Solution of enamel is a chemical process, and follows known laws of solution. Variation in H-ion concentration of a liquid markedly affects its solvent action on enamel. Acid-neutralizing power of saliva (a) is definitely affected by diet, high-carbohydrate diet decreasing it ; diet high in protein, and also high in vegetables of low carbohydrate-content, increasing it; (b) is usually increased by chewing paraffin, gum, etc.; and (c) may drop or rise shortly after eating, returning to normal in a few hours, depending to a great extent upon the nature of the food. All of these conditions, and possibly other factors that may temporarily affect salivary composition, must be controlled in any attempt to show relationship between acid-neutralizing power of saliva and caries.
References: J. Den. Res., 1931, 1932, 1933, 1937.