Cyclic fatigue resistance in NiTi files by four different sterilization methods.

The cyclic fatigue resistance of Pedoflex NiTi files that have been expose to four sterilization techniques. Hence, a total of fifty Pedoflex NiTi rotary instruments were selected at random and were assigned to five groups according to the type of the sterilization method used and five sterilization cycles carried out in each group. After the sterilization procedure, the evaluation of all files under cyclic fatigue resistance was done on a simulated curved canal model up to fracture. It was discovered that nickel-titanium alloy was very susceptible to thermal and mechanical stresses. Autoclave sterilization with the help of thermal treatment improved the crystallographic arrangement of the alloy and led to greater flexibility. The repeated cycles do not significantly reduce fatigue life and that autoclaving may even enhance cyclic fatigue resistance, thereby supporting evidence based decisions on safe reuse of heat treated pediatric NiTi instruments in high volume clinical settings.