Methods (differential diagnosis, investigations, and treatment method)
Local anesthesia was achieved by a mandibular nerve block with 2% lidocaine and epinephrine 1:100,000 (Daroupakhsh, Tehran, Iran). After isolation with rubber dam, the Caries was removed and Access Cavity was achieved with high‐speed diamond round bur number 2 (Jota AG,Rüthi , Switzerland) and continuous water spray under a dental operating microscope (Zumax Medical Co., Suzhou New District, China). Working length was determined as 23 mm by an electronic apex locator (Dempex, DEM Ltd., Barnstaple, Devon, England), which was confirmed radiographically (Figure 3.B). The glide path was obtained using the rotary path files numbers 13, 16, and 19 with a 2% taper (M3, Changzhou, China) throughout the working length. Root canal were chemomechanically prepared by crown‐down technique with M3 rotary files (UDG, Changzhou, China) up to size 25/04 under copious irrigation with 5.25% sodium hypochlorite. After taking cone‐fitting confirmation radiograph (Figure 3.C), The irrigation of root canal system process followed the protocol described in Case 1. the root canal were dried with sterile paper points (META, Chugbuk, South Korea) and obturated with gutta‐percha (META, Chugbuk, South Korea) and AH plus sealer (Dentsply DeTrey, Konstanz, Germany) using warm vertical technique by FastFill warm obturator (Fast Fill Obturation System, Eighteeth, china). Cavit (Cavisol, Tehran, Iran) was applied as a temporary restoration (Figure 3.D) and the patient was referred for permanent restoration.