A method of manufacturing an endodontic instrument using an
electrochemical (ECG) grinding process. An instrument blank is formed
from stock material, and an electric current is applied between an
electrically conductive grinding wheel, acting as a cathode, and the
instrument blank, acting as an anode. A continuous stream of electrolyte
fluid, a conductive aqueous solution, is applied at an interface between
the grinding wheel and the instrument blank, the electrolyte fluid having
an associated volume and pressure. The instrument blank is advanced past
the electrically conductive grinding wheel to remove material from the
instrument blank to form at least one cutting flute. The electric current
applied between the grinding wheel and the instrument blank is reduced,
and the instrument blank is advanced past the grinding wheel again to
form a finish surface, e.g., a sharp cutting edge, on the at least one
cutting flute. The process may be repeated to form an endodontic
instrument having a plurality of cutting flutes. The cutting flutes may
be helically or non-helically shaped. The instrument blank is formed of
an electrically conductive material, such as nickel titanium or stainless
steel. In one variation, the electric current may be eliminated entirely
during the final finishing pass. The volume and pressure of the
electrolyte may be varied. Endodontic instruments formed by the method of
the present invention are also disclosed.