To achieve the objectives of vertical condensation, it is necessary to produce:
The root canal preparation should develop a continuously tapering cone. This shape mimics the natural canal shape. Funnel-shaped preparation of canal should merge with the access cavity so that instruments will slide into the canal. Thus, the access cavity and root canal preparation should form a continuous channel.
Textbook of endodontics, 3rd edition Nisha Garg, Amit Garg
A cylindrical canal
A conical canal
A tapering conical canal
A straight canal