Effectiveness of Fluoride Varnishes for White Spot Lesion Prevention and Remineralization during Orthodontic Treatment: A Randomized Controlled Trial

Abstract

<b><i>Introduction:</i></b> This study investigated the effectiveness of titanium tetrafluoride (TiF₄) varnish compared to sodium fluoride (NaF) varnish for preventing and remineralizing white spot lesions (WSLs) in individuals undergoing orthodontic treatment. <b><i>Methods:</i></b> This randomized, placebo-controlled, and double-blinded study was conducted with sixty-five adolescents who were selected based on caries activity and then randomized into three parallel groups: G1 (placebo varnish), G2 (5% NaF varnish), and G3 (4% TiF₄ varnish). Volunteers received varnish application weekly for the first 4 weeks, after 6 (T1) and 12 (T2) months. The measured outcomes included prevention of new WSLs and reversal/progression of WSLs, assessed by Nyvad and International Caries Detection and Assessment System (ICDAS) indices, as well as quantitative light-induced fluorescence. χ², ANOVA, and Kruskall-Wallis tests were applied. The level of significance was set at 0.05, and post hoc Bonferroni test for <i>p</i> values was performed to correct for multiple comparisons. <b><i>Results:</i></b> 1,274 teeth were included; 70.5% were Nyvad 0, and 29.5% were Nyvad 1, with no differences between the groups at baseline (T0). Regarding ICDAS, 70.5% were ICDAS 0, 21.6% were ICDAS 1, and 7.9% were ICDAS 2. G1 showed an increasing prevalence of WSLs at T1 and maintained stable at T2; G2 exhibited a decline at T2, while G3 experienced a decrease at T1 and T2 (<i>p</i> &lt; 0.01). Incidence of WSLs at T2 was 10.2% (G1), 5.6% (G2), and 1.4% (G3). The percentage of teeth initially scored as Nyvad 0 that progressed to Nyvad 1 was 13%, 6.8%, and 1% for G1, G2, and G3, respectively. Conversely, the percentage of teeth initially scored as Nyvad 1 that regressed to Nyvad 0 or Nyvad 2 (T0–T2) was 14%, 49.3%, and 74.4%, respectively (<i>p</i> &lt; 0.001). As for the ICDAS index, regression was observed in 6.5%, 17.8%, and 24%, while progression was observed in 14.9%, 7.7% and 0.9% for G1, G2, and G3, respectively (<i>p</i> &lt; 0.001). Significant differences among the 3 groups for integrated fluorescence loss (mean ± SD, G1: −14.28 ± 9.47, G2: −11.10 ± 11.49, and G3: −6.77 ± 11.00) were found at T2 (<i>p</i> &lt; 0.01). <b><i>Conclusion:</i></b> Both varnishes demonstrated the ability to prevent and remineralize WSLs. However, TiF₄ varnish exhibited the most effective control over WSLs during the 12-month orthodontic treatment.