Diseases & Conditions

Abscessed Tooth - Tooth Abscess

Overview, Causes, & Risk Factors

When a tooth becomes infected is is called an abscessed tooth. Pus collects in a pocket that forms in the bone at the end of the root. An abscess almost always begins in the central or pulp area of the tooth and spreads into the surrounding bone.

What is going on in the body?

When the nerve and blood vessels inside the tooth pulp begin to decay, it causes the cells to die. The area then becomes infected with bacteria that break down the healthy tissue forming pus. An abscessed tooth usually starts with a deep cavity or caries. Left untreated the cavity can extend into the tooth pulp. The pus that collects in the center of the tooth eventually spreads to the bone tissue at the end of the root. Most of the time, this causes a toothache and soreness in that part of the mouth. Even though the toothache may come and go,the abscess will remain until it is treated.

Second to tooth decay, trauma is the most common cause of tooth abscess. This can consist of a hard blow to the tooth or a fracture from biting on a hard object. Tooth trauma is a much less common cause of tooth abscess than tooth decay.

What are the causes and risks of the infection?

Tooth abscess occurs when decay attacks the central area of the tooth pulp. This can be avoided by treating cavities when they are small. Once a tooth abscess forms, treatment is always necessary to stop the process. Root canal therapy can sometimes save the tooth.

Symptoms & Signs

What are the signs and symptoms of the infection?

Symptoms of an abscessed tooth include:

  • tooth sensitivity to heat or cold
  • tooth soreness that may come and go
  • mild toothache
  • severe toothache that may throb
  • increased pain when lying down
  • tooth soreness or pain when chewing
  • bad taste or bad mouth odor
  • possible fever
  • swelling around tooth or in jaw
  • pus drainage in mouth
  • swollen glands
  • loss of appetite
  • sleeplessness
  • general sick feeling

  • Diagnosis & Tests

    How is the infection diagnosed?

    A dentist can diagnose a tooth abscess by examining the tooth, reviewing the symptoms, and looking at the X-rays. If a tooth becomes sensitive to heat or cold, a dentist may be able to prevent a tooth abscess by treating the problem at an early stage.

    Prevention & Expectations

    What can be done to prevent the infection?

    Tooth abscess can be avoided by treating cavities early. Good brushing and flossing habits, regular dental check ups, and avoiding excessive amounts of sugary or starchy foods also help prevent tooth abscess.

    What are the long-term effects of the infection?

    Left untreated a tooth abscess can lead to general infection in the body. With prompt treatment, the tooth may be saved and serious complications from infection can be prevented.

    The following can happen when a tooth abscess is not treated properly:

  • loss of the tooth
  • spread of the infection to other parts of the jaw
  • spread of infection to other parts of the body

  • Treatment & Monitoring

    What are the treatments for the infection?

    There are two basic treatments for a tooth abscess. Root canal therapy can get rid of the infection and save the tooth in most cases. In root canal therapy, the infected tissue in the central part of the tooth pulp is removed. The area is then sealed to prevent continued infection. Surgery to remove the infected material from the bony tissue around the root is sometimes needed. The tooth itself may need to be repaired with a crown after root canal therapy.

    If root canal therapy is not successful, the tooth usually has to be pulled. Antibiotics alone will help symptoms only temporarily. A tooth abscess cannot be permanently cured without root canal therapy or the removal of the tooth.

    What happens after treatment for the infection?

    If root canal therapy is successful and the tooth is properly repaired afterward, it can last indefinitely. Removing the tooth before the infection has spread to the rest of the body also solves the problem.


    Author:Marvin Goldfogel, DDS
    Date Written:
    Editor:Cafiero, Celeste, MA
    Edit Date:05/26/00
    Reviewer:Daniel C. Pizzi, DMD
    Date Reviewed:04/20/01