Discoloration of dental carious lesions (a review)

The discoloration of dental carious lesions is a marked feature which has received relatively little attention from dental researchers. In this short review, possible causes are considered: the formation of Maillard pigments, melanins, and lipofuscins, and the uptake of food dyes, metals, and bacterial pigments. It is concluded that the Maillard reaction between proteins and small aldehydes produced by bacteria probably accounts for the discoloration.