不同连接设计种植全口义齿的三维光弹应力分析

目的：研究常规半口义齿、种植杆卡覆盖义齿及种植固定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。方法：用三维光弹应力冻结切片法，对在牙合力作用下的应力状况进行应力冻结，并分别在切牙区、尖牙区、前磨牙区、第一磨牙区、第二磨牙区作３ｍｍ厚切片；并在４颗种植体周围作包含种植体的５ｍｍ厚切片，分析其内部的应力分布状况。结果：种植覆盖义齿的种植体周围骨界面，牙槽骨的应力值均比常规义齿及种植固定义齿低，无论是哪种形式的种植义齿，都易发生远中种植体受力过大而松动。结论：种植覆盖义齿具有良好的力学特性；在义齿设计时应采取措施保护远中种植体。

Three-dimensional photoelastic stress analysis of implant-supported full dentures with different connectors

Objective: To investigate the stress distribution under occlusal force in the supporting tissuealveolar bone and implant resulted from normal single complete dentures, implantsupported overdentures and fixed implant dentures. Methods: Threedimensional photoelastic frozen section method was used to stressfreeze the stresssituation of occlusal force, and 3 mm slices were made from the areas of incisor, canine, premolar, first molar, second molar; 5 mm slices were made from the surrounding area and including the four implants to analyse the stress distribution in the slices. Results: The stress in the implantbone interface, alveloar bone surrounding the implant of the implantsupporeted overdentures was lowerthan that of the normal dentures and the fixed implant dentures. all the implant dentures were easy to be loosen by the more presured distal implants. Conclusion: The implantsupported overdentures show better mechanical characteristic. It is important to use some necessary methods to protect the distal implant in denture planning.