Introduction: The aim of this study was to evaluate the antibacterial effectiveness of 2.5% sodium hypochlorite on endocanal bacteria related to the time contact Within root canal.
Materials and methods: 110 teeth were prepared and inoculated with Enterococcus feacalis. All teeth were irrigated with a same volume and exposed a period ranging 1 to 10 min. Canals were sampled before and after time contact.
Results: All time reduced the number of bacterial cells within the root canal (p > 0.05). There was no significant difference after the time contact of 3 min (p > 0.05). Lack of effectiveness might be caused by irrigant to reach microorganism in dentinal tubules.