AIM: To re-examine a population after 20 years and evaluate changes in prevalence of endodontic treatment and apical periodontitis, as well as the technical quality of root fillings.
METHODOLOGY: One hundred and fifteen out of an original 200 patients living in the northern part of Sweden were re-examined with a full mouth radiographic survey after 20 years. Frequencies of root canal treated teeth, apical periodontitis and quality parameters of root fillings were registered.
RESULTS: The frequency of root canal treated teeth increased significantly (P < 0.05) from 13.9% at the first investigation to 17.7% after 20 years. There was also a statistically significant increase (P < 0.05) in teeth with apical periodontitis from 3.3% to 6.8%. Apical periodontitis both in connection with root canal treated teeth and teeth without endodontic treatment, had increased during the follow-up period. Even though the quality of the root fillings had improved, there was no corresponding improvement of the apical status in teeth with root fillings.
CONCLUSIONS: There is still a great need for endodontic treatment in the Swedish population, and no improvement in apical health was found during this 20-year follow up.