Table 3: Chromatic evaluation pre and post bleaching ( Mean values, standard deviation, mean differences, P. value).

	CHROMATICA SCALE VALUE				ΔE SPECTROPHOTOMETER
	LED LAMP PHOTO ACTIVATION		LASER PHOTOATIVATION		LED LAMP PHOTO ACTIVATION		LASER PHOTO ACTIVATION
	Pre-bleaching	Post bleaching	Pre bleaching	Pre-bleaching	Post-bleaching	Pre-bleaching	Post-bleaching	Post-bleaching
Mean	6.22	10.33	6	10.88	6	10,5	5,7	11
STD,ERROR	1,64	2,64	2,17	2,31	1,56	2,72	2,04	2,42
DIFFERENCE	4,11		4,88		4,5		5,3
PVALUE	0,00059		0,00014		0,0006		0,00017