Methods (differential diagnosis, investigations, and treatment method)
Upon obtaining informed consent, the treatment plan started with the administration of local anesthesia using a buccal infiltration of 1.8 ml of 2% lidocaine with 1:100000 epinephrine (Daroupakhsh, Tehran, Iran). A rubber dam was placed to ensure an aseptic environment. The access cavity was prepared using a high-speed diamond round bur No. 2 (Jota AG, Rüthi, Switzerland) under continuous water spray, aided by a dental operating microscope (Carl Zeiss, Meditec Inc., Dublin, CA, USA). The access cavity was refined with a diamond fissure bur No. 2 (Jota AG, Rüthi, Switzerland). Frequent irrigation with sodium hypochlorite and saline enlarged the pulp chamber .Two canal orifices were identified and explored with a #15 C-file (VDW, Munich, Germany). Coronal preflaring was achieved using an SX instrument (M3, Changzhou, China). The working length was determined using an apex locator (Root ZX, J. Morita, Japan) and confirmed radiographically.The glide path was manually obtained using C-pilot (VDW, Munich, Germany) numbers 6, 8, and 10, followed by the use of rotary path files numbers 13, 16, and 19 with a 2% taper (M3, Changzhou, China) throughout the working length.The SP1 gold rotary system was utilized, with the S1 rotary file (UDG, Changzhou, China) reaching the working length through a picking motion. Subsequently, the canals were shaped using the M3 rotary system up to size 25/04. The canals were irrigated with 20ml of 5.25% NaOCl and normal saline throughout the instrumentation process.the activation of sodium hypochlorite in the root canal was performed using sonic activation (SI) with Endoactivator system (Dentsply Tulsa Dental Specialties) for 30 seconds per canal. The final irrigation of the root canal system was performed using 17% EDTA. Master cone of size 25/04% for the buccal canal and 30/04% for the palatal canal were selected (Figure 1. B).The canals were thoroughly dried with sterile paper points (META, Chungbuk, South Korea), and obturation was completed using Gutta-percha (META, Chungbuk, South Korea) and AH-plus sealer (Dentsply DeTrey, Konstanz, Germany) using the warm vertical technique by FastPackand and FastFill (Eighteeth, china) warm obturator. Finally, Cavit (Cavisol, Tehran, Iran) was applied as a temporary restoration (Figure 1. C).