Evaluation of shear bond strength of orthodontic brackets using trans-illumination technique with different curing profiles of LED light-curing unit in posterior teeth

Progress in Orthodontics

Table 2 Shear bond strength values in all six groups

	N	Mean (MPa)	Standard deviation	Standard error	Minimum (MPa)	Maximum (MPa)
Group 1	10	13.6	0.44	0.13	13.0	14.1
Group 2	10	13.9	0.54	0.17	13.4	14.8
Group 3	10	2.9	0.34	0.11	2.4	3.5
Group 4	10	3.5	0.37	0.11	2.9	3.9
Group 5	10	4.9	0.62	0.19	4.1	6.1
Group 6	10	8.4	0.94	0.29	7.2	9.5
Total	60	7.9	4.59	0.59	2.4	14.8

Group 1 (control): 40 s, 650 mW/cm², buccal; group 2 (control): 40 s, 800 mW/cm², buccal; group 3: 40 s, 650 mW/cm², lingual; group 4: 80 s, 650 mW/cm², lingual; group 5: 40 s, 800 mW/cm², lingual; group 6: 80 s, 800 mW/cm², lingual. The highest mean bond strength was seen in group 2 and the lowest value was in group 3.