In vitro antimicrobial activity of several concentrations of NaOCl and Octenisept in elimination of endodontic pathogens.

Objective: The objective of this study was to test and compare the in vitro effectiveness of sodium hypochlorite (NaOCl), and octenidine hydrochloride (Octenisept) at different concentrations in the elimination of resistant microorganisms including S. aureus, E. faecalis, and C. albicans over a range of time intervals.

Study Design: A broth dilution test was performed, and the timing for irrigants to kill microbial cells was recorded. Then the samples were compared by using Kruskal-Wallis test, with significance level at P less than .05. Also minimum inhibitory concentration (MIC) of Octenisept was evaluated.

Results: The in vitro antimicrobial effect of the most effective concentrations of the tested irrigants were ranked from strongest to weakest as follows: 100% Octenisept, 50% Octenisept, 5.25 % NaOCl, and 2.5 % NaOCl.

Conclusions: The antimicrobial action is related to type and concentration of the irrigants as well as the microbial susceptibility.