Possible Basis for the Cariostatic Effect of Inorganic Phosphates

Abstract

INORGANIC phosphates are effective in reducing dental caries when added as supplements to cariogenic diets fed to rodents¹, and when added to chewing gum² and to breakfast cereal eaten by children³. Because the caries process may be influenced by pellicle proteins⁴, and salivary proteins adsorbed to human enamel are differentially eluted by water and orthophosphate solutions⁵, we reasoned that the cariostatic effect of phosphate might involve one or both of the following processes: (a) differential elution of proteins adsorbed on enamel; (b) modification of the enamel surface resulting in an alteration of the acquired protein layer. To test this hypothesis in a model system we have studied the effects of phosphates on enzymes adsorbed to human enamel.