Changes in endodontic status 1973-1993 among 35-year-olds in Oslo, Norway.

Epidemiological investigations from Scandinavia have documented high prevalence of apical periodontitis and inferior quality and results of endodontic treatment performed in general practice. The present investigation is part of a 20-year follow-up study on oral health in 35-year-old Oslo citizens focusing on endodontic conditions. The results indicate reduced prevalence of apical periodontitis and statistically significant improvement in endodontic status compared with results from a similar study performed in 1984.