Parotid gland function and dentin apposition in rat molars

Previous studies have clearly established the down-regulating effect of a sucrose-rich diet on primary dentinogenesis in rat molars. Earlier observation of the negative effect of a high-sucrose diet on a parotid function involved in the control of intradentinal solute movement led us to hypothesize that parotid gland function(s) may have a role in regulating dentinogenesis. Dentin apposition in 1st and 2nd molars of young rats was measured by planimetry in sagittal sections. The following experimental variables were tested: standard and high-sucrose diets, removal of the parotid or the submandibular/sublingual glands, and diets in powder or pellet form. Removal of the submandibular/sublingual glands and changes in diet consistency did not significantly affect dentin apposition. Dentin apposition was significantly depressed by the high-sucrose diet or following parotidectomy. A further decrease followed the combination of the two treatments. Parotid glands appeared to exert a positive effect on dentin apposition in rat molars.