Color Change and Color Stability of White Spot Lesions Treated with Resin Infiltration, Microabrasion, or Nano-Hydroxyapatite Remineralization: An In Vitro Study.

Background: We compared the camouflage effect of three white spot lesion (WSL) treatments (infiltration, nano-hydroxyapatite (nHAP) remineralization, and microabrasion) and color stability of the treated surfaces. Methods: Fifty sound extracted teeth were used in the study. WSLs were created on 40 buccal dento-enamel specimens through the use of acidic methylcellulose gel. These specimens were randomly assigned to treatment groups (n = 10 per group): negative controls, nano-hydroxyapatite (nHAP), resin infiltration, and microabrasion. After the treatment, all 50 specimens were immersed in coffee for 7 days. Color measurements were performed four times: at baseline (T0), after the demineralization procedure (T1), after the treatments (T2), and after immersion in coffee (T3). Results: No restoration of the initial enamel color was observed in any of the groups. The ICON and MA groups exhibited the highest masking effect, with the mean ΔE_T0-T2 = 7.46, although the differences among the study groups were insignificant. All three treatments increased the resistance of WSLs to discoloration in coffee compared to the negative control group; however, infiltration (∆E_T2-T3 = 4.13) and microabrasion (∆E_T2-T3 = 3.49) showed a better color stability tendency than nHAP remineralization (∆E_T2-T3 = 7.26). Conclusions: Despite its well-known remineralizing and desensitizing effects, nHAP showed the least masking effect for WSLs and lower color stability compared to resin infiltration and microabrasion. However, none of the methods allowed for complete restoration of the original color. After the discoloration procedure, the color changes in the white spots treated with microabrasion and infiltration were comparable to those of the sound enamel.