[Epidemiology on the relationship between 8020 and clinical prosthodontics].

The tooth conditions of Japanese people have improved year by year, and it may be possible to achieve 8020 in the near future. On the other hand, over 40% of people had experienced prosthodontic treatment including dentures and bridges between the age of 45-54, and about 80% between the age of 65-74. Therefore, the rate of people who have a prosthodontic crown in their mouth are thought to be higher even in the young population. Prosthodontic treatment is important for recovering from severe defect of caries or for controlling occlusal trauma derived from malocclusion. However, it is difficult to manage prosthetically treated teeth for a long time in the oral environment because their treatments have been done for those who still have the risk of missing teeth. In this report, the relationship between achieving 8020 and prosthodontic treatment is discussed with the results of a study on extraction causes and the risks of prosthetically treated teeth. The results showed that the main cause of extraction of prosthetically teeth was periodontal disease, that 74.1% of the prosthetically treated teeth were non-vital, and that the prevalence of root fracture was different between vital and non-vital. These findings suggested that the comparison of the cause of missing teeth, especially, the risk of missing prosthodontically treated teeth, should be discussed after the standardization of periodontal conditions.