ASSESSMENT OF THE PERIAPICAL AND CLINICAL STATUS OF CROWNED TEETH OVER 25 YEARS

Objectives: The purpose of this study was to examine radiographically changes in the periapical status and compare the clinical status of te eth with a vital pulp and root-filled teeth restored with crowns and b ridge retainers during 25 years. Methods: During 1967/68, 114 patients received prosthodontic treatment by senior dental students at the Osl o Dental Faculty. In all, 291 teeth with a vital pulp and 106 root-fil led teeth were restored with 158 prostheses. All root-filled teeth wer e restored with a cast dowel and core. The casts were made in a type-3 gold alloy, and cemented with zinc phosphate cement. Forty-six teeth were restored with crowns and 351 teeth with bridge retainers. Radiogr aphs were taken preoperatively, immediately after cementation, and eve ry fifth year. Two independent observers assessed the periapical statu s on the radiographs according to the PAI-index. At the 25 years exami nation, 32 patients (28%) with 101 restored teeth (24%) remained in th e study. Survival rates of the prostheses and of the restored teeth we re estimated using Kaplan-Meyer non-parametric statistics. Results: Th e PAI-score of the periapical status deteriorated in 13 vital and four root-filled teeth. The survival rates of the fixed prostheses were no t influenced by the pulp vitality of the restored tooth at the baselin e. The survival rates of the restored teeth with a vital pulp and of t he root-filled teeth were similar. Clinical failures were recorded on approximately one-third of the restored teeth. The main reason for too th failure was caries (12%), and for the teeth with a vital pulp also pulpal deterioration (10%). Estimates of the proportions of crowned te eth with a vital pulp that will remain free from signs and symptoms of pulpal deterioration were 98% after five years, 92% after 10 years, 8 7% after 20 years and 83% after 25 years. Conclusions: The incidence o f periapical lesions on radiographs of crowned teeth was low during 25 years observation. Crowned, root-filled teeth with a high quality end odontic treatment and an optimal morphology of the dowel and core have a similar survival rate as crowned teeth with a vital pulp. A high pr oportion of crowned teeth with a vital pulp will remain free from sign s and symptoms of pulpal deterioration over 25 years. (C) 1997 Elsevie r Science Ltd.