An abscess is pus that collects in a small, contained space within the body. It occurs as a result of a bacterial infection, when inflamed tissues secrete fluid (pus) that consists of bacteria, white blood cells and cellular debris. If this pus is unable to drain from the area, it pools and forms an abscess.

Abscesses can occur anywhere in the body, including the mouth. Dental abscesses may occur at the tip of a tooth’s root or in the area between the teeth and gums. An abscess may develop at any age after the teeth have erupted.

A tooth abscess may develop after bacteria gains access to the pulp (the innermost, living core of the tooth), causing an infection inside the tooth. Bacteria can reach the pulp through a crack or decay in tooth enamel. If this infection goes untreated (the diseased tissue in the pulp is not removed) pus can begin to build up in the root of the tooth, near the jawbone, forming an abscess.

The infection can spread into the ligaments that secure the tooth to the jawbone and to the jawbone itself. When infection occurs in the bone surrounding teeth, bone loss may occur. This causes teeth to become loose and may lead to tooth loss.   

An abscess can form in the gums when food and bacteria gather in deep pockets of space between the teeth and gums. These pockets usually appear in people with periodontal disease (when the gums pull away from the teeth). When food or other debris remain embedded deep in the gums, bacteria can grow, and an abscess may form. In addition, an untreated abscess may cause scar tissue to develop, which can result in a fistula (tunnel in tissue) for drainage.

Most dental abscesses cause considerable pain. It is important to consult a dentist immediately if a dental abscess is suspected. The abscess will not heal itself – it requires treatment.