The discoloration of dental carious lesions is a marked feature which
has received relatively little attention from dental researchers. In t
his short review, possible causes are considered: the formation of Mai
llard pigments, melanins, and lipofuscins, and the uptake of food dyes
, metals, and bacterial pigments. It is concluded that the Maillard re
action between proteins and small aldehydes produced by bacteria proba
bly accounts for the discoloration. (C) 1998 Elsevier Science Ltd. All
rights reserved.