上颌全口义齿后牙排列位置对腭部基托应力影响的有限元分析

Three dimensional finite elements analysis of effect of posterior teeth arrangement on stress of denture base in the maxillary complete denture

目的运用三维有限元的方法分析上颌全口义齿后牙不同排列位置时上颌全口义齿腭侧基托的应力应变,进一步探讨上颌全口义齿基托的折断机理。方法采用Ansys有限元应力分析大型结构分析软件,建立三维数学模型,改变上颌全口义齿后牙排列位置,分别向颊侧平行移动2mm、4mm、6mm,计算腭侧基托各部位应力应变值。结果上颌全口义齿后牙从牙槽嵴顶向颊侧分别外移2mm、4mm、6mm,腭侧基托的应力应变值随外移量的增加而增加(P<0.05)。结论上颌全口义齿排牙时,后牙颊侧外移量的增加,导致腭侧基托中部应力应变值逐步增加,是引起基托断裂的重要原因之一。提示上颌全口义齿后牙排列以位于牙槽嵴顶为宜,其颊侧外移量最好不超过2mm。

Objective To investigate the effect of posterior teeth arrangement on stress of denture base in the maxillary complete demure by 3-d finite elements analysis. Methods The large constructive instrument software was used to establish a 3-D model The stress of the denture base in different arrangement of posterior teeth in the maxillary complete denture was measured. Results The stress was significantly increased when posterior teeth were moved 2mm,4mm and 6mm from alveolar crest to buccal side （ P 〈 0. 05 ） and the stress increased with the moved distance. Conclusion Buccal movement of the posterior teeth was the important reason for the fracture of complete denture base.