Dental caries and plaque formation from diets containing sucrose or glucose in gnotobiotic rats infected with Streptococcus strain IB-1600.

I. Techniques were devised for the operation of a new small-scale gnotobiotic rat unit. 2. The unit was then used to compare the cariogenicity of sucrose and glucose under carefully controlled conditions in the presence of a single strain of a streptococcus, as gnotobiotic experiments by other workers had given conflicting results. 3. Streptococcus IB-1600 was implanted into thirty-four rats, which were then fed on highsugar dicts under gnotobiotic conditions for 5 or 8 weeks from weaning. The level of caries was significantly higher on the sucrose than on the glucose diet, but thcrc was no significant difference in the extent of soft coronal dental plaque.