In vitro Evaluation of the Remineralizing Potential and Color Change of Modified Fluoride Varnish with Polyvinylpyrrolidone-Coated Silver Nanoparticles on Incipient Enamel Lesions in Primary Teeth.

BACKGROUND: Dental caries is closely associated with biofilms and characterized by cycles of demineralization and remineralization that weaken tooth structure over time. Given the need for effective prevention and enhanced remineralization, developing a more esthetic and efficient approach is essential in improving oral health outcomes. PURPOSE: The present study aimed to assess the remineralizing potential and color change of modified fluoride varnish with polyvinylpyrrolidone-coated silver nanoparticles (PVP-coated AgNPs) on incipient enamel lesions in primary teeth. MATERIALS AND METHOD: In this in vitro study, 130 caries-free primary canine teeth underwent caries induction and were randomly assigned to one of three treatments: (1) fluoride varnish (FV), (2) silver diamine fluoride (SDF), and (3) FV with PVP-coated AgNPs. After thermocycling-aging and an eight-day pH cycling regimen, the remineralization effects and color change were evaluated by enamel microhardness (EMH) test and spectrophotometric color assessment. Ten samples were used for surface morphology assessment with field emission scanning electron microscopy and energy-dispersive X-ray spectrometry (FESEM-EDS). One-way ANOVA and Tukey's post-hoc tests were used for data analysis (p Value<0.05). RESULTS: The highest average±SD recovery of EMH values was found in the SDF group (52.43±2.58), followed by FV with PVP-coated AgNPs group (43.21±1.73), and FV group (35.60±1.36), respectively (all, p< 0.001). The voids on the demineralized enamel surface were partially coated with newly deposited minerals in FESEM images of all groups. SDF Group had the best calcium/ phosphorus ratio among the intervention groups (2.58± 0.001); followed by FV with PVP-coated AgNPs group (1.94±0.001) and FV group (1.91± 0.001), respectively. The color change of enamel samples treated with FV and modified FV with PVP-coated AgNPs was clinically imperceptible (all, ∆E < 3.3), whereas SDF-treated samples caused distinct staining (p< 0.001). CONCLUSION: FV with PVP-coated AgNPs effectively remineralizes incipient enamel lesions in primary teeth with minimal color change, offering a promising alternative to SDF.