Clinical efficacy of different irrigation protocols in teeth with chronic apical periodontitis: Randomized clinical trial - a pilot study

Introduction/Objective. Effective disinfection of the root canal system is essential for successful endodontic treatment. This study aimed to determine the most effective final irrigation protocol. Methods. This randomized clinical trial investigated the antimicrobial efficacy of three irrigation protocols in 30 patients with asymptomatic apical periodontitis in single-rooted teeth. The groups were: (1) 2.5% sodium hypochlorite (NaOCl) + 17% ethylenediaminetetraacetic acid (EDTA); (2) NaOCl + EDTA + 2% chlorhexidine (CHX); and (3) the same as Group 2 with sonic agitation (EndoActivator). Microbial samples were collected at three intervals and analyzed using endpoint and real-time PCR targeting seven key endodontic pathogens. Results. Group 3 demonstrated the greatest bacterial reduction across all time points, with CHX-containing protocols significantly outperforming NaOCl + EDTA alone. Sonic activation further enhanced irrigant efficacy, notably reducing P. gingivalis. Despite improvements, complete bacterial eradication was not achieved, and E. faecalis and F. nucleatum remained persistent. Conclusion. While limitations in microbial sampling and profiling exist, the results underscore the importance of combining chemical agents and mechanical activation to manage complex root canal infections effectively.