Prevalence of apical periodontitis of root canal-treated teeth and retrospective evaluation of symptom-related prognostic factors in an urban South Korean population

Objectives. This study aimed to investigate the prevalence of apical periodontitis among root canal-treated teeth in an urban South Korean population and evaluate prognostic factors for periapical radiolucency and its symptoms. Study design. The periapical status of 896 root canal-treated teeth was evaluated by using digital panoramic radiography. Five prognostic factors were analyzed: length and density of the root filling, presence of crown restoration, probability of unilateral bite, and presence of missing canals. Results. The prevalence of apical periodontitis among root canal-treated teeth in the study population was 22.8%, and 29.3% of these teeth had received dental treatment for pain relief. Evaluation of the prognostic factors indicated that inadequacy of endodontic treatment was more predictive of apical periodontitis than the absence of a crown restoration. Conclusion. Inadequate root filling length appeared to be the most important prognostic factor related to apical periodontitis and its acute symptoms among root canal-treated teeth. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:795-799)