SALIVARY DILUTION OF 1-1000 SODIUM FLUORIDE SOLUTION USED AS A MOUTHWASH

¹ Dental Division, Metropolitan Life Insurance Co., New York, N. Y.

Through accurate measurements on 100 individuals selected at random, the rate of dilution of a 1-1000 aqueous solution of sodium fluoride held in the mouth for 2 and 3 minute periods was ascertained. We found that in 2 minutes the solution changed from 1-1000 (0.1%) to a 1-1032 (0.0969%) solution; while in 3 minutes there is a change from 1-1000 (0.1%) to a 1-1052 (0.0951%) solution. A loss of volume occurred in 9% of all cases tested, but these cases were excluded from the foregoing computation.

A subdivision of data into various categories showed that a definitely greater increase in volume occurred among males than among females on the average, and in persons of both sexes in the age group 50 to 59, though all younger age groups showed fairly uniform increases. Season and conducting of the test before or after the process of dental cleansing made little difference in the result.

In the instances where a loss of volume occurred it is estimated that possibly 6% of the dose administered was swallowed. This finding should be taken in consideration in prescribing mouth rinse of greater toxicity than the present one.