Table 5. Mean values and standard deviations of enamel mineral loss area (ΔZ) of sound and demineralized enamel.
| Groups | ΔZ | ||||
|---|---|---|---|---|---|
| Sound enamel | Demineralized enamel | ||||
| Control | 199.3 | (57.8)Aa | 578.4 | (74.7)Ab | |
| HP | 565.3 | (87.2)Ba | 962.6 | (121.8)Cb | |
| HPF | 494.3 | (51.9)Ba | 842.4 | (91.7)Bb | |
| HPC | 509.4 | (45.7)Ba | 868.8 | (69.6)Bb | |
Mean values followed by distinct letters differ statistically at 5%, according to three-way ANOVA and Tukey test (p<0.05). Uppercase letters compare treatments (in columns) and lowercase letters compare time (in row).
Asterisks (*) compare each enamel condition within time
C: control
HP: 35% hydrogen peroxide
HPF: fluoride-based bleaching agent containing 35% hydrogen peroxide
HPC: calcium-based bleaching agent containing 35% hydrogen peroxide