不同咀嚼功能下全瓷固定桥牙弓曲率的 三维有限元研究

目的 研究不同咀嚼功能下，全瓷固定桥牙弓曲率对固定桥应力数值及分布的影响。方法 通过 逆向工程建立以左上尖牙缺失后左上侧切牙、左上第一双尖牙为基牙的全瓷固定桥数字模型，并按照牙弓曲 率建立4 组模型。每组模型分别在固位体、桥体施加负载，用三维有限元法分析固定桥应力数值及分布情况。 结果 随着牙弓曲率的增加，固定桥内部的第一主应力以及等效应力值随之增加；载荷大小相同的情况下，侧 切牙组所表现的应力极值大于第一双尖牙组。结论 固定桥牙弓曲率及载荷位置是影响其应力数值和分布的 重要因素。牙弓曲率越大，固定桥应力值越大；载荷位置越远离第一双尖牙，固定桥应力值越大。

Three-dimensional finite element study on arch curvature and different masticatory functions of all-ceramic fixed bridge

Objective To study the influence of arch curvature and different masticatory functions of allceramic fixed bridge on stress and its distribution. Methods With reverse engineering method, the digital model of all-ceramic fixed bridge was inverted based on left upper incisor and left upper first premolar. According to the arch curvature of the fixed bridge, four sets of models were established. Each model was loaded on either retainers or the pontic. Stress value and the distribution of the fixed bridge were analyzed by the three-dimensional finite element method. Results With the increase of arch curvature of the fixed bridge, the first principal stress and the equivalent stress value of the fixed bridge increased significantly. Under the same load condition, the stress extremum of the second incisor group were obviously upregulated compared with that of the first premolar group. Conclusion Increase of the arch curvature, stress value of the fixed bridge, and distance away from first premolar the load position is closely associated with increase of stress of the fixed bridge.