Although
diamine silver fluoride (AgF: (NH3)2AgF) stains teeth black, it is known as a very effective agent to prevent the
dental caries progress. In order to find another
fluoride that has a similar anticariogenic effect without changing tooth color, we prepared
ammonium hexafluorosilicate (SiF: (NH4)2SiF6), in which the
silver of AgF is replaced with
silicon. In this study, the anticariogenic effect of SiF was evaluated using bovine teeth.
Fluoride solutions, SiF, AgF,
acidulated phosphate fluoride (APF), and
sodium fluoride (NaF), were applied to bovine enamel and dentine blocks, and the depth of demineralization was measured after exposure to a demineralizing
solution for 24 h. Also,
fluoride was applied to a simulated dentine caries specimen to evaluate the caries progress-preventing ability. For the dentine specimens,
mineral loss (Delta Z) was also measured with microradiography. We found that SiF treated enamel showed better
acid resistance than specimens treated with NaF or APF. AgF treated enamel also showed similar
acid resistance, but was stained black. SiF and AgF treated caries-affected dentine showed reduced demineralization when exposed to a demineralization
solution for 24 h.
Mineral loss (Delta Z) was reduced to 85% and 75%, respectively. Although the
acid resistance of the SiF treated teeth was inferior to that of the AgF treated teeth, we consider that SiF has good potential as anticariogenic agent, since it increased
acid resistance without changing tooth color.