Fluoride Action Network


Dental fluorosis and osteofluorosis from using drinking water contaminated with the fluoride ion (F) have been reported from many countries including the People’s Republic of China and India. Because fluoride is excreted by the kidney and the toxic effects of F are more severe when renal failure is present, Imprinting control region (ICR)-derived glomerulonephritis (ICGN) mice, which have been used as a model of renal failure, could be a useful model for osteofluorosis. In the present study, ICGN mice and ICR mice were administered F at 0, 25, 50, 100, and 150 ppm in their drinking water for 4 weeks. The femurs of the mice were photographed and analyzed by microdensitometry. The teeth were stained with hematoxylin and eosin. While no significant differences in any bone indexes were found in the ICGN groups, the mean values for bone mineral content and bone mineral density of the left femur from the male ICR 150 ppm group were significantly higher than those of the control group mice (p<0.001). Partial heterogeneous calcification of the tooth dentine was observed in the ICGN mice exposed to 150 ppm. ICGN mice may be used as a model for dental fluorosis. However, ICR mice, particularly males, with an exposure period of 2–4 mo, may be a better animal model for osteofluorosis.