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

The mean incidence of additional treatment indicative of unfavorable endodontic outcome was 0.7% per year during the first 10 years, but the mean incidence was greater during the first 2 years. Five factors were associated with an unfavorable outcome; however, confounders cannot be excluded from the associations.