NiTi instrument were introduced over two decade ago to improve the shaping and cleaning ability of root canals.NiTi instruments are highly flexible and super elastic.Advantageously NiTi rotary shaping files have nearly eliminated the iatrogenic instrumentation complication that are often connected to endodontic steel instrument.Since their first appearance ,instrument design has changed considerably,progress has been made in manufacturing as well as alloy processing.Traditionally files has been produced according to empiric designs,and even today many instrument are still devised by individual clinicians rather than developed through an evidence-based approach.The development of a new files now days is a fast and market driven process.Each generation of instrument has had something new to offer and is intended to improve upon previous generations.Many variable and physical properties influence the clinical perforamance of NiTi rotaries.Ultimetly clinical experience,handling properties,safety,and case outcome should decide the fate of a particular instrument design.

Dr Amrutha Sathianath ,PG Student Department of Conservative Dentistry And Endodontics,J S S Dental College and Hospital,Mysuru,Karnataka,India.