Cell Survival After Exposure to a Novel Endodontic Irrigant

Abstract : Endocyn, a pH-neutral solution of hypochlorous acid and hypochlorite has been developed for use as an endodontic irrigant. The purpose of this study was to evaluate the effect of Endocyn on human periodontal ligament (PDL) fibroblasts and rat osteosarcoma cells (UMR-106) and compare this with other commonly used endodontic irrigants. Methods: To determine cytotoxicity, cultured PDL and commercially purchased UMR-106 cells were exposed to 1%, 5%, 10%, 20%, and 50% concentrations of Endocyn, 6% NaOCl, 17% EDTA, and 2% CHX for 10 minutes, 1 hour, and 24 hours by dissolving the irrigants into cell medium. Distilled water was used as the control. The cells were rendered fluorescent with Calcein AM to allow microscopic examination and determination of survival. Comparison of cell survival was performed by using an unpaired, 2-tailed Student t-test (p0.05). Results: Compared to distilled water, Endocyn showed no increased cytotoxicity to PDL cells at 10 minutes for all concentrations tested. The 20% and 50% concentrations of Endocyn resulted in a 10% decrease in PDL cells at 1 hour, while the 50% concentration resulted in a 20% decrease in PDL cells at 24 hours. At all concentrations, Endocyn showed no increased cytotoxicity to UMR-106 cells at 10 minutes and 24 hours and a slight increase (10%) in cytotoxicity at 1 hour. All other experimental irrigants demonstrated significant cytotoxicity to both PDL and UMR-106 cells at all time intervals. Conclusion: Endocyn was less cytotoxic to PDL and UMR-106 cells compared to other commonly used endodontic irrigants.