Abstract
Fluoride is known to have a strongly cariostatic effect, and molybdenum is thought to have a mildly cariostatic effect. (NH4)2MoO2F4 containing both fluoride and molybdenum has been shown to prevent dental caries and also depress the severity of dental caries in experiments with rats. Furthermore, (NH4)2MoO2F4 does not discolor the teeth.
The purpose of this study was to investigate the mechanism of the cariostatic effect of (NH4)2MoO2F4 from the viewpoint of the effects on dentin. The reaction of (NH4)2MoO2F4 with dentin powder, the effect of (NH4)2MoO2F4 on Brushite and Whitlockite formation, on collagen, and on intact dentin blocks were examined.
The results were as follows:
1) Reaction of 10,000 ppmF (NH4)2MoO2F4 with dentin powder produced CaF2 and increased F uptake more than NaF and NH4F. It is considered that molybdenum enhance the effects of fluoride.
2) (NH4)2MoO2F4, similar to NaF and NH4F, produced apatite in the synthesis of Brushite and Whitlockite.
3) The collagen treated with (NH4)2MoO2F4 at pH 5.5-6.0 was resistant to collagen ase.
4) (NH4)2MoO2F4 increased the acid resistance of dentin not only immediatly after the treatment but also up to 7 days after.
5) With (NH4)2MoO2F4 treatment of dentin, CaF2 was produced and both fluoride and molybdenum penetrated into dentin. After 8 weeks, apatite crystals grew in the dentinal tubules. In summary, these results suggest that (NH4)2MoO2F4 gives cariostatic properties to dentin.
