三种不同金属基底烤瓷冠边缘适合性的对比研究

目的 对比研究镍铬合金、贵金属合金和金沉积三种不同金属基底烤瓷冠的边缘适合性,为临床应用提供参考.方法 采用离体活髓前磨牙24颗,环氧树脂包理后随机分为3组,常规牙体预备后分别制作镍铬合金、贵金属合金和金沉积基底烤瓷冠各8颗,用硅橡胶印模材料代替粘固剂将3组烤瓷冠粘固于牙预备体上,硬固后取出硅橡胶,利用金属显微镜测量硅橡胶的厚度,比较3组修复体边缘的适合性,进行统计分析.结果 金沉积烤瓷冠与贵金属烤瓷冠的边缘适合性在统计学上有差异（ P〈0.05）,金沉积烤瓷冠和贵金属烤瓷冠边缘适合性均与镍铬合金烤瓷冠有显著的统计学差异（ P〈0.01）.结论 金沉积烤瓷冠和贵金属烤瓷冠的边缘适合性良好,二者均优于镍铬烤瓷冠. 关键词：烤瓷冠;金沉积;边缘适合性

An Compared Study on the Adaptation of Porcelain Fused- to-metal Restorations Made from Three Different Alloys

Objective To compare the adaptation of porcelain fused-to-metal（PFM） restorations made from Ni-Cr alloy,precious alloy and galvanized forming after cementation and to provide a theory guidance for their application. Methods 24 extracted premolars were divided into three groups randomly,after standard tooth preparation, three kinds of crowns （Ni-Cr） alloy,precious alloy and galvanized forming were manufactured.The silicone rubber was used to cement the three kinds of crowns on their prepared premolars.The mean thickness of silicone rubber after cementation was measured in vitro using the Olympus metal microscope stereomicroscope to compare adaptation of three kinds of crowns in different position and the data were analyzed by t-test. Results Significant difference was found between the cement thickness of precious alloy crown and galvanized forming crown （P〈0.05）,while both of these two kinds of crown had significant difference in cement thickness with Ni-Cr crown（P〈0.01）. Conelusion The adaptation of precious alloy crown and galvanized forming crown are superior to Ni-Cr crown. Among 3 types,the adaptation of galvanized forming crown was the best,but that of Ni-Cr crown was poor.