Bone regeneration after topical BMP‐2‐gene delivery in circumferential peri‐implant bone defects

Objectives: The aims of this study were to evaluate the rate of bone formation and osseointegration after topical gene delivery with a liposomal vector system carrying bone morphogenetic protein (BMP)‐2 cDNA in combination with a collagen carrier and autologous bone as a carrier in freshly created peri‐implant bone defects. Materials and methods: Eight domestic pigs received nine calvariae defects each (10 × 7 mm). A dental implant was inserted into the centre of each defect. In the test groups, the remaining space was filled with the liposomal vector/BMP‐2 complex combined with a collagen carrier ( n =18) or an autologous bone graft ( n =18). Control groups were collagen only ( n =18) and autologous bone graft only ( n =18). Results: There was a significant difference in mineralisation rate in the BMP‐2/bone graft (29.9%± 4.8 and 68.3%± 7.2) and bone graft only (22.6%± 2.6 and 49.4%± 13.9) groups after 7 and 28 days. Mineralisation values were also significantly higher in the BMP‐2/collagen group (21.2%± 16.2 and 53.1%± 12.5) compared with the collagen‐only group (8.2%± 7 and 41%± 8.1) in two different regions after 28 days. Also the bone‐to‐implant contact was significantly increased in the BMP‐2/bone graft group after 28 days and in the BMP‐2/collagen group after 7 and 28 days compared with their control groups. Conclusions: The results of this study show a significantly positive effect of liposomal vector/BMP‐2 on bone regeneration and osseointegration in bony circumferential peri‐implant defects.