Dental chromogen

Dental chromogens are organic molecules responsible for the discoloration of teeth, categorized into extrinsic stains (surface-level) and intrinsic stains (incorporated into the enamel or dentin) [2]. These molecules often contain chromophores—chemical groups such as conjugated double bonds that absorb specific wavelengths of light, resulting in visible color [1]. Common sources include dietary polyphenols, tannins from tea or coffee, and tobacco-derived compounds [2]. In clinical dentistry, chromogens are the primary targets for bleaching agents like hydrogen peroxide and carbamide peroxide [3]. These agents act by generating reactive oxygen species that oxidize the chromogens, breaking their complex chemical structures into smaller, colorless fragments [3, 4]. While effective for aesthetic improvement, the process can lead to transient side effects such as tooth sensitivity and gingival irritation [4]. The efficacy of treatment is typically measured by the reduction in the concentration or complexity of these molecules within the dental matrix [1].

Other names

Dental stain moleculesTooth pigmentsExtrinsic stainsIntrinsic stainsChromophoresTanninsPolyphenols

Oxidation of conjugated double bonds within chromophores, leading to the fragmentation of large pigmented molecules into smaller, colorless or less-pigmented compounds [1, 3].