烤瓷熔附金属全冠边缘微渗漏与两种角度肩台影响的比较

Effect of two different shoulders on the microleakage of porcelain-fused-to-metal crowns

背景:肩台的形态将直接关系到患者基牙的健康和最终修复体的质量。目的:采用循环加载和温度循环试验观察两种肩台制备后的烤瓷熔附金属全冠冠边缘的微渗漏程度。方法:选年龄40-50岁因牙周炎导致拔除的新鲜磨牙40颗,随机分成两组。以标准备牙的要求制作烤瓷熔附金属全冠,将肩台分别制备成120°和90°。通过体外实验,对两种肩台制备后的烤瓷熔附金属全冠行循环加载和温度循环试验,测试其冠边缘微渗漏的程度。结果与结论:循环加载和温度循环试验显示,无论是唇侧边缘还是舌侧边缘,120°型肩台设计更容易引起微渗漏,而90°型肩台颈缘微渗漏机会小。说明烤瓷熔附金属全冠修复体颈缘设计以90°型肩台较为理想,微渗漏机会小。

BACKGROUND：Morphology of the shoulder is directly related to the health of patient＇s abutment and quality of final prosthesis.OBJECTIVE：To observe the microleakage of porcelain-fused-to-metal of two shoulders by cyclic loading and thermal cycling test.METHODS：Forty recently extracted molars from patients with periodontal disease,aged 40-50 years,were collected and randomly divided into two groups.The porcelain-fused-to-metals were prepared with the standard prepared criteria,and the shoulders were designed into 120° and 90°.Then the cyclic loading and thermal cycling tests were performed in vitro on the porcelain-fused-to-metal of two shoulders to detect the microleakage.RESULTS AND CONCLUSION：This study discover that there are significant differences between two groups after cyclic loading and thermal cycling processing,which increased microleakage of porcelain-fused-to-metal with 120° shoulder,and 90° shoulder has the lowest level of microleakage no matter on labial edge or the tongue edge.It demonstrates that 90° shoulder is the best performance to resist microleakage for porcelain-fused-to-metal and 90° shoulder,design can minimize occurrence of secondary caries.