Safety Memo discs (SMD) are reusable accessories that are intended to be used in combination with endodontic files. They are usually mounted and delivered with sterile or non-sterile instruments, but they can also be delivered separately, non-sterile, in a standard packaging. They consist of a small thin silicone disc used to control endodontic instrument fatigue. The disc has 4 or 8 detachable petal shaped sections. Petals are intended to be removed manually after each use. The number of remaining petals indicates the further possible uses. SMD can be either “not perforated” or “pre-perforated” (0.5 or 0.9mm) in order for the user to select the appropriate SMD depending on the file’s diameter and therefore ensure that the disc is tightly maintained on the instrument.