Often, regular brushing is not enough to remove stains from discolored teeth. Hydrogen peroxide is an oxidizing agent that penetrates the enamel and dentin. The released oxygen radicals cause the oxidation of color molecules, making teeth white again.
Hydrogen peroxide and carbamide peroxide, an urea-hydrogen peroxide complex, are the primary bleaching components in tooth whitening products such as whitening toothpastes, bleaching powders, bleaching strips, bleaching pens, or bleaching gels.
Persulfates and food-grade calcium peroxide are also used for effective teeth whitening in oral care products for home use.