不同角度桩核的应力分析

Three dimensional Finite Element Analysis of the Effects of Posts and Cores with Different Angles

目的 本实验模拟临床前牙采用制成一定角度铸造桩核的方法 ,以改善前牙排列情况。方法 采用Ansys有限元分析软件对不同角度桩核在牙根内的应力分布情况进行分析。结果 牙根内应力与载荷力和牙长轴形成交角的大小成正相关关系 ,牙根内应力分布趋势与交角的方向有关 ,并且施力点与釉牙骨质界距离越近 ,对牙根应力影响越大。结论 临床上采用铸造桩核矫治个别唇向错位上前牙时 ,应避免核桩过度倾斜 ,并注意牙备时保证唇舌侧根管壁厚度及完成修复后的调牙合 ,以免发生根折。

Objective The test is an analogue of the conditions that cast post and core can be made with different angles to get the core incline lingually or facially in clinic, so that the arrangement of the anterior teeth may be improved. Methods Analyse the stress distribution and concentration in the dentin of posts and cores with different angles by Ansys three dimensional finite element stress analysis method. Results The stress in root was positively related to the angles between the load and the axis of the tooth, the stress distributoin in dentin was related to the direction of the core but not related to the angles. The closer the distance from the load to cemento enamel junction,the greater the effect of the load on the stress in dentin. Conclusion When the cast post and core with angle was used to rectify the facially malpositional maxillary anterior teeth, the core should not be inclined lingually excessively. It is important to assure the thickness of the facial and lingual canal wall during tooth preparing and to adjust the occlusion so that the root fracture can be avoided.