Objective: This prospective study aims to evaluate the one-year and two-year outcomes of root canals with apical periodontitis obturated in the presence or absence of cultivable micro-organisms, and define the influence on endodontic treatment outcome from different independent variables.
Methods: 87 patients with 45 exposed and 43 unexposed canals who previously participated in a microbiological study of primary endodontic infections were invited back for review in 12 and 24 months after endodontic treatment. The review involves clinical examination, questionnaire interview and radiographic assessment in order to determine the treatment outcomes. The influence of independent variables, such as gender, age, tooth location, etc., on the treatment outcome, has also been analysed.
Results: A total of 85 teeth of 84 patients were reviewed one and two years after obturation. Chisquare test for trend showed that the one-year radiographic healing of apical lesions was significantly different between culture-positive and negative canals (P<0.05). However, there is no significant difference in the two-year radiographic healing between the two groups of canals (P>0.05). None of the independent variables was found to be significant in affecting the endodontic treatment outcome on logistic regression analysis.
Conclusion: The presence of positive culture prior to obturation seemed to affect the healing of periapical tissues in a one-year review, but the effect appeared to be temporal and not affected the long-term outcome.