摘要： 目的： 比较不同悬臂设计下颌种植支持全口义齿的骨及种植体应力分布特点，为临床种植修复提供生物力学分析依据。方法： 建立3组下颌6个种植支持全口义齿的三维有限元模型，悬臂分别为3、6、9 mm。在悬臂末端垂直加载100 N的力。结果： 种植全口义齿悬臂末端垂直加载时，末端种植体骨应力集中，易发生松动失败；末端种植体及中间种植体颈部应力集中，易发生植入体与基桩连接失败；连梁应力集中在与末端种植体连接处，此处易发生折断。悬臂长度增加骨应力、种植体应力及连梁应力明显增加。结论： 悬臂越短越有利于力的均匀分布。6个种植体支持短悬臂修复设计较符合生物力学分布原理。

关键词: 无牙下颌, 固定修复, 牙种植, 应力, 有限元方法

Abstract: Objective: This study was aimed to investigate the stress distribution within the 3 mm, 6 mm, and 9 mm distal cantilevered fixed prostheses supported by dental implants. Methods: A 3D edentulous mandibular bone was modeled from computed topography (CT) images of the patient. Physiomechanical parameters of cancellous and cortical bone were analyzed with Mimics 10.0 software. Vertical force of 100 N was loaded to the distal cantilever of fixed prostheses. Results: The maximum stresses were found at the terminal implant-bone interface. The magnitude of the stress at implant and the implant bone interface decreased when the distance between implant and the point of loading increased. Therefore, the bone around the terminal implant was easily to absorb and the terminal implant was easily to fracture. In the immediate vicinity of the terminal implant, the maximum compressive stress appears at the gingival part of the distal cantilever arm of the framework and the maximum tensile stress at the occlusal part. Hence, the framework will easily to brake  at this part. The distal cantilevers of implant-supported fixed prostheses adversely influenced the stress even distribution among implant-bone interface or implants. Conclusion: The shorter the distal cantilevers, the better the distribution of the stress. Six implants supporting short distal cantilevers restoration design may meet the principles of biomechanics distribution.

Key words: edentulous mandible, fixed prostheses, dental implant, stress, finite element method

中图分类号: 

• R782.13

• O242.21