Periapical Abscess

A periapical abscess is a collection of pus, usually from an infection that has spread from a tooth to the surrounding tissues.

The body attacks an infection with large numbers of white blood cells; pus is the accumulation of these white blood cells, dead tissue, and bacteria. Usually, pus from a tooth infection drains into the gums first, so the gums swell near the root of the tooth. Depending on the location of the tooth, the pus may drain into soft tissues (cellulitis), causing swelling in the jaw, or drain to the floor of the mouth, in the area of the cheeks, or even to the skin.

A dentist treats an abscess or cellulitis by eliminating the infection and draining the pus, which requires oral surgery or root canal treatment. Dentists often prescribe antibiotics to help eliminate the infection, but removing the diseased pulp and draining the pus are more important.