You Su-lan, Huang Yuan-liang, Sun Min, Xu Wei
Department of Stomatology, Shanghai East Hospital Affiliated to Tongji University, Shanghai 200120, China.
Shanghai Kou Qiang Yi Xue. 2009 Dec;18(6):567-71.
To investigate the stress distribution of 2 kinds of distal cantilevered fixed prostheses supported by 4 or 6 dental implants in edentulous mandible with three-dimensional finite element method.
The first design was 4 implants supported fixed prostheses with 6mm distal cantilever; the second design was 6 implants supported fixed prostheses with 6mm distal cantilever. Vertical force of 100 N was applied to the distal cantilever of fixed prostheses.
The bone stress was concentrated at the cortex of mandible. The maximum bone stress was at the cortex near the second implants from the point that the vertical force was applied. The maximum implant stress was at the terminal and medium implant-prostheses interface.
The bone around the terminal implant is easily to absorb and the terminal and medium implants are easily to fracture. The maximum stress of the implants and prostheses of two kinds of design are almost same(239Mpa). Two kinds of design can be applied in the clinic. 6 mm distal cantilevered fixed prostheses supported by 6 implants have the less bone stress than 4 mm distal cantilevered fixed prostheses in edentulous mandible.
采用三维有限元方法研究在下颌无牙颌中由4颗或6颗牙种植体支持的2种远端悬臂式固定义齿的应力分布情况。
第一种设计为4颗种植体支持的带有6mm远端悬臂的固定义齿；第二种设计为6颗种植体支持的带有6mm远端悬臂的固定义齿。在固定义齿的远端悬臂上施加100N的垂直力。
骨应力集中在下颌骨皮质。最大骨应力出现在从施加垂直力的点起第二颗种植体附近的皮质处。最大种植体应力出现在末端和中间的种植体 - 义齿界面处。
末端种植体周围的骨容易吸收，末端和中间种植体容易折断。两种设计的种植体和义齿的最大应力几乎相同（239MPa）。两种设计均可应用于临床。在下颌无牙颌中，由6颗种植体支持的6mm远端悬臂式固定义齿比由4颗种植体支持的4mm远端悬臂式固定义齿的骨应力更小。
