Histoehemical Studies on Enzymes Acting on Glycosyl Compounds, Phosphoryl-Containing Anhydrides and Phosphoamides in Human Carious Dentine

Abstract

Fresh, undecalcified sections from (1) in situ excavated carious dentine or from (2) specimens with carious and sound dentine from extracted human teeth were cut in a cryostat and the localization of various hydrolytic enzymes demonstrated histochemically. It was observed that the hydrolysis of β-glucuronidase, α-glucosidase, β-glucosidase, β-galactosidase, ATPase, and phosphoamidase substrates could be demonstrated (a) in dental plaque, (b) in the superficial necrotic layer and in the infected zone of carious dentine, and (c) also in the decalcified carious dentine, where Gram staining revealed no microorganisms. Additionally, the hydrolysis of β-glucuronidase and α-glucosidase substrates could be observed (d) in the predentine layer. No hydrolysis of chitobiase substrate could be observed in any zone of carious dentine, nor any of the substrates in normal sound dentine. These findings were thought to further map the catabolic events during the propagation of dentine caries, especially in the enzymic degradation of mucopolysaccharides of the organic stroma of the dentine.