Abstract
An extension of the work previously published, (Jour. Dental Res. 24, 235, 1945) indicates that oxalates and fluorides (which form insoluble Ca salts), and soluble Pb, Ba and Ag salts (which form insoluble phosphates), protect teeth from acid decalci-fication in vitro, and reduce the "apparent" insolubility of tooth enamel, and Ca phosphate in lactic acid sol.