Table 3. The values of color difference (ΔE) with standard deviations, according to material, solution, and time of measurement.
| Material | Z250 | Z550 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Evaluation period | Water | Tea | Coffee | Coca-Cola | Water | Tea | Coffee | Coca-Cola | |||
| ΔE1 (1.- 7. day) |
4.49 (+1.20) | 4.55 (+1.26) | 1.79 (+0.64) | 4.50 (+1.04) | 7.61 (+1.64) | 1.25 (+0.46) | |||||
| ΔE2 (1.- 14.day) |
6.99 (+1.04) | 6.20 (+1.42) | 1.46 (+1.38) | 5.65 (+1.66) | 10.42 (+2.46) | 1.22 (+0.83) | |||||
|
ΔE3
(1.-30.day) |
0.94 (+0.17) | 10.23 (+2.23) | 9.36* (+1.39) | 0.71 (+0.61) | 0.91 (+0.30) | 8.46 (+1.59) | 13.23* ( +2.11) | 1.80 (+0.81) | |||
| ΔE4 (after bleaching) | 2.37 (+0.39) | 1.59 (+0.45) | 2.48 (+0.34) | 2.73 (+0.23) | 1.92 (+0.55) | 3.12 (+0.90) | |||||
| *Statistically significant differences (p = 0.01) in a color difference between two tested materials at a specific time | |||||||||||