What dental procedure is used to fix a toothache?

It varies. Your tooth ache may be caused by an infection in the tooth or gums, or a fracture, or a cavity, or trauma to the tooth. You need to see your dentist to find out the cause so that they can develop a plan to fix the issue.
Depends. It really depends on the cause of the pain. You must visit your dentist to find out the cause of this toothache.
Toothache. If the toothache is due to the nerve of the tooth then the treatment of choice is root canal therapy. However, if the pain is due to tooth fracture and periodontal abscess then the treatment is either extraction (in case of cracked tooth syndrome) of periodontal surgery (in case of periodontal abscess).