后牙烤瓷修复冠、桥疲劳寿命的测定

摘要

目的:测定后牙烤瓷修复冠、桥的疲劳寿命.方法:制作后牙烤瓷冠、桥试件各3个,进行疲劳寿命测定,分别在实验进行0、16、48、80、160h时,用体视显微镜下咬合部位瓷层表面状态,至320h后实验结束,在扫描电镜下观察.结果:各组烤瓷冠桥体均未出现明显的瓷崩裂现象,但在咬合部位及其附近均出现的微裂隙长达30～50μm.结论:烤瓷修复体具有相当优良的机械力学性能,可以作为后牙的永久性修复体.%Objective To measure the fatigue life of porcelain fused metal (PFM) crown and bridge of posterior teeth.Methods PFM crown and bridge of anterior teeth were made for measurement of its fatigue life.The surface of porcelain on bitting area were observed by stereoscopic zoom microscopes after 0h、 16h、48h、80h、 160h,and by scaning electric microscopes (SEM) after 320h.Results Each PFM crown and bridge of posterior teeth had no procelain cracks in evidence after experiment,however there were some microscopic wears among 30～50μm appeared on the surface of functional area by SEM after simulating mastication 20 years.Conclusion PFM restorations of posterior teeth have rather fine mechanics characteristic.It may last 20 years even longer by using normal masticatory force.