Abstract:

Objective To investigate the effect of different concentrations of fluoride on the expression of transforming growth factor-β1（TGF-β1）, and explore the mechanism of dental fluorosis. Methods 40 Wistar rats were randomly divided into three groups, and supplied with low dose F-（60 mg·L-1, 13 rats）, high dose F-（120 mg·L-1, 13 rats） and distilled water（control group, 14 rats） respectively. After 10 weeks, hematoxylin-eosin（HE） and immunohistochemistry staining were used to observe the changes of the ameloblasts and the expression of TGF-β1 in rat incisors. Results The fluoride groups showed typical symptoms of dental fluorosis. The surfaces of the rat teeth fed with fluoride appeared chalky color and cross striation on the enamel surface. The HE staining showed that the morphous of
ameloblast were disarranged and cellular derangement, even appeared vacuolar change. TGF-β1 were expressed both in ameloblast of the secretory and maturation stage, and also in stellate reticulum and stratum intermedium. The expression of TGF-β1 in rat’s ameloblasts in experiment group was significantly lower than that in the control group （P<0.01）, yet low dose group and high dose group still had no significant difference（P>0.05）. Conclusion By inhibiting the expression of TGF-β1 in ameloblast, fluoride interferes the normal signal transduction between epithelial and mesenchymal, and affect the differentiation and development of enamel, so leading to the occurrence of dental fluorosis.