A 24-year-old woman came to a dentist to receive sanation. Objectively on the masticatory surface of the 37 tooth there is a deep carious cavity connected with the dental cavity. The cavity probing is painless, no reaction to thermal stimuli is observed in the tooth, percussion is painless. EOD is 108 microamperes. X-ray shows traces of filling material in the rooth canal of the 37 tooth, periodontal fissure is enlarged and deformed. Make the diagnosis: