Efficiency of NaOCl and laser-assisted photosensitization on the reduction of Enterococcus faecalis in vitro.

To investigate the action of a red laser associated with a photosensitizer on the reduction of Enterococcus faecalis in dental root canal in vitro. Thirty prepared teeth with single canals were contaminated. The chemical group was irrigated with 0.5% NaOCl and left flooded for 30 minutes. In the laser group, a paste-based photosensitizer was maintained in the root canals for 5 minutes, and then irradiated with a laser at 685 nm using an optical fiber for an E of 1.8 J during 3 minutes. After treatment, the canal content was collected, serially diluted, and cultured to determine the number of colony-forming units. Photosensitizer alone or laser alone did not have any bactericidal effect. Chemical solution reduced viable bacteria in 93.25%. Laser photosensitization resulted in a reduction of 99.2%, a significantly higher bacterial reduction than NaOCl. Laser photosensitization was effective for reducing E. faecalis in root canals and could be an adjunct to endodontic treatment.