Effect of a Single Application of TiF4 Varnish versus Daily Use of a Low-Concentrated TiF4/NaF Solution on Tooth Erosion Prevention in vitro

Abstract

This study investigated the isolated and combined effect of a single application of TiF₄ or NaF varnish versus daily use of a solution containing a low concentration of TiF₄/NaF against tooth erosion in vitro. A total of 90 bovine enamel and 108 root dentin samples were treated as follows: control (no treatment), solution containing TiF₄/NaF (500 ppm F^-, pH 4.4), NaF varnish (24,500 ppm F^-, pH 5.0), TiF₄ varnish (24,500 ppm F^-, pH 1.0), TiF₄ varnish + solution, and NaF varnish + solution. The erosive challenges were performed 4 × 90s/day (0.1% citric acid, pH 2.5) and, between them, the samples were immersed in artificial saliva. The tooth loss was measured using contact profilometry (after 7 days for dentin and after 7, 10, and 14 days for enamel). All treatments were effective in reducing tooth loss, except NaF varnish for enamel on day 7 (p < 0.0001). TiF₄/NaF solution and TiF₄ varnish did not differ with respect to enamel loss for 10 days; thereafter, TiF₄ varnish lost its protective effect compared to TiF₄/NaF solution. The combination of vehicles was more effective in reducing enamel loss than both varnishes on their own but not compared to the solution. For dentin, TiF₄ varnish was more effective than NaF varnish, while TiF₄/NaF solution and NaF varnish were similar. The combination of vehicles improved the protective effect only when compared to NaF varnish on its own (p < 0.0001). Both types of TiF₄ applications, isolated or combined, were effective against tooth erosion, but some differences in their performance were seen between enamel and dentin.