Survival of root filled teeth in general dentistry in a Swedish county: a 6-year follow-up study

Objective The purpose of the present study was to investigate the survival rate of root filled teeth in general dentistry in a Swedish county and to identify risk predictors with a significant influence on the survival rate. Materials and methods This is a retrospective 6-year follow-up study on 1642 recall patients with 1720 teeth root filled in general dentistry in the Public Dental Service in the county of Stockholm, Sweden. Background variables were collected from the database at baseline as potential predictors of tooth loss. The outcome variables were extraction during the 6-year follow-up period and the reason for the extraction. Stepwise Cox regression analysis was adopted in order to investigate the influence of the potential risk predictors on the risk for tooth extraction. Results Nine percent of the root filled teeth were lost after 6 years. The most frequent reason for tooth loss was fracture and/or cracks (58%). The survival rate of the root filled teeth increased significantly for younger patients, root filled teeth with metal crowns (96%) and high quality of the root filling (93%). The survival rate differed significantly between tooth groups with the lowest survival for molars (83%). Composite fillings were significantly associated with lower quality of the root fillings. Conclusions Ninety-one percent of the root filled teeth survived after 6 years. The survival rate was significantly higher for teeth with root-fillings of high quality and metal crowns as well as for root filled teeth in younger patients. The lowest survival rate was found for molars.