关键词: 金属烤瓷冠, 银钯合金, 牙周指数, 牙周致病菌, 龈沟液, 肩台设计

Abstract: Objective    To evaluate the influence of silver-palladium alloy as the materials of inner crown in subgingival and subgingival shoudler design on periodontal tissue after repairing. Methods    A total of 83 clinical diseased teeth were chosen in this study. Totally 39 teeth were repaired with silver-palladium alloy porcelain crown in subgingival shoulder design，and the other 44 were repaired with silver-palladium alloy porcelain crown in supergingival shoulder design. Follow-up visits were performed at 6 months and 12 months after operation. The changes of periodontal sulcus bleeding index and weight of gingival crevicular fluid （GCF） were observed. IL-1β，TNF and the positive rates of Pg，Aa，Tf，Fn and Pi by PCR in GCF were detected. Results    In the silver-palladium alloy porcelain crown group in subgingival shoulder design，there were significant differences in periodontal sulcus bleeding index and the weight of GCF between pre- and the 12th month post-restoration（P < 0.05），while there was no significant difference in IL-1β，TNF and the positive rates of Pg，Aa，Tf，Fn and Pi by PCR in GCF between pre- and the 12th month post-restoration（P > 0.05）. In the silver-palladium alloy porcelain crown group in supergingival shoulder design.，there was no significant difference in periodontal sulcus bleeding index，the weight of GCF，IL-1β，TNF and the positive rates of Pg，Aa，Tf，Fn and Pi by PCR in GCF between pre- and 12th post-restoration（P > 0.05）. Conclusion    Silver-palladium alloy is an ideal substrate material of porcelain fused to metal crown. The silver-palladium alloy porcelain crown in subgingival shoudler may have an potential adverse effect on periodontal tissue to a certain degree compared with that in supergingival shoulder design.

Key words: porcelain fused to metal crown, silver-palladium alloy, periodontal index, periodontopathic bacteria, gingival crevicular fluid, shoulder design