Endodontic treatment of maxillary lateral incisors with anatomical variations
A 26-year-old male in good health was referred to the endodontic clinic of Kyungpook National University Dental Hospital for root canal treatment of the maxillary right lateral incisor. The root canal treatment had been initiated by a general dentist, who opted for a referral after observing its unusual root canal morphology. Clinical examination revealed a sinus tract labially to the lateral incisor and swelling at this level. There was tenderness to palpation and percussion. Radiographically, a diffuse radiolucent area was noticed at the apices of roots of the maxillary right lateral incisor (). The sinus tract was traced with a gutta-percha cone to tooth #12 that showed a second root surrounded by a radiolucent area. The pulpal diagnosis was previous endodontic treatment and the periapical diagnosis was chronic apical abscess with sinus. There appeared to be two roots that had distinct root canal space.\nA rubber dam was applied, and temporary sealing material was removed. The principle canal was found easily but the second canal was not negotiated. At the following visit, because the second canal was not negotiated again while the patient had labial swelling with fever and pain, incision and drainage was performed at the labial swollen area (). At the third visit, the second canal was negotiated with ultrasonic instruments under an operating microscope. The second canal was located at the corresponding part of palatogingival groove in the pulpal chamber of the tooth. After removing dentin carefully with an ultrasonic device, an orifice was detected by using a size 10 stainless steel K-file (Mani, Tochigi, Japan). Both canals were cleaned and shaped with stainless steel K-files using the step-back technique. Radiograph revealed a narrow second canal, which was prepared with 2 mm increments per each size of file (.025 taper).\nAfter preparation, the root canals were irrigated with 17% ethylenediaminetetraacetic acid (EDTA) followed by 5% sodium hypochlorite solution and dried with sterile paper points. The root canals were obturated with gutta-percha using cold lateral compaction technique with an epoxy resin sealer (AH Plus, Dentsply De Trey GmbH, Konstanz, Germany) (). After verifying that the root canal filling was complete with a radiograph, the crown was restored with a composite resin (Gradia PA2, GC, Alsip, IL, USA). At six month examination, the tooth was asymptomatic and there was no radiolucency around the root apex ().