Chromophores in tooth enamel and dentin

Chromophores in tooth enamel and dentin are the chemical entities responsible for the color and discoloration of teeth, consisting primarily of organic compounds with conjugated double bonds and certain metal ions (Kwon & Wertz, 2015). These molecules are located within the hydroxyapatite crystal lattice of the enamel and the collagen-rich matrix of the dentin, where they absorb specific wavelengths of light to produce visible staining (Joiner, 2006). In dental therapeutics, these chromophores are the primary targets for bleaching agents such as hydrogen peroxide and carbamide peroxide. These agents function by generating reactive oxygen species, such as hydroxyl radicals, which attack the double bonds of the chromophores through oxidation (Eimar et al., 2012). This process breaks the large, pigmented molecules into smaller, non-pigmented fragments, thereby increasing the lightness of the tooth. While the removal of chromophores is largely a cosmetic procedure, it is also used to treat pathological conditions like dental fluorosis and tetracycline-induced staining (Joiner, 2006). Clinical challenges associated with targeting these molecules include the risk of transient dentin hypersensitivity and potential irritation of the surrounding gingival tissues (Kwon & Wertz, 2015).

Other names

Dental chromophoresTooth pigmentsIntrinsic stainsExtrinsic stainsOrganic dental stains

Oxidation of conjugated double bonds in organic pigments; reduction of molecular weight of pigments; alteration of light absorption properties