Table 3. Two by Two Mann–Whitney U Tests of Means Values of Smear Layer Scores in Different 3 Regions of Root Canal In Study Groups .

Groups	Comparing Areas	P Value
Control	Coronal-Middle	0.199
	Coronal-Apical	0.17
	Middle-Apical	0.483
1% NaOCl LAI	Coronal-Middle	0.014
	Coronal-Apical	0.001
	Middle-Apical	0.637
2/5% NaOCl LAI	Coronal-Middle	<0.001
	Coronal-Apical	<0.001
	Middle-Apical	0.105
5% NaOCl LAI	Coronal-Middle	0.001
	Coronal-Apical	0.008
	Middle-Apical	0.853