Self adjusting file system: A Review

To discuss new concept in endodontic world, the self-adjusting file (SAF), and compare its unique features compared with other rotary nickel-titanium file systems.As far as relatively straight and narrow root canals with a round cross-section are concernedthe goal of cleaning and shaping may be easily and reproducibly achieved with rotary files.The SAF file is hollow and to adapts to the cross-section of the root canal it is designed as a thin cylindrical nickel-titanium lattice. A single file is used throughout the procedure. A transline- (in-and-out) vibration is performed when it is inserted into a path initially prepared by a # 20 K-file and operated. The circumferential pressure allows the file’s abrasive surface to gradually remove a thin uniform hard-tissue layer from the entire root canal surface, that gives canal  a similar cross-section but of larger dimensions.