There are two main types of teeth whitening: chemical and physical. In the case of chemical teeth whitening, the tooth is treated externally or internally with a whitening agent containing hydrogen peroxide, and then, when illuminated with a special light, an oxidation process begins, breaking down double covalent bonds into single bonds, which makes the teeth permanently whiter.

The oxide of each compound is lighter than the compound itself, so we can lighten even several shades of color.

So, during the release of hydrogen peroxide from the applied substance, the large dark macromolecules that cause discoloration are oxidized to smaller, light or colorless molecules. The oxidizing agent can be used in different forms and concentrations, depending on the cause of the discoloration and the treatment chosen. The color change occurs in the dentin, not in the enamel.