Table 1 Bracket groups, mean values of friction, width, inter-bracket distance, and first- and second-order critical contact angles

Lower lingual

A1

In-Ovation L

4.73

2.18

2.73

8.19

4.21

A2

7th Generation

3.19

1.77

3.11

10.13

5.31

A3

New STb

1.1

2.53/1.50

2.43/3.42

12.13

3.71

A4

O.R.J.

1.79

2.28

2.72

7.80

3.91

A5

OldSTb

2.32

2.04

2.82

8.77

4.50

Lower labial

A6

Forestadent

3.17

2.57

5.13

6.92

3.77

A7

Ormco Mini Diamond

2.65

2.68

4.46

6.63

3.60

A8

G&H Ceramic

4.64

2.83

4.35

6.26

3.41

Upper lingual

B1

7th Generation

4

2.36

3.48

7.56

3.91

B2

O.R.J.

2.43

2.81

3.56

6.32

3.34

B3

OldSTb

2.1

2.53

3.84

7.03

3.71

B4

New STb

1.79

2.56/1.51

3.89/4.58

12.04

3.68

B5

In-Ovation L

2.6

2.17

3.82

8.21

4.22

Upper labial

B6

Forestadent

3.27

3.55

6.30

4.99

2.68

B7

Ormco Mini Diamond

2.62

3.49

6.07

5.08

2.71

B8

G&H Ceramic

4.38

3.48

6.04

5.08

2.69