The purpose of this research performed in rats (Rattus norwegicus) was to observe if there is a synergic action of fluorine and zinc in order to obtain a greater reduction in dental caries. The study incolved three groups of rats receiving: a) zinc silicofluoride - 1 ppm, b) sodium fluoride - 1 ppm and c) tap water. All groups included males and females, and were divided in sub-groups in accordance with cariogenic and non cariogenic diets. The data were treated by analysis of variance and the main conclusions obtained were the following: 1st) The group of zinc silicofluoride has shown less caries than the sodium fluoride group, but the difference was not statistically significant. When both groups a and b were compared to group c, the results were significant. 2nd) The rats receiving zinc silicofluoride or sodium fluoride have shown higher levels of fluorine in the bone ashes but the difference between them was not statistically significant. 3rd) The rats of both groups - zinc silicofluoride and sodium fluoride - have shown bone demineralizantion at equal level.
