Mineralized Bone Allograft Research Articles

The potential of the mineralized bone allograft block as an appropriate candidate for bone tissue engineering in periodontology

The potential of the mineralized bone allograft block as an appropriate candidate for bone tissue engineering in periodontology

Sinus Augmentation Using Mineralized Bone Allografts: A 6-Month Histological and Histomorphometric Analysis.

The aim of this study was to evaluate, after a six-month healing period, the histological and histomorphometric results of mineralized bone allograft used in lateral sinus augmentation procedures. Twenty-one pneumatized maxillary sinuses with residual bone height ≤ 4mm were grafted with a mixture of 1/1 cortical and cancellous mineralized bone allograft using lateral sinus floor elevation. Six months later, during implant placement, a core biopsy was retrieved for histological and histomorphometric evaluation. Biopsies showed mature cancellous bone with no signs of acute or chronic inflammatory reactions. Higher magnification revealed new lamellar bone, active osteocytes and normal lamellar arrangement around Haversian canals interspersed with osteocytes in lacunae. At grafted bone periphery, a high concentration of osteoblastic/osteoclastic couple was noted, indicating active bone remodeling. Histomorphometric evaluation revealed an average vital bone content of 30.32% (25.00-44.00%), and a percentage of residual non-vital bone of 18.06% (14.05-25.00%). Histological and histomorphometric evaluation indicated that the mixture of 1 to 1 cortical and cancellous mineralized bone allograft promoted de-novo bone formation and can be predictably used for sinus augmentation procedures.

Effect of Enamel Matrix Derivative and N-Acetyl Cysteine on Proliferation and Osteogenic Activity of Dental Pulp Stem Cells.

Successful bone regeneration often requires induction by signaling molecules. Enamel matrix derivative (EMD) is said to enhance initial phases of healing. N-acetyl cysteine (NAC) is a molecule assumed to enhance osteogenesis and induce osteoblastic differentiation. This study sought to compare effects of EMD and NAC on proliferation, mineralization, and enzymatic activity of dental pulp mesenchymal stem cells (DPSCs). DPSCs were cultured on mineralized bone allograft (MBA) powder. After 24 hours, EMD in concentrations of 10, 50, and 100 μg/mL and NAC in 5 mM concentration were added. Methyl thiazolyl tetrazolium (MTT) assay was used for cell proliferation assessment at 1, 2, and 3 days. Osteoblastic differentiation of DPSCs was evaluated at 30 days, by alizarin red staining and assessment of alkaline phosphatase (ALP) activity. Both EMD and NAC caused time-dependent reduction of cell proliferation compared with the negative control. Maximum proliferation of DPSCs was observed in the 10 μg/mL EMD group at all time points, whereas NAC caused higher ALP activity and mineralization of DPSCs compared with EMD. In vitro application of NAC, as a signaling molecule, may effectively enhance bone regeneration by the induction of mineralization and enzymatic activity, despite the resultant reduction in cell proliferation rate.

In Vitro Activity of Dental Pulp Stem Cells versus the Bone Marrow Stem Cells Cultured in Presence of a Bone Allograft.

Introduction - Scaffolds and cells are two important components in bone tissue engineering. There is a gap of information about stem cell activity next to bone substitutes. Thus, the aim of this in vitro study was to compare the proliferation and differentiation of bone marrow stem cells (BMSCs) and dental pulp stem cells (DPSCs) in presence of freeze-dried bone allograft (FDBA). Method and Materials - DPSCs and BMSCs were cultured and placed on mineralized bone allograft. Cell proliferation was analyzed by the methyl thiazolyl tetrazolium (MTT) assay after 24, 48, and 72 h. To compare the enzymatic activity and mineralization of cells, the alkaline phosphate (ALP) test and alizarin red staining were performed at 30 days. Data were analyzed by ANOVA. Results - The rate of proliferation of DPSCs was higher at 48 and 72 h. ALP activity was significantly higher in DPSCSs (P < 0.05), while alizarin red staining did not show any significant difference between the groups in formation of calcified nodules. DPSCs showed higher cell proliferation and osteoblastic differentiation than BMSCs. Conclusion - Considering the easier and less invasive isolation of DPSCs, a combination of DPSCs and allograft can be a good choice for bone regeneration, especially in the dentoalveolar area.

