abscess /ab″səs/ [L, abscedere, to go away] , 1. a cavity containing pus and surrounded by inflamed tissue, formed as a result of suppuration in a localized infection, characteristically caused by staphylococci but also caused by parasites and foreign substances. Healing usually occurs when an abscess drains, is incised, or is permanently removed from the body. If an abscess is deep in tissue, drainage is done by means of a sinus tract that connects it to the surface. In a sterile abscess, the contents are not the result of pyogenic bacteria. Abscesses are able to form in almost any location on or within the body. Abscess formation can cause redness, pain, warmth, and swelling. 2. an abscess that develops anywhere along the root length of a tooth. It is usually characterized by pain caused by the pressure of pus against the nerve tissue within the tooth or within the periodontal tissues, redness caused by blood accumulation, and swelling caused by the suppuration. The source of the bacteria that causes the infection is the normal oral flora. See also periapical abscess.
