Granted Patent
Utility
US 4,746,292 · App. 07/033,251
Tool and method for removing a parted endodontic file
Inventor:
William B. Johnson
Patented Case
View Patent ↗
Granted: May 24, 1988
Filed: Apr 2, 1987
Inventor
William B. Johnson
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.