Table 1.

Mean static frictional resistance of 4 bracket systems using 0.014 and 0.018 x 0.025 archwires at 0° and 7°

Bracket system	Mean force (N)* [standard deviation]
	0° Angulation		7° Angulation
	0.014 wire	0.018 x 0.025	0.018 x 0.025
Self ligating ceramic	2.28a [0.7]	2.92c [0.5]	6.5f [0.1]
Metal slot ceramic	1.76a [0.4]	2.55c [1.1]	8.0g [0.2]
Conventional ceramic	4.34b [0.4]	4.68e [0.6]	9.2h [0.3]
Conventional metal	1.74a [0.4]	3.63d [0.3]	7.7i [0.1]

*Means with the same superscript are not significantly different (P > 0.05) using ANOVA and Tukey's multiple comparisons (N = 50).