A Digital Microscopic Inspection of Dentinal Defects after Using Endodontic Retreatment Files

Table 3

Distribution of defects among teeth.

	Group				Kruskal–Wallis H	Sig.
	Negative control	Positive control	PTUR	XP
Apical	0^a	0^a	6^b	1^a	17.380	0.001
Middle	0	2^a	3^a	3^a	3.247	0.355
Cervical	0^a	0^a	4^b	0^a	12.643	0.005
Overall	0^a	2^a	13^b	4^a	23.114	<0.001

Only presence of defect is listed in the table; however, both presence and absence are used for the calculation of Kruskal–Wallis H. Differences significant at . ^a,bDifferences in superscript indicate significance of difference <0.05 using Mann–Whitney U test.