[Histochemical studies of three kinds of enzymes in dentinal caries]

Aminopeptidase, acid phosphatase and nonspecific esterase in dentinal caries were investigated by histochemical method in this study. It was found that in contrast with Gram's stain, the several hydrolytic enzymes were all located within the region where bacteria invaded the dentine. This suggested that the enzymes were produced by the bacteria invading dentinal tubules. According to previous study of the functions of these enzymes, it was speculated that in the process of dentinal caries, aminopeptidase and acid phosphatase may be involved in the decomposition of structural protein of dentinal organic matrix and non-specific esterase in the decomposition of structural lipids of dentine.