TABLE 1.

Diameter values (mm) before and after use compared to the advertised nominal size

		Tip size D0 (diameter) measurement
		Before		After
File brand	Advertised tip size	Mean	P value	Mean	P value
ProTaper Universal F2	0.250	0.231±0.007	<0.001	0.225±0.006	<0.001
Channels C2		0.276±0.016	<0.001	0.272±0.008	<0.001
ProTaper Gold F2		0.219±0.016	<0.001	0.211±0.011	<0.001

*D0: Diameter measured at the first cutting edge of the file