Table 2.

Mean changes in values L*a*b* and total Color change dE* of all groups, after immersing group II, III and IV in tea solution at the end of 24 hour after bleaching

Groups		dL*	da*	db*	dE*
I	Mean	- 0.08	0.098	0.04	0.19
	SD	(± 1.67)	(±0.59)	(±1.17)
	P-value	P > 0.05	P > 0.05	P > 0.05
		NS	NS	NS
II	Mean	-1.30	0.404	2.57	4.64
	SD	(± 4.27)	(± 0.63)	(± 2.62)
	P-value	P < 0.05	P > 0.05	P > 0.05
		S	NS	NS
III	Mean	-3.48	0.312	0.61	3.50
	SD	(± 1.61)	(± 0.61)	(± 1.93)
	P-value	P < 0.05	P > 0.05	P > 0.05
		S	NS	NS
IV	Mean	-2.2	0.466	0.58	3.16
	SD	(± 0.61)	(± 0.42)	(± 2.63)
	P-value	P > 0.05	P > 0.05	P > 0.05
		NS	NS	NS

SD = Standard deviation, NS = Statistically non significant, S = Statistically significant