夹层技术修复楔状缺损后牙颈部硬组织应力分析

目的 研究不同厚度复合树脂的夹层技术修复楔状缺损后,牙颈部硬组织的应力分布.方法 模拟建立下颌第一前磨牙颊舌向剖面模示图,选择3种不同厚度复合树脂的夹层技术模拟充填缺损区,采用二维有限元应力分析法,对牙颈部做应力分析.结果 随着复合树脂厚度增加,缺损附近的应力减小.复合树脂厚度由0.5mm增至0.8 mm和由0.8 mm增至1.1 mm时,缺损深部最大主应力分别减少33%和41%.结论 夹层技术修复楔状缺损,在保证玻璃离子水门汀垫底厚度的前提下,以增加复合树脂厚度为宜.

Two dimensional finite element stress analysis of teeth with wedge-shaped defects restored by sandwich technique

Objective To investigate the stress distribution at the cervix with simulating restoration by sandwich technique. Methods A longitudinal section model of a mandiblar premolar with wedge-shaped defect was established and simulatedly restored by three different thickness of composite resin with sandwich techniques respectively, and the stress in cervical region was studied by two dimensional finite element analysis. Results The stress in cervical region declined with the increase of thickness of composite resin, and when the thickness of composite resin rised from 0. 5 mm to 0. 8mm and from 0. 8mm to 1. 1mm ,the maximum stress reduced by 33 % and 41% respectively. Conclusion With the sandwich technique, thicker composite resin could achieve better effect as long as the thickness of glass inomer cement can protect pulp.