Histochemical studies on calcified tissues. 3. Amino acid histochemistry of carious dentine and dentinal reactions to caries.

Abstract

Although there has been a number of biochemical studies on carious dentine, the localization of any changes recorded is generally not possible due to the sampling techniques employed. Carious human teeth, which had clinical details available, were fixed in neutral buffered formalin. The teeth were bisected to produce ground sections and a hemisection, which was decalcified in 10% formic acid and embedded in paraffin or ester wax 1960. Methods applied to 6-Min serial sections were: FDNB, FDNB-H-acid, Millon, Barrnett and Seligman, coupled tetrazonium (Tetraz), Tetraz for tyrosine, DMAB-nitrite, Sakaguchi, anionic dyes and their appropriate blocking agents. The sclerotic layer was richer in histidine than normal dentine. Lower amounts of arginine, lysine and histidine were observed in areas of active destruction by several techniques. In highly pigmented carious dentine, arginine was found to be higher than in the rest of the carious dentine. All of these data compared favorably with previously published biochemical data, particularly that of Armstrong though we were able to localize the changes more precisely.