The invention is an instrument for cleaning and/or shaping and/or widening a root canal. The instrument is an inflatable balloon, which allows the inner volume enclosed by the instrument, its outer contour, or both to change as a result of the forces exerted upon it while working, thereby shaping the instrument to the three-dimensional contour of the channel. The outer surface of the balloon is coated with abrasive material. A preferred embodiment of the instrument is an endodontic file for use in the cleaning, shaping, and widening stages of a root canal procedure.
