Fracture of ProFile nickel-titanium rotary instruments: a laboratory simulation assessment

Area of Science:

• Endodontics
• Dental Materials Science

Background:

• Nickel-titanium rotary instruments are widely used in endodontic procedures.
• Instrument fracture is a potential complication during root canal preparation.

Purpose of the Study:

• To determine the incidence of ProFile nickel-titanium rotary instrument fracture.
• To assess the safety of ProFile instruments for dental students in laboratory simulations.

Main Methods:

• 360 dental students prepared 1440 simulated and 1440 natural root canals using ProFile instruments.
• A standardized crown-down technique with fracture prevention measures was employed.
• Instrument fracture incidence was monitored and data on fragment characteristics were collected.

Main Results:

• Overall ProFile instrument fracture incidence was 0.36% (0.41% in plastic, 0.31% in natural canals).
• Fractured instruments were predominantly size 25, 0.04 taper (67%).
• Most fragments (81%) were located in the apical third, with a mean length of 3 mm.

Conclusions:

• ProFile nickel-titanium rotary instruments demonstrated a low fracture incidence in this simulation.
• The instruments are considered safe for use by dental students in laboratory settings.
• Implementing preventive measures can further minimize the risk of instrument fracture.