The rate of acid formation from sugar is generally greater in saliva of caries-susceptibles than in that of caries-immunes. A salivary test for susceptibility or immunity to caries, based upon this fact, has been devised. Acid production is determined by measurement of calcium dissolved from powdered enamel. Several mouth organisms, especially yeast, are capable of decalcifying enamel. Symbiotic relationships exist between mouth organisms, notably between yeast and B. acidophilus. Acids other than lactic, produced by microorganisms, dissolve enamel. Reactions involved in production of acids by microorganisms are enzymic in nature.
References: J. Am. Den. Assoc. (Den. Cosmos), 1936, 1937.