Mandibular first molar with C-shaped root canal system: a two-case report / 华西口腔医学杂志

The root and canal anatomy of the mandibular first molar is highly complicated. A mandibular first molar with a C-shaped root canal system is rare. This article describes two different cases of this system. Case 1 has a complete C-shaped fused root. The root canal is characterized by a mesial lingual root canal and a C-shaped fused root canal. Case 2 has a C-shaped fused root in the buccal region and a distal lingual root. The root canal is characterized by a type Ⅱ-Ⅰroot canal in the buccal region and a distal lingual root canal.

Incidence of C-Shaped Root Canal Systems in Mandibular Second Permanent Molar and the Effect of One-Visit Root Canal Treatment / 天津医药

Objective To investigate the incidence of C-shaped root canal systems in mandibular second perma?nent molar of patients in the First People’s Hospital of Yunnan Province, and compare the success rate between one-and two-visit root canal treatment. Methods Two hundred and sixty mandibular second molars were recruited from the pa?tients in the department of endodontics of our hospital, and teeth with C-shaped root canal were categorized by using radio?graphic classification criteria and the modified Melton’s method. Teeth with C-shaped root canal systems were then random?ly divided into two groups to receive one-or two-visit root canal treatment, and success rates of 6-month post-operation were compared between two groups. Results Eighty out of 260 mandibular second molars exhibited C-shaped canals (30.77%). Radiographic examination showed that 25 teeth belonged to typeⅠ(31.25%), 32 teeth typeⅡ(40.00%) and 23 teeth typeⅢ(28.75%) in two groups. As for modified Melton’s method, the incidence rates were 21.25%, 48.75%, 16.25%and 13.75% for C1,C2,C3a and C3b, respectively, while C4 was not found. The success rates were 78.94% (30/38) and 81.08%(30/37) for A group and B group, respectively, with no statistically significant difference between two groups ( 78.94 vs 81.08, P>0.05). Conclusion Results indicate a frequent incidence of C-shaped root canal system of mandibular per?manent second molars in our hospital. One-visit root canal treatment is an effective way for treating C-shaped canals in man?dibular permanent second molar.