comparative antibacterial efficacy of endemic satureja khuzistanica jamzad essential oil, sodium hypochlorite and chlorhexidine gluconate solutions as root canal irrigations

background: the aim of this study was to compare the antibacterial efficacy of endemic satureja khuzistanica jamzad (skj) essential oil as root canal irrigation versus 2.5% sodium hypochlorite and 2% chlorhexidine gluconate.     methods: in current in vitro experimental study, fifty four single-rooted teeth were randomly divided into 6 groups of 9 samples: 2.5% sodium hypochlorite (naocl), 2% chlorhexidine gluconate (chx), 0.31 mg/ml skj, 0.62 mg/ml skj, positive and negative controls. each tooth was instrumented, sealed and autoclaved. then, test groups were inoculated with e. faecalis , treated with irrigation solution and viable bacterial counts in intracanal dentin chips were determined.  utilizing spss 18 software, collected data were analyzed by kruskal-wallis one way analysis of variance (p = 0.05). results: 99.94 % and 99.50% reduction in bacteria load after 5 min treatment with naocl and chx were detected, respectively. similarly, 99.97% and 99.96% reduction in bacterial counts were observed after 5 min application of 0.62 mg/ml and 0.31 mg/ml skj essential. no significant differences were detected among the four irrigation solutions (p = 0.755). conclusion: skj essential oil with the minimum inhibitory concentration (mic) of 0.31 mg/ml could be an effective antibacterial irrigation solution.