Medicine: New Weapon

The exact cause of tooth decay has always puzzled dentists. Researchers have recently looked with the deepest suspicion at Lactobacillus acidophilus, a germ found in saliva. Thus far, the most practical weapon against the germ, which apparently attacks the teeth from the outside, has been fluorine, introduced into the enamel as the teeth are being formed.

Last week a nonprofit group called the Eastern Graduate Research Foundation announced a new campaign against Lactobacillus and a three-year program to test it. The new weapon is a tooth powder containing dibasic ammonium phosphate and urea (a synthetic nitrogen compound). The powder is supposed to break down tooth film, slow down growth of bacteria and neutralize the acid created by Lactobacillus. In preliminary experiments, the foundation claims, it has reduced decay as much as 35%.

As guinea pigs, the foundation, cooperating with the Poloris Co., which manufactures one type of ammoniated powder called Amm-i-dent, has chosen the schoolchildren of Mahopac, N.Y. (pop. 1,109). Some 500 Mahopac pupils from kindergarten through the tenth grade will be asked to brush their teeth twice a day with Amm-i-dent. Free X rays and periodic dental examination will provide a running check on the experiment. Its sponsors hope that the new powder will prove effective against decay, regardless of the tooth-owner’s age.