Mechanical and Metallurgical Properties of Various Nickel-Titanium Rotary Instruments

Figure 4

SEM images of the fractured surface of instruments after the torsional test: (A, a) ProFile, (B, b) K3, (C, c) One Shape, (D, d) ProTaper NEXT, (E, e) Reciproc, (F, f) WaveOne, (G, g) HyFlex CM, and (H, h) TF. All images at low magnification (A–H, ×200) show concentric circular abrasion marks and a “torn off” appearance. Skewed fibrous dimples near the center of rotation can be observed at a higher magnification (a–h, ×1,000).