EFFECTS OF HIGH-LEVELS OF FLUORIDE ON BONE-FORMATION - AN IN-VITRO MODEL SYSTEM

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.