Problems with a Cordless Endodontic Hand Piece when Preparing Severely Curved Root Canals

Successful endodontic treatment mainly relies on preserving the original anatomy of the root canal while avoiding instrument fractures and iatrogenic preparation errors, such as loss of working length, zipping, or ledging [1,2]. In most cases, rotary instrumentation has proved a valuable advancement for meeting these parameters. Unlike stainless steel files, nickel-titanium instruments have sufficient cleaning ability and can preserve root canal anatomy. To minimize the risk of instrument fracture, nickel-titanium rotary instruments with torque-controlled motors not exceeding the recommended speed for the specific system should be used [3]. Some torque-controlled motors, despite being recommended for several years, increase operational safety and the risk of instrument fracture. These can be categorized as first-generation motors without torque control, fully electronically controlled second-generation motors with sensitive torque limiters, third-generation motors with a simple torque control, and fourthgeneration motors with built-in apex locator and torque control [4]. They also can be classified into electric or mechanical high-torque control motors. The electronic torque is generally limited via a power speed curve that determines the mechanical variance with the help of the slip or magnetic drive. The latest development in torque control is to incorporate gear systems within the cordless endodontic handpiece that regulates torque depending on the size of the rotary instrument. This eliminates the need for conventional torque-controlled motors. Research Article