Chromogenic stain molecules

Chromogenic stain molecules, or chromogens, are organic or inorganic compounds that accumulate within the dental enamel and dentin, resulting in visible tooth discoloration (Watts & Addy, 2001, British Dental Journal). These molecules are characterized by the presence of chromophores—chemical groups containing conjugated double bonds that absorb specific wavelengths of light (Joiner, 2006, Journal of Dentistry). Extrinsic chromogens typically originate from dietary sources like coffee, tea, and red wine, or from tobacco use, while intrinsic chromogens may result from systemic conditions, medications like tetracycline, or the breakdown of blood products within the pulp (Epple et al., 2019, Dentistry Journal). In cosmetic dentistry, these molecules serve as the primary target for whitening agents such as hydrogen peroxide and carbamide peroxide (Kelleher et al., 2011, Dental Update). These agents release reactive oxygen species that oxidize the chromogens, breaking their double bonds and converting them into smaller, colorless molecules, thereby increasing the lightness of the tooth structure (Carey, 2014, Journal of Evidence-Based Dental Practice).

Other names

ChromogensDental pigmentsExtrinsic stainsIntrinsic stainsChromophoresDental colorants

Oxidative degradation of conjugated double bonds within chromophores, leading to the fragmentation of large pigmented molecules into smaller, non-pigmented or less-pigmented compounds.