Does Bleaching Affect the Microleakage of Class II Restoration with Bulk-Fill Composite?

Table 1

Frequency and percentage of each degree of microleakage in the studied groups.

Groups	Degrees of microleakage	Frequency	The significance level
Group 1 (Z250 composite without bleaching)	0	0	0.476
	1	9 (45%)
	2	11 (55%)
	3	0
Group 2 (Tetric EvoCeram composite without bleaching)	0	0
	1	11 (55%)
	2	9 (45%)
	3	0
Group 3 (Z250 composite with bleaching)	0	0
	1	8 (40%)
	2	12 (60%)
	3	0
Group 4 (Tetric EvoCeram composite with bleaching)	0	0
	1	6 (30%)
	2	14 (70%)
	3	0