垂直负荷对种植体边缘骨应力分布的影响

Analysis of stress distribution of bone around the implant on vertical loads

目的 比较不同部位施加不同的垂直负荷对种植体边缘骨的应力分布的影响。方法采用电阻应变片法测试单个种植牙和 2个种植体支持的固定桥在垂直负荷时种植体边缘骨的应力。结果 负荷大小、负荷点以及二者的交互作用都可影响应力分布。单个种植牙的应力集中在种植体的颈部和根尖部 ,2个种植体支持的固定桥应力易集中在种植体近负荷点侧的根尖部、颈部 ,尤其是近负荷点的种植体。在游离端施加负荷时 ,应力与负荷大小、悬臂长度成正比。结论 减小咬合力、避免使用游离端种植义齿可以减小种植体边缘骨的应力 ,尤其是远中种植体。

Objective To analyze the stress distribution of bone around the implant on vertical loads.Methods Four linear strain gauges were placed in strategic locations. The vertical loads were applied at different points. The result of the stress was recorded at each gauge. Results The load,the location of load and their interactions indicated statistically significant difference in the distribution of stress. For the single-implant-supported fixed prosthesis the greater stress values were showed at the strain gauges positioned in the implant′s cervical and apical area near to loading points. For the two-implant-supported fixed bridge the greater stress values were showed at the stress gauges positioned in the two implants cervical and apical area near to loading points,especially at the implant near to loading points. As loads were applied at the cantilevered points,the magnitude of stress was directly proportional to the magnitude of load and the cantilevered length. Conclusions For the design of the implant-supported prosthesis the relief of load and the avoidance of cantilevered prosthesis should be considered to reduce the stress of the bone around the implant