What Is a Tooth Abscess?

A tooth abscess is a pus-filled sac that forms in the tissues surrounding a tooth’s root. It usually occurs when bacteria penetrate the hard outer layers of a tooth and spread to the pulp (the blood vessels and nerves that make up the soft core of each tooth), causing the pulp to die.

The body’s white blood cells’ response to bacteria and dead pulp tissue results in pus accumulation, which may spread to the surrounding tissue at the root end and cause a painful abscess. Left untreated, the abscess may erode a channel through the jawbone to the gum or the skin of the face or neck, forming a boil. The boil may eventually burst, relieving pain.

The abscess may also cause swelling in the side of the face or in the neck, severe pain, difficulty opening the mouth and fever. Severe, untreated abscess-related jaw infections may extend beyond the jaw to involve important structures in the head and neck or more distant sites.

What Causes Tooth Abscess?

  • The most common cause is tooth decay.
  • An abscess may result when gingivitis or periodontitis goes unchecked.
  • An abscess may develop after injury to a tooth.
  • Occasionally, tooth pulp dies spontaneously for no apparent reason, resulting in abscess formation.

Symptoms of Tooth Abscess

  • Persistent aching or throbbing in the affected tooth. Severe pain when biting or chewing
  • Difficulty opening the mouth or swallowing
  • Tooth discoloration
  • Sensitivity to hot or cold foods and drinks
  • Tenderness, redness or swelling in the gum around the affected tooth
  • A foul taste in the mouth if the abscess forms a boil and bursts
  • Bad breath or foul taste in mouth
  • Swelling and tenderness of the lymph nodes along the side of the face
  • Fever and general malaise
  • Open, draining sore on the gums

Tooth Abscess Prevention

  • Practice careful oral hygiene including brushing teeth at least twice a day and daily flossing between teeth and gums. See a dentist at least once a year.
  • Have decay treated promptly.
  • Undergo root canal treatment or extraction of the infected tooth before an abscess can form.

Tooth Abscess Diagnosis

  • Dental examination and x-rays.

How to Treat Tooth Abscess

  • Rinse with warm salt water to ease pain until you can see a dentist.
  • An over-the-counter pain reliever can help reduce discomfort. Stronger analgesics may be prescribed.
  • The dentist may drill a small hole through the crown of the infected tooth into the pulp, to release the pus. The pulp cavity and root canals are cleaned out and disinfected (root canal procedure). After the infection has subsided, the cavity is filled and the tooth is fitted with a crown. (Severe infection must be drained surgically to prevent the spread of infection beyond the jaw.)
  • If the tooth cannot be saved, it will be extracted.
  • Antibiotics may be given to fight infection.

When to Call a Doctor

  • The pain of a tooth abscess usually prompts a visit to the dentist as soon as possible. But if pain eases as an abscessed boil bursts or if swelling has spread to the face or neck, see a dentist immediately.


Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference

Simeon Margolis, M.D., Ph.D., Medical Editor

Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at HealthCommunities.com

Published: 04 Oct 2011

Last Modified: 09 Mar 2015