Spiral computed tomographic evaluation and endodontic management of a maxillary canine with two canals
A 25-year-old, South-Indian female patient reported with the chief complaint of intermittent pain in the front right upper jaw region for the past 2 months, which had increased in intensity for the past 3 days. She also complained of food impaction in the same region for the past 1 year. The patient's medical history was non-contributory. On clinical examination, the patient's oral hygiene was moderate and there was a deep carious lesion in relation to the right maxillary canine, which was tender on percussion []. Electrical pulp testing and cold pulp testing elicited a delayed response. A pre-operative radiograph [] was obtained, which revealed encroachment of pulp space by dental caries and there was widening of periodontal ligament space. On the basis of clinical and radiographic findings, a diagnosis of acute exacerbation of a chronic apical periodontitis was made. Hence, the tooth was prepared for non-surgical endodontic treatment. The patient received local anesthesia of 2% lignocaine with 1:80,000 epinephrine (Indoco remedies Ltd., Promoted by Warren pharmaceuticals, Goa, India). A rubber dam was placed, and a conventional endodontic access cavity was prepared in the right maxillary canine.\nThe pre-operative radiograph showed a thin layer of dentin in the middle-third of the canal, indicating that there were two separate canals in the body of the root. This followed the Vertucci's Type-III canal configuration (single canal leaving the access preparation, which divides into two within the body and re-unites to exit as one canal). Clinical view of the prepared access cavity portrayed the canals like premolars, where one was placed buccally and the other placed palatally []. The access cavity was sealed with a sterile cotton pellet and Coltosol (Coltene Whaledent, Switzerland). To confirm the unusual morphology and to search for any additional roots and root canals a spiral CT scanning was decided to be performed.\nCT scan was done with a multi-detector CT scanner taken at 16 slices/second, as per recommendations given by Diederichs et al. to reduce the radiation dosage (collimation, 1 mm; pitch, 2; tube voltage, 80 kV; tube current, 40 mA) and all the protective measures were taken to protect the patient from radiation.[] Axial images were transmitted to a commercially available dental program (Denta scan, Advantage Windows; General Electric, Buc, France) to reformat panoramic and cross-sectional images in all three planes. The CT images confirmed the radiographic findings of Vertucci's type-III canal configuration [Figures and ] and no additional canals or roots other than the two located canals. A striking feature was that the same canal configuration was found in the contra-lateral canine, which was absolutely healthy []; and also the mandibular central and lateral incisors, canine and the first premolars showed bifid canal pattern bilaterally. These findings can help the patient in the future because, at any point if the patient needs to undergo an endodontic procedure, these CT images can serve as an excellent guide to provide a quality endodontic treatment.\nAt the next visit, the working lengths of each canal were estimated by means of an electronic apex locator (Root ZX; Morita, Tokyo, Japan) and then confirmed by a radiograph. The canals were initially instrumented with #15 nickel-titanium files (Dentsply Maillefer, Switzerland) under irrigation with 2.5% sodium hypochlorite (Prime Dental Products Pvt. Ltd, Thane, India). Coronal flaring was carried out by using Gates-Glidden drills (numbers 3 and 2; Mani. Inc, Japan). Both the canals were cleaned and prepared by hand nickel-titanium files with the conventional step-back technique. Calcium hydroxide intracanal medicament (Apexcal, Ivoclar, Vivadent, Liechtenstein) was placed in the root canal and the orifice was sealed with a sterile cotton pellet and Coltosol. One week later, calcium hydroxide was removed and the canals were obturated with zinc oxide – Eugenol sealer and laterally condensed gutta-percha points. After completion of root canal treatment, a final radiograph was taken to establish the quality of the obturation []. The tooth was restored with a visible light-cured composite (Ceram-X duo, Dentsply India Pvt ltd, Delhi, India) to build up the missing tooth structure. The adjacent lateral incisor, which was non vital, was also root canal treated and restored with light cured composite restoration.