Color evaluation was performed using a colorimeter, which expresses color coordinates according to the CIELab color system. Other methods of color determination have been used in dentistry, including visual assessment and spectrophotometry, with the instrumental methods generally being considered more precise, as they eliminate subjective errors.19 More importantly, the CIELab color system is widely popular and was developed for characterization of colors based on human perception. In this system color difference value, ΔE, is expressed as a relative color change between successive color measurements. It is generally agreed that a value of ΔE ≥ 3.3 is considered clinically perceptible.20–22