The purpose of this study was to determine the number of rotations to fracture (cyclic fatigue) of the Profile® Vortex™ files (Dentsply Tulsa Dental Specialties, Tulsa, OK) compared to the EndoSequence™ files (Brasseler USA, Savannah, GA) using an in-vitro apparatus simulating a curved canal. Two hundred Profile® Vortex™ files of 25mm length were divided equally into ten groups, one for each of the Profile® Vortex™ files 20/0.04, 20/0.06, 25/0.04, 25/0.06, 30/0.04, 30/0.06, 35/0.04, 35/0.06, 40/0.04, and 40/0.06. Two hundred EndoSequence™ files of 25mm length were divided equally into ten groups of the same tip and taper sizes analogous to the Profile® Vortex™ file groups. Files were rotated at 500 rpm in a fixed groove in the metal block of the apparatus. The angle of deflection for all files was fixed at 33 degrees, determined using the Schneider method. The time from initiation of rotation to fracture was recorded and rotations to fracture were calculated. The data collected was analyzed using a multi-way ANOVA, followed by specific post-hoc contrasts comparing the two brands for each tip and taper combination. The results demonstrated that the Profile® Vortex™ files required significantly greater rotations to fracture than the EndoSequence™ (p < 0.001) in all tip sizes in both 0.04 and 0.06 tapers. Profile® Vortex™ files exhibited a greater resistance to cyclic fatigue than the EndoSequence™ files.