Most abscesses in the roots of teeth cannot be eliminated on their own. An abscess in the root is usually a sign of chronic periapical infection and should be treated promptly to prevent its further development. The most common cause of periapical infection is the spread of infectious material within the root canal through the apical foramen of the root into the periapical tissue, causing a bacterial infection that usually does not heal on its own without treatment. The disease is mainly caused by bacteria in the necrotic pulp tissue within the root. If the infected necrotic pulp tissue is not removed, the source of infection will always be present, and even if the acute symptoms of periapical infection are eliminated by taking anti-inflammatory drugs, the remaining bacteria will still proliferate and develop, leading to the formation of periapical infection again.