オーバーデンチャーの支台歯の予後 : 維持のためのポストを持たないメタルコーピングについて

overdenture

北海道歯学会

北海道歯学雑誌

The aim of this study was to clarify the effect of metal copings without post for abutment teeth of overdentures. Out-patients who visited the Clinic of Removable Prosthodontics at Hokkaido University Hospital, from April 2012 to March 2013, and who fulfilled the following criteria were selected : metal copings without post for overdentures were inserted, metal copings were bonded by adhesive cements, metal copings were used for more than 6 months. The endpoint of this study was defined as the extraction and loss of coping (e.g. removal and loss of cementation). Variables were age, gender, number of remaining teeth, Eichner classification, and Miyachi’s classification. Also included were the variables, number of occlusal support, location of abutment tooth, endodontic therapy, fracture or perforation of abutment tooth, remaining structure of tooth, and coping form. Statistical analyses were performed with Kaplan-Meier analysis and Cox proportional hazards analysis. Forty-three patients with 114 abutment teeth for overdentures were selected. The three- and five-year cumulative survival rate of abutment teeth was 95.1% and 92.7%, respectively. The three- and five-year cumulative survival rate of copings was 88.5% and 72.8%, respectively. In this study, Cox proportional hazards analysis revealed that all of the variables had no significant influence on the survival of the copings and the abutment teeth. It is suggested that the metal copings without post contributed to a good prognosis of abutment teeth for overdentures.