Improving biocompatibility and corrosion resistance of anodized AZ31 Mg alloy by electrospun chitosan/mineralized bone allograft (MBA) nanocoatings

A novel nanofibrous coating containing chitosan and mineralized bone allograft (MBA) nanoparticles was fabricated on AZ31 magnesium alloy via electrospinning in order to enhance corrosion and biocompatibility behavior in a physiological environment. A number of specimens were initially anodized to assess its effect on the improvement of the adhesion between the electrospun nanofibrous coating and the substrate. The coated materials were characterized by using SEM, EDS, FT-IR, and TG. Wettability and the adhesion of the coatings were also studied. In addition, hydrogen evolution and corrosion resistance were evaluated by conducting the immersion test, electrochemical polarization, and EIS tests, respectively. The results showed that both chitosan and chitosan/ MBA composite nanocoating improved the corrosion resistance. Cytotoxicity examination using fibroblast cells indicated that the presence of MBA nanoparticles in chitosan nanofibrous coating has preferable cell adhesion and proliferation. On the whole, application of both chitosan and chitosan/ MBA nanoparticles composite nanofibrous coatings on pre-anodized magnesium appears to be a promising approach in enhancement of the corrosion and biological behavior of magnesium-based biomaterials.

Comparative Histological and Histomorphometric Results of Six Biomaterials Used in Two-Stage Maxillary Sinus Augmentation Model after 6-Month Healing.

Objectives To evaluate the performances of six different bone substitute materials used as graft in maxillary sinus augmentation by means of histological and histomorphometric analysis of bone biopsies retrieved from human subjects after a 6-month healing period. Materials and Methods Six consecutive patients (3 males, 3 females, aged 50-72 years), healthy, nonsmokers, and with good oral hygiene, presenting edentulous posterior maxilla with a residual bone crest measuring ≤ 4 mm in vertical height and 3 to 5 mm in horizontal thickness at radiographic examination, were selected to receive sinus augmentation and delayed implant placement. Under randomized conditions, sinus augmentation procedures were carried out using mineralized solvent-dehydrated bone allograft (MCBA), freeze-dried mineralized bone allograft (FDBA), anorganic bovine bone (ABB), equine-derived bone (EB), synthetic micro-macroporous biphasic calcium-phosphate block consisting of 70% beta-tricalcium phosphate and 30% hydroxyapatite (HA-β-TCP 30/70), or bioapatite-collagen (BC). After 6 months, bone core biopsies were retrieved and 13 implants were placed. Bone samples were processed for histological and histomorphometric analysis. CT scans were taken before and after surgery. After 4 months of healing, patients were restored with a provisional fixed acrylic resin prosthesis, as well as after further 2-4 months with a definitive cemented zirconia or porcelain-fused-to-metal crowns. Results There were no postoperative complications or implant failures. The histological examination showed that all biomaterials were in close contact with newly formed bone, surrounding the graft granules with a bridge-like network. No signs of acute inflammation were observed. The histomorphometry revealed 20.1% newly formed bone for MCBA, 32.1% for FDBA, 16.1% for ABB, 22.8% for EB, 20.3% for HA-β-TCP 30/70, and 21.4% for BC. Conclusions Within the limitations of the present investigation, all the six tested biomaterials showed good biocompatibility and osteoconductive properties when used in sinus augmentation procedures, although the FDBA seemed to have a better histomorphometric result in terms of newly formed bone and residual graft material. This trial is registered with ClinicalTrials.gov Identifier (Registration Number): NCT03496688.

The use of mineralized bone allograft as a single grafting material in maxillary sinus lifting with severely atrophied alveolar ridge (1-3 mm) and immediately inserted dental implants. A 3- up to 8-year retrospective study.

