Abstract
Using DD series diets that contain purified ingredients, a content of 15% sucrose was more cariogenic than only starch in Sprague-Dawley and Long-Evans rats. Raising the sucrose level above 15% did not increase caries. Similar results were produced by ad lib and programmed-frequency feeding; the latter eliminated any differences in cariogenicity that might have resulted from altered feeding behavior with different-tasting diets. In contrast, with diets of the 2000 series that contain some natural ingredients raising the sucrose level above 15% increased caries incidence, in Sprague-Dawley rats an almost linear response was found between dietary sucrose content and caries. The basal composition of a ration can markedly affect the caries response to increasing sucrose levels.