Influence of coronal restorations on the periapical health of endodontically treated teeth

The purpose of the study was to evaluate a possible relationship between th e quality of the coronal restoration, the root canal obturation and the per iapical status of endodontically treated teeth. Full mouth series of radiog raphs from randomly selected patient charts at the Dental Faculty, Universi ty of Oslo were examined. A total of 1001 endodontically treated teeth rest ored with a permanent restoration were evaluated independently by two exami ners. According to a predetermined set of radiographic criteria, the techni cal quality of the root filling of each tooth was scored as either good (GE ) or poor (PE), and the technical quality of the coronal restoration was sc ored as good (GR) or poor (PR). The root and the surrounding structures wer e then evaluated and according to the periradicular findings, the treatment was categorized as success or failure. The success rate for all endodontic ally treated teeth was 67.4 % (n=1001). Teeth with root canal posts had a s uccess rate of 70.7% (n=527) and teeth without posts had a success rate of 63.6% (n=472). The two groups with technically good endodontics had the hig hest success rates, In combination with technically good restorations the s uccess rate was 81% (GE + GR, 81%) and combined with technically poor resto rations the success rate was 71% (GES PR, 71%). The two groups with technic ally poor endodontics combined with either good restorations or poor restor ations had significantly lower success rates (PE + GR, 56% and PE + PR, 57% ). The technical quality of the endodontic treatment as judged radiographic ally was significantly more important than the technical quality of the cor onal restoration when the periapical status of endodontically treated teeth was evaluated.