Figure Mandibular right first molar: A) initial radiograph, extensive mesial caries, widening of PDL, double curvature (Bull’s eye view); B) working length determination; C) cone fit confirmation; D) final radiograph, obturation, apical seal, temporary restoration; E) 8-month follow-up, coronal seal

Case 3

A 41-year-old woman, systematically healthy, was referred to the endodontics department of the faculty due to the separation of the file in the mesiobuccal canal of the mandible right first molar. The broken file was retrieved by examining the radiograph with the help of ultrasonic tips and the loop technique (Kamand, Suzhou, Zumax). The framed material of the orifice shaper separated at the radix and the broken file was bypassed using C-files #8,10,15 (VDW, Munich, Germany). (Figure 5). After the bypass, shaping, and instrumentation of the channels were done as described previously. The ethylene diamine tetraacetic acid (EDTA) 17% (Master-dent, monroe, USA) irrigation was the only deference. normal saline was used for final irrigation (Figure 6). Follow-up was done 9 months later and the patient reported no pain or discomfort. Observing and examining the radiograph also showed the success of the treatment process (Figure 6D) <Figures 5 & 6>.