The primary aim of our study was to evaluate the efficacy of mineralized bone allograft alone in sinus floor augmentation with simultaneous implant placement in cases with severe atrophy of the residual maxillary bone (bone height < 4mm). Thirty-five dental implants were placed in 29 patients who underwent sinus augmentation via traditional lateral window technique from 2008 to 2013. Patients with residual alveolar height between 1 and 3mm at the site of implantation were included in the study. The height of residual bone was initially estimated by plain panoramic X-ray and reevaluated intraoperatively by precise micrometric measurement at the site of implantation. Implants of 13mm height and 3.5 or 4.3mm in diameter were inserted simultaneously. Mineralized bone allograft was used alone to augment the sinus floor. No wound dehiscence was recorded. In one case there was a postoperative site infection which subsided with antibiotics without implant failure. One implant migrated during the postoperative period to the maxillary sinus and was removed. One implant failed. The remaining 33 implants were successfully loaded. Follow-up ranged from 3 to 8years. Maxillary sinus lift in severely absorbed alveolar ridges with simultaneous implant placement could be safely performed using mineralized allograft alone, rendering the procedure less invasive and less time-consuming.

Lateral bone augmentation in narrow posterior mandibles, description of a novel approach, and analysis of results.

Combination of particulate grafts and collagen membranes is widely used for augmentation of bony defects for implant placement. Fixation of the barrier membrane may avoid complications due to unfavorable mechanical properties and poor stability leading to collapse of the augmented area. To evaluate a new simplified method for resorbable collagen membrane fixation in lateral bone augmentation procedures in narrow posterior mandibles. This retrospective study analyzed 16 procedures performed in 15 patients who followed lateral ridge augmentation procedures before implant placement in the posterior mandible. A particulate mineralized bone allograft was covered with a cross-linked resorbable collagen barrier membrane, which was fixated with a single, nonresorbable pin. Complications were registered and results analyzed on pre and post op measurements on computerized tomographic scans. Descriptive statistical analysis and ANOVA with repeated measures were performed. No complications were recorded. Average bone gain was 3.3 mm at implant platform level and 4.29 mm at 3 mm apically, both, statistically significant. All sites had sufficient bone width allowing implant placement. Thirty-three implants placed in the augmented areas, integrated and survived for over a 2-year follow-up. The simplified membrane fixation procedure enables large horizontal bone gain with minimal complications while allowing adequate implant placement.

Surface characteristics of three commercially available grafts and adhesion of stem cells to these grafts.

Reconstruction of bone defects is often performed using bone autografts. However, limitations associated with the use of autografts led to the use of bone substitute materials. The purpose of this study was to compare the surface characteristics of three commercially available grafts namely allografts, xenografts and alloplasts. This in vitro study was conducted on beta-tricalcium phosphate (β-TCP) alloplast, a mixture of demineralized bone matrix and mineralized bone allograft (DBM&MBA) and natural bovine bone mineral (NBBM) xenograft. Presence of apatite groups on the surface of samples was assessed by X-ray diffraction (XRD) while the presence of functional groups was evaluated using Fourier transform infrared spectroscopy (FTIR). Also, dental pulp stem cells (DPSCs) were cultured on the surface of samples and their adhesion was evaluated under a scanning electron microscope (SEM). The FTIR showed a relatively similar pattern for NBBM and TCP samples and a different pattern in DBM&MBA. The results of XRD analysis also showed similarities between NBBM and TCP with sharper peaks than the DBM&MBA sample. The SEM micrographs showed that at 24 hours, no cell was detectable on the surface of NBBM sample; whereas, elongated cells were noted on the surface of TCP and DBM&MBA samples. The patterns of β-TCP and NBBM samples in XRD and FTIR spectroscopy showed high resemblance but they had different behaviors with respect to cell adhesion.

Use of Bone Morphogenetic Protein-2 in Molar Extraction Sockets for Immediate Implant Placement: A Prospective Case Series.

