不同设计形式RPD对支持组织应力分布影响的光弹分析

目的:探讨分裂式设计与RPI设计制作的钴铬合金铸造支架RPD修复KennedyⅠ类缺损对支持组织应力分布的影响,为优化义齿设计提供实验依据。方法:分别以分裂式设计和RPI设计两种设计形式的钴铬合金铸造支架RPD修复下颌牙双侧游离缺失,用三维光弹应力冻结切片技术测试义齿加载后对基牙和缺牙区牙槽骨的应力分布,并加以分析比较。结果:钴铬合金分裂式设计的铸造支架RPD承受压力沿基牙牙体长轴传导,基牙远中所受扭力较小。结论:对于KennedyⅠ类牙列缺损,钴铬合金分裂式设计的铸造支架RPD使支持组织受力均匀、合理,减小了基牙受到的扭力,达到基牙保护的目的,是一种值得推广的设计。

The photoelastic study of the stress distribution on the supporting tissues of removable partial dentures with different designs.

Objective： To study the stress distribution on the supporting tissues of Kennedy Class I removable partial dentures with splitting and RPI designs of CoCr alloy, in order to provide basis for the application of casting frame flexible denture. Method： Mandible bilateral distal-extension edentulous were restored with RPDs in splitting and RPI designs of CoCr alloy.Three dimensional photoelastic frozen section method was used to test the stress distribution on abutment and e- dentulous alveolar.The stress of two forms dentures were compared with each other. Result： The metal framework removable partial denture with splitting exhibited lower torque on the distal of the abutment teeth, and the stress transferred to the abutments though the long axel of teeth. Conclusion： Among Kennedy class I removable partial dentures, the metal frame- work removable partial denture with splitting exhibits better stress pattern,reduce the torque tO the abutment,protect the abutment, and should be considered as a preferable design.