Bactericidal Efficacy Of New Electrolyzed Water

Objectives: New electrolyzed water (pH: about 8), which is prepared by electrolysis with low frequency vibration, shows the excellent bactericidal activity similar to other electrolyzed waters such as strong acid and neutral electrolyzed waters. This new type of electrolyzed water has active ingredient nanobubbles in itself and shows high durability of bactericidal activity. In this study, the applicability of new electrolyzed water to sterilization of dental instruments and impression tray was examined. Methods: New electrolyzed water, which was stored in shaded container in the room temperature for 3 to 4 months after preparation by a manufacturer, was used for an experiment. Several instruments and impression tray with their surfaces being contaminated with the level of 10⁶ to 10⁷ bacteria were immersed in new electrolyzed water with or without ultrasound. After treatment, the total numbers of surviving bacteria on them were examined and effective treatment conditions by this water were showed clear. In comparison, similar examination for the neutral electrolyzed water just after the preparation was conducted. Results: The instruments having simple configuration such as reamer, explorer and impression tray could be sterilized by one-minute immersion in any electrolyzed water tested, while those of complicated configuration such as burs and point required much longer time for equivalent sterilization. When the ultrasonic cleaning action was added in any electrolyzed water, all the instruments and impression tray were sufficiently sterilized by one-minute treatment. Even if new electrolyzed water was stored for 3 to 4 months, it showed the same effects as neutral electrolyzed water just after preparation. Conclusions: Sterilization efficacy of new electrolyzed water for dental instruments and impression tray were found to be excellent with no significant differences between two electrolyzed waters. It was suggested that new electrolyzed water may well be available as the disinfectant for dental instruments and impression tray.