Comparing Cyclic Fatigue of the new GT® Series XTM Files to the Original ProFile® GT® Rotary Instruments

The purpose of this study was to test the number of rotations to fracture of the M-Wire GT® Series X(TM) rotary files compared to the original ProFile® GT® rotary files in a simulated curved canal. Eighty GT® Series X(TM) files of 25mm length were divided into eight groups of ten, one for each of the new GT® Series X(TM) files. Eighty original ProFile® GT® files of 25mm length were divided into eight groups of the same tip and taper sizes consistent with the GT® Series X(TM) file groups. Files were rotated at 300 rpm. While the angle may have slightly changed due to the flexure property of the file, the angle was the same for each file with the same tip and taper. The time to fracture was recorded and rotations to fracture were calculated. The data collected was analyzed using a two-way ANOVA, followed by specific post-hoc contrasts comparing the two brands for each tip and taper combination. The results show the M-Wire GT® Series X(TM) files were significantly more resistant to fracture by cyclic fatigue than the ProFile® GT® rotary instruments for the following tip and taper sizes: 20/.04, 30/.04, 30/.06, 30/.08, and 40/.08. The following tip and taper sizes: 20/.06, 40/.04, and 40/.06 were not statistically significant