多根管桩核技术的临床应用及力学分析

Clinical and experimental evaluation of a single-piece core with auxiliary posts cast post in multirooted posterior teeth

目的回顾ParaPost预成桩与铸造桩核联合应用的多根管桩核技术对磨牙残根的临床修复效果。探讨多根管桩核技术修复时,桩的数目、长度与固位的关系。方法选择4颗牙尖均缺损或仅存1颗牙尖的磨牙残根病例69例,进行ParaPost预成桩与铸造桩联合应用的桩核修复,观察临床效果。收集因牙周病拔除的离体牙5例,将铸造桩与不同数目和长度的预成桩组合,建立25个实验模型,进行拉力实验测其抗脱位力。结果临床30个月追踪成功率为95%。拉力实验表明桩的数目增加最大脱位力增加,同等长度时多桩的最大脱位力大于单桩。结论ParaPost预成桩与铸造桩联合应用的多根管桩核技术是修复磨牙残根的有效方法。

Objective To introduce the technique of cast post with parapost in posterior teeth, and to investigate the relationship between the retention and the number and length of the posts in molars. Methods Firstly, experiments in vivo were performed. After root canal therapy, the posterior teeth with three or more missing cusps were selected and restored with cast post and parapost cast, then access the efficacy. Mechanical experiments in vitro were also performed. We changed the number and length of the paraposts, then use the pulling machine （Shimadzu Autograph） to record the maximal load that causes dislocation of the posts. Results After 30 months, about 95 % cases in clinic was successful Increasing the number of post will enhance the retention. Increasing the number of parapost and at the same time decreasing the length of both cast post and parapost can also supply enough retention. Conclusion The technique of cast post with parapost can restore molars which were severely destroyed effectively.