不同加载条件下粘固层厚度对瓷贴面的应力分布影响

Stress distribution of porcelain laminate veneer with different thickness of bonding layer in different loading methods

目的分析不同加载条件下粘固层厚度对瓷贴面的应力分布影响。方法将上中切牙用环氧树脂包埋,精密机床逐层切削,数码成像。用Pro/ENGINEER软件生成瓷贴面模型,用Pro/MECHANICA软件进行有限元分析。结果在正中牙合加载状态下,减小粘固层厚度,瓷贴面的应力明显减小,在对刃牙合和深覆牙合两种加载方式下,减小粘固层厚度,各部位的应力有所减小,但变化不明显。正中牙合加载状态下切端对接型瓷贴面的颈部内侧出现一高应力区,而切端包绕型瓷贴面未出现。结论在正中牙合加载状态下,减小粘固层厚度可以降低瓷贴面的应力。

Objective To assess the effect on stress distribution of porcelain laminate veneer with different thickness of bonding layer in different loading methods. Methods The permanent upper incisor embedded in epoxy resin was ground by a numerical controlled lathe machine in 100 μm per layer. Then digital photograph of each layer was taken and input into computer. The two-dimensional sections were reconstructed into three-dimensional model by using pro-engineer. The stress distribution was analyzed by pro-mechanica. Results The stress decreased with the diminish of the thickness of bonding layer at normal bite occlusion, but no obviously difference at overbite occlusion and edge to edge occlusion. Only feathered incisal design showed a high stress area at the inner cervix. Conclusions Diminish the thickness of bonding layer can decrease the stress of porcelain laminate veneers at normal bite occlusion.