上颌全口义齿基托多因素三维有限元分析

Effect of palatal vault, cusp inclination and position of artificial teeth on the stress distribution in the base of the maxillary complete dentures

目的:研究不同腭穹隆形状时,人工牙排列位置、牙尖斜度对上颌全口义齿基托应力分布状况的影响,为上颌全口义齿修复的优化设计提供理论依据。方法:应用三维有限元应力分析法,研究在不同腭穹隆形状时,人工牙排列位置、牙尖斜度对上颌全口义齿基托应力分布状况的影响。结果:各种载荷条件(三种腭穹隆形状、五种人工牙排列位置)下,随着牙尖斜度的增加,基托的应力增大。后牙颊向偏离牙槽嵴顶,前牙唇向偏离牙槽嵴时,基托应力集中区的强度均发生变化。三种腭穹隆形状时,基托应力集中强度依次为:腭穹隆低平、腭穹隆适中、高腭穹隆。结论:牙尖斜度、腭穹隆形状和人工牙的排列位置对上颌全口义齿基托的应力集中状况有明显的影响作用。提示临床行全口义齿修复时,应考虑患者腭穹隆形状,选择适当牙尖斜度的人工牙,特别是腭穹隆低平患者。

Objective: To study the stress distribution in the base of the maxillary complete dentures (MCD) with palatal vault, cusp inclination and position of artificial teeth so as to provide the theoretical basis for the best design of MCD. Methods: 3-D FEM was used to study the effects of the stress distribution in the base of MCD with different palatal vault, cusp inclination and position of artificial teeth. Results: As the cusp inclination grew, the stress concentration in the base increased in different loading conditions. The stress concentration was changed when artificial teeth went away from alveolar ridge. The stress concentration in the base of low palatal vault was stronger than the medium, and the medium was stronger than the deep. Conclusions: The palatal vault, cusp inclination and position of artificial teeth have a clear influence upon the stress concentration in the base of MCD. Special attention should be paid to palatal vault and cusp inclination for making complete dentures especially for flat palatal vault.