种植体周围骨缺损的beagle犬动物模型的建立

Establishment of animal model of peri-implant bone defect

目的评估重组人骨形成蛋白2(rhBMP-2)及不同载体在口腔种植植骨手术中对成骨性能的影响、成骨特点以及所成骨与种植体的骨结合情况,建立一种符合种植体周围骨缺损特点的动物模型。方法以beagle犬为实验动物,拔除其双侧下颌前磨牙和第一磨牙,3个月后左右两侧各植入埋入式螺纹种植体各4枚,种植体颊侧形成3 mm×4 mm的裂开性骨缺损,缺损处分别植入浸润了0.05 mg/mL和0.2 mg/mL浓度rhBMP-2的珊瑚羟基磷灰石人造骨和可吸收胶原海绵或珊瑚羟基磷灰石人造骨与可吸收胶原海绵空白对照。分别于种植体植入后2、4、8、12周处死动物,取材制作种植体——骨磨片。结果 8只实验犬均无死亡,饮食、活动正常,3号犬有2枚种植体颈部暴露,种植体松动。组织病理学观察可见,随着时间延长,各组种植体周围骨缺损处的新生骨组织增加。与空白对照组相比,rhBMP-2处理的缺损内新生骨组织量较多,骨种植体结合率较高。结论本研究采用的建模方法,形成了统一的种植体颊侧颈部-中部的3 mm×4 mm的裂开性骨缺损区,较符合种植临床实际情况,能达到较好地模拟种植体周围常见骨缺损的目的 ,为今后种植体周围骨缺损修复的研究奠定了基础。

Objective To create an animal model of peri-implant bone defect and to evaluate the effect of recombinant human bone morphogenetic protein-2（rhBMP-2）carriers on bone regeneration and osseointegration of dental implant.Methods Bilateral mandible implants were performed in 8 beagle dogs.Subsequently Buccal peri-implant dehiscence（3 mm×4 mm） were surgically created.Further implant with rhBMP-2（0.05,0.2 mg/mL） in absorbable collagen sponge（ACS） or coraline hydroxyapatite（CHA） was applied to the defect.Animals were sacrificed at 2,4,8 and 12 week after implantation for non-decalcified ground sections of implants.Results Successful heal was observed in all except for Dog 3 with implant neck exposure and loosening of two implants.Recombinant human bone morphogenetic protein-2 induced increase of bone formation and bone-implant contact was observed by histology in peri-implant defects.Conclusion Peri-implant bone defect canine model is successfully created with surgical creation of peri-implant dehiscence defect in beagle dog for investigation of bone formation in peri-implant defect.