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. Pre operative X Ray dental film shows a blurred image of the canal system, canals are not visible and pulp chamber is almost not visible. Looking at these features it may not be possible to diagnose a C shape canal but we must suspect either this canal configuration or severe fibrosis/calcification.
“C” shape canals are a real challenge to preparation and may cause technical complications such as transportation, steps, stripping with perforation in the thin wall area or blockage of the canal.
This procedure requires a full understanding of this anatomy to prepare an optimal access cavity to pulp chamber through a PFM abutment, 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.
Endodontist. Case Study Number 319947.
This 3D video of a “C” shaped second mandibular molar from the rootcanalanatomyprojectblogspot.com displays the complex anatomy of such a root canal system. In just a few second the video gives a better understanding on how difficult the cleaning and filling tasks of a “C” shape root canal may be.
Last september, a new generation of endodontic file has been presented at the CAE meeting in Quebec city-Canada by Dr Zvi Metzger, Professor and Chair Department of Endodontology school of Dental Medicine at Tel Aviv University. Although at the moment, the Self Adjusting File System (SAF System) is not yet readily available everywhere in Canada, this innovative endodontic file adapts to root canal shape thus, may represent in a near future, a valuable approach to more efficient debridement in C shape canals and a safer way to address thin wall section that is always present in this anatomical variation. Here is a promotional video showing how it works.