| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2001: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2000: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
Hydrogen peroxide is one of active oxygen species, and the hydroxyl radical, which is strong active oxygen, generated from hydrogen peroxide by chemical reactions. In the tooth whitening, hydrogen peroxide is the most popular agent. We detected hydroxyl radical from hydrogen peroxide with lights or lasers irradiation.
In the electron spin resonance spin-trapping technique, hydroxyl radical was linearly generated using under 1mol/1 hydrogen peroxide and ultraviolet irradiation time for 20-40 s, then detected volume of hydroxyl radical was plateau.
In the experiment of light or laser irradiation to hydrogen peroxide, the amounts of hydroxyl radical generated from hydrogen peroxide after irradiation were in the order : plasma lamp > halogen lamp > He-Ne laser > Yellow He-Ne laser. In addition, the hydroxyl radical was detected by plasma lamp irradiation more than Ar laser or CO_2 laser.
In the experiment of the root canal dentin surfaces were observed using SEM after applied several concentrations of hydrogen peroxide the intertubular dentin and peritubular dentin were resolved by high concentration of hydrogen peroxide, and long time application of hydrogen peroxide.
In the study for human gingival fibroblasts, numbers of survival cells of human gingival fibroblasts were decreased after being treated by hydrogen peroxide, hydrogen peroxide with light irradiation, respectively. The cytotoxicity effect on human gingival fibroblasts was in the order hydrogen peroxide with light irradiation > hydrogen peroxide > light irradiation.
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