The invention is an instrument for cleaning and/or shaping and/or widening
a channel that exists in or through a solid object. The design of the
instrument the superelastic and shape memory properties of the material
from which it is made, allow 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. A preferred embodiment of the
instrument is an endodontic file for use in the cleaning, shaping, and
widening stages of a root canal procedure.