Table 4.

Results of statistical analyses (t-test and Mann–Whitney rank sum test) of pull-off force values obtained on different samples.

comparison	d.f.	test statistics	P	significantly different
glass vs wax
C36	48	t = 8.733	<0.001	yes
C40	48	t = 6.317	<0.001	yes
C44	—	T = 197	0.163	no
C50	—	T = 268	0.762	no
between wax
C36 vs C40	18	t = −1.252	0.226	no
C36 vs C44	—	T = 81	0.076	no
C36 vs C50	—	T = 58	<0.001	yes
C40 vs C44	—	T = 92	0.345	no
C40 vs C50	18	t = −4.082	<0.001	yes
C44 vs C50	18	t = −1.467	0.160	no

d.f., degrees of freedom; P, probability value; t, t-test statistics; T, Mann–Whitney rank sum test statistics; yes, significantly different; no, no significant difference.