 and 5 mm apical to the CEJ, respectively. Treatment of multiple gingival recession defects with VISTA and SCTG led to stable gingival thickness gains and shows promise as a strategy for phenotype modification therapy.

The Ball Technique for Peri-implant Soft Tissue Augmentation Using a Xenogeneic Collagen Matrix: A Technical Report.

In the maxillary anterior region, augmentation to correct a soft tissue deficiency is often required for an esthetic outcome and long-term implant therapy success. This case series of three patients presents a novel approach for soft tissue augmentation using xenogeneic collagen matrix balls in the esthetic zone around the implants. This technique avoids a secondary donor site compared to autogenous connective tissue graft. With this technique, a horizontal soft tissue volume increase (range: 3 to 5 mm) was observed postsurgically and maintained at later follow-ups. The described ball technique offers a viable method for peri-implant mucosal augmentation in the maxillary anterior region.

Functionalized Scaffold and Barrier Membrane with Anti-BMP-2 Monoclonal Antibodies for Alveolar Ridge Preservation in a Canine Model.

INTRODUCTION: The aim of this study was to investigate the ability of anti-bone morphogenetic protein 2 monoclonal antibody (anti-BMP-2 mAb) to functionalize scaffolds to mediate bone regeneration in a canine model. MATERIALS AND METHODS: The mandibular right premolar 4 (PM4) was extracted in eight beagle dogs and grafted with anti-BMP-2 mAb+anorganic bovine bone mineral with 10% collagen (ABBM-C) and porcine bilayer native collagen membrane (CM). The ABBM-C and CM were functionalized with either anti-BMP-2 mAb (test group) or an isotype matched control mAb (control group). Animals were euthanized at 12 weeks for radiographic, histologic, and histomorphometric analyses. Outcomes were compared between groups. RESULTS: 3D imaging using cone beam computed tomography (CBCT) revealed that sites treated with ABBM-C and CM functionalized with anti-BMP-2 mAb exhibited significantly more remaining bone width near the alveolar crest, as well as buccal bone height, compared with control groups. Histologic and histomorphometric analyses demonstrated that in anti-BMP-2 mAb-treated sites, total tissue volume was significantly higher in the coronal part of the alveolar bone crest compared with control sites. In anti-BMP-2 mAb-treated sites, bone formation was observed under the barrier membrane. CONCLUSION: Functionalization of the ABBM-C scaffold and CM appeared to have led to bone formation within healing alveolar bone sockets.

Revisiting major anatomical risk factors of maxillary sinus lift and soft tissue graft harvesting for dental implant surgeons.

The anatomical variations of the maxillary sinus septa, greater palatine artery, and posterior superior alveolar arteries might cause unexpected complications when they are damaged. Dentists who know these structures well might hope to learn more practical knowledge to avoid and assess injury preoperatively. Therefore, this review paper aimed to review the reported anatomy and variations of the maxillary sinus septa, greater palatine artery/nerve, and posterior superior alveolar artery, and to discuss what has to be assessed preoperatively to avoid iatrogenic injury. To assess the risk of injury of surgically significant anatomical structures in the maxillary sinus and hard palate, the operator should have preoperative three-dimensional images in their mind based on anatomical knowledge and palpation. Additionally, knowledge of the average measurement results from previous studies is important.

Three-Dimensional Volumetric Analysis of Multiple Gingival Recession Defects Treated by the Vestibular Incision Subperiosteal Tunnel Access (VISTA) Procedure.

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Retrospective Analysis of the Outcome of Ridge Preservation with Anorganic Bovine Bone Mineral: Marginal Bone Level at Implants Placed Following Healing of Grafted Extraction Sockets.

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.

Treatment of multiple recession defects with vestibular incision subperiosteal tunnel access (VISTA): A retrospective pilot study utilizing digital analysis.

OBJECTIVE: To examine the correlation between initial site-specific characteristics of patients with multiple gingival recession defects and the outcome of root coverage therapy. MATERIALS AND METHODS: Pretherapy and post-therapy study models of 21 patients (154 teeth) with multiple gingival recession defects, treated with Vestibular Incision Subperiosteal Tunnel Access (VISTA), were optically scanned. Three-dimensional analysis of superimposed preoperative and postoperative images was performed. Linear and surface root coverage were calculated and correlated to various clinical and/or anatomical parameters. A multilevel statistical analysis was conducted, adjusting for the correlation among multiple observations. RESULTS: The mean percentages of linear root coverage were 96.2 ± 13.1% and 84.3 ± 14.4% for Miller Class I/II and Class III recessions, respectively. The mean percentages of root surface area coverage were 92.1 ± 12.0% and 78.6 ± 15.7% for Miller Class I/II and III defects, respectively. Root prominence, initial recession width and posterior tooth type were negatively correlated with linear and root surface area coverage. Initial recession depth was negatively correlated with root surface area coverage. Initial gingival margin thickness was positively associated with both linear and root surface area coverage. CONCLUSION: The results of the present study identified important positive and negative site-specific characteristics that may have utility in predicting the outcome of root coverage. CLINICAL SIGNIFICANCE: This study used sensitive 3-dimensional digital analysis tools to examine the correlation between initial site-specific characteristics of patients with multiple gingival recession defects and the outcome of periodontal root coverage therapy. Results demonstrated that initial root prominence, loss of interdental tissue (Miller Class III), molar tooth type, initial recession depth and width were negatively correlated with the outcome of periodontal root coverage achieved. Conversely, initial gingival margin thickness was associated with increased percentage of root coverage. These site-specific characteristics may serve as important risk indicators to predict the outcome of root coverage procedure.

