ASSOCIATION OF FREE ARGININE AND LYSINE CONCENTRATIONS IN HUMAN PAROTID-SALIVA WITH CARIES EXPERIENCE

We determined the free-amino acid content of stimulated parotid (ducta l) saliva from two groups of adult subjects whose caries experiences w ere markedly different. The levels of free arginine and free lysine in the parotid saliva of caries-free adults were significantly higher th an those found in the parotid saliva of individuals with a history of dental decay. There was no correlation, however, between the levels of these amino acids and the DMFS score within the caries-susceptible gr oups. Microbial catabolism of dibasic amino acids contributes to the n eutralization of plaque acids and may partially account for the higher resting plaque pH observed in caries-free subjects. Alternatively, th e elevations observed in free levels of arginine and lysine may reflec t a systemic alteration in amino acid metabolism which is common to th e caries-free group of subjects.