THE EFFECT OF EARLY WEANING ON DENTIN FORMATION AND DENTINAL CARIES IN RATS

The effect of early weaning on caries progression, dentin formation, a nd dentin mineralization was examined in four groups of rats. Two grou ps received a normal diet and were weaned on day 18 or 21, and another two received a sucrose-rich diet and were weaned on day 18 or 21. At age 35 days the lower molars were sectioned sagittally, and the areas of dentin formation and of the dentinal caries were quantified. The wi dth of the predentin zone was measured from histologically stained sec tions of maxillary molars. Early weaning reduced dentin formation in t he group on the high-sucrose diet only the first days; later this effe ct was partially caught up with. A high-sucrose diet significantly inc reased caries frequency and extension of caries lesions compared with a normal diet in both early weaned and normally weaned groups. The eff ect of early weaning on caries frequency and extension in the high-suc rose group was insignificant compared with the normally weaned group o n a high-sucrose diet. The predentin zone was wider in the sucrose gro ups than in the control groups at the end of the experiment. These res ults indicate that the effect of sucrose on dentin formation was depen dent on the stage of physiologic dentin formation, but early weaning a s such did not affect this.