The effect of two sucrose diets on formation of dentin and predentin in growing rats.

The effect of two high-sucrose diets on dentinal caries, dentin formation, and the predentin width was studied in Sprague-Dawley rats. Rats were weaned at the age of 3 weeks and for 4 weeks fed a non-cariogenic commercial rat food (R36) for control, a high-sucrose Stephan-Harris (S-H) diet, or a new high-sucrose (sR36) diet in which most of the barley and wheat flour of the control R36 diet were replaced by sucrose. The areas of dentinal caries, the areas of dentin formation, and the width of predentin and dentin were quantified. Both high-sucrose diets induced dentinal caries, and both reduced dentin formation and increased the width of predentin compared with the control diet. Moreover, rats fed the S-H high-sucrose diet showed significantly greater progression of caries and reduction of dentin formation relative to rats fed the new high-sucrose diet, sR36. The high-sucrose diet thus was a substrate for caries-inducing microbes and a significant, but possibly not the exclusive, substrate for host modulation of odontoblast function.