Histochemical Study of Dentin in Hydrocortisone- and Fluoride-Treated Rats

¹ Department of Anatomy, School of Medicine, University of Southern California, Los Angeles, California; National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland; and NIDR Visiting Scientist, Hebrew University and Hadassah Medical School, Jerusalem, Israel

Female rats were injected intramuscularly with 2.5 mg. of hydrocortisone acetate daily for 30 days. A second group of similar rats were injected with the suspension vehicle and thus acted as controls. Half of each group received either distilled water or 75 p.p.m. F in drinking water. Histologic sections of incisal dentin from all groups were stained by various histochemical methods in an effort to determine the influence of hydrocortisone, fluoride, or hydrocortisone-fluoride administration on bone. The fluoride-treated dentin stained deep red with periodic acid-Schiff stain and exhibited an abundance of Alcian blue-positive material, which was also metachromatic in nature. These staining reactions would indicate that there was an alteration in the organic matrix, particularly the ground substance; a situation which produced an interference in the calcification of the dentin.