Bone Formation Following Implantation of Bone Biomaterials Into Extraction Sites

Abstract

Adequate bone volume is imperative for the osseointegration of endosseous implants, but postextraction resorption and remodeling may challenge implant placement. The use of bone biomaterials has been advocated to fill extraction sites and to enhance primary implant stability during osseointegration. The objective of the case series was to evaluate bone formation histologically and biomechanically in extraction sites following implantation of three commercially available bone biomaterials to compare their ability to allow guided bone regeneration. Thirty-six periodontally involved teeth were extracted from eight healthy non-smoking subjects. At least two bone biomaterials, a synthetic sponge based on polylactic-polyglycolic acid technology (FIS), bovine porous bone mineral (BPBM), or a natural coral derivative physically and chemically transformed into a calcium carbonate ceramic (COR), and one non-grafted control were applied to the extraction sockets within each subject and were covered by an expanded polytetrafluoroethylene device. The devices were removed after 2 months, and trephine biopsies were obtained from each site 4 months later. At that time, endosseous implants were placed in 25 of the sites, and healing abutments were placed; measurements were taken 4 to 6 months later with an electronic mobility testing device. The percentage of residual biomaterial was 5.6% +/- 8.9% for FIS (P <0.001), 20.2% +/- 17.0% for BPBM (P <0.05), and 12.0% +/- 16.4% for COR (P <0.001). The amount of residual biomaterial after 6 months showed a significant relationship with the insertion torque measurements during the first third of implant insertion (P <0.05) and with values of the electronic mobility testing device at the abutment connection (P = 0.05). Histologically, new bone apposition was seen on BPBM particles. FIS sites showed similar ingrowth of blood vessels and osteocytes as empty controls. All sites revealed good primary stability at implant insertion and proper implant rigidity at abutment placement, indicating that early implant osseointegration was not influenced by the application of bone biomaterials used in this study.