Variability of the diameter and taper of size #30, 0.04 nickel-titanium rotary files.

This investigation examined the variability of tip diameter (D0) and taper measurements among four different brands of #30, 0.04 nickel-titanium (NiTi) rotary files (n=15/brand). With all brands, the mean percent D0 difference from the manufacturer's reported (nominal) diameter (Profile GT, 1.73+/-2.03%; Endo Sequence, 3.38+/-3.91%; K3, 4.56+/-2.36%; Profile, 6.13+/-4.07%) indicated that files tended to be larger than the nominal diameter. A 1-factor ANOVA and Tukey's post hoc test revealed a statistically significant difference (p0.05) of brand on the mean percent difference of the measured taper compared to the nominal taper with the majority of measurements at either 0.039 or 0.040 taper.