An abscess is an area of pus that forms as part of the body's effort to fight a bacterial infection. The immune system sends white blood cells to the area to try to get rid of the bacteria. Pus contains both live and dead cells. It also contains enzymes. An abscess forms when there is no way for pus to drain.
Abscesses can form in almost any part of the body. In the mouth, abscesses form in the gums, teeth or roots of teeth. Bacteria can enter and cause an abscess in several ways:
- Through trauma (food or debris embedded deep in the gum)
- Through decay (a cavity) that leads into the tooth nerve and blood vessel (dental pulp)
- Through a deep gap (pocket) between the teeth and gums, in someone with gum (periodontal) disease
People with a lowered resistance to infection have an increased risk of developing an abscess.
At first, an abscess may cause a toothache, which can be severe. The tooth's nerve also can become infected. If the infection burrows through to the gum, it can form a visible swelling (boil). Once the boil breaks open, the pain often gets much better. However, dental treatment is still needed.
If the abscess does not drain, the infection can spread to other areas of the head and neck. In this case, it can become life-threatening.
The main symptom is throbbing pain that won't go away. At first, the tooth will be sensitive to heat and pressure from chewing. Later, you may develop a fever. Lymph nodes under the jaw or in the neck may swell and become tender. You also may feel pain in the sinus area. If the abscess breaks open, a sudden rush of foul-smelling and foul-tasting fluid will spill into your mouth.
Usually, your dentist can diagnose a tooth abscess by examining your mouth. He or she may push on the swollen area of the gum. The dentist also may do a nerve (pulp) test on the affected tooth to see if it is still alive. A pulp test can involve:
- Gentle tapping on the tooth
- Temperature testing
- Using an electric tester
Your dentist also will take an X-ray to look for loss of bone around the tip of the tooth's root. The empty space where bone has been lost looks dark on an X-ray.
Once the abscess is drained, most symptoms go away quickly or within a few days. However, the abscess will not be cured unless the cause is eliminated.
Good oral hygiene can help prevent abscesses. This means that you need to keep teeth and gums free of food. Regular dental checkups are also important. Teeth that have decay (cavities) can be treated before they become painful, infected or abscessed. If you have a weakened immune system because of a medicine you are taking or a health condition, let your dentist know before every appointment. You may receive antibiotics before the appointment to reduce the risk of infection.
Saving an abscessed tooth begins with draining the infection. If the soft tissue is swollen and soft to the touch, it will be pierced to allow drainage of the infection (pus). The tooth then will need to be opened up. The dentist will remove the nerve and any infected pulp inside the canals in the tooth's root or roots. After this step, the dentist will need to fill the canal. Various materials may be used. Common ones include gutta percha, a rubber-like material, and resilon, a synthetic resin-based sealer. This procedure is called root canal treatment.
If there is no swelling, the infection can be drained directly from the inside of the tooth using root canal treatment.
Treatment to remove diseased tissue should be started as soon as possible. If the abscessed tooth cannot be saved, it should be removed (extracted). This removes the source of the infection and allows the jawbone and gums to heal.
If the abscess is in the gums, your dentist may suggest that you rinse with warm salt water a few times a day for several days. The usual formula is to mix one-eighth of a teaspoon of salt in 8 ounces of water.
You may be prescribed antibiotics to help kill the infection.
You should have dental X-rays six months later. This can show whether healthy bone and tissue are filling the area of the abscess. If the bone does not fill in after the treatment, you may need to visit a specialist. An endodontist or oral surgeon can surgically remove a persistent abscess.
If you have a toothache or notice evidence of an abscess on your gum, visit your dentist. Even if the abscess drains and the pain decreases, a visit to the dentist for complete treatment is crucial. Old abscesses that are not painful can become painful and swollen again at any time.
The outlook is excellent if the abscess is found promptly and you get the right treatment.