A dental abscess is a pus pocket associated with a specific damaged tooth. There are five types, though most instances are either periapical abscess or a periodontal abscess.

Your teeth are made up of a hard white protective layer, the enamel,which covers and protects a softer yellow tissue, called dentin.At the very centre of the tooth is the soft pulp, where blood vessels and nerves are found. Your tooth is connected to the jaw by very strong fibres which are together called the periodontal ligaments. Dental plaque is a soft sticky film made up mainly of bacteria which forms on the teeth and is present in all mouths. Plaque bacteria convert sugars from the diet to produce acids which softens the tooth surface, starting the process of tooth decay. Holes in the enamel may then develop, that if neglected, eventually reach the centre of the tooth. When the bacteria reach the tooth pulp, white blood cells pour into the affected area and pus forms producing an abscess in the tooth. If this is not drained, the abscess will affect the bone around the root.

Symptoms & Treatment

Abscesses can be extremely painful or painless. Pain can be sharp, dual, shooting or throbbing and impossible to touch. It can extend beyond the actual infection into surround cheek and gums. If there is no pain, swelling can still be a problem. Heat will only inflame the boil, but cold compresses to the cheek and jaw can ease some pain. If the abscess is seated deeply into the bone, it can drain into the surrounding tissue, creating excessive swelling in the face or lymph glands in the neck. Migraines can also happen as the pain spreads. The first action is to eliminate the bacterial infection. This can be done by opening and draining the sore or with antibiotics. The next step depends on whether the tooth can be salvaged. If so, a root canal therapy can be performed. If not, the tooth needs to be removed and the offending or damage tissue removed.

Types

Periapical abscess: The outcome of a prolonged infection at the very tip of a tooth root. It is treated by drainage through the tooth; in addition it may require treatment with antibiotics. A permanent root filling is pertained at a later stage to prevent further infection. 

Periodontal abscess: Begins in the soft tissues that surround and support a live tooth.It is usually associated with gum disease,when the gums become inflamed and separate from the tooth allowing bacteria to collect in the pocket surrounding the tooth root. Periodontal abscess is initially treated by deep cleaning of the pocket allowing drainage of the pus. Surgery is sometimes needed at a later date to reshape the gums. If left untreated, tooth may also be extracted as a result of a dental abscess. In addition, the bacteria from the dental abscess can spread to other areas including through the nearby bone and into the air filled spaces behind the cheek bones.Infections that spread very wildly within the head and neck can be life threatening but are very rare. 

Gingival abscess: Only ails the gum tissue and doesn’t infect the tooth or ligaments that connect it to its socket.

Pericoronal abscess: Results from an infected crown in a tooth.

Combined periodontic-endodontic abscess: The joining of a tooth-tip and gum infection. 

Treatment

The first line of treatment is to remove the bacterial products from the site. Dentists achieve this by making an opening and draining the pus from the swelling. Patient is prescribed antibiotics. After thorough examination dentist decides if tooth can be saved or not by root canal therapy. If RCT is not useful, tooth may need to be extracted along with the damaged tissues.