Department of Epidemiology and Public Health, Tokyo Dental College.
Ito Dental Clinic.
Bull Tokyo Dent Coll. 2023 Jan 11;63(4):159-165. doi: 10.2209/tdcpublication.2022-0009. Epub 2022 Nov 15.
Fixed partial dentures (FPDs) made of 12% Au-Pd alloy are covered under Japan's national health insurance system. The survival rate of such 3-unit fixed FPDs remains unknown, however. The purpose of this retrospective study was to assess their survival rate in the replacement of first molars. A total of 140 FPDs were included, and the endpoint was removal of an FPD. During the observation period, 43 FPDs were removed. The FPD survival rate was 70.2% at 10 yr, 58.2% at 15 yr, and 42.1% at 20 yr according to the Kaplan-Meier method. The estimated mean survival period was 19.4 yr. The main reasons for FPD loss were dental caries (27.9%), separation from the abutment tooth (18.6%), and pulpitis (18.6%). Single factor analysis using the log-rank test showed that two factors influenced FPD survival: a smaller gonial angle and deep pockets around the abutment teeth. This effect was not statistically significant in either case, however (p>0.05). The present results suggest that the prevention of caries and of the separation of the dentures from the abutment teeth are important factors in the long-term survival of FPDs.
采用 12%金钯合金制作的固定局部义齿（FPD）被纳入日本国家健康保险体系的保障范围。然而，这类 3 单位固定 FPD 的生存率仍不清楚。本回顾性研究的目的是评估其在第一磨牙替换中的生存率。共纳入 140 个 FPD，终点为 FPD 被移除。在观察期间，有 43 个 FPD 被移除。Kaplan-Meier 法显示，10 年时 FPD 的生存率为 70.2%，15 年时为 58.2%，20 年时为 42.1%。估计的平均生存时间为 19.4 年。FPD 丢失的主要原因是龋齿（27.9%）、与基牙分离（18.6%）和牙髓炎（18.6%）。使用对数秩检验的单因素分析显示，有两个因素影响 FPD 的生存：下颌角较小和基牙周围深袋。但在这两种情况下，这种影响均无统计学意义（p＞0.05）。本研究结果表明，预防龋齿和义齿与基牙分离是 FPD 长期生存的重要因素。
