[Preventive effect of 10% (NH4)2MoO2F4 solution on artificial root-surface caries in vitro]

The aim of this study is to determine the preventive effect of F-Mo preparation on artificial root-surface caries. 60 premolar teeth extraced for orthodontic purpose were divided into five groups. A window was prepared on every tooth. They were treated by 10% (NH4)2MoO2F4, 38%Ag (NH4)2F, 2% NaF, 7.3% (NH4)2MoO4 and deionized water for 2 minutes and three times. They were then put in the fluid contained cariogenic bacteria for 96 hours to produce root caries. The root surface lesion of every tooth was examined and analysed by micro-radiography, SEM and spectrum. The result showed that the lesion depth of the groups treated by 10% (NH4)2MoO2F4 and 38%Ag (NH4)2F were significantly smaller than the other groups, and the surface of windows are more integrate and smooth, and mean mineral concentration is more higher than those of the other groups. It can be concluded that 10% (NH4)2MoO2F4 solution has greater inhibit effect to the development of root caries, so as the 38% Ag(NH4)2F solution. But the former discolored the tooth much less than the latter.