Carbonyl-binding Compounds as Inhibitors of Experimental Caries in Rats

¹ National Institute of Dental Research, National Institutes of Health, Public Health Service, U. S. Department of Health, Education, and Welfare, Bethesda, Maryland

Three different carbonyl-binding compounds were found to inhibit the development of sulcal caries in Sprague-Dawley rats when incorporated separately into a coarse corn particle, high-sugar diet. An 82 per cent reduction in caries score was obtained when carboxylemethoxylamine hemihydrochloride was fed in the diet at a level of 0.004 molar for the first week and 0.002 molar for the remainder of the 90-day test period. Feeding of 0.016 molar sodium metabisulfite resulted in an inhibition of 86 per cent. Rats fed the aldehyde-binding agent dimedone at a level of 0.029 molar in the diet showed a 55 per cent reduction in caries score. Relative effectiveness of these three compounds as caries-inhibiting agents generally paralleled their growth- inhibiting properties for a variety of micro-organisms, including lactobacilli, streptococci, staphylococci, micrococci, candidae, leptotrichiae, diphtheroids, and neisseriae. Subinhibitory concentrations of carboxylmethoxylamine hemihydrochloride and dimedone apparently had no effect on lactate production by a rat oral streptococcus, in contrast to earlier observations indicating that subinhibitory concentrations of sodium metabisulfite can depress lactate production by this organism.