Abstract
Enamel demineralization and subsequent white spot lesion (WSL) formation represent common adverse complications during fixed orthodontic therapy due to prolonged plaque stagnation around brackets. This 6-month double-blind, randomized controlled trial investigated the clinical efficacy of a novel sustained-release bioactive fluoride varnish (containing nano-hydroxyapatite and 5% sodium fluoride) in preventing enamel demineralization compared to a standard 5% sodium fluoride (NaF) varnish and a non-fluoridated control. Eighty adolescent and young adult patients (aged 13–22 years) undergoing comprehensive fixed orthodontic therapy were randomly allocated to three groups: experimental novel varnish (n = 27), standard NaF varnish (n = 27), and placebo control (n = 26), applied at bonding, 8 weeks, and 16 weeks. Primary outcomes were the incidence and severity of WSLs evaluated using the International Caries Detection and Assessment System (ICDAS-II) and Quantitative Light-Induced Fluorescence (QLF) metrics (mean fluorescence loss, ΔF, and lesion area, WS-Area) at baseline, 3 months, and 6 months. After 6 months, the novel varnish group exhibited a significantly lower incidence of newly developed WSLs (11.1%) compared to the standard NaF (25.9%) and placebo groups (53.8%; p < 0.001). QLF analysis confirmed significantly less fluorescence loss (ΔF: −5.82% ± 1.21%) and minimal lesion surface area in the experimental cohort relative to controls. The novel sustained-release varnish effectively arrests enamel demineralization around orthodontic brackets, offering superior enamel protection throughout active treatment.
