Design Features of Rotary Instruments in Endodontics

The last decade has been witness to phenomenal growth in endodontic technology. The introduction of these new technologies has resulted in endodontics becoming easier, faster and most importantly, better. Principal among these is Nickel Titanium (NiTi) rotary instrumentation that results in consistent, predictable, and reproducible shaping. The purpose of this article is to review the design features of different rotary instruments used for pulp space preparation. Individual design features affect the performance of NiTi rotary instruments. Important mechanical features include the variability of taper, rake angle, cross-sectional geometry, tip configuration, design of blades, helical angle and pitch. These design features influence flexibility, cutting efficiency and safety. In this review design features of commonly used NiTi rotary systems are summarized.