Evaluation of the color stability of materials used in the resin infiltration technique for artificial white spot lesions

Purpose: This study aimed to evaluate the color stability of a resin infiltration technique used for treating artificial white spot lesions (WSLs) through an accelerated aging test.Materials and Methods: Twelve human maxillary central incisors were prepared to create artificial WSLs and restored with an infiltration resin (ICON).Control groups were restored with conventional composite resins in shades A1 and A3.5.For the accelerated aging test, specimens were stored in distilled water at 60°C for 30 days to simulate over one year of clinical service.Color characteristics were measured at baseline, 5, 15, and 30 days using a spectrocolorimeter for Commission Internationale de l'Eclairage (CIE) L*, a*, b* values and a dental colorimeter for shade analysis.Results: All groups exhibited total color differences (ΔE*) exceeding the previously reported threshold (ΔE* = 3.3).At 30 days, the mean ΔE* values for the infiltration resin, composite resin A1, and composite resin A3.5 were 5.55, 6.45, and 4.0, respectively.Discoloration was primarily driven by a decrease in brightness (ΔL*) and an increase in yellowness (Δb*).No statistically significant differences in color stability were found between the infiltration resin and the conventional composite resin groups.Conclusion: Although the resin infiltration material demonstrated significant discoloration under accelerated aging conditions, no statistically significant differences were found compared with the tested composite resins.Overall, all materials exhibited ΔE* values exceeding the perceptibility threshold under the conditions of this study.(