THE MAILLARD REACTION IN DEMINERALIZED DENTIN IN-VITRO

The Maillard reaction between carbohydrate and protein has been propos ed as a cause of the browning of carious lesions. The aim of the prese nt investigation was to determine the occurrence of this reaction in b ovine dentin collagen in vitro and to establish the effect of the reac tion on the proteolytic degradation of bovine dentin collagen in vitro . Slices of demineralized bovine dentin were incubated with 0.2 M gluc ose or buffer for 10 weeks at 37 degrees C. The formation of initial ( furosine) and advanced (pentosidine) products of the Maillard reaction in dentin exposed to glucose was confirmed by HPLC. After reduction w ith NaBH4 to prevent intermediate Maillard products from further react ion, slices were either degraded with collagenase for fluorescence mea surement or incubated with trypsin or pepsin to assess enzymatic degra dation. Fluorescence characteristic for the Maillard reaction increase d in glucose-exposed slices. Degradation of collagen by pepsin, but no t by trypsin, was greatly depressed following glucose pretreatment. Th is may indicate an altered sensitivity to proteolytic degradation; the Maillard reaction thus has a potential role in caries arrestment.