[The effect of fluoride on the metabolism of teeth and bone in rats]

To investigate the effect of fluoride on the metabolism of teeth and bone in rats, and to probe the mechanism of pathogenesis of dental fluorosis.

A total of 48 Wistar rats were randomly and equally divided into 4 groups including control group (distilled water), low-dose group(NaF,50 mg/L), medium-dose group (NaF,100 mg/L) and high-dose group (NaF, 150 mg/L). After 8 weeks, the rats were sacrificed under anesthesia, and serums were collected. The biochemical technique was used to test serum calcium. Changes in the fluorine content in serums and teeth of each group were analyzed with fluoride ion selective electrode method. Radioimmunoassay was employed to detect the levels of osteocalcin (OC), parathormone (PTH) and calcitonin (CT), respectively. SPSS13.0 software package was used for statistical analysis.

The fluorine content in serum and teeth in the fluoride group were significantly higher than that of the control group (P<0.05), and increased with the increasing concentrations (F value was 11.234 and 275.148 respectively, P<0.01). The level of calcium in serum (F=3.906, P<0.05) in the fluoride group was significantly lower than in the control group. The level of PTH and OC in serum in medium and high-dose group were significantly higher than in the control group (P<0.01), with the level of CT in high-dose group decreased significantly (P<0.01). The differences of the level of OC, PTH, CT between groups were significant (F value was 8.548, 3.801 and 5.121 respectively, P<0.05).

Fluoride affects the metabolism of teeth and bone in rats and OC, PTH, CT plays a key role in the pathogenesis of dental fluorosis.