局部应用重组人甲状旁腺激素(1-34)对即刻种植骨整合的作用

摘要

背景:在小鼠胫骨种植模型的研究中,有学者发现负载重组人甲状旁腺激素(1-34)的CaP涂层种植体可在早期就显示强大的成骨作用,但并未将这种涂层应用于口腔环境中.目的:分析局部应用重组人甲状旁腺激素(1-34)对兔即刻种植后骨整合的作用.方法:将9只新西兰大白兔随机分为实验组(6只)和对照组(3只),拔除每只兔上下4颗切牙后在拔牙窝下段填塞冻干骨,实验组24个拔牙窝上段即刻植入含有重组人甲状旁腺激素(1-34)的CaP涂层钛螺纹钉,对照组12个拔牙窝上段即刻植入CaP涂层钛螺纹钉.植入后4,8,12周获取完整上下颌骨标本,进行大体与组织学观察、扭矩实验测试、X射线及骨密度分析.结果与结论:①两组螺纹钉周围新生骨量均随时间延长而升高,实验组螺纹钉周围X射线灰度值始终高于对照组(P<0.05);②实验组植入后不同时间点的扭矩值高于对照组(P<0.05);③植入后4-12周下颌骨标本组织学观察显示,实验组成骨细胞较为活跃,新生骨与成熟骨出现早于对照组,于植入4周时即可见大量新生血管,而对照组植入8周时仅可见少量新生血管;④结果表明,局部应用重组人甲状旁腺激素(1-34)能够促进早期种植体周围新骨形成,提高种植体-骨界面结合强度,增强种植体稳定性.%BACKGROUND: Based on a mouse model of tibial implantation, some scholars have found that the CaP-coated implant with recombinant human parathyroid hormone (1-34) (PTH(1-34)) shows strong osteogenesis effect at early stage, but this coating has not been applied in the oral environment.OBJECTIVE: To explore the role of local application of PTH(1-34) on immediate implant osseointegration . METHODS: Nine New Zealand white rabbits were randomly divided into two groups (six in experimental group and three in control group). All of the tooth sockets were filled with heterogeneous freeze-dried bone firstly after four incisors of each rabbit were extracted. In the experimental group, a titanium screw with PTH(1-34) loaded CaP coating was implanted into each tooth socket, while in the control group, a titanium screw with only CaP coating was implanted. The animals were executed respectively at 4, 8, 12 weeks after operation, and the intact maxillary and mandibular specimens were harvested and tested by gross observation, bone density analysis, torque test, histologic al observation, X-ray observation.RESULTS AND CONCLUSION: The gray value and maximum torque value of regenerated osseous tissue at different time points in the experimental group were significantly higher than those in the control group (P < 0.05). Within 4-12 weeks after implantation, regenerated and mature bone tissue appeared earlier in the experimental group than the control group. A large amount of new blood vessels were seen in the experimental group at 8 weeks after implantation, while in the control group, there were only few new blood vessels. To conclude, the local application of PTH(1-34) can promote bone formation, improve the implant-bone bonding strength, and enhance the stability of the implant.