Healing of buccal dehiscence defects at implant sites using demineralized tooth matrix

Abstract

Background: Following tooth extraction, the remodeling of the alveolar ridge could result in compromised dimensions for implant placement. Subsequently, the peri-implant bone defect would appear during implant placement, thus bone augmentation with bone grafting material is required to repair the defect. An autograft is considered as gold standard by its osteogenesis, osteoinductive, and osteoconductive properties. Despite the benefits associated with the use of autogenous bone, the limitations include small quantity, requiring the 2nd surgical site as well as increasing the risk of donor site morbidity, surgical costs and time. Therefore, the attempts to develop new bone graft substitutes have been conducted for several years. In this study, we develop fabricating protocols to transform the extracted human tooth to become a new bone graft material for use as an autologous graft in clinical practices, initially for small peri-implant bone defects. Objective: The aim of this study was to compare the clinical and radiological outcomes of autologous demineralized tooth matrix(Auto-DTM) with a resorbable membrane (test group) to an anorganic bovine bone xenograft with a resorbable membrane (DBBM; control group) in the treatment of buccal dehiscence-type defect at implant site. Materials and methods: Twelve buccal dehiscence defects during dental implant installation were repaired using DBBM (n=7) or Auto-DTM (n=5). The auto-DTM was prepared form the patient's own wisdom teeth and prepared according to PSU protocol before surgery. During implant installation at stage I surgery, the buccal dehiscence defects (width, height and area) were measured clinically and reconstructed using guided bone regeneration(GBR) technique with either DBBM or Auto-DTM and covered by a bioresorbable porcine-derived collagen membrane (Bio- Gide®). The stage II surgery was scheduled after the healing period of 4-6 months. Regarding radiographic evaluation, cone beam computed tomography (CBCT) were performed at immediately after stage I surgery and at 3-month of follow-up. The CBCT data was collected and analyzed by mean of specific softwares including One volume viewer and ITK-SNAP. Clinical parameters including soft tissue appearance, defect size (width, height and area) and graft integration, and radiographic parameters including midbuccal bone thickness and marginal buccal bone volume, were measured and analyzed. Results: All patients have uneventful healings. Soft tissue color and texture were not affected by grafting materials and surgical procedures. The buccal contour improved significantly after grafting, regardless of graft materials. Significant defect reduction was observed in both groups (P<0.05). In addition, there was no statistically significant difference in the percentages of defect reduction between the two groups (P>0.05). The graft integration between the surrounding host bone and Auto-DTM particles appeared more consolidate than the DBBM significantly (P<0.05). Radiographically at 3-month follow-up, the marginal buccal bone thickness and buccal bone volume obtained in the Auto-DTM group were not significantly different from the DBBM group (P>0.05). Conclusion: The autologous DTM can be used to repair the small-sized defects such as peri-implant dehiscence or fenestration defect reconstruction with comparable clinical and radiographic outcomes as the widely-used commercial xenograft(DBBM).