The Effect of Bonding Surface Design on Shear Bond Strength of 3D-Printed Orthodontic Attachments

Table 1

Shear bond strengths in different groups (MPa) (n = 20).

Groups	Min	Max	Mean (SD)	Confidence interval (95%)
				Lower bond	Upper bond
1	1.28	3.75	2.45 (0.79)	2.08	2.82
2	4.12	7.62	6.09 (1.02)^ab	5.61	6.57
3	6.40	10.49	8.39 (1.37)	7.74	9.03
4	9.39	13.25	11.57 (1.18)	11.01	12.12
5	3.83	7.32	5.42 (1.2)^a	4.86	5.98
6	4.25	8.93	6.66 (1.3)^b	6.03	7.29

1: Flat surface without any feature (negative control group). 2: Concentric circles with no cuts. 3: Concentric circles with 16 cuts. 4: Concentric circles with 32 cuts. 5: Anchor pylon. 6: Mesh-based metal attachment (positive control group). Letters a and b show insignificant differences.