Prevalence of apical periodontitis and results of endodontic treatment in middle‐aged adults in Norway

The present investigation based on a random sample of 50-year-olds from Oslo, Norway, indicate a prevalence of apical periodontitis of 3.5% of the teeth present. Forty-four percent of the endodontically treated teeth presented with a radiographically detectable periapical radiolucency. There was a statistically significant negative correlation between the quality of the root fillings evaluated and prevalence of apical periodontitis.