過去12年間の口腔インプラント治療に関する後ろ向き調査

抄録

Many previous clinical studies have reported the successful application of dental implants for functional reconstruction of edentate and partially edentate jaws. However, few of those studies focused on the Japanese population. In fact, most of the studies that focused on the Japanese population were cross-sectional in design or excluded patients who were lost to follow-up; therefore, the findings from such studies have low reliability. Moreover, the studies focused on implant survival after the insertion of superstructures, and very few studies have separately investigated the acquisition and maintenance of osseointegration.
The purpose of the present study was to build a useful database to help patients choose the most appropriate treatment. It was a follow-up study based on existing clinical records, and covered all participants and implants. In this study, we analyzed the survival rate and clearly investigated separately the acquisition and maintenance of osseointegration.
The rate of acquisition of osseointegration was calculated by dividing the number of implants acquired by the total number of implants placed. The rate of maintenance of osseointegration was evaluated using life-table analyses, which included an intention-to-treat parameter.
The study consisted of a consecutive series of 161 women and 56 men (mean age: 60.3±9.5 years) who received osseointegrated dental implants at the Department of Dentistry and Oral Surgery, Yata Cooperative Clinic, from January 1999 to December 2010. A total of 637 implants were placed.
About 625 implants acquired osseointegration, and functioned with superstructures; 5 of these implants failed to maintain osseointegration. Around 40 implants were lost to follow-up (rate of tracing: 93.6%). The rate of acquisition of osseointegration was 98.1%, while that of maintenance of osseointegration for 12 years was 99.1%. Thus, we conclude that follow-up surveys on the long-term prognosis of dental implants should be conducted more frequently to expand the available clinical data on this subject.