Management of mandibular first molar with four canals in mesial root
A 37-year-old male patient with a noncontributory medical history reported to our department with discomfort and pain in the right mandibular region. History of present illness showed that there were few episodes of recurrent pain in that region for the past 1 year. There was a large carious lesion and a draining sinus in relation to left mandibular first molar with pain on palpation in the periapical region. Pulp testing with cold and electric pulse tester (EPT) was nonresponsive. Intraoral periapical (IOPA) radiograph revealed a large radiolucency around the periapex of left mandibular first molar []. Gutta-percha tracing of sinus showed that the sinus originated from the periapical radiolucency around the tooth. It was diagnosed as pulpal necrosis with symptomatic apical periodontitis. Treatment plan was explained to the patient and endodontic treatment was initiated under rubber dam isolation. Three canals were located, two in the mesial and one in the distal. Under magnification, it was evident that the mesiobuccal (MB) and mesiolingual (ML) were placed well apart with an isthmus joining the two canals. With the above mentioned pulpal floor anatomy over the mesial root, a possibility of MMcanalwas anticipated in the isthmus between MB and ML. On exploration with DG-16, there was a “catch” or a “stick” feeling where a MM canal was located close to MB canal. The distance between the MM canal and ML canal with a prominent isthmus between the two, prompted us to look for a second MM canal. Further exploration on the isthmus revealed one more “stick” feeling which on penetration with profinder revealed to be a second MM located closer to the ML canal []. IOPA radiograph revealed one MM joining the MB canal and another joining the ML canal in the middle third []. The orifices were enlarged using #2 GatesGlidden Drill (Mani, Japan) to enhance access and visualization. After confirming the working length with an apex locator (Root ZX, J Morita, Tokyo, Japan), the mesial canals were enlarged up to size 25-6% (M two, DentsplyMaillefer) and the distal canal was instrumented with hand K-files (DentsplyMaillefer) by crown down method with apex enlarged to size40. Intracanal medicament of 2% chlorhexidine was placed and closed dressing was given. Since the anatomy was unusual, a cone beam computed tomography (CBCT) image was taken to confirm the anatomy []. CBCT image confirmed the presence of two MM canals of which one joined the MB and another joined the ML canal at the middle third and exited as a single canal at the apex. This was followed by an intracanal medication with CaOH (Dentocal, Anabond Stedman) with chlorhexidine (Asep-RC, Anabond Stedman) after a week for 3 weeks. CaOH was not placed in the first sitting as the radiopaque CaOH may obscure the CBCT image. Obturation was performed at the third appointment using cold lateral compaction of gutta-percha and AH-26 (Dentsply Maillefer) as a root canal sealer. Figure and shows the IOPA images immediately after obturation in buccal and distal view. is 6 month follow-up image showing a good healing of the periapical lesion.