The name comes from the letter “C” shape appearance of a very large isthmus in the pulp chamber floor when viewed from above. This isthmus or groove is the result of the merging of some or all of the root canals at the cervical area near the pulp chamber floor. Incidence is 2,7% in Caucasian and up to 13% in asian population. “C” shape canals are a real challenge to preparation of root canal treatment and may cause technical complications such as transportation, steps, stripping with perforation in the thin wall area or blockage of the canal.
The following link to a short video of the tooth in 3D gives a better understanding on how difficult the cleaning and filling tasks of a “C” shape root canal may be.
This procedure requires a full understanding of this anatomy to prepare an optimal access cavity to pulp chamber, to know where to look for the root canal entries and to be cautious about the thin wall area. This endodontic procedure also requires much more operating chair time for debridment. No rapid techniques does exist to shape clean and fill those peculiar root canal shapes. This specific endodontic procedure also justifies the use of a dental operative microscope to better see what we are doing and lower the risk of procedural mistakes.