Fractographic analyses of three ceramic whole crown restoration failures
Fractographic analyses of three ceramic whole crown restoration failures
复制标题
DOI：
10.1016/j.dental.2005.01.006
复制
发表时间：
2005-10-01
期刊：
影响因子：
5
通讯作者：
Scherrer, SS
中科院分区：
文献类型：
--
作者：
Quinn, JB;Quinn, GD;Scherrer, SS
目的：发展断裂学技术对三个临床失败的陶瓷全冠进行失效分析。方法：对临床上3种不同陶瓷材料系统的全冠修复失败进行研究。这些系统包括适用于冷等静压氧化铝芯材的适当贴面、注射成型氧化铝/铝镁管材和热压二硅酸锂。分别使用光学显微镜和扫描电子显微镜，以及由四个断裂仪进行分组检查，对表面形貌进行了经典断口特征检查。结果：三种修复体均表现出许多共同的断裂学特征，其中最重要的是唤醒毛刺。当接近的裂纹前沿被脆性材料中的小气泡或不连续扫过，留下痕迹时，就会出现尾迹。由此产生的特征可以用来追溯裂纹的发展到最初的起始区。在牙冠的贴面部分发现尾迹刺很常见，创建尾迹刺地图的策略使得在所有三种修复中都可以从核心区向外追踪裂缝路径。断裂起始区位于环向应力较高的区域。另一个有用的骨折特征是压缩压缩，这是弯曲应力的指示，在两次入射光学照明下最明显。意义：这项研究表明，断口分析可以有效地用于陶瓷全冠的失败。低入射光下的光学检测和尾迹毛刺测绘是发展起来的有前途的技术。在研究的三个标本中，环状应力是一个值得关注的问题，在分析其他全冠失效时应该考虑到环状应力。(C)2005年牙科材料学会。爱思唯尔有限公司出版。保留所有权利。
Objectives: Develop fractographic techniques to perform failure analyses of three ceramic whote-crown clinical failures. Methods: Three clinical whole-crown failures of different ceramic material systems were studied. The systems included appropriate veneers applied to core materials of cold isostatically pressed alumina, injection molded alumina/alumina-magnesia spinet, and hot pressed lithium disilicate. The surface topography was examined for classical fractographic features, utilizing both optical and scanning electron microscopes independently as well as group examination by four fractographers. Results: All three restorations displayed many common fractographic features, the most important of which was wake hackle. Wake hackle occurs when an approaching crack front sweeps by a small bubble or discontinuity in a brittle material, leaving a trail. The resulting traits can be used to trace back crack progression to an initial starting area. Wake hackle was found to be common in the veneer portions of the crowns, and the strategy of creating a wake hackle map enabled crack paths to be traced from a core area outward in all three restorations. The fracture origin areas were located where hoop stresses are high. Another helpful fracture feature was compression curt, an indication of flexural stress, most visible under tow incident optical lighting. Significance: This study indicates that fractographic analyses can be productively performed on ceramic whole-crown failures. Optical examination under low incident lighting and wake hackle mapping were developed as promising techniques. Hoop stress was implicated as a concern in the three studied specimens, and should be considered when analyzing other whole-crown failures. (c) 2005 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.