OBJECTIVETo study the effects of fluoride on the proliferation and differentiation of osteoblasts in sucking rats and the antagonism of vitamin Cin vitro.

METHODSThe enzyme digesting method was used to isolate the rat osteoblasts; the proliferative response was determined by the percents of reduced alamarBlue; the activity of alkaline phosphatase (ALP) was measured by ELISA method.

RESULTSThe proliferation of sucking rat osteoblasts was increased at 0.10 - 1.00 mmol/L of NaF, whereas inhibited at >or= 2.00 mmol/L. ALP activity was increased at 0.01 - 0.05 mmol/L of NaF, and decreased at >or= 0.10 mmol/L. The inhibition on proliferation and differentiation at 2 mmol/L NaF was antagonized by vitamin C.

CONCLUSIONFluoride had a two-phase effect on osteoblasts, vitamin C could antagonize the inhibitory effect of higher concentration of fluoride on proliferation and differentiation of osteoblasts.