Introduction: Clinical assessment of the efficacy of novel root canal disinfection protocols is an important focus in endodontic research. This randomized double-blinded study assessed the antibacterial efficacy of a final rinse with BioPure MTAD (MTAD) and intracanal medication with 2% chlorhexidine gel (CHX) in teeth with apical periodontitis.
Methods: Canals in 30 teeth (single-rooted and multi-rooted) were prepared by using 1.3% NaOCl, rinsed with MTAD or saline in random sequence, medicated with CHX for 7 days, irrigated with 1.3% NaOCl, and filled. Bacteriologic root canal samples were obtained by aspiration before (1A) and after (1B) canal preparation, after the final rinse (1C), after CHX was flushed (2A), and after final irrigation (2B). Bacteria were enumerated by epifluorescence-microscopy (EFM) by using 2 staining methods and by colony-forming-unit (CFU) counts after 14 days of incubation.
Results: Bacterial counts (EFM) in 1B were greater than 95% decreased from 1A. Low bacterial densities in 1B, 1C, 2A, and 2B did not differ significantly from each other. EFM counts were consistently higher than CFU counts.
Conclusions: The final rinse with MTAD and medication with CHX did not reduce bacterial counts beyond levels achieved by canal preparation with NaOCl.