An In Vitro Cyclic Fatigue Analysis of Different Endodontic Nickel-Titanium Rotary Instruments

Abstract Introduction The study compared Twisted File (TF) with 3 traditionally manufactured systems to determine whether changes in the manufacturing process improved the cyclic fatigue resistance. Methods Four rotary file systems, (1) ProFile (PF), (2) Mtwo, (3) K3, and (4) TF, were tested in artificial canals with 45° and 90° angles of curvature. Ten instruments each of the 4 file systems were tested in both angles of curvature (n = 10). All instruments had identical size and taper (.06/0.25 tip diameter). Results A statistically significant difference ( P P > .05) in both canal curvatures; however, statistically significant difference ( P Conclusions Under the conditions of this study, size .06/0.25 TF was significantly more resistant to fatigue than the other 3 instrument systems produced with the traditional grinding process.