rhBMP-2在种植体周围骨缺损修复中应用的组织学观察

目的:研究rhBMP-2及不同载体在种植体周围骨缺损修复中的应用。方法:在beagle犬下颌骨植入种植体,颊侧形成裂开性骨缺损,置入复合了不同浓度rhBMP-2的珊瑚羟基磷灰石人造骨(CHA)或可吸收胶原海绵(ACS)。种植体植入后2、4、8、12周,获取含种植体骨标本,进行组织学观察。结果:2周时,rhBMP-2组可见极少量的新生骨组织。4周时,rhBMP-2/ACS组新骨组织由牙槽骨顶端向缺损区中心方向生长;rhBMP-2/CHA组人造骨颗粒内部和周围出现呈岛状生长的新生骨组织。8周时,rhBMP-2/ACS组的新骨形成大片状结构;rhBMP-2/CHA组人造骨颗粒周围较多骨岛形成。12周时,rhBMP-2组的缺损区内骨量和骨高度进一步增加,与种植体形成骨性结合。浓度为0.05 mg/ml和0.2 mg/ml,载体为CHA或ACS促进骨再生作用差异无统计学意义。结论:以CHA或ACS为载体rhBMP-2能促进种植体周围骨缺损区内的骨组织再生并与种植体表面较好地结合。

Effect of rhBMP-2 on bone regeneration and osseointegration in peri-implant defects——Histological observation

Objective: To investigate the effects of rhBMP-2 in bone formation and osseointegration in peri-implant defects.Methods: 8 implants were placed in each of 8 beagle dogs.Dehiscence defects were surgically created on the buccal side of each implant.rhBMP-2 at 0.05 mg/ml or 0.2 mg/ml was combined into absorbable collagen sponge(ACS) or coraline hydroxyapatite(CHA) respectively and applied into the defects.ACS or CHA alone were used as the control.Animals were sacrificed 2,4,8 and 12 weeks after implantation respectively,non-decalcified ground sections of the bone samples with the implants were made and observed under microscope.Results: 2 weeks after implantation,the newly generated bone was minimal.4 weeks after implantation,in rhBMP-2/ACS group formations of trabeculae of woven bone could be seen in the defects,in rhBMP-2/CHA the CHA particles were surrounded by newly formed bone.8 weeks after implantation,in rhBMP-2/ACS group the newly formed bone consisted woven bone and lamellar bone.In rhBMP-2/CHA group islands of newly generated bone were dispersed throughout the defect area.12 weeks after implantation,in all rhBMP-2 groups,the newly generated bone increased.More bone was well adapted to the implant surface.No significant difference was observed between 0.05 mg/ml and 0.2 mg/ml rhBMP groups or between ACS and CHA groups.Conclusion: rhBMP-2 combined with CHA or ACS may promote bone regeneration and osseointegration in peri-implant defects.