Table 3. Means and standard deviations of the objective assessment of color change and the mean difference (95% CI).
| Color evaluation tool | Groups | Mean difference (95% CI) | Equivalence | p-value** | ||
|---|---|---|---|---|---|---|
| Evaluated time | Tip without brush | Tip with a brush | [p-value]* | |||
| CIELAB (ΔE ab ) | Baseline vs. 1 week | 6.0 ± 3.4 | 6.4 ± 4.4 | −0.4 (−1.4 to 0.7) | Yes; p<0.01 | 0.50 |
| Baseline vs. 2 weeks | 7.3 ± 3.2 | 7.3 ± 3.4 | 0.1 (−1.0 to 1.2) | Yes; p<0.01 | 0.88 | |
| Baseline vs. 3 weeks | 8.6 ± 3.2 | 8.5 ± 3.6 | 0.2 (−0.8 to 1.1) | Yes; p<0.01 | 0.73 | |
| Baseline vs. 1 month | 8.2 ± 2.8 | 8.5 ± 3.8 | −0.3 (−1.4 to 0.7) | Yes; p<0.01 | 0.48 | |
| CIEDE (ΔE 00 ) | Baseline vs. 1 week | 4.2 ± 2.6 | 4.5 ± 3.3 | −0.3 (−1.1 to 0.4) | Yes; p<0.01 | 0.41 |
| Baseline vs. 2 weeks | 4.9 ± 2.5 | 5.0 ± 2.7 | −0.1 (−0.8 to 0.6) | Yes; p<0.01 | 0.74 | |
| Baseline vs. 3 weeks | 5.7 ± 2.4 | 5.6 ± 2.7 | 0.1 (−0.6 to 0.8) | Yes; p<0.01 | 0.81 | |
| Baseline vs. 1 month | 5.5 ± 2.2 | 5.8 ± 2.9 | −0.3 (−1.1 to 0.4) | Yes; p<0.01 | 0.38 | |
| Whiteness index (ΔWI D ) | Baseline vs. 1 week | 5.5 ± 4.9 | 3.9 ± 5.9 | 1.6 (−0.1 to 0.3) | Yes; p<0.01 | 0.07 |
| Baseline vs. 2 weeks | 8.9 ± 6.8 | 7.0 ± 6.6 | 1.9 (−0.05 to 3.8) | Yes; p<0.01 | 0.06 | |
| Baseline vs. 3 weeks | 9.5 ± 5.4 | 7.2 ± 5.8 | 2.3 (1.2 to 3.3) | Yes; p<0.01 | 0.00004 | |
| Baseline vs. 1 month | 10.5 ± 6.3 | 8.9 ± 6.4 | 1.6 (0.6 to 2.6) | Yes; p<0.01 | 0.03 | |
*The p-value shown is the higher of the two p-values from the upper and lower one-sided tests (TOST-P test); **Paired t-test.