Tooth Bleaching Using Low Concentrations of Hydrogen Peroxide in the Presence of a Nonthermal Plasma Jet

To investigate the tooth bleaching effect of a low concentration hydrogen peroxide (H
₂
O
₂
) assisted by a nonthermal plasma, extracted human teeth were treated by a nonthermal plasma in the presence of varying concentrations of hydrogen peroxide gel. The results showed that combining plasma treatment with a low concentration hydrogen peroxide (6%) achieved a superior bleaching effect compared with a high concentration of hydrogen peroxide (35%) in the absence of a plasma. Furthermore, the bleaching efficacy did not significantly increase with increasing H
₂
O
₂
concentration above 6% in the presence of the plasma. Compared with the control group (hydrogen peroxide without plasma), the plasma generated two to three times as many ·OH radicals, which are believed to be one of the key reactive species that contribute to the bleaching effect.