Table 2.

Mean and standard deviation values of ΔE.

Group		N	Mean	P-value
Baking soda	ΔE 1	15	7.7 (5.1)
	ΔE 2	15	23.7 (2.9)	0.000
	ΔE 3	15	27.9 (3.4)
	ΔE 4	15	39.3 (4.2)	0.000
Activated charcoal	ΔE1	15	4.9 (2.6)
	ΔE2	15	24.9 (2.4)	0.002
	ΔE3	15	28.7 (4.8)
	ΔE4	15	40.3 (3.7)	0.000
Strawberries	ΔE1	15	6.7 (2.7)
	ΔE2	15	23.5 (2.2)	0.001
	ΔE3	15	30.7 (5.7)
	ΔE4	15	38.2 (4.8)	0.000
Turmeric	ΔE1	15	4.9 (2.7)
	ΔE2	15	29.1 (3.6)	0.164
	ΔE3	15	30.7 (4.4)
	ΔE4	15	44 (2.9)	0.000
Colgate Optic Whitening toothpaste	ΔE1	15	4.3 (2.3)
	ΔE2	15	25.6 (2.7)	0.001
	ΔE3	15	28.8 (2.6)
	ΔE4	15	42.3 (4.4)	0.000
Opalescence 20 %	ΔE1	15	3.9 (2.1)
	ΔE2	15	27.2 (1.6)	0.000
	ΔE3	15	30.3 (1.8)
	ΔE4	15	43.3 (1.9)	0.000