During last decade several new nickel-titanium (NiTi) instruments for manual canal preparation as well as for use in rotary endodontic handpieces have been developed and marketed in order to facilitate the difficult and time consuming process of cleaning and better shaping the root canal system.. This speed and efficiency made signal appointment endodontics possible even in cases with complex root anatomy. The super elasticity of NiTi alloy allow these instruments to flex more than stainless steel instruments before exceeding their elastic limits, allowing easier instrumentation of curved canals while minimizing canal transportation. Nickel-titanium (NiTi) hand & rotary techniques developed to improve root canal preparation these instruments offers possibilities for improving the speed of treatment, as well as achieving greater precision and accuracy. This book specially emphasize on the nickel titanium and its role in dentistry.