Cariogenicity of Invert Sugar in Long-Term Rat Experiments

In order to study a possible microbial adaptation to invert sugar, 10 groups of Wistar rats, 12 animals per group, were fed a diet containing 56% of either (1) equal amounts of fructose and glucose (invert sugar), or (2) sucrose, by use of an automatic feeding machine. The rats in the first invert sugar group were not infected. After 60 days, samples taken from the oral cavity in each animal in this group were cultured, pooled and then transmitted to a second invert sugar group. Subsequently, a third invert sugar group was infected with material from the second invert sugar group and this procedure was repeated with 10 groups of rats. Parallel with each invert sugar group a sucrose group was also run. The animals in all 10 sucrose groups were infected with a fresh culture of four strains of Streptococcus mutans. In all groups, either fed invert sugar or sucrose, both fissure and smooth surface caries were found. Animals in the sucrose groups developed on an average 1.2 times as many sulcus lesions (p