Precision cast dental instrument

Abstract

An endodontic file (200) is provided particularly adapted for the removal of tooth structure, decayed or damaged nerve tissues or dentine material on the interior walls of a root canal or dentine and/or enamel from the external tooth wall. The endodontic instrument includes a shaft (202) having a shank portion (204) and a generally elongated working portion (206). The working portion preferably includes cutting or abrading features (232) adapted upon rotation and/or reciprocation of the instrument to cut, abrade or remove tissue from the interior walls of a root canal or dentine and/or enamel from the external tooth wall. The working portion extends from a proximal end (207) adjacent the shank portion to a distal end (208) terminating at a tip (250). The entire instrument and/or at least the working portion thereof is formed of an amorphous or essentially amorphous material having no or essentially no detectable crystalline structure and/or from a nanocrystalline material having an average crystalline grain size less than about 1 μm. The instrument may be formed by conventional grinding operations or by direct casting, forging or molding, in a manner producing an integral as-molded instrument having one or more sharp cutting edges. The instrument is inexpensive to manufacture and exhibits improved cutting-edge sharpness, wear resistance, lubriciousness and resistance to breakage.

Dependencies are inferred from the claim text.