拔牙创愈合过程对邻近微种植体稳定性影响的组织学研究

Effect of healing process of dental extraction wound on the stability of microscrews implanted nearby:a histopathological study

目的通过拔牙创愈合的生理过程对邻近微种植体-骨界面骨质改建的影响进行研究。方法选取8只健康雄性Beagle犬,按不同愈合时间段(1、3、8、12周)采用完全随机分组方式分成4组,拔除每只Beagle犬下颌第3和第4双尖牙(P3、P4)。实验组微种植体邻近拔牙创区域(P3、P4区域),对照组微种植体位于第2双尖牙(P2)和第1磨牙(M1)区域。分别在植入微种植体后愈合的第1、3、8、12周处死动物。制备去除微种植体脱钙组织切片,对处于不同阶段的种植体-骨界面进行组织学观察。结果第1周,实验组和对照组均表现为明显的炎症性反应。第3周,实验组主要表现为骨吸收,对照组主要表现为骨重建。第8周,实验组和对照组均表现为骨界面基质钙化,骨界面的网状骨已逐渐向板层骨过渡。第12周,实验组和对照组微种植体-骨界面出现钙化的层状骨。结论拔牙创对微种植体周围骨改建进程会产生影响,在植入早期,邻近拔牙创的微种植体-骨界面炎症反应和骨吸收效应明显重于对照组,此期即刻加载风险较大。

Objective To investigate the effect of the physiological healing process of dental extraction wound on bone structure reconstruction around bone-implant interface.Methods Eight male Beagle dogs were randomly divided into four groups according to different healing time（1,3,8 and 12 weeks） after dental extraction.The third and the fourth premolars（P3 and P4） were extracted from each dog.The microscrews were implanted into the adjacent areas of P3 and P4 in the experimental group,and were implanted into the areas of the second premolar（P2） and the first molar（M1） in the control group.The dogs were sacrificed at 1,3,8 and 12 weeks,and histomorphological observation was performed at different healing time after implantation.Results At 1 week after implantation,obvious inflammatory reactions were observed at bone-implant interface in both of the experimental group and the control group.New bone was formed on the bone-implant interface of the control group,and bone resorption was detected in the experimental group at 3 weeks after implantation.At 8 weeks after implantation,bone matrix became calcification,and the reticulated bone transformed into lamellar bone at the bone-implant interface in both of the experimental group and the control group.At 12 weeks after implantation,there was obvious bone formation between the threads of the microsrews in both of the experimental group and the control group.Conclusion The healing process after implantation is affected by dental extraction.At the early stage of implantation,the degree of inflammatory reaction and bone absorption at bone-implant interface was more significant in the experimental group than that in the control group,thus increasing the immediate loading risk.