Long-term retention of TiF4 and SnF2 after topical application to dentin in dogs

As part of an evaluation of the potential of topical application of TiF4 in the prevention or arrest of root caries, the longevity of the titanium-rich glaze and the long-term retention of titanium and fluoride in exposed dentin surfaces were examined in dogs. For comparison, the effect of fluoride in combination with another cation, tin, was studied as well. Facets of exposed dentin were prepared in two beagles and treated for 1 or 4 min with either a TiF4 or an SnF2 solution (1.1 M F, native pH). After 3, 7, or 21 wk, the experimental surfaces were analyzed for fluoride, titanium, tin, and calcium using an electron microprobe. Dentin surfaces treated with TiF4 for 1 min showed fluoride concentrations ranging from less than 0.15% to 1.03%, while those treated for 4 min with SnF2 showed values from 0.22% to 1.28%. The calcium analyses revealed partial surface demineralization in one half of the SnF2-treated specimens, while this was a rare finding in the TiF4 group. The findings show that a brief application of TiF4 to exposed dentin results in approximately the same increase in fluoride content as a 4-min application of SnF2, with, however, less surface demineralization. In addition, the presence of a surface glaze may impart an added benefit to the use of TiF4 as a topical agent in the prevention of root caries.