Static and Dynamic Cyclic Fatigue Resistance of Nickel-Titanium Rotary Instruments in a Double-Curved Stainless Steel Artificial Canal

The present study aims to measure the number of cycles leading fracture (NCF) instruments in static and dynamic cyclic fatigue situations under body temperature stainless steel double-curved canals. framework was constructed establish movement occurring at a stable temperature. A step motor, holding system for an endodontic handpiece, created out artificial canal file mounted on handpiece. total 30 ProTaper Universal Next (Dentsply Sirona, Maillefer, Ballaigues, Switzerland) were divided into three groups 10 per group. For group 1 (10 PTU F2), files rotated cycles. 2 F2) 3 PTN X2), Files using proprietary programs, times before recorded. Data analyzed survival probabilities regression with life data. had largest NCF, condition least. New modes rotation, material, design have affected resistance instrument.