Objective: This study investigated the long-term (1-4 years) outcome of the endodontic treatment of teeth with apical periodontitis lesions performed by undergraduate students using a defined antimicrobial protocol.
Study design: Treatment protocol included a crown-down instrumentation technique, apical enlargement to predetermined sizes and apical level, irrigation with 2.5% sodium hypochlorite, and intracanal medication with calcium hydroxide/camphorated paramonochlorophenol (CPMC) paste. The first 100 teeth from patients who returned for follow-up were examined. The outcome was assessed based on radiographic and clinical criteria as healed (success), healing (uncertain), or not healed (failure).
Results: Overall results showed that 76% of the teeth healed, 19% were healing, and 5% had not healed. Most healed cases (75%) or failed cases (80%) were already evident at 2 years. Seven cases took 4 years to heal completely.
Conclusions: The low failure rate observed in this study reinforces the importance of using an evidence-based antimicrobial strategy during endodontic treatment of teeth with apical periodontitis.