This prospective case series enrolled consecutively qualifying patients that required immediate dental implant placement in large, uncontained, fresh molar extraction sites using recombinant human bone morphogentic protein-2/absorbable collagen sponge (rhBMP-2/ACS) combined with mineralized bone allograft. A total of 11 patients with 15 extraction sites missing bony walls were enrolled for treatment in this prospective case series. The clinical and radiographic effectiveness of rhBMP-2/ACS combined with mineralized bone allograft supported healing of immediately placed implants. Implants were uncovered at 4 to 6 months and were clinically and radiographically evaluated for ridge preservation and implant integration. All extraction sites exhibited ridge preservation and implant integration 1 year following restoration.

Subantral Augmentation With Mineralized Cortical Bone Allograft Material: Clinical, Histological, and Histomorphometric Analyses and Graft Volume Assessments.

The aim of this study was to clinically and histologically evaluate the effect of using mineralized cortical bone allograft in sinus lift augmentation and to 3-dimensionally quantify volumetric changes in maxillary sinuses augmented over a 2-year period. Eleven patients affected with less than 3 mm of residual ridge were enrolled in the study. After sinus grafting with a mineralized bone allograft, the site was covered with a collagen wound dressing. During implant placement 4 months later, a biopsy was obtained for histological and histomorphometry evaluations. Bone volume changes were also evaluated. Biopsies showed mature cancellous bone with a predominantly lamellar structure. The well-vascularized intertrabecular spaces were filled with connective tissue and bone marrow. Histomorphometry evaluations revealed a mean 43.76 ± 1.47% of bone marrow, 40.16 ± 1.35% of mineralized bone and 16.59 ± 0.55% of woven bone. The mean of residual particles was 0.47 ± 0.01%. Volumetric measurements showed a mean volume of grafted material 16.24 ± 1.55 cm at T0, 14.48 ± 1.48 cm at T1, and 13.06 ± 1.39 cm at T2. The mean volume retraction was 10.83% of the initial total volume at (T0-T1) and 9.8% at (T1-T2). The clinical and histological results indicated that mineralized cortical bone allograft promoted de novo bone formation and can be used for sinus lift procedure.

Socket Preservation Therapy with Acellular Dermal Matrix and Mineralized Bone Allograft After Tooth Extraction in Humans: A Clinical and Histomorphometric Study.

The aim of this study was to analyze through clinical and histomorphometric parameters the use of acellular dermal matrix (ADM) with or without mineralized bone allograft (AB) on bone formation in human alveoli after a 6- to 8-month healing period. A total of 19 patients in need of extraction of the maxillary anterior teeth were selected and randomly assigned to the test group (ADM plus AB) or to the control group (ADM only). Clinical and histomorphometric measurements and histologic analysis were recorded 6 to 8 months after ridge preservation procedures. Clinical parameters and amount of mineralized and nonmineralized tissue were measured and analyzed. In the clinical measurements, the test group showed reduced bone loss in the buccopalatal dimension after 6 to 8 months (intragroup analysis P < .01). Histologic findings showed higher percentages of mineralized tissue and lower percentages of nonmineralized tissue in the test group when compared with the control group (P < .05). In this randomized controlled clinical and histomorphometric study in humans, acellular dermal matrix in association with mineralized bone allograft reduced alveolar bone loss in the anterior maxillae both in height and width after a follow-up period of 6 to 8 months.

Vertical bone augmentation using recombinant bone morphogenetic protein, mineralized bone allograft, and titanium mesh: a retrospective cone beam computed tomography study.

This retrospective study evaluated the use of a composite graft of recombinant human bone morphogenetic protein-2 (rhBMP-2) and particulate mineralized bone allograft protected by a titanium mesh for vertical bone augmentation. A review of data on patients from four oral and maxillofacial surgery practices in the United States who required vertical augmentation prior to implant treatment was conducted. Vertical augmentation was accomplished with rhBMP-2 in an absorbable collagen sponge (ACS) carrier and particulate allograft. Cone beam computed tomography was used to measure vertical bone gains using this technique. Sixteen vertical ridge augmentation procedures were performed in 15 patients. The maximum vertical bone gains ranged from 4.4 to 16.3 mm. The average maximum vertical bone gain was 8.53 mm. The procedure allowed implant placement in all patients. Forty implants were inserted into the grafted ridges after a minimum of 6 months of healing. All implants integrated and were used for prosthetic support. This study suggests that rhBMP-2/ACS and particulate mineralized bone allograft protected by a titanium mesh offers favorable vertical bone gains to allow dental implant placement.

