REDUCED ORAL TEMPERATURES AND ACID PRODUCTION RATES IN DENTAL PLAQUES

¹ U. S. Naval Medical Research Laboratory, U. S. Naval Submarine Base, New London, Conn.

Changes were measured in the pH of 176 dental plaques on men living in Antarctica following a carbohydrate rinse given at room temperature and a second rinse given 75 minutes later. The intervening time was spent in temperatures ranging from -31° F. to -57° F. The first rinse showed the usual increase in plaque acidity. The second rinse produced no such increase, and thus indicated that the exposure to cold greatly inhibited or completely attenuated bacterial action. Lactobacillus counts taken at room temperature and retaken after the subjects' exposure to the cold showed a marked decrease. Decrease in bacterial action was found to be positively correlated with decrease in tooth surface temperatures.