Table 3.

Mean Δa*, Δb*, ΔL* values in the first and the fourth readings (after 4 weeks).

	1st reading at 24 h			4th reading after 1 month
	Δb*	Δa*	ΔL*	Δb*	Δa*	ΔL*
Baking soda	6,33	−0,37	22,66	−0,44	0,18	39,27
Activated charcoal	6,82	−0,46	23,72	−1,96	0,53	39,96
Strawberries	3,86	0,29	23,23	−2,46	1,44	37,93
Turmeric	8,3	−1,91	27,84	−4,89	0,34	43,57
Colgate Optic Whitening toothpaste	3,93	−0,95	25,21	−3,10	1,45	42,0
Opalescence 20 %	1,48	−0,48	27,03	−4,79	−0,13	42,97