Enhancement of Bone Augmentation in Osteoporotic Conditions by the Intermittent Parathyroid Hormone: An Animal Study in the Calvarium of Ovariectomized Rat.

PURPOSE: Intermittent parathyroid hormone (PTH) is the commonly used therapeutic approach for patients with severe osteoporosis. The goal of this study was to elucidate the effect of the intermittent PTH treatment on guided bone augmentation (GBA) in the calvarium of ovariectomized (OVX) rats. MATERIALS AND METHODS: Surgical ovariectomy on 14 rats and sham surgery on 7 rats were conducted on all rats as the first surgery. GBA surgery was conducted 8 weeks following the first surgery in the rat calvarium by placing 5-mm-diameter cylindrical plastic caps. Following surgery, rats were treated with 40 µg/kg PTH (OVX-PTH) or saline (Sham-Saline, OVX-Saline) via intraperitoneal injection three times per week during the all-observational period. Longitudinal microcomputed tomography (micro-CT) imaging was performed every 2 weeks following the GBA surgery without euthanasia, and the amount of newly generated bone volume (BV) was calculated. All rats were euthanized 12 weeks after GBA surgery, and histology was obtained. Sections stained with hematoxylin and eosin were used for the quantitative analysis of newly generated tissue, and immunohistology was used to visualize Runx2-positive cells and TRAP-positive cells. RESULTS: Throughout the monitoring period, the BVs of OVX rats without PTH treatment (OVX-Saline) were significantly lower than that of the other two groups at weeks 8 and 12 in micro-CT analysis. During all experimental periods, the BV was highest in the OVX rats that were treated with PTH (OVX-PTH). Histologic analysis confirmed the result of micro-CT, and determined that the OVX-PTH presented a greater number of Runx2-positive cells. The number of TRAP-positive multinucleated osteoclasts was highest in OVX-PTH rats; there were no significant differences between the other two groups. CONCLUSION: The results of this study suggest that treatment with intermittent PTH was associated with increased newly regenerated bone volume in ovariectomized rat calvarial bone augmentation, which may have important clinical implications.

A Histologic and Histomorphometric Retrospective Analysis of the Outcomes of Ridge Preservation Using Anorganic Bovine Bone Minerals and a Nonresorbable Membrane.

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.

Influence of estrogen deficiency on guided bone augmentation: investigation of rat calvarial model and osteoblast-like MC3T3-E1 cells.

The effect of estrogen deficiency in bone augmentation, and the mechanisms by which estrogen deficiency impedes osteoblast differentiation and collagen matrix production, were examined. Twenty female Jcl:Wistar rats were divided into two groups: ovariectomized rats; and control rats. Guided bone augmentation was performed by positioning plastic caps in the calvarium of all animals at 8 wk after ovariectomy or sham surgery. Micro-computed tomography and histological sections were used to determine the amount of bone augmentation within the plastic caps. At 8 wk, there was statistically significantly less newly formed bone volume in ovariectomized rats. Immunohistological staining revealed the rare alignment of runt-related transcription factor 2-positive osteoblast-like cells and collagen I-positive bundle fibers in ovariectomized rats. In cell culture experiments, pre-osteoblast-like cells, MC3T3-E1, were treated with the estrogen receptor antagonist, fulvestrant. In treated cells, alkaline phosphatase activity remained high, whereas Alizarin Red staining was completely inhibited. Extracellular staining intensity of collagen I was decreased after fulvestrant treatment. Consistent with these observations, gene-expression analysis confirmed that fulvestrant treatment led to weaker expression of mRNA for osteogenic transcription factors and bone matrix protein-related genes. The results demonstrate that estrogen deficiency suppresses osteoblast differentiation and collagen matrix production in bone augmentation.

Retrospective Analysis of the Outcome of Ridge Preservation with Anorganic Bovine Bone Minerals: Microcomputed Tomographic Assessment of Wound Healing in Grafted Extraction Sockets.

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.

Collagen sponge functionalized with chimeric anti-BMP-2 monoclonal antibody mediates repair of nonunion tibia defects in a nonhuman primate model: An exploratory study.

