Cyclic fatigue resistance in NiTi files by four different sterilization methods

Area of Science:

• Endodontics
• Materials Science

Background:

• Nickel-Titanium (NiTi) rotary instruments are widely used in endodontic procedures.
• Sterilization is crucial for instrument safety, but its effect on NiTi cyclic fatigue resistance requires investigation.

Purpose of the Study:

• To evaluate the cyclic fatigue resistance of Pedoflex NiTi files after exposure to different sterilization techniques.
• To determine the impact of repeated sterilization cycles on the fatigue life of NiTi instruments.

Main Methods:

• Fifty Pedoflex NiTi rotary instruments were randomly assigned to five groups, each subjected to a different sterilization method and five cycles.
• Cyclic fatigue resistance was assessed using a simulated curved canal model until fracture.

Main Results:

• Nickel-titanium alloy is susceptible to thermal and mechanical stresses.
• Autoclave sterilization, through thermal treatment, improved crystallographic arrangement and flexibility.
• Repeated sterilization cycles did not significantly reduce fatigue life; autoclaving potentially enhanced resistance.

Conclusions:

• Autoclave sterilization may improve the cyclic fatigue resistance of pediatric NiTi instruments.
• Evidence supports the safe reuse of heat-treated pediatric NiTi instruments in high-volume clinical settings.