Severe Mandibular Atrophy Treated With a Subperiosteal Implant and Simultaneous Graft With rhBMP-2 and Mineralized Allograft: A Case Report

A 71-year-old patient was successfully rehabilitated by means of a 3D model-derived, hydroxyapatite-coated titanium subperiosteal mandibular implant. The implant was specifically designed to allow bone augmentation. The deficient bone was simultaneously grafted with mineralized bone allograft and recombinant bone morphogenetic protein -2 (rhBMP-2). The 32-month postoperative cone beam computerized tomography follow-up showed vertical bone augmentation beneath the implant frame.

Comparison of the Ex Vivo Expansion of UCB-Derived CD34+ in 3D DBM/MBA Scaffolds with USSC as a Feeder Layer.

Ex vivo expansion of hematopoitic stem cells is an alternative way to increase umbilical cord blood (UCB)-CD34+ cells for bone marrow transplantation. For this purpose demineralized bone matrix (DBM) and mineralized bone allograft (MBA) as two scaffolds based on bone matrix and stem cell niche, were simultaneously used to enhance the effect of human mesenchymal progenitor cells (MPCs) - unrestricted somatic stem cells (USSCs) - as a feeder layer. USSCs were isolated and characterized by morphological and immunological analysis then seeded on both scaffolds as a feeder layer. UCB-CD34(+) were isolated by MACS method and were co-culture expanded by USSC in 3D and 2D environments. After 3 weeks expansion, cells were counted and were assessed by karyotype, flow cytometry, clonogenic activity, and long-term culture-initiating cells (LTC-IC). Co-culture expansion in DBM and MBA was 29.22-fold and 27.77-fold, no significant differences in colony and LTC-IC were obtained. Maximum number of colonies belonged to the day 14 with the 73% CFU-GM (Colony Forming Unit- Granulocyte/Macrophage) in contrast to the day 0 which was BFU-E/CFU-E (Burst/Colony Forming Unit-Erythroid). Flow cytometry indicated that the percentage of CD34+ marker was decreased in USSC co-culture and the highest percentage was observed in simple 2D culture. Because of acid extraction in the DBM production process, mineral materials were removed and the protein background that was more flexible was presented. Therefore these results suggest that USSC-DBM can be a suitable ex vivo mimicry niche by intensifying of surface/volume ratio and supporting the stem cell differentiation and expansion.

Expanded vs. dense polytetrafluoroethylene membranes in vertical ridge augmentation around dental implants: a prospective randomized controlled clinical trial

This prospective randomized controlled trial was designed to test the performance of titanium-reinforced dense polytetrafluoroethylene (d-PTFE) membrane vs. titanium-reinforced expanded polytetrafluoroethylene (e-PTFE) membrane in achieving vertical bone regeneration, both associated with a composite grafting material. The study enrolled 23 patients requiring bone augmentation with guided bone regeneration (GBR) procedures for placing implants in atrophic posterior mandibles (available bone height <7mm). Implants were inserted and left to protrude from the bone level to achieve the programmed amount of vertical regeneration. Defects were filled with a composite bone graft (50% autologous bone and 50% mineralized bone allograft) and randomly covered with either an e-PTFE membrane (control) or a d-PTFE membrane (test). Membrane removal was performed after 6months, and changes in bone height were recorded. Seventy-eight implants were inserted in 26 mandibular sites contextually to vertical ridge augmentation procedures. The healing period was uneventful in all sites, and the vertical defects were satisfactorily filled with a newly formed hard tissue. Mean defect fill after 6months was 5.49mm (SD±1.58) at test sites and 4.91mm (SD±1.78) at control sites. The normalized data (percentage changes against baseline) did not show any statistically significant difference between test and control groups (P=NS). Based on the data from this study, both d-PTFE and e-PTFE membranes showed identical clinical results in the treatment of vertical bone defects around implants, using the GBR technique. The membrane removal procedure was easier to perform in the d-PTFE group than in the e-PTFE group.

