Variability of the diameter and taper of size #30, 0.04 gutta-percha cones

The purpose of this investigation was to examine variability of gutta-percha (GP) cone tip diameter (D(0)) and taper among five different brands of #30, 0.04 GP cones (n = 15/brand). Mean percent D(0) difference from the manufacturer's reported (nominal) diameter of Maillefer (-15.42 +/- 7.16%) and Lexicon (-12.76 +/- 4.98%) were significantly different (p < or = 0.05) from Maxima (3.18 +/- 7.06%), Diadent (3.62 +/- 11.37%), and K(3) (7.27 +/- 7.84%), which were not significantly different from each other but exhibited diameters larger than the nominal diameter as indicated by positive values. Mean taper percent difference of Maxima (-3.00 +/- 3.80%) was significantly different (p < or = 0.05) from Lexicon (3.67 +/- 3.64%) and Maillefer (6.67 +/- 3.49%), with comparisons to Diadent (-0.17 +/- 6.37%) and K(3) (1.50 +/- 6.93%) not significantly different (p > 0.05) from each other or any other brand. Based on the evidence, there is significant variability between GP cone brands for both diameter and taper, with Maxima and Diadent, respectively, exhibiting the smallest mean difference from manufacturer's nominal tip diameter and taper. However, the high standard deviation values associated with most of the diameter and taper differences from nominal values also suggest high variability within individual brands.