Effects of Particle Size of Corn and Sugar Diets and of Mastication on Caries Incidence in Osborne-Mendel Rats

¹ Experimental Caries Research Laboratory, Dental Institute, University of Zürich, Switzerland

In 108 Osborne-Mendel rats, caries incidence and, especially, initiation of lesions were studied as effected by nine comparable coarse- and fine-corn and -sugar diets under mastication and non-function. Diets containing 66 per cent corn induced markedly less initial sulcal lesions than did corresponding diets containing 66 per cent sugar. The diets containing fine particles caused more initial lesions than the coarse-particle diets, this difference being less marked in the corn diets. On the corn diets there were more sulcal lesions under mastication than under non-function, the reverse being true for the sugar diets. Diet 580 turned out to be the most cariogenic of all food mixtures tested. The implications caused by coarse dietary particles and by food selection are discussed.