When a tooth smiles at you that signals danger!! A C-shaped root canal often formed because of failure of the Hertwig’s epithelial root sheath to fuse on the lingual or buccal root surface or it may also be formed by coalescence because of deposition of the cementum with time. (Melton DC, 1991, JOE). There are multiple fins and connections in a C shaped root canal making it difficult to completely disinfect. I will describe my experience dealing with such canals.
IDENTIFICATION???
We can identify a C shaped canal with a pre-operative radiograph by careful observation. some features observed are:
The pulp chamber is large in the occluso-apical dimension and with a low bifurcation.
The semicolon-type C-shaped root canals often present with
(i) fusion or close proximity of two roots,
(ii) a large distal root canal,
(iii) a narrow mesial root canal and
(iv) a blurred image of a third canal in-between.
ACCESS OPENING:
The canals are usually located in the centre of the tooth and more toward the buccal end. it can be seen as continuous C or semicolon shaped.
• working length radiographs are more helpful whereas preoperative radiographs are the least effective in diagnosing the C-shaped cases. (Lambrianidis T,2001). Two characteristics for configuration:
– instruments tending to converge at the apex and/or
– may exit at the furcation may resemble a perforation of the furcation.
(Jafarzadeh H, 2007)
CLEANING AND SHAPING:
• Gates-Glidden burs should not be used to prepare the mesiobuccal and buccal isthmus areas. (Melton DC, 1981, JOE). A continuous circumferential filing along the periphery of the C canal and is irrigated with copious amounts of 5.25% NaOCl. HAFI (Hedstrom files) are especially effective for efficient tissue removal. It should be remembered that there is a higher risk of root perforation at the thinner walls of C-shaped canals during shaping and post space preparation procedures. Both buccal and lingual canal walls are frequently narrower at mesial locations. ( Yılmaz Z, 2006)
OBTURATION:
IT Warm vertical obturation ensures 3D fill of such complex anatomies. or collateral would be an alternative. Single come obturations do not ensure complete filling of the canals.
Placement of posts or anti-rotational pins in the mesiolingual and mesiobuccal areas of C-shaped root invites perforation.
• The clinician must be aware of the impact this anatomy as when surgical endodontics is indicated.
• The absence of furca contraindicates hemisection or root amputation.
• The intercanal communications or fins visualized on the serial sections reinforce the difficulty the clinician would encounter after apicoectomy with the retro-preparation and eventual retro-filling.
• If endodontic surgical intervention is indicated for a molar with C-shaped root canal anatomy, strong considerations should be given to extraction, retro-filling, and intentional replantation.
(Cooke HG,1979 )
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