Background: Root canal disinfection needs to be improved because actual techniques are not able to eliminate all microorganisms present in the root canal system. The aim of the present study was to investigate the in vitro cytotoxicity of FotoSan (CMS Dental APS, Copenhagen Denmark), 17% EDTA and 2% chlorhexidine.
Material/Methods: Fibroblasts of periodontal ligament from healthy patients were cultured. FotoSan (with and without light activation for 30 sec.), 17% EDTA and 2% chlorexidine were used for the cell viability tests. Untreated cells were used as control. The cellular vitality was evaluated by MTT test. The production of reactive oxygen species (ROS) was measured using an oxidation-sensitive fluorescent probe. Results were statistically analyzed by ANOVA, followed by a multiple comparison of means by Student-Newman-Keuls, and the statistical significance was set at p<0.05.
Results: MTT tests showed that cytotoxic effects of FotoSan (both photocured and uncured) were statistically lower (p<0.05) than that observed using 2% Chlorhexidine, while no significant differences were found in comparison with 17% EDTA. No alterations in ROS production were detectable in any of the tested materials.
Conclusions: Since the toxicity of the FotoSan photosensitizer, both light-activated and not light-activated, is similar to common endodontic irrigants, it can be clinically used with precautions of use similar to those usually recommended for the above-mentioned irrigating solutions.

Keywords: Photosensitizing Agents - toxicity, Light, Fibroblasts - radiation effects, Disinfection - methods, Cell Death - drug effects, Anti-Bacterial Agents - toxicity, Reactive Oxygen Species - metabolism