In order to develop an in vitro model for the study of the effects of
different agents on biomineralization, a three-dimensional cell cultur
e system was investigated at different levels of fluoride. Rat fetal o
steoblasts were seeded onto collagen discs and maintained in a culture
medium for 40 days. Results showed that, at 40 days, the cultured mat
rices had a Ca:P ratio, mineral content and Fourier transform infrared
(FTIR) spectrum that were close to those seen for normal rat bone. Vi
able cells, observed by light microscopy, were present in the matrix a
t 40 days. The formation of a mineralized matrix in this experimental
set-up provided a model for exploring in vitro the effects of high lev
els of fluoride on bone. The fluoride content of the mineral formed in
the cultures showed a dose-dependent increase in fluoride content wit
h time. Also, an increase in the crystallinity of the apatite in the p
resence of fluoride, was observed by FTIR. The Ca:P ratio and percenta
ge mineral by weight showed no apparent differences among the groups.
The three-dimensional model used for this study has the potential to b
e a powerful tool in the study of time-dependent effects of drugs and
other factors on osteoblast cell functions and subsequently on matrix
mineralization.