Surgical Management of Oro-Antral Communications Using Resorbable GTR Membrane and FDMB Sandwich Technique: A Clinical Study

The paper describes a new technique for closure of the oro-antral communication, in which both hard (bone) and soft tissue closure was achieved. The technique uses a Guided Tissue Regeeration (GTR) membrane and Freez Dried Mineralized Bone (FDMB) allograft for closure of the defect. Aim of the study was to assess the advantages of the surgical management of oro-antral communications using resorbable GTR membrane and FDMB sandwich technique. A total 10 patients were selected in whom dental extractions were complicated by formation of oro-antral communication (OAC). The resorbable guided tissue regeneration membrane (PERIOCOL-GTR) and freeze dried mineralized bone allograft material was used. Some cancellous granules of freeze dried bone allograft was sandwiched between sheaths of appropriately trimmed collagen membrane which was previously sutured together on three sides using 3/0 resorbable polyglycolic acid suture (vicryl). The fourth side was then adequately closed using the same suture after the bone graft had been inserted, thus creating a closed sandwich. The prepared sandwich was then tucked into the OAC in such a way that it formed a convexity towards the sinus and a concavity towards the alveolar bone. The rough surface of the sandwich is faced to the alveolar bone and additional bone graft is filled into this concavity. Suturing done without tension. Post-operative orthopantomogram was taken to radiologically quantify the amount of bone grafting/augmentation and closure of oro-antral fistula. There was an average of 11.84mm bone formation after 6months, the average width preserved and obtained was 6.9 mm. By the end of 4months there was evidence of bone formation in 7 subjects and in three subjects bony trabeculae formed was almost similar to the adjacent bone. By the end of 6months follow-up of 7 subjects showed trabeculae indistinguishable from the adjacent bone. The study was done in 10 patients with a follow-up period of 6months and found to be excellent in the formation of new bone. The technique is simple and excellent for closure of the oro-antral communications especially when subsequent placement of end osseous implant is considered without the need of donor site surgery for bone grafting.

Growth Factor‐Mediated Sinus Augmentation Grafting With Recombinant Human Platelet‐Derived Growth Factor‐BB (rhPDGF‐BB): Two Case Reports

Introduction: In the following two case reports, growth factor‐mediated sinus augmentation surgery is used to treat significant posterior maxillary alveolar bone deficiency. At initial examination, preexisting subsinus alveolar bone height was ≤3 mm. A composite graft of anorganic bovine bone mineral (ABBM) + mineralized bone allograft was combined with recombinant human platelet‐derived growth factor‐BB (rhPDGF‐BB) for augmentation grafting via a traditional maxillary lateral wall osteotomy approach to the sinus. In both cases, early implant placement and loading following sinus grafting, as well as long‐term clinical follow‐up, document potential benefits of growth factor‐mediated bone regenerative sinus augmentation procedures. The significantly abbreviated durations seen in these two cases between sinus augmentation grafting and implant placement and prosthetic restoration, to the best of our knowledge, have not been previously reported in the literature.Case Presentations: Two adult males presented with severe posterior maxillary alveolar bone atrophy, with a maximum subsinus bone height of 3 mm in patient #1 and &lt;1 mm in patient #2. For each patient, a 50:50 particulate composite graft of ABBM and mineralized allograft was hydrated with 1 mL of 0.3 mg/mL rhPDGF‐BB. Four and one‐half (4.5) and 3.5 months following grafting in patient #1 and #2, respectively, implants were placed and core biopsy specimens obtained. Histologic examination of osteotomy cores demonstrated significant amounts of vital bone for each patient. Definitive implant‐supported restorations in full occlusion were placed 8.5 and 7.5 months following sinus grafting for patient #1 and #2, respectively. Three (3) and 2.4 years following implant placement, all implants were well integrated, with no evidence of radiolucency at the implant‐to‐bone interface.Conclusion: The addition of tissue‐engineered proteins, i.e., rhPDGF‐BB, to sinus augmentation protocols may allow earlier implant placement secondary to accelerated bone formation following grafting in the severely pneumatized sinus and may provide for increased long‐term positive clinical outcomes.

