S file

Files with great cutting ability, are the most effective files for root canal treatment. They are designed as composition of two cutting edges of H-files. They can be used as files (up and down movement in the canal with a slight turn up to 90 degrees) or reamers (360 degrees turning movement in the canal). They have a millimeter scale etched on the blade (18 to 25 mm from the tip), which facilitates the determination of the working length of the canal.