In the practice of endodontics, clinicians may encounter a variety of unwanted procedural accidents and obstacles to normally routine therapy, at almost any stage of treatment.
One of these procedural problems is intracanal NiTi rotary files fracture. The relatively recent advent of rotary NiTi root canal instruments has led to a perceived high risk of instrument fracture. Fracture of rotary NiTi instruments may occur without warning, even with brand new instruments. Distortion of rotary NiTi instruments is often not visible without magnification.
Instrument fracture occurs because of reduced metal fatigue and/or torsional resistance. The reasons include canal morphology and curvature, manufacturing processes and instrument design, instrument use times and technique, rotational speeds and operator experience. Finally, operator skill, manufacturer modifications and limiting file reuse have been demonstrated to be significant in reducing fracture incidence indicating the importance of a prevention strategy.