A tooth abscess is a collection of pus in the center of a tooth. It is treated with antibiotics, pain-relieving measures, and in some cases a root canal.
The pus in a tooth abscess collects because there is a bacterial infection in the tooth. Your immune system fights the infection by sending out white blood cells to attack and kill the bacteria. The abscess ends up being a "melting pot" for those blood cells, the live and dead bacteria, and dead tooth tissue.
Treatment can help save the tooth, reduce pain, and prevent life-threatening complications. Antibiotics are used to destroy the bacteria. To help the pain, the doctor may suggest salt-water rinses and pain relievers such as acetaminophen or ibuprofen. In cases where the infection has spread to the root of the tooth, a root canal may be a way to save the tooth. In cases of serious infection, the tooth may have to be removed. Surgery may be needed to drain the pus from the abscess and to prevent life-threatening complications such as a spread of the infection to the brain, heart, or lungs.