Table 1. Distribution of the fracture modes among different groups.

Groups	Fracture modes, n (%)			P-value
	Adhesive failure	Mixed failure	Cohesive failure
Fisher's exact test was used to compare the differences in treatment outcomes. aCompared with the control group; bcompared with the 35% H3PO4 15 s + SB2 group; ccompared with the 35% H3PO4 30 s + SB2 group. Bold values indicate P<0.05. SBU: Single Bond Universal; SB2: Single Bond 2.
Control	10 (100)	0	0
SBU	9 (90)	1 (10)	0	0.136a
35% H3PO4 15 s + SB2	8 (80)	2 (20)	0	0.305a
35% H3PO4 15 s + SBU	7 (70)	3 (30)	0	0.060a, 0.264b
35% H3PO4 30 s + SB2	6 (60)	4 (40)	0	0.025 a
35% H3PO4 30 s + SBU	3 (30)	5 (50)	2 (20)	0.005a, 0.211c