Outcome of Nonsurgical Root Canal Retreatment of Teeth with Persistent Apical Periodontitis Treated with Foraminal Enlargement and 2% Chlorhexidine Gel: A Retrospective Cohort Study.

Introduction: Nonsurgical root canal retreatment (NS-RCRT) becomes necessary when primary endodontic procedures fail. This study evaluates the efficacy of NS-RCRT using 2% chlorhexidine gel and foraminal enlargement techniques, aiming to assess whether these approaches enhance periapical healing outcomes and success rates compared to traditional NS-RCRT techniques reported in the literature.

Methods: This retrospective cohort study analyzed 120 teeth diagnosed with persistent apical periodontitis, from 80 patients who underwent NS-RCRT between January 2014 and December 2018 at a specialist's private practice. Data were collected following the Preferred Reporting Items for Observational Studies in Endodontics 2023 guidelines. Periapical healing was evaluated using digital periapical radiographs by three calibrated examiners. The outcome of the treatment was analyzed through descriptive statistics and bivariate analyses, including the Chi-Square and Fisher's Exact tests. Treatment outcomes were deemed successful if they showed complete or incomplete repair and unsuccessful if no repair was observed.

Results: The average follow-up period was 30 months. Under loose criteria, 92.50% (n = 111) of the teeth were categorized as successful, and 7.5% (n = 9) as unsuccessful. Bivariate analysis indicated that the radiographic restoration of apical transportation was the only factor that significantly influenced the outcome.

Conclusions: NS-RCRT performed in a single visit using the foraminal enlargement technique and 2% chlorhexidine gel demonstrated high success rates and may be an effective alternative to tooth extraction. This method promoted periapical healing and could significantly improve NS-RCRT protocols. Further prospective studies are recommended to corroborate these findings.