RESUMO
ABSTRACT: Introduction. One of the most frequently used color analysis system is the Vita 3D Master toothguide. No study has evaluated if there are color differences between the same Vita 3D Master shades obtained from natural teeth, which could determine changes in the color selection. Objective. To determine ΔEab in natural teeth within the corresponding shade given by a spectrophotometer and compare our results with the AT and PT thresholds reported in the literature. Materials and Methods. We obtained 3818 tooth shade data L*a*b from 200 patients in an ambulatory setting. All color differences (ΔEab) between the same Vita 3D Master shades were registered. Mean, range and standard deviation values were determined. Results. We found a wide dispersion of the ΔEab values within each Vita 3D Master shade. When comparing our results with the PT and AT values available in the literature we found a wide dispersion of the ΔEab values, discordant in up to 53% of the cases. Conclusions. We suggest a revision of the available thresholds. Further research is warranted in this field to improve our understanding of color selection and matching. Clinical significance: The available thresholds for assessing color differences in dentistry probably need to be reviewed.