Table 3. Mean values (SDs) of ∆E* of yellow group in each concentration over aging period.
| ∆ E | 12 h | 24 h | 48 h | 72 h |
|---|---|---|---|---|
| Group | ||||
| Abbreviation: SD, standard deviation. Note: Tukey test with a level of significance of 0.05. Groups with the same superscript uppercase letter per column or lowercase letter per row are not significantly different ( p > 0.05). a Values of ∆ E * > 1.0a. | ||||
| Yellow - control | 0.48 (0.05)Aa | 0.71 (0.07)Bb | 0.98 (0.10)Ca | 1.40 a (0.02)Da |
| Yellow - 0.5% ZnO | 0.44 (0.07)Aa | 0.70 (0.10)Ba | 0.79 (0.05)Ca | 0.98 (0.03)Da |
| Yellow - 1.0% ZnO | 0.62 (0.06)Aa | 0.77 (0.10)Ba | 0.85 (0.05)Ca | 1.04- (0.04)Da |
| Yellow - 1.5% ZnO | 0.21 (0.01)Ab | 0.43 (0.05)Bb | 0.48 (0.06)Cb | 0.62 (0.03)Db |
| Yellow - 2.0% ZnO | 0.35 (0.06)Ab | 0.37 (0.04)Bb | 0.51 (0.07)Cb | 0.69 (0.03)Db |