Aim: In vitro evaluation and comparision of the antimicrobial efficacy of 0.1% octenidine dihydrochloride (OCT), of 2% chlorhexidene (CHX) and 2% chitosan  as root canal irrigant against E. faecalis within the dentinal tubules at 200µ and 400µm depth.

Materials and Methods: Seventy two freshly extracted mandibular molars were decoronated and the mesial root specimen was standardized till working length. E.faecalis (strain MTCC 439) was grown on brain heart infusion sheep blood agar plate until seven days and the decoronated root specimens collected were divided into four groups (n=18) based on irrigation protocol: Group 1 – 2% chlorhexidene (CHX), Group 2 - 0.1% octenidine dihydrochloride (OCT), Group 3- 2% chitosan and Group 4 – normal saline . Each specimen was irrigated with particular irrigant till 3 minutes. Dentin shavings were obtained from root specimens using diamond disc and these dental chips were used to calculate the colony forming unit at 200µ and 400µm depth. The data obtained after the experiment was statistically analyzed.

Results: Non significant difference has been shown by group 1when compared with group 2 while significant difference has been shown by group 3 when compared with group 1 and group 2 by taking into account that group 4 is taken as control group. Significant difference was found when all the groups 1-4 were compared at 200 and 400 µm depth.

Conclusion: It was observed and evaluated that antimicrobial efficacy of 2% chitosan against e. faecalis was found to be higher as compred to 2% chlorhexidene (CHX) and 0.1% octenidine dihydrochloride (OCT) both at 200µ and 400µm depth.