GREATER CONCENTRATION OF DIETARY SUCROSE DECREASES DENTIN FORMATION AND INCREASES THE AREA OF DENTINAL CARIES IN GROWING RATS

The effect of increasing dietary sucrose concentration on dentin forma tion and dentinal caries progression was studied. Weanling Wistar rats received 15, 30 or 43 g/100 g sucrose in a diet; for reference, anoth er group was fed a nonpurified diet. At the onset, tetracycline was in jected to mark the dentin formed during the experiment. After 6 wk, lo wer molars were sectioned sagittally; the areas and thicknesses of the dentin formation during the experiment and dentinal caries lesions we re quantified separately in the first and second molars. Feeding the 4 3% sucrose diet resulted in a significantly lower dentin formation tha n in other diet groups (P < 0.05). The differences obtained from the a rea measurements were supported by thickness measurements. In the firs t molar, the 43% sucrose diet resulted in a significantly greater area of dentinal caries than in the other sucrose groups. The number and s everity of caries lesions clearly increased as the concentration of su crose in the diet increased (r = 0.5, P < 0.05 and r = 0.6, P < 0.05, respectively). This study suggests that the increase in the concentrat ion of sucrose in the diet reduces dentin formation and increases the area of dentinal caries as well as the number and severity of caries l esions; the critical sucrose concentration appears to be between 30 an d 43 g/100 g.