自然牙根支持及种植牙支持式下颌全口覆盖义齿的三维有限 …

研究自然牙根支持和种西基牙支持覆盖义齿在咀嚼过程中其周围骨皮质应力的差异，为改善种植覆盖义齿的修复效果提供依据。方法 借助于ＣＴ扫描与计算机辅助设计手段，用三维有限元方法比较自然牙根支持式与种植牙支持式覆盖义齿在采用不同固位装置，没咬合力状态下，支持组织应力分布的差异。

Three dimensional finite element analysis on the mandibular complete overdenture supported by nature roots or implants]

OBJECTIVE: To investigate the stress distribution around the bone tissue of overdenture supported by teeth roots or implants in the process of mastication which may assist to improve the design of the dentures. METHODS: By means of CT scan, CAD and a three distribution finite element methods to study the stress distribution of the supporting tissue of overdenture supported by roots or implants when various attachment retentive apparatus and various bite forces were applied. RESULTS: No matter overdenture supported by roots or implants the stress distribution on bone tissue are difference between the bar and stud attachments, However these difference were minor compared with the difference caused by the direction of force. The stress value of cortical bone around the roots or implants with twenty degree oblique force is 2.2-3 times higher than that with vertical force. Overdenture supported by implants produced 2.5-4 times higher stress in the cortical bone around than that of overdenture supported by roots when various superstructures or various loads were applied. CONCLUSION: It must consider to reduce the stress peaks and provent bone resorption by increasing the number of implants and using the force-breaking design of implant super-strcture when the overdenture were supported with implants only.