Root Morphology and Instrumentation Implications Practice Test

In severely curved canals, keeping the natural shape of the canal is best achieved by using flexible nickel-titanium instruments and first establishing a glide-path, then gently shaping. NiTi files are superelastic, so they can follow curved walls with less tendency to straighten the canal, reducing transportation, ledges, and perforations. Creating a glide-path with small, flexible files gives a smooth, predictable route to the apex and protects against instrument lock or transportation when larger files are used later. With a clear glide-path, apply gentle, controlled motions and gradual enlargement rather than forcing files; this lets the instrument follow the canal’s curvature and preserves dentinal walls and original canal anatomy.

The other approaches risk distortion: rigid stainless steel files tend to straighten curved canals and create deviations; ignoring curvature and using large files can gouge or perforate the canal; relying on irrigation alone without shaping cannot establish the anatomy or prepare the canal.