表 2.

3种镍钛锉的冠方段NCF和折断段长度

Comparison of coronal NCF and fragment length of the three nickel-titanium files

Nickel-titanium files	Coronal NCF，x±s					Coronal fragment length/mm，x±s
	24 ℃	65 ℃	t	P		24 ℃	65 ℃	t	P
* P < 0.05，TruNatomy vs. ProTaper Gold and ProTaper Next; # P < 0.05，TruNatomy at 24 ℃ vs. TruNatomy at 65 ℃. NCF, number of cyclic fatigue.
TruNatomy	618.3±75.3*#	454.2±45.4*	3.810	0.007		4.8±0.3	4.8±0.2	-0.078	0.940
ProTaper Gold	327.5±111.8	268.3±31.4	1.259	0.244		4.5±0.4	4.8±0.2	-1.170	0.286
ProTaper Next	376.7±67.9	283.8±31.7	2.459	0.057		4.6±0.4	4.5±0.5	0.266	0.796
F	14.034	36.102				0.424	0.786
P	0.002	0.001				0.665	0.480