Evolution of Mechanised Endodontic File Systems

The evolution of rotary nickel-titanium instruments are aimed to achieve sufficient cleaning and shaping as well as preserving the root canal anatomy. Most of the NiTi rotary systems are based on continuous rotational movement. Later, the reciprocating instruments were proposed that have a characteristic reciprocating and oscillating motion. Further, for preservation of the exact internal anatomy of canals as well as minimising the dentin loss during cleaning and shaping, a revolutionary instrument, Self-adjusting file was introduced. Since, traditional NiTi rotary files require multiple exchange of file sizes, Single file endodontic concept came up that required a minimum or no glide path and only a single file for complete instrumentation for majority of root canals. Rotary endodontic instrumentation has therefore succeeded in providing with consistent canal shapes, good centric ability, less debris extrusion and faster preparation time. Currently, there is a wide array of rotary NiTi systems with different design features. This dissertation would discuss the evolution of various file systems, their metallurgical properties, design, features, advantages and disadvantages.