Histologic Analysis of Healing After Tooth Extraction With Ridge Preservation Using Mineralized Human Bone Allograft

Ridge preservation was developed as a therapy to prevent severe bone resorption after tooth extraction. The purpose of this study is to determine if there is any difference in the amount of new bone formation ≈3 months after extraction and ridge preservation compared to that after ≈6 months. Minimally traumatic extraction with ridge preservation using mineralized human bone allograft was performed at 38 single-rooted tooth sites in 33 subjects. Sixteen sites healed for an average of 14 weeks (early healing), whereas 22 sites were allowed to heal for an average of 27 weeks (delayed healing) before harvesting bone core samples. Histomorphometric analysis was performed to determine the percent of new bone formation, residual graft particles, and connective tissue/non-mineralized structures for each site. All specimens showed evidence of new bone formation, with most of the residual graft particles surrounded intimately by woven bone. No statistically significant differences in the amount of newly formed bone or residual graft particles were found between the two groups. Overall, the early healing group demonstrated a mean of 45.8% new bone, 14.6% residual graft material, and 39.6% connective tissue/non-mineralized tissue. The delayed healing group showed mean values of 45%, 13.5%, and 41.3%, respectively. The results of this study suggest that waiting ≈6 months after tooth extraction and ridge preservation using mineralized bone allograft does not provide a greater amount of new bone formation or less residual bone particles compared to that after only ≈3 months.

Comparison of Dermal Matrix and Polytetrafluoroethylene Membrane for Socket Bone Augmentation: A Clinical and Histologic Study

Remodeling and resorption of the alveolar crest, specifically at the buccal aspect, characterize the healing extraction socket. These result in narrowing and shortening of the alveolar ridge, which compromise esthetics and complicate restoration. Alveolar ridge augmentation has been proposed to facilitate future site restoration by minimizing ridge resorption. Therefore, the purpose of this study was to compare extraction socket healing and alveolar ridge alteration after socket augmentation using bone allograft covered with an acellular dermal matrix (ADM) or polytetrafluoroethylene (PTFE) membrane. Twenty non-smoking healthy subjects were selected. Each subject required maxillary premolar, canine, or central incisor tooth extraction. The extraction sites were debrided and grafted with a mineralized bone allograft that was covered with an ADM or PTFE membrane. Postoperative appointments were scheduled at 2, 4, and 8 weeks. After 16 weeks of healing, final measurements were performed, and trephine core biopsies were obtained for histomorphometric analysis. Implants were placed immediately after biopsy harvesting. Eighteen subjects completed the study. All sites healed without adverse events and allowed for implant placement. PTFE membranes exfoliated prematurely, with an average retention time of 16.6 days, whereas the ADM membranes appeared to be incorporated into the tissues. Buccal plate thickness loss was 0.44 and 0.3 mm, with a vertical loss of 1.1 and 0.25 mm, for ADM and PTFE, respectively. Bone quality assessment indicated D3 to be the most prevalent (61%). Histomorphometric analysis revealed 41.81% versus 47.36% bone, 58.19% versus 52.64% marrow/fibrous tissue, and 13.93% versus 14.73% particulate graft remaining for ADM and PTFE, respectively. No statistical difference was found between the two treatment groups for any of the parameters. All sites evaluated showed minimal ridge alterations, with no statistical difference between the two treatment modalities with respect to bone composition and horizontal and vertical bone loss, indicating that both membranes are suitable for alveolar ridge augmentation.