种植体直径和长度对支持组织应力分布的影响

目的：观察种植体直径、长度变化时由种植体支持的下颌种植覆盖义齿，在牙合力作用下其支持组织——牙槽骨及种植体周围的应力分布状况，探讨种植体长度和直径变化对支持组织应力分布的影响规律。方法：用三维光弹应力冻结切片法，对４种不同长度，３种不同直径的种植体支持的种植覆盖义齿，在牙合力作用下的应力状况进行应力冻结，并在相应部位切片观察，以了解各种状况下其支持组织的应力分布状况。结果：种植体长度变化对种植体周围骨界面及牙槽骨应力的大小有较大的影响，两者呈负相关关系；而在临床常用的几种直径种植体中，直径变化对种植体周围骨界面及牙槽骨应力的影响不大。结论：在种植义齿设计时，应着重考虑种植体长度变化对种植体周围骨界面及牙槽骨应力的影响，种植体直径变化可不作考虑。

The influence of implant diameter and length on the stress distribution in the supporting tissues

Objective: To observe the stress distribution in the supporting tissuealveolar bone and implant under occlusal force. Methods:Threedimensional photoelastic frozen section method was used to stressfreeze the stresssituation under occlusal force of the overdentures sopported by implants with four different length and three different diameter; slices from corresponding areas were made to investigate the stress distribution in the supporting tissues in different situations. Results: A negative correlation between implant diameter or length and the strees distribution in the implantbone interface or the alveolar bone was found. But among the several most widely used implants with different diameter, no significant difference was observed about the stress distribution in the implantbone interface and alveolar bone surrounding the implants. Conclusion: The length of supporting implants must be considered in the design of implant denture.