Characterization of a Novel TiF<sub>4</sub> Inclusion Complex and in vitro Evaluation of Its Effect on Inhibiting Enamel Demineralization

Abstract

<b><i>Introduction:</i></b> Titanium tetrafluoride (TiF<sub>4</sub>) is an anticariogenic agent with high remineralizing potential. However, the acidic pH of TiF<sub>4</sub> solution can limit its clinical application. The present study aimed to prepare and characterize a new TiF<sub>4</sub>-dendrimer inclusion complex and evaluate its ability to inhibit enamel demineralization under pH cycling conditions. <b><i>Methods:</i></b> PEG-citrate dendrimer and TiF<sub>4</sub>-dendrimer inclusion complex were synthesized and their molecular structures were evaluated using Fourier-transform Infrared Spectroscopy (FTIR), Hydrogen Nuclear Magnetic Resonance (HNMR), and Liquid Chromatography-Mass Spectrometry (LC-MS) tests. Forty-eight enamel samples were prepared and randomly divided into four groups: distilled water (negative control), TiF<sub>4</sub> solution (T), dendrimer solution (D), and TiF<sub>4</sub>-dendrimer solution (TD). The microhardness of the samples was measured initially. Next, the samples underwent pH cycling, were exposed to the solutions, the microhardness was measured again, and microhardness loss was calculated. EDX analysis was performed on the surface and cross-sectional segments of the samples. <b><i>Results:</i></b> The microhardness loss was significantly higher in control (−65.1 ± 6.0) compared to other groups. No significant difference was observed between T (−47.9 ± 5.6) and D (−41.7 ± 12.0) and also D and TD (−40.5 ± 9.4) in this regard. Microhardness loss was significantly higher in T compared to TD group. The TD samples showed similar fluoride and titanium content in both surface and subsurface regions, while the T group had higher concentrations in the surface region. Moreover, the TD solution had a higher pH of 3.4 compared to the T solution’s pH of 1.1. <b><i>Conclusion:</i></b> No significant difference was observed between the efficacy of TiF<sub>4</sub>-dendrimer and TiF<sub>4</sub> solution in inhibiting demineralization while TiF<sub>4</sub>-dendrimer solution had the added advantage of having a higher pH.