A 20-year-old man complains of spontaneous pain attacks (5-7 minutes) in the area of 36 that occur for the last 24 hours. Objectively in 36 there is a deep carious cavity on the masticatory surface. Probing is painful at one point, response to cold stimulus is painful, with an aftereffect that lasts for 5 minutes. Percussion is painless. X-ray shows root canals to be slightly curved, canal lumen is clearly visible. The tooth is planned to be used as an abutment for a dental bridge. What is the optimal treatment method in this case?