Background: To evaluate the effect of an orthodontic resin modified with various concentrations of silver-nanoparticles (AgNPs) on enamel color. Material and Methods: Twenty lower premolars were collected and divided into four groups (n = 5) according to the concentration of AgNPs (0.05%, 0.1%, 0.5%, and 1% wt/wt). Additionally, a group bonded with a conventional resin was used as control (n=5). Previous to the bracket bonding, enamel color was measuring with a spectrophotometer. Specimens were stored for 6 months in deionized water. Brackets were debonded and color changes of enamel were calculated with the CIEDE 2000 formula (ΔE00). One-way ANOVA and Tukey test were used to assess the color change (α =.05). Results: The control group showed the lowest ΔE00 values, and no significant difference was observed when compared to the group with 0.05% of AgNPs (P >.05). The highest color change was observed in the group with 1% of AgNPs (ΔE00 = 8.04±1.48), however no significant difference was observed between groups with 0.1% and 0.5% AgNPs. Conclusions: The incorporation of AgNPs into orthodontic resin result in tooth color alteration. Lower concentrations of AgNPs should be considered to minimize negative changes in enamel color.