[The effect of different concentrations of fluoride on the expression of Smad2/3 in ameloblast of rat incisor].

Purpose: To investigate the effect of different concentrations of fluoride on the expression of Smad2/3 which is a specific intracellular signal transduction molecule of TGF-β, and to explore the mechanism of dental fluorosis in rat.

Methods: Forty Wistar rats were randomly divided into 3 groups.HE and immunohistochemistry were used to detect the changes of the ameloblasts and the expression of Smad2/3 in rat incisors. MetaMorph microscope images analysis system and SPSS12.0 software package were used to analyze the images and data.

Results: Typical symptoms of dental fluorosis were found in the fluoride group. The expression of Smad2/3 in the ameloblasts in the experimental group was significantly lower than that in the control group (P<0.01); but the difference was not significant between the low-dose group and high-dose group(P>0.05).

Conclusions: By inhibiting the expression of Smad2/3 in ameloblasts, fluoride affects the differentiation and development of enamel,leading to the occurrence of dental fluorosis in rat.