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Dental Abscess

  1. What is a dental abscess?
  2. Symptoms
  3. Diagnosis
  4. Treatment
  5. FAQs

What is a dental abscess?

An abscess is a pocket of pus that forms within body tissues. Abscesses are the result of an infection, usually one localised in the area where the abscess forms. They are almost always accompanied by swelling and inflammation. Dental abscesses are abscesses affecting the teeth and adjacent jaw tissue. Abscesses result from a bacterial infection, which causes a collection of pus.[1]

Each tooth is made up of several layers. The outermost layer is the enamel which covers a softer layer, the dentin. Dentin and enamel are the tooth’s protective layers. Underneath the dentin is the pulp, where the tooth’s nerves and blood vessels are situated. The pulp runs down the center of the root of the tooth, which connects the tooth to the underlying bone of the upper or lower jaw. Infections in the pulp can therefore easily spread into the bone of the jaw. Likewise, if the gum around the tooth becomes infected, the tooth is at risk of damage as well. Some abscesses affect the pulp first and spread to the bone, while others affect the surrounding tissues of the gum and do not start in the pulp.

In abscesses, the presence of plaque[2] and gingivitis[3] are likely to make the situation worse. Antibiotics are sometimes necessary to control the infection.[4] If treated correctly, dental abscesses are not life