Table 2.

Surface roughness comparison according to bracket material, adhesive system, and etchant-type (SD: Standard Deviation, M: Metal, C: Ceramic, TE: Total-Etch, SE: Self-Etch, PC: Pre-Coated, FF: Flash-Free, **: Statistically Significant with p < 0.01, t-test).

Surface Roughness Comparison According to Bracket Material
Adhesive type	Etchant Type	Bracket Material	Mean Difference (Post & Pre)	SD	p-value
PC	TE	M	1.077	0.488	0.420
		C	0.916	0.430
	SE	M	0.468	0.332	0.988
		C	0.470	0.304
FF	TE	M	0.700	0.378	0.967
		C	0.708	0.439
	SE	M	0.444	0.191	0.494
		C	0.522	0.318
Surface Roughness Comparison According to Adhesive System
Bracket Material	Etchant Type	Adhesive System	Mean Difference (Post & Pre)	SD	p-value
M	TE	PC	1.077	0.488	0.057
		FF	0.7	0.378
	SE	PC	0.468	0.332	0. 841
		FF	0.444	0.191
C	TE	PC	0.916	0.430	0.275
		FF	0.708	0.439
	SE	PC	0.47	0.304	0.698
		FF	0.522	0.318
Surface Roughness Comparison According to Etchant Type
Bracket Material	Adhesive System	Etchant Type	Mean Difference (Post & Pre)	SD	p-value
M	PC	TE	1.077	0.488	0.003**
		SE	0.468	0.332
	FF	TE	0.70	0.378	0. 059
		SE	0.444	0.191
C	PC	TE	0.916	0.430	0.011**
		SE	0.470	0.304
	FF	TE	0.708	0.439	0.271
		SE	0.522	0.318