Effects of titanium fluoride on caries inhibition and elemental distribution in the tooth structure: Comparisons with sodium fluoride at the same fluoride concentration and pH values

Titanium fluoride (TiF[Formula: see text] reduces mineral loss and lesion depth more effectively than sodium fluoride (NaF). However, the pH values of TiF 4 and NaF solutions are different. This study aimed to evaluate the effects of TiF 4 solution on the inhibition of demineralization and elemental distribution in root dentin in comparison with NaF solution at the same pH and fluoride concentrations. This study was conducted using 0.5% TiF 4 or 0.675% NaF solution adjusted to pH 5 or pH 7. Bovine dentin specimens of 200 [Formula: see text]m thickness were subjected to pH cycling (pH 4.5 and 7.0; 6 cycles/day; simulated oral conditions) for eight weeks to prepare artificial carious dentin. During this cycle, the specimens were soaked in each solution once a week for 5 min. The control group involved no fluoride application during the test period. After cycling, the demineralization depth was measured and the calcium, fluorine, and titanium distributions were analyzed and calculated using an in-air micro-proton-induced X-ray emission (PIXE)/proton-induced gamma emission (PIGE) system at TIARA. At pH 7, TiF 4 solution yielded a lower lesion depth than the NaF solution. The NaF solution at pH 7 showed lower fluorine concentration than that with the other fluoride solutions. Thus, TiF 4 is more effective in inhibiting demineralization than NaF in a solution adjusted to pH 7. Moreover, the presence of titanium may strengthen the tooth structure.