Impact of Peracetic Acid on the Dynamic Cyclic Fatigue of Heat-Treated Nickel-Titanium Rotary Endodontic Instrument

Figure 3

Scanning electron micrographs of failed files: (a) control subgroups, (b) 0.002% PAA subgroups, (c) 0.35% PAA subgroups showing the lateral view of the fractured files having numerous cracks near the fracture sites (thick arrows), with surface wear (erosion) of the cutting edges represented by short straight lines. The cross-sectional views of crack initiation areas (dotted line) and surface pitting with voids (thin arrow).

(a)

(b)

(c)