(Dental Abscess; Abscessed Tooth)
A tooth abscess is a sac of infected material called pus in a tooth or the gums.
Abscess Between Tooth and Gum
Copyright © Nucleus Medical Media, Inc.
A tooth abscess is caused by bacteria. It begins when bacteria invade and infect a tooth. This results in pus build-up. When the pus is unable to drain, an abscess results.
Conditions that allow bacteria to invade a tooth include:
- Severe tooth decay
- Break or crack in a tooth that lets bacteria invade the pulp
- Failed root canal treatment
Factors that may increase your chance of a tooth abscess include:
- Build up of tartar or calculus beneath the gum line
- Poor dental hygiene leading to cavities and periodontal diseases
A tooth abscess may cause:
- Throbbing/lingering pain in a tooth or gum area
- Pain when biting
- Pain from hot or cold
- Sudden tooth pain
- Redness, tenderness, or swelling of the gums
- Bad breath or foul taste in mouth
- Open, draining sore on the gums
If left untreated, complications of tooth abscess include:
- Loss of tooth and surrounding tissues or bone
- Spread of infection to surrounding tissue or bone
Your dentist will ask about your symptoms and medical history. A detailed exam of your teeth and gums will be done.
Images may need to be taken of the tooth and surrounding bone. This can be done with x-rays.
A sample of the abscess fluid may be taken and tested.
Removal of Abscess Via Root Canal
If an abscess results from tooth decay or a break or crack in the tooth:
- The tooth and surrounding tissue is numbed and a hole is drilled through the top of the tooth.
- Pus and dead tissue are removed from the center of the tooth.
- The interior of the tooth and the root canals are cleaned and filled with a permanent filling.
- A crown is placed on the tooth to protect it.
If an abscess results from infection between the tooth and gum:
- The abscess is drained and thoroughly cleaned.
- The root surface of tooth is cleaned and smoothed.
- In some cases, surgery to reshape the gum is done to prevent a repeat infection.
Tooth Extraction (Removal)
- Tooth extraction may be required if:
- Tooth decay and/or tooth infection is too extensive for filling or root canal treatment.
- The break or crack in the tooth is too severe to be repaired.
- The infection or loss of tissue/bone between the tooth and gum is severe.
If the tooth is extracted, it will be replaced with a:
- Partial bridge
- Tooth implant
- Antibiotics to fight residual infection of the tooth or gums
- Over-the-counter pain relief drugs, such as ibuprofen or acetaminophen
To help reduce your chance a tooth abscess:
- Brush your teeth with fluoride toothpaste after meals or at least twice per day.
- Floss between your teeth and gums every day.
- Get regular dental check-ups and teeth and gum cleanings every 6 months.
Mouth Healthy—American Dental Association http://www.mouthhealthy.org
The Canadian Dental Hygienists Association http://www.cdha.ca
Accessed March 18, 2013.
Beers MH, Fletcher AJ. The Merck Manual of Medical Information—Home Edition. New York, NY: Simon and Schuster, Inc.; 2000.
Dental abscess. NHSinform website. Available at:
Updated October 4, 2011. Accessed March 18, 2013.
Root canals. American Dental Association Mouth Healthy website. Available at:
Accessed March 18, 2013.
Last Updated: 9/30/2013