Patent ID: 7785174
Filing Date: 2010-08-31
Classification: A61C,B24B,Y10T

Abstract:
1. A method for producing an endodontic instrument having at least one helical cutting edge, comprising the steps of: providing a blank having a cylindrical portion for fixing the blank in a supporting spindle, and a generally conical portion which is to be machined by a grinding process to form an active part of the endodontic instrument which includes the helical cutting edge, wherein the helical cutting edge of the active part of the endodontic instrument has a final shape which defines a first envelope, and wherein the conical portion of the blank has a shape which defines a second envelope which approximates, and which is slightly larger than the first envelope defined by the final shape of the helical cutting edge of the active part of the endodontic instrument after being machined; cutting a hollowed-out, helical groove which develops the helical cutting edge by displacing the blank in a direction of advancement, and slowly rotating the blank in front of a rotary grinder; repeating the cutting step for a plurality of times corresponding to a selected number of cutting edges for the endodontic instrument; and providing the conical portion of the blank with a diameter which does not exceed a corresponding diameter of the active part of the endodontic instrument by more than 20% for every diameter defined along the active part of the endodontic instrument.