Koichi Yoshino1,2, Koji Ito3, Masahiko Kuroda3, Naoki Sugihara4. 1. Department of Epidemiology and Public Health, Tokyo Dental College, 2-9-18 Kandamisaki-cho, Chiyoda-ku, Tokyo, 101-0061, Japan. ko-yoshi@d8.dion.ne.jp. 2. Kyushikai, Kuroda Dental Clinic, 3-5-5-7F Uchikanda, Chiyoda-ku, Tokyo, 101-0047, Japan. ko-yoshi@d8.dion.ne.jp. 3. Kyushikai, Kuroda Dental Clinic, 3-5-5-7F Uchikanda, Chiyoda-ku, Tokyo, 101-0047, Japan. 4. Department of Epidemiology and Public Health, Tokyo Dental College, 2-9-18 Kandamisaki-cho, Chiyoda-ku, Tokyo, 101-0061, Japan.
Abstract
OBJECTIVES: The purpose of this study was to clinically investigate double-crown-retained removable partial dentures (DRPDs) and abutment teeth at dental clinics. MATERIALS AND METHODS: Only cases with complete arch reconstruction were included. Endpoints were replacement of denture and loss of abutment tooth. A total of 213 dentures with 1030 abutment teeth were analyzed. RESULTS: During the observation period, 32 dentures were replaced. The mean observation period was 12.7 (± 6.6) years (range 3 to 36). By the Kaplan-Meier method, survival rate at 10 years was 94.7% and at 20 years was 70.8%. Estimated mean survival period was 27.1 years. Cox regression analysis showed that risk factor for replacement was good occlusion as indicated by Eichner index groups A to B3 (HR 2.81). The main reason for denture replacement was loss of abutment teeth. Survival rate of abutment teeth at 10 years was 83.8% and at 20 years was 66.3%. The analysis revealed six risk factors: male gender (HR 1.76), age range 65-89 years (HR 1.51), posterior teeth (HR 1.60), higher number of present teeth in opposite jaw (HR 1.69), lower number of abutment teeth (HR 1.76), and short inner crown (HR 2.28). CONCLUSION: DRPDs last over 20 years, making them a durable investment in one's oral health; their survival is influenced by loss of abutment teeth. CLINICAL RELEVANCE: In cases where there are few teeth remaining in a jaw, DRPDs represent a suitable treatment that makes use of the remaining teeth, even if the abutment teeth are non-vital.
OBJECTIVES: The purpose of this study was to clinically investigate double-crown-retained removable partial dentures (DRPDs) and abutment teeth at dental clinics. MATERIALS AND METHODS: Only cases with complete arch reconstruction were included. Endpoints were replacement of denture and loss of abutment tooth. A total of 213 dentures with 1030 abutment teeth were analyzed. RESULTS: During the observation period, 32 dentures were replaced. The mean observation period was 12.7 (± 6.6) years (range 3 to 36). By the Kaplan-Meier method, survival rate at 10 years was 94.7% and at 20 years was 70.8%. Estimated mean survival period was 27.1 years. Cox regression analysis showed that risk factor for replacement was good occlusion as indicated by Eichner index groups A to B3 (HR 2.81). The main reason for denture replacement was loss of abutment teeth. Survival rate of abutment teeth at 10 years was 83.8% and at 20 years was 66.3%. The analysis revealed six risk factors: male gender (HR 1.76), age range 65-89 years (HR 1.51), posterior teeth (HR 1.60), higher number of present teeth in opposite jaw (HR 1.69), lower number of abutment teeth (HR 1.76), and short inner crown (HR 2.28). CONCLUSION: DRPDs last over 20 years, making them a durable investment in one's oral health; their survival is influenced by loss of abutment teeth. CLINICAL RELEVANCE: In cases where there are few teeth remaining in a jaw, DRPDs represent a suitable treatment that makes use of the remaining teeth, even if the abutment teeth are non-vital.