用有限元法比较粘接桥与固定桥支持组织的应力分布

Comparison of the stress distribution of oral supporting tissue be- tween a fixed bridge and a resin bridge with a finite element method

作者用Ａｕｔｏ－ＣＡＤ模拟口腔修复体的设计，采用三维有限元法分析了粘接桥与固定桥支持组织的应力分布情况．结果表明：粘接桥与固定桥一样具有传递及分散直接受载牙的负荷能力，减轻了直接受载牙的负荷．但是，当桥体上垂直加载时，粘接桥修复时基牙牙周膜应力分布不如固定桥修复时基牙牙周膜内应力分布均匀，且桥体下缺牙区粘膜的应力值较高．提示粘接桥修复时更应充分考虑基牙条件，缺牙区间隙的大小及修复材料的选择．

A three-dimensional finite element model was used to investigate the stress distribution of oralsupportion tissues when the analogue denture design of a fixed bridge and a resin- bonded bridge was donewith auto-CAD software system in computer. The result indicated a resin-bonded bridge could transfer theloads from one abutment to another and reduced the magnitude of the loading-tooth as a fixed bridge did. Loaded on the pontic vertically, the distribution of the stresses in periodontal ligament was less uniform witha resin- bonded bridge than a fixed bridge and the magnitude of stresses were higher in edentulous area mucosawith a resin- bonded bridge. Abutment condition, the space of edentulous area, the proper choice ofprosthodontic materials should be considered especially when a resin- bonded bridge was used.