To confirm the diagnosis of pulpitis, the original filling of the treated tooth is removed and the root filling is also removed, and the root canal is probed with specialized dental instruments. If the tooth is painful and the pain disappears after root canal treatment, the diagnosis is basically confirmed. If there is a missing root canal and there is pain from hot and cold acid irritation, biting pain and spontaneous pain, the tooth can be diagnosed as having residual pulpitis. Pulpitis requires root canal treatment to completely cure the pulpitis.