Retrieval of a separated nickel-titanium instrument using a modified 18-guage needle and cyanoacrylate glue: a case report
An 18-year old girl reported to the Department of Conservative Dentistry & Endodontics with pain in her right mandibular first molar (#46). On examination a carious exposure was found in the tooth #46. The tooth showed a negative response to electric pulp testing (EPT) and cold testing. The intra-oral periapical (IOPA) radiograph also revealed slight periapical changes in relation to tooth #46. Therefore a diagnosis of pulp necrosis was made and endodontic treatment was started in tooth #46. The access opening was made and the canals were located and the working length was established with size 20 K stainless steelhand files (Dentsply Maillefer, Ballaigues, Switzerland). During the cleaning and shaping procedures for coronal shaping, a ProTaper shaper SX (Dentsply Maillefer) separated in the mesiolingual canal of the tooth.\nOn taking the radiograph the separated instrument fragment was found within the coronal portion of the canal (). The fragment was well past the orifice of the canal and far enough to be removed by forceps. Removal of the fragment was attempted with various small forceps and pliers but without success, as a sufficient grip of the fragment could not be established. Ultrasonic scaler was also used but the instrument could not be loosened probably because it was locked within the dentinal wall of the root canal. Therefore an alternative method to retrieve the instrument fragment was used as follows:\nGates Glidden drill (GG No.3) was used to remove dentine surrounding the coronal end of the separated fragment (). An 18-guage needle was modified by cutting it with a carborandum disc from the tip to transform it into a microtube (). The modified needle microtube was then inserted into the canal so that it engulfed the coronal end of the separated fragment. Some cyanoacrylate glue was dropped into the microtube and then the tube was placed again into the canal engulfing the coronal end of the separated fragment. The outside of the tube was coated with petroleum jelly. The modified needle microtube was kept in place without disturbance for about three minutes to ensure proper adhesion of the separated fragment with the microtube. The separated fragment adhered to the microtube was then removed as a single unit by giving slight counterclockwise rotation and simultaneous pull out motion (). A confirmatory radiograph was taken and the working length was then reconfirmed (). The cleaning and shaping was completed and the tooth was obturated with laterally condensed gutta-percha and zinc oxide-eugenol based sealer (). The tooth stays in normal function two years after the endodontic treatment ().