A Novel approach to controlling performance of endodontic files

A new method of controlling the performance of SMA endodontic files is explored. Endodontic files are dental instruments for root canal procedures, used to remove infected tissue from the root of a tooth. Generally, root canals follow curved paths, which puts a high demand for flexibility and fatigue resistance on the endodontic file. To achieve acceptable performance, binary nickel-titanium has become the dominant material for use in endodontic files. To further enhance flexibility and fatigue resistance, modern endodontic files are designed with the austenitic transformation temperature above body temperature. However, this softens the cutting edges, potentially decreasing the cutting efficiency, and exposing the file to dulling due to wear. In this study, we present a novel process that affects the material properties of the endodontic file in an extremely localized manner. This results in control of the stiffness of the file to achieve the desired flexibility without negatively altering the hardness of the cutting edges. This represents a new paradigm of controlling the material properties of an endodontic file to achieve high performance without compromise.