title: Generation of free radicals and/or active oxygen by light or laser irradiation of hydrogen peroxide or sodium hypochlorite.
abstract: Generation of free radical and/or active oxygen by light or laser irradiation of hydrogen peroxide (H2O2) or sodium hypochlorite (NaClO), which have been used for tooth whitening or root canal irrigation, was investigated using electron spin resonance spectroscopy combined with a spin-trapping technique. When H2O2 was exposed to light or laser radiation, the amount of hydroxyl radical generated changed according to the concentration of H2O2 and irradiation time. The amount of 5,5-dimethyl-1-pyrrolidone-(2)-oxyl-(1) (DMPO-X) also changed in accordance with irradiation time. The amounts of hydroxyl radical generated from H2O2 after irradiation were in the order: plasma lamp > halogen lamp > He-Ne laser > Yellow He-Ne laser. On the other hand, the amounts of DMPO-X generated from NaClO after irradiation were in the order: plasma lamp > Yellow He-Ne laser > halogen lamp > He-Ne laser.
authors.affiliation: Department of Endodontics, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
authors.forename: Midori
authors.initials: M
authors.lastname: Kashima-Tanaka
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Tsujimoto
authors.forename: Kohji
authors.initials: K
authors.lastname: Kawamoto
authors.forename: Naoki
authors.initials: N
authors.lastname: Senda
authors.forename: Koichi
authors.initials: K
authors.lastname: Ito
authors.forename: Muneyoshi
authors.initials: M
authors.lastname: Yamazaki
mesh_terms: D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000032:analysis*; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000528:radiation effects*; D017665:Hydroxyl Radical / Q000032:analysis; D007834:Lasers; D008027:Light; D017382:Reactive Oxygen Species / Q000032:analysis*; D012973:Sodium Hypochlorite / Q000737:chemistry / Q000528:radiation effects*; D013113:Spin Labels; D019097:Spin Trapping; D013997:Time Factors
chemical_list: C025634:5,5-dimethylpyrrolidin-2-one-1-oxide; D003497:Cyclic N-Oxides; D005609:Free Radicals; D017382:Reactive Oxygen Species; D013113:Spin Labels; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D012973:Sodium Hypochlorite