How does dental bleaching work?

Dental bleaching is a common treatment in the dental sector.
To change the intrinsic shade of a tooth, the bleaching agents must spread inside and through the enamel, reaching and penetrating the enamel-dentin interface and interacting in the underlying dentin with the chromophores (staining substances), pigments and ions that change the shade of the tooth.

Basically, all dental bleaching techniques use hydrogen peroxide (H2O2) as the active principle: either directly or through the decomposition of other chemical substances, like carbamide peroxide.

The H2O2 released generates different radicals or ions depending on the pH value, the temperature, the effect of light, in addition to the presence of co-catalysers and metallic reagents. These different types of oxygen have oxidative and reductive properties that break up the bonds of staining molecules or reduce the coloured metallic oxides, making them colourless.

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