不同直径压头对磨牙e.max全瓷冠失效模式的影响  

Fracture mode of e.max crowns submitted to indenter with different diameters

作　　者：张骏[1] 赵克[1] 王勤琴[2] 范丹妮[1] 吴小平[1] 张新平[2] 

机构地区：[1]中山大学光华口腔医学院.附属口腔医院.口腔医学研究所,广州510055 [2]华南理工大学材料科学与工程学院材料科学与技术研究所

出　　处：《中华口腔医学研究杂志（电子版）》2008年第4期21-23,共3页Chinese Journal of Stomatological Research(Electronic Edition)

基　　金：国家自然科学基金面上项目(30872908);广东省自然科学基金(7001542)

摘　　要：目的比较不同直径压头对e.max全瓷冠抗折强度及失效模式的影响。方法20个e.max全瓷冠随机分为A、B两组,分别采用直径为4mm、10mm的压头进行抗折试验,记录试件的抗折载荷值,体视显微镜观察其失效模式。结果两组试件抗折载荷值差异有统计学意义(P=0.012)。A组试件破坏局限于修复体,可见加载区域的锥状裂纹及起于黏结界面的放射状裂纹;B组试件由近远中向裂为两瓣,伴有基牙的损伤。结论不同直径压头对全瓷冠抗折载荷及失效模式均有影响。大直径压头加载时,冠的抗折载荷值大于小压头加载;小直径压头加载时,其折裂模式与临床全瓷冠的失效模式相似。Objective To investigate the effect of indenter with different diameters on the fracture resistance and mode of the posterior e.max crowns. Methods Twenty e.max crowns were divided equally into two groups （A and B）, and then were subjected to compressive load using two indenters with different diameters of 4 mm and 10 mm respectively. The failure load value （N） and the fracture mode of the crowns were recorded, and faliure modes of the failured crowns were examined using a stereomicroscope. Results Statistical analysis showed a lower mean fracture load of group A crowns than that of group B crowns （P=0.012）. Both cone-shaped cracks and the radical cracks initiated from adhesive interface were observed in group A crowns, while group B crowns fractured throughout mesio-distally accompanied by tooth fracture. Conclusions The diameter of the spherical indenter has an obvious influence on fracture resistance and fracture mode of the all-ceramic crowns. The crowns loaded with large diameter spherical indenter exhibit higher fracture resistance values than those loaded with small one. When loaded by a small diameter indenter, the all-ceramic crowns exhibited similar failure mode as usually seen in clinical.

关 键 词：牙瓷料 修复体 失效分析 失效模式 

分 类 号：R783[医药卫生—口腔医学]