Medicine: Dentocillin

Nobody knows for sure what causes tooth decay. But since acid-producing bacteria are now blamed by most cavity detectives, an antibiotic to check the bacteria looked like a good bet. Last week, with the blessing of the Food & Drug Administration, the Andrew Jergens Co. offered druggists just such a prescription item: Dentocillin, a tooth powder containing penicillin.

The new tooth powder had been tested first in the laboratory by Dr. Helmut A. Zander of Tufts College Dental School. Then schoolchildren in Walpole, Mass, were used as human guinea pigs. In the first year, 216 children at the Stone School, who used powder containing penicillin, got 55% fewer cavities than 162 children at the Plimpton School, who used a powder identical in ingredients except for the penicillin. In the second year, the Stone School showed 54% fewer cavities than Plimpton, which seemed to prove that mouth bacteria did not become resistant to penicillin.

Dr. Zander also found that only six out of almost 4,500 subjects later tested were sensitive to the penicillin powder or became sensitive to penicillin after using it. But many doctors and dentists were still not convinced that it was a good idea to use penicillin indiscriminately in the mouth. If there were no unfavorable reactions, they argued, it must be because the penicillin was immediately flushed out of the mouth—in which case it would have little or no effect on tooth decay, either. There was still a lot to be said for a tooth cleanser consisting of nine parts elbow grease and one part water.