Green-Synthesized Nano-Silver Fluoride for Remineralization of Enamel Lesions in Primary Teeth: A Comparative In Vitro Study with SDF and SDF/KI

<b>Background</b>: Early caries management is essential to enable reversal of white spot lesions without the further need for operative interventions, especially in primary dentition. Silver-based compounds can be quite effective in arresting caries lesions; however, a major drawback is teeth staining. This study aimed to evaluate the remineralization potential and aesthetic effects of novel, green-synthesized nano-silver fluoride (NSF) on artificial white spot lesions in primary teeth in comparison to 38% silver diamine fluoride (SDF) and silver diamine fluoride/potassium iodide (SDF/KI). <b>Materials and Methods</b>: NSF was synthesized using green tea extract. Sixty primary teeth specimens with artificial enamel lesions were randomly divided into five groups depending on the applied material: 38% SDF, 38% SDF/KI, single and double application of NSF, and control group. Treatments were followed by pH cycling. Surface microhardness and photographic analysis were conducted to assess remineralization and staining. Statistical analysis was conducted using non-parametric tests including Kruskal-Wallis and Mann-Whitney U tests with Bonferroni correction. <b>Results</b>: The greatest increase in microhardness was observed in the group receiving double NSF application. Its remineralizing potential was comparable to that of 38% SDF/KI, with no statistically significant difference (<i>p</i> = 1.000). Importantly, NSF-treated samples exhibited no teeth discoloration, unlike the black staining observed in SDF and SDF/KI groups. <b>Conclusions</b>: Green-synthesized NSF is a promising alternative to conventional SDF and SDF/KI, offering remineralization benefits without compromising aesthetics. The eco-friendly formulation and non-staining properties support its potential for clinical use in pediatric dentistry.