SUBSTANCES CAPABLE OF DECREASING THE ACID SOLUBILITY OF TOOTH ENAMEL

¹ Chemical Division, the Procter and Gamble Company, Ivorydale, Ohio, and Tufts College Dental School, Boston, Mass.

One hundred forty-seven substances, comprising compounds of fifty-seven elements, have been tested for possible effect on the acid solubility of powdered tooth enamel. The investigations were carried out independently in two laboratories by slightly different procedures. The substances were dissolved in water or acetic acid buffer and placed in contact with enamel powder for a few minutes. Acid solubility of enamel after this treatment was compared with the solubility before treatment.

Twenty-seven compounds were more active in reducing acid solubility than 0.1 per cent NaF, and thirty-eight were less active but definitely effective. Compounds of cations of Groups III and IV of the periodic table were among the most active substances. Several other compounds of fluoride were more active than sodium fluoride in depressing enamel solubility.