Color
Two operators calibrated performed color evaluation in the study, according to ISO/TR 28642, To evaluate the subjective color, the VITA Classical (VITA Zahnfabrik, Bad Säckingen, Germany) and VITA Bleachedguide 3D-MASTER (VITA Zahnfabrik, Bad Säckingen, Germany) scales were used, and the color change was evaluated by the variation of the VITA scale units (ΔSGU). 