Tooth whitening: How does it work

Tooth discoloration is classified as extrinsic or intrinsic, with extrinsic stains arising from accumulation of residue on the surface of the tooth, and intrinsic discoloration from stains within the enamel or dentin. For both types of stains, tooth whitening with hydrogen peroxide is a common treatment. Hydrogen peroxide likely exerts its effects by interacting with chromophores within the tooth structure, acting via what is known as the “chromophore effect.” Despite having the desired cosmetic effect, however, hydrogen peroxide treatment also may likely affect sound tooth tissue; and the unknowns surrounding unwanted side effects remain a concern. Here, the etiology of extrinsic and intrinsic stains is summarized, as is our current understanding of hydrogen peroxide treatment and mechanisms of action. This information might guide further research and development efforts to create new technology for the treatment of tooth discoloration.