Table 2.

Mean and standard deviation of L, a, b values at baseline, and ΔL, Δa, Δb values at measurement intervals. Same small superscript letter indicates no statistical difference in the column p†: The significance level of ΔE values between groups p‡: The significance level between ΔE1 and ΔE2 values

Materials	Baseline		After staining		After repolishing
Cerasmart	L*	76.38±2.03	ΔL1	-1.08±2.54	ΔL2	0.54±1.92
	a*	0.76±0.67	Δa1	2.90±1.14	Δa2	-0.70±1.14
	b*	14.30±1.95	Δb1	2.41±1.14	Δb2	1.09±1.08
Ceram X	L*	78.26±0.45	ΔL1	-4.52±1.96	ΔL2	-1.34±1.63
	a*	1.07±0.37	Δa1	3.27±2.21	Δa2	-1.01±1.52
	b*	17.05±2.02	Δb1	3.15±2.24	Δb2	-1.66±1.82
Charisma Smart	L*	75.23±1.70	ΔL1	-1.23±2.29	ΔL2	1.69±2.09
	a*	0.45±0.88	Δa1	2.80±1.50	Δa2	-0.39±1.57
	b*	13.57±1.79	Δb1	5.85±2.28	Δb2	1.82±2.12