Root canal (also called root canal treatment or endodontic therapy) is a dental procedure to treat infection or inflammation inside a tooth, specifically involving the pulp—the soft inner tissue containing nerves, blood vessels, and connective tissue within the tooth’s root canals. It becomes necessary when the pulp is irreversibly damaged or infected, most often due to deep decay, repeated dental procedures, cracked or fractured teeth, trauma, or faulty crowns, allowing bacteria to enter and cause abscesses, severe pain, or swelling. The condition presents as intense, throbbing toothache (often worse with hot/cold/sweet stimuli or biting), sensitivity to temperature, swelling in the gums or face, tenderness in nearby lymph nodes, or a persistent bad taste/pus drainage; in some cases, it may be painless if the nerve has died. Untreated, it can lead to spread of infection to surrounding bone or systemic issues.