A retreatment of the canal or orthograde preparation aims to completely remove the existing filling material, reach areas that were left untreated during a previous procedure, and thus ensure complete disinfection of the root portion. With the NiTi Endo ReStart file system, this task can be effectively but controlled in just a few steps. The Endo ReStart files have a constant taper of 5%, a diameter of 0.25 mm, a length of 25 mm, a tip with 2 surfaces, are sterile, and for single use.