Early loading of implants in vertically augmented bone with non-resorbable membranes and deproteinised anorganic bovine bone. An uncontrolled prospective cohort study.

Purpose: To evaluate the success rate 1 year after loading of early loaded implants placed in vertically augmented bone using deproteinised bovine bone (Bio-Oss®) and a titanium-reinforced membrane (Gore-Tex®). Materials and methods: Twenty patients provided 25 sites that were treated with vertical guided tissue regeneration (GBR) using Bio-Oss and expanded polytetrafluoroethylene titanium-reinforced membranes. After 1 year of healing, the membranes were removed and 64 implants were placed (baseline) and loaded 30 days later. Standardised periapical radiographs were obtained at baseline and 1 year thereafter. One independent assessor clinically evaluated the amount of tissue regenerated and peri-implant bone level based on the radiographs. Outcome measures were prosthesis success, implant success, complications, amount of vertically regenerated bone, peri-implant marginal bone levels and histology. Results: No patient dropped out. A total of 23 out of 25 sites healed uneventfully. Two sites showed early membrane exposure. In these sites, the surgery was repeated with success 2 months later. Clinical evaluation showed a mean vertical bone defect of 5.6 mm (SD 1.7). Mean vertical bone gain after GBR was 5.2 mm (SD 1.5). The histology of five samples retrieved from four patients showed a total percentage of xenograft and new bone of 52.6%, with dispersed graft particles surrounded by layers of bone. All implants were stable after 1 year of function, yielding a survival rate of 100%. Statistically significant peri-implant bone loss (0.95 mm; SD 0.21; 95% confidence interval 0.85 to 1.05; P 0.001) was observed radiographically from baseline to the 1-year follow-up. Conclusions: This prospective cohort study shows that by using deproteinised bovine bone and a non-resorbable titanium-reinforced membrane, vertical bone gain can be obtained and implants can be loaded after 30 days. The vertical regenerated tissue exhibited good stability over 1 year of implant function. Keywords: bone regeneration, bone substitute, implants, membrane Conflict of interest: All materials used in this study were purchased by the author and it is therefore free of any commercial or institutional interest.