Erosion-inhibiting effect of sodium fluoride and titanium tetrafluoride treatment in vitro

The prevention of dental erosion with fluoride is still largely unknown territory. It was the aim of this study to determine the erosion-inhibiting effect of topical neutral 1% sodium fluoride (NaF) application and an application of a 4% titanium tetrafluoride (TiF₄) solution compared with no treatment. Ten bovine incisors were selected and three enamel samples prepared from each tooth. One sample from each tooth was assigned to one of three experimental groups. The experimental treatments were: no fluoride application (control); 4 min application of neutral 1% NaF gel; and 4 min application of 4% TiF₄ solution. All of the specimens were repeatedly exposed to 50 mM citric acid solution containing 0.4 mM CaCl ₂, and 2.2 mM KH₂PO₄ at pH 3.0 over four consecutive days. The acid exposure was performed in intervals and the intensity was increased over the days of the experiment. Enamel dissolution was determined by calcium content measurement of the acid solution after exposure, using atomic absorption spectroscopy. A statistically significant erosion-inhibiting effect was found for both NaF and TiF₄ treatments compared with the control group from an erosion exposure time of 3 min. The reduction of calcium loss, however, was higher for the TiF₄-treated specimens than the NaF-treated. From 16 min of erosion exposure, the erosion-inhibiting effect was significantly stronger in the TiF₄ than the NaF group. The relative reduction of calcium loss compared with the control group remained stable for the TiF₄ group, whereas for the NaF group the relative reduction decreased with cumulative erosion time. It is concluded that topical TiF₄ application provides a potential treatment option in erosion prevention.