Table 1.

Specific P values obtained from Tukey’s post hoc test of mean of difference in lightness (ΔL) and total color change (ΔE) of white tooth discoloration, obtained from before treatment photograph (T1), just after treatment photograph (T2), and 6 months after treatment photograph (T3) of Group A and Group B

Parameter compared	P value between Group A and Group B
ΔL1	0.45
ΔL2	<0.001*
ΔL3	<0.001*
ΔE1	0.07
ΔE2	<0.001*
ΔE3	<0.001*

*Level of significance P < 0.05