Effect of cyclic torsional preloading on cyclic fatigue resistance of ProTaper Next and Mtwo nickel—titanium instruments. G Ital Endodon [Internet]. 2015 Jun. 30 [cited 2025 Oct. 11];29(1):3-8. Available from: https://www.giornaleitalianoendodonzia.it/gie/article/view/56