Endodontic Instruments. Catalog of over 260 automated endodontic instruments from around the world, past and present, of stainless steel, nickel titanium and niti treated, cylindrical, rotary and reciprocating movement.
https://ferrariendodontia.com.br/wp-content/uploads/2022/11/Instrumentos.pdf
Endodontic instruments In: Machado, Ricardo. Endodontics: Biological and Technical Principles. Available at: GEN Group, GEN Group, 2022.
Brief historical perspective
The first instruments specially developed for mechanical preparation of the root canal were manuals made of carbon steel and then of stainless steel. The latter are still widely used, but they present low flexibility, especially in diameters larger than 25, even with reduced conicity (.02 mm/mm). The rigidity of manual stainless steel instruments is often related to significant changes in the original shape of the root canal and iatrogenesis.19-21
The use of instruments driven by pneumatic or electric micromotors at different speeds (from 3,000 to 20,000 rpm) is an old practice in Endodontics. Largo and Gates-Glidden burs, used to enlarge the entrance and straight portion of the root canal, respectively, are classic examples of rotary instruments used to facilitate biomechanical preparation. However, their use is also associated with errors and accidents.22-27
At the end of the 20th century, hand-held endodontic instruments made of nickel-titanium (NiTi) were launched in the market. Compared to their precursors, these instruments had more flexibility and less cutting ability. Later, motor-driven NiTi rotary instruments were produced that were able to perform mechanical preparation faster and safer with a speed of 150 to 600 rpm.28,29
Currently, NiTi instruments are driven at similar speed (150 to 800 rpm) by means of counter-angles and electric motors of different brands. The former are usually coupled to conventional pneumatic micromotors and have speed-reducing devices. They are light and ergonomic, and most feature a push button or press button clamp system.15,16,28,29
The electric motors have specific programs for various systems and allow different torque, speed, and movement values to be set according to the operator's preferences.
Currently, the two main kinematics used for automated root canal preparation are continuous right hand rotation and reciprocating movement (box "Definition of reciprocating movement in Endodontics").18 For this purpose, different instruments and systems can be used.
