Retrieval of a metallic obstruction from the root canal of a premolar using Masserann technique
A 55-year-old male patient, who reported for endodontic retreatment, required the management of a metallic obstruction found in the root canal of tooth 34 (left mandibular first premolar) to facilitate retreatment in the same tooth. Periapical radiographic examination of tooth 34 showed the metallic obstruction, which was suspected to be separated instrument, in the middle-third of the root canal with a poor Gutta-percha obturation extending only up to the obstruction. Furthermore, the root outline of tooth 34 revealed the possibility of an anatomical variation in the form of an additional root or a canal []. In the treatment plan, a decision was taken to negotiate the obstruction and explore the possibility of an additional canal in tooth 34. The gutta-percha obturation was removed using Xylene (Merck specialties, Mumbai, India) and H-files (Dentsply Maillefer, Ballaigues, Switzerland). Bypassing of the obstruction was attempted using size 08 and size 10 K-files (Dentsply Maillefer). However, bypassing failed as the obstruction was found tightly wedged into the root canal dentin and it was decided to retrieve the metallic obstruction by using a Masserann Kit (Micro Mega, Besancon, France).\nThe coronal access in tooth 34 was refined using diamond points (Shofu Preparation Kit, Japan). Radicular access to the obstruction was straightened by the sequential use of gates-glidden drills (Mani Inc., Japan). Since the size of the obstruction was not known, end cutting trephan having an appropriate diameter was selected by superimposing it over the obstruction on the radiograph. The trephan was run at slow speed in anticlockwise direction to cut the radicular dentin around the obstruction. The apical advancement of the trephan was radiographically monitored []. When coronal portion of the obstruction was freed from the dentin, extractor tube of 1.2 mm diameter was guided into the canal to encircle and grip the obstruction. The encirclement of the obstruction by the extractor tube was radiographically confirmed [] and the plunger rod of the tube was rotated in a clockwise direction to snugly grip the obstruction against the wall of the extractor tube. Following the confirmation of gripping the obstruction using tactile sense, the extractor tube was gently turned in back and forth motions to loosen and retrieve the obstruction from the canal. Retrieval of the obstruction from the canal of tooth 34 was radiographically confirmed []. Closer observation of the obstruction revealed that it was the fragment of a separated H-file [].\nA ledge was detected apical to the site of obstruction in tooth 34 following the retrieval of the obstruction. The ledge was negotiated using size 10 K-file. Further exploration of the pulp space revealed the presence of an additional canal. Following canal negotiation, working length was determined using the apex locator (Propex, Dentsply Maillefer) and radiographs []. Canals were shaped and cleaned in a crown down manner using NiTi files (ProTaper, Dentsply Maillefer). Irrigation was carried out using 2.5% sodium hypochlorite and 2% of chlorohexidine. Calcium hydroxide (Calcicur, VOCO, Germany) was used as an intracanal medicament.\nIn the subsequent visit, canals of tooth 34 were obturated using Gutta-percha points (ProTaper, Dentsply Maillefer), sealer (AH-plus, Dentsply Maillefer) and lateral compaction method. The access opening was restored with silver amalgam [] and the patient was suggested to undergo post endodontic treatment.