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

Objective. To investigate the action of a red laser associated with a photosensitizer on the reduction of Enterococcus faecalis in dental root canal in vitro. Study design. 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. Results. 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. Conclusion. Laser photosensitization was effective for reducing E. faecalis in root canals and could be an adjunct to endodontic treatment. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;102:e93-e98)