The Cariogenicity of Dietary Sucrose at Various Levels in Two Strains of Rat Under Unrestricted and Controlled-Frequency Feeding Conditions

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; however, raising the sucrose level above 15% did not increase caries. Similar results were produced by ad libitum and programmed-frequency feeding, the latter eliminated any differences in cariogenicity that might have resulted from altered feeding behaviour 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. It is concluded that the basal composition of a ration can markedly affect the caries response to increasing sucrose levels.