腺相关病毒介导的骨形态发生蛋白7基因促种植体周骨缺损修复的实验研究

目的观察载bmp7基因的腺相关病毒（rAAV- BMP7）复合Bio- Oss的基因治疗方法对种植体周骨缺损修复的影响。方法体外构建载bmp7基因的腺相关病毒，并与Bio- Oss复合。6只雄性新西兰大白兔双侧胫骨植入种植体，并制备直径8 mm、深4 mm的种植体周骨缺损，A组骨缺损区填入rAAV- BMP7/Bio- Oss复合物；B组仅填入Bio-Oss；C组不充填材料。术后4、8周分期处死动物，取样进行组织学观察和形态学分析。结果A、B组骨缺损处均有新骨形成，A组较B组新骨形成更早、新生骨量更多、骨成熟程度更高（P<0.05）。结论rAAV- BMP7复合Bio- Oss较单纯植入Bio- Oss能更快、更有效地促进种植体周围骨缺损形成新骨，新骨量大且成熟度高，并能形成理想的种植体- 骨结合界面。

Effect of Bio-Oss loading with rAAV-BMP7 on regeneration of bone defects around dental implant

Objective To evaluate in vivo gene delivery of Bio-Oss coated with adeno-associated virus-mediated human bone morphogenetic protein 7(rAAV-BMP7/Bio-Oss) for bone regeneration around dental implants. Methods In vitro rAAV-BMP7 were constructed and compounded with Bio-Oss. In 6 male New Zealand rabbits, two hydroxya- patite(HA) coated titanium dental implants were placed respectively to each animal in the bilateral tibia metaphysis. Before implantation, a standardized gap(8 mm in width, 4 mm in depth) was created between the implant surface and the surrounding bone walls. Rabbits were randomly divided into three groups(group A, B, C). Gaps of group A were filled with rAAV-BMP7/Bio-Oss(n=4), gaps of group B were filled with Bio-Oss alone(n=4), and gaps of group C were filled with nothing(n=4). The rabbits were sacrificed at 4 and 8 weeks respectively, and the sclerous tissue slices obtained, then histology and histomorphometric analysis were conducted. Results Histological and histomorphometric analysis revealed an enlarged bone-forming area in the bone defects of group A and B at 4 and 8 weeks after implantation. Greater bone-implant contact was achieved with rAAV-BMP7/Bio-Oss than with Bio-Oss alone and this difference was statistically significant(P<0.05). Conclusion rAAV-BMP7/Bio-Oss can induce a stronger peri-implant bone reaction and larger new bone formation than Bio-Oss alone in the treatment of bone defects adjacent to titanium dental implants.