Recombinant human bone morphogenetic protein (BMP)-2 is an FDA-approved therapy for nonunion tibia fracture, though it has a number of biological and practical disadvantages. Our research group has developed a novel tissue engineering strategy termed antibody-mediated osseous regeneration. This entails application of anti-BMP-2 monoclonal antibodies (mAbs) to capture endogenous BMP's to mediate in vivo bone formation. This has been documented in a number of animal models. The present exploratory study sought to investigate the application of antibody-mediated osseous regeneration for repair of nonunion tibia defect in a nonhuman primate model. A 20 mm segmental osteotomy was performed in tibia of 6 Macaca fascicularis and was implanted with absorbable collagen sponge that was functionalized with chimeric anti-BMP-2 or isotype matched control mAb. Cone beam computed tomography (CBCT), histologic and histomorphometric analyses were performed 12 weeks post-operatively. CBCT analyzed by quantitative 3D volumetric analysis revealed that sites implanted with absorbable collagen sponge functionalized with anti-BMP-2 mAb demonstrated numerically higher mineralized tissue (408 ± 127 mm3) compared with sites implanted with isotype matched control mAb (214 ± 81 mm3), though the difference was not statistically significant ( p = 0.09). Histologic and histomorphometric analysis showed de novo bone formation with greater ( p < 0.01) percentage of bone volume in sites implanted with anti-BMP-2 (41.3 ± 4.4%), compared with isotype matched control mAb (14.6 ± 5.6%). Results from the present exploratory study provide evidence for the potential of anti-BMP-2 mAb to mediate repair of a large segmental tibia defects in a nonhuman primate model. Therapeutic antibodies have generally been shown to have great safety and efficacy profile, though their application in tissue engineering has been limited in the past. Following further investigation, anti-BMP-2 mAbs immobilized on appropriate scaffold may have application in repair of large skeletal defects without the need for exogenous growth factors.

Collagen Sponge Functionalized with Chimeric Anti-BMP-2 Monoclonal Antibody Mediates Repair of Critical-Size Mandibular Continuity Defects in a Nonhuman Primate Model.

Antibody-mediated osseous regeneration (AMOR) has been introduced by our research group as a tissue engineering approach to capture of endogenous growth factors through the application of specific monoclonal antibodies (mAbs) immobilized on a scaffold. Specifically, anti-Bone Morphogenetic Protein- (BMP-) 2 mAbs have been demonstrated to be efficacious in mediating bone repair in a number of bone defects. The present study sought to investigate the application of AMOR for repair of mandibular continuity defect in nonhuman primates. Critical-sized mandibular continuity defects were created in Macaca fascicularis locally implanted with absorbable collagen sponges (ACS) functionalized with chimeric anti-BMP-2 mAb or isotype control mAb. 2D and 3D analysis of cone beam computed tomography (CBCT) imaging demonstrated increased bone density and volume observed within mandibular continuity defects implanted with collagen scaffolds functionalized with anti-BMP-2 mAb, compared with isotype-matched control mAb. Both CBCT imaging and histologic examination demonstrated de novo bone formation that was in direct apposition to the margins of the resected bone. It is hypothesized that bone injury may be necessary for AMOR. This is evidenced by de novo bone formation adjacent to resected bone margins, which may be the source of endogenous BMPs captured by anti-BMP-2 mAb, in turn mediating bone repair.

Alveolar ridge dimensional changes following ridge preservation procedure with novel devices: part 3 - histological analysis in non-human primate model.

OBJECTIVES: This study sought to investigate the histological changes following tooth extraction, ridge preservation and augmentation, using novel devices designed to obturate the oral orifice of extraction sockets (SocketKAP™) and provide structural support for sockets with defective bony walls (SocketKAGE™) in a non-human primate model. MATERIAL AND METHODS: Six Macaca fascicularis were imaged by cone beam computed tomography to register their preoperative alveolar bone. Three teeth were extracted in each animal, yielding intact socket walls and were divided into three intervention groups: unassisted healing negative control (Group A); SocketKAP™ (Group B); filled with anorganic bovine bone mineral (ABBM) + SocketKAP™ (Group C). Three additional teeth were extracted in each animal, followed by surgical resection of the entire buccal alveolar bone and divided into three groups: negative control (Group D); SocketKAP™ + SocketKAGE™ (Group E); ABBM + SocketKAP™ + SocketKAGE™ (Group F). Animals were euthanized after 12 weeks, and treatment sites were examined by histology and histomorphometric analysis. RESULTS: Control sockets with unassisted healing (Groups A and D) underwent severe loss of bone width, height and total area (approximately 40-60% loss). Application of SocketKAP™ in sites with intact walls, as well as SocketKAP™ plus SocketKAGE™ in sites with defective buccal walls lead to higher preservation of alveolar bone height after 12 weeks post-intervention. Addition of ABBM leads to the highest degree of alveolar bone dimensional preservation. Control sites with unassisted healing (Groups A and D), as well as sites treated with extraction socket devices (Groups B and E) without ABBM yielded higher percentage of vital bone, compared with sites filled with ABBM (Groups C and F). No adverse histological responses were noted to SocketKAP™ or SocketKAGE™ devices. CONCLUSIONS: SocketKAP™ + SocketKAGE™ devices proved effective in reducing post-extraction alveolar bone resorption mediating favorable wound healing within sockets. Addition of ABBM was associated with reduced volumetric loss, although the bone fill was characterized by less mature as well as more woven bone.