Evaluation of an ultrasonic technique to remove fractured rotary nickel-titanium endodontic instruments from root canals: An experimental study

Abstract

The use of nickel-titanium rotary instruments in endodontic practice is increasing. One frequently mentioned problem is fracture of an instrument within the root canal. To date, there is no consistently safe and successful technique for removing these fractured instruments. This study evaluates the use of an ultrasonic technique to remove fractured rotary nickel-titanium instruments from narrow, curved canals in both simulated (resin blocks) and mesiolingual canals of extracted mandibular first molars. A technique using ultrasonic tips, combined with the creation of a "staging platform" and the use of the dental operating microscope, was consistently successful and safe at removing fractured..