Osseointegration of Titanium Implants Following Guided Bone Regeneration Using Expanded Polytetrafluoroethylene Membrane and Various Bone Fillers

The purpose of this study was to evaluate the percentage of bone-to-implant contact following guided bone regeneration using expanded polytetrafluoroethylene (e-PTFE) membranes and various bone fillers in a beagle dog model. A staged approach was used for initial bone regeneration of surgically created defects and subsequent implant placement in newly regenerated ridges. Three months after bilateral extraction of the mandibular premolars and first molars, rectangular, distal-extension defects that included the entire width of the ridge buccolingually were surgically created in the alveolar processes. All defects were covered with an e-PTFE membrane, and several bone fillers were placed, in a randomized fashion, under the membrane: autogenous bone, demineralized freeze-dried bone, anorganic bovine bone, tricalcium phosphate granules, and collagen sponge. One site in each animal was treated with e-PTFE barrier membrane alone as control. Following an 8-month healing period, nonsubmerged titanium implants (36 total) were placed in regenerated bone following membrane removal. Three months later, the animals were sacrificed, and nondecalcified buccolingual sections were evaluated histometrically for bone-to-implant contact. All sites demonstrated high percentages (50% to 65%) of bone-to-implant contact, with no significant differences across the various treatment groups. In addition, all tested bone fillers formed a complex that supported and maintained the osseointegrated implants in a healthy state, with no apparent signs of peri-implantitis. Using a staged approach, the present study provided histologic and histometric evidence that implants placed in entirely regenerated bone can achieve and maintain osseointegration, regardless of the type of bone fillers used.