- The primary mechanism by which dental bleaching agents achieve tooth whitening is through the oxidation of organic pigmented molecules within the tooth structure.
- Dental bleaching agents, such as hydrogen peroxide or carbamide peroxide, penetrate the enamel and dentin to reach chromogenic molecules responsible for tooth discoloration.
- These agents release reactive oxygen species that break down complex pigmented molecules into smaller, less colored or colorless compounds.
- This chemical reaction leads to a visible whitening effect.

- It is important to note that the process does not involve reduction of mineral content in enamel, which could otherwise weaken the tooth structure.
- Similarly, bleaching is distinct from treatments that involve deposition of calcium phosphate crystals (which aim to remineralize teeth) or chelation of metal ions in dentin.

In summary:
- Dental bleaching works by oxidation, targeting organic pigmented molecules.
- This results in the breakdown of stains, thereby lightening tooth color.
- The mineral content of enamel remains largely unaffected.

Reference: Sturdevant's Art and Science of Operative Dentistry, 7th Edition, Chapter 28: Tooth Whitening, Page 600