Comparative In-Vitro Evaluation of 810 nm Diode Laser and Fluoride Varnish in the Remineralization of Artificial White Spot Lesions on Smooth Enamel Surfaces

Objective: This in-vitro study aimed to compare the efficacy of 810 nm diode laser irradiation and 5% sodium fluoride varnish in promoting the remineralization of artificially induced white spot lesions (WSLs) on smooth enamel surfaces. Materials and Methods: Ten extracted human premolars were prepared by inducing WSLs through immersion in a demineralizing solution (pH 4.4). Each tooth was divided longitudinally into two treatment groups. The left surface (Group L) received diode laser irradiation (1 W, continuous mode, 60 seconds), while the right surface (Group R) was treated with 5% sodium fluoride varnish for four hours. Surface mineral changes were assessed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX), focusing on calcium (Ca) and phosphorus (P) weight percentages. Normality was verified using the Shapiro–Wilk test, and comparisons between groups were made using independent-samples t-tests. Results: Both treatment methods led to increased calcium and phosphorus concentrations. The fluoride varnish group exhibited a significantly higher increase in calcium compared to the laser group, while phosphorus levels rose similarly in both groups. SEM images demonstrated clearer surface mineralization in the varnish group, correlating with enhanced enamel microhardness. Conclusion: Under the experimental conditions of this study, both the diode laser and fluoride varnish showed potential in enhancing enamel remineralization. However, fluoride varnish appeared to provide a greater increase in calcium deposition, which may suggest higher remineralization efficacy compared to laser treatment alone.