Introduction: Chitosan has high antibacterial properties, chelating ability, biocompatibility and biodegradability. Sodium hypochlorite (NaOCl) is considered the gold standard irrigant solution. The aim of this in vitro study was to assess the antibacterial effectiveness of chitosan-citrate 0,6% as an irrigant and to compare with the antibacterial effectiveness of NaOCl 2,5%. Materials and Methods: A total of thirty extracted single-rooted human teeth were used for the purpose of this in vitro assessment. The teeth were allocated to each group: Group I (n=15) – after inoculation with E.faecalis disinfection with NaOCl 2,0% was done and Group II (n=15) - after inoculation with E.faecalis the disinfection was with chitosan-citrate 0,6%. Teeth were prepared to evaluate the colony-forming units (CFU/mL) after disinfection and for SEM analysis to observed Enterococcus faecalis biofilm removal. Results: The assessment of CFU/mL showed significant reduction of the survival rate of E. faecalis from biofilms after disinfection with chitosan-citrate solution 0,6% compared to the disinfection with NaOCl 2,0% The analysis of scanning electron microscopy (SEM) after disinfection with chitosan-citrate 0,6% illustrated dentin walls with no bacterial biofilm or with minimum bacterial biofilm. Conclusion: Chitosan-citrate 0,6% showed high antibacterial activity and enabled removal of bacterial biofilm.
