In vitro bactericidal activity of photo-irradiated oxydol products via hydroxyl radical generation.

The oxidative power of hydroxyl radicals has been applied to disinfection systems for the purpose of oral hygiene by utilizing blue light-induced photolysis of hydrogen peroxide (H₂O₂) in our laboratory. In the present study, the bactericidal potential of blue light-irradiated oxydol products via hydroxyl radical generation was compared with that of 3% (w/v) H₂O₂. Eleven commercially available oxydol products were used in the present study. Even though a few of the products that contained ethanol, a hydroxyl radical scavenger, as an additive showed slightly lower hydroxyl radical yield as compared with 3% (w/v) H₂O₂, the blue-light irradiation of each oxydol product for 3 min showed similar or superior bactericidal activity against Staphylococcus aureus to that of 3% (w/v) H₂O₂. The results strongly suggest that any of the oxydol products tested in the present study can be used as a source of hydroxyl radicals for the disinfection technique developed in our laboratory.