Effect of duration and dilution on antimicrobial efficacy of octenidine hydrochloride as an intracanal medicament with chitosan carrier against Enterococcus faecalis – A modified direct contact test

BACKGROUND: The ambiguity in key influential factors such as minimal time for effective action, dilution, and need of drug carrier for intracanal medicaments necessitates a microbial analysis that aids in the potential selection of an intracanal medicament for ensuring optimal root canal disinfection. AIMS: This study aims to evaluate the antimicrobial efficacy of octenidine hydrochloride (OHC) and gold standard calcium hydroxide (Ca(OH) (2)) as intracanal medicaments, both independently and along with chitosan (CTS) as medicament vehicle against the common resistant endopathogen – Enterococcus faecalis. MATERIALS AND METHODS: A modified direct contact microbial test was used to evaluate the amount of surviving bacteria after predetermined contact time (2, 5, 20, and 60 min) and 5-fold serial dilution of the intracanal medicaments. The experiment was carried out under aseptic conditions and performed in triplicate to ensure reproducibility. STATISTICAL ANALYSIS USED: The results were analyzed by Kruskal–Wallis analysis of variance followed by pairwise comparisons by Mann–Whitney U-test. RESULTS AND CONCLUSIONS: The results showed that all the four medicament groups were able to show the maximum antimicrobial efficacy against E. faecalis at 60 min time interval and that the antimicrobial efficacy of OHC and Ca(OH) (2) was at its peak when used alone. The study thereby concluded that the addition of CTS as a carrier did not enhance the antimicrobial efficacy of OHC or Ca(OH) (2) against E. faecalis.