Additional Treatment Indicative of an Unfavorable Endodontic Outcome in a Swedish County—A 10-year Observational Study

This study's aim was to calculate the incidence of first additional endodontic treatment or extraction as the result of an unfavorable endodontic outcome following orthograde root canal treatment (RCT) performed by general dental practitioners during a 10-year period and to identify possible predictors for outcomes. A randomized cohort of 280 individuals (and as many teeth) with an orthograde RCT was followed for over 10 years. Dental records were reviewed, and individuals were recalled when data were missing. The following terminal events indicative of unfavorable endodontic treatment outcome were orthograde retreatment, surgical endodontics, and tooth extractions exclusively due to endodontic reasons. Selected variables related to individuals and treatment (pre-, intra-, and postoperative) were harvested to analyze possible associations with the terminal events. Unadjusted survival analysis and Cox regression analysis were performed and P