THE TOXICITY OF IODOACETIC ACID AND ITS QUANTITATIVE RELATIONS TO INHIBITION OF GLYCOLYSIS AND DENTAL CARIES

¹ Department of Pharmacology, University of Lund, and the Department of Oral Surgery, State Dental School, Malmö, Sweden

In comparing the I-ac inhibitory effect in in vitro saliva-glucose-enamel tests with the in vivo effect on caries in rats, the in vitro tests show 10 times the inhibitory effect shown by the animal tests. The difference is modified depending upon which type of caries is used for the calculation. A distinct caries inhibition is obtained with an I-ac concentration of 0.002 per cent in the food.

The LD₅₀ in peroral administration of I-ac in rats has been determined to be 116 ± 13 mg. per kilogram body weight.

The safety margin of I-ac is too narrow to permit its practical application as a caries prophylactic. The absence of toxic changes in experimental animals confirms the applicability of the principle of supplementing caries-producing diet with compounds having local action such as I-ac. For this purpose substances of lower acute toxicity must be found.

In the study of drugs inhibiting the glycolysis of dental caries, this experimental procedure may serve as a basis for comparison.