Effectiveness of different endodontic irrigants against Enterococcus faecalis: an ex vivo study.

Aim: To evaluate the effectiveness of different endodontic irrigants against Enterococcus faecalis (ATCC 29212).Methods: Seventy bovine mandibular incisors were prepared, inoculated with a bacterial strain for 60 days and divided into the following groups: positive control; negative control; 2.5% NaOCl; 17% EDTA; 0.2% chitosan; 2.5% NaOCl + 0.2% chitosan; and 2.5% NaOCl + 17% EDTA. The irrigation protocol was performed using an experimental peristaltic pump device, with the irrigating solutions circulating within the apparatus at a constant flow for 10 min. Paper-point samples were then collected from the root canals and immersed in 7 mL of brain heart infusion broth, followed by incubation at 37°C for 48 h. Bacterial growth was assessed by turbidity of the culture medium.Results: E. faecalis was present in all samples after the use of different irrigants.Conclusion: The different irrigants tested were not effective in completely eliminating dentin bacterial contamination with E. faecalis.