Deformation and Fracture of Mtwo Rotary Nickel-Titanium Instruments After Clinical Use

Comparison among Manual Instruments and PathFile and Mtwo Rotary Instruments to Create a Glide Path in the Root Canal Preparation of Curved Canals

“…Similarly, other studies have reported that smaller instruments have greater chances of presenting distortion and fracture than larger ones (34,35). Although the variable time of preparation was not the object of the present study, the mean time required by the 3 different types of instruments to create the glide path were similar.…”

Assessment of the Separation Incidence of Mtwo Files Used with Preflaring: Prospective Clinical Study

“…Whenever separation or distortion occurred, the kit was discarded, except when using the 10.04 file, which could be replaced at any time because of its high rate of deformation and separation (18).…”

“…According to these authors, the procedure reduces the risk of fatigue and instrument locking along the root canal walls, which could favor instrument separation (6,13,23,29). In contrast, other studies confirmed the effectiveness of using Mtwo instruments following the manufacturer's recommendations, ie, without previous cervical preflaring and manual preparation (7,9,18,30).…”

Comparison of Cyclic Fatigue Resistance of Three Different Rotary Nickel-Titanium Instruments Designed for Retreatment

“…However, the main problem with the rotary NiTi instruments is the risk of fracture during clinical use (12). Moreover, removal of filling materials in curved canals is a difficult task, and instrument breakage or distortion is more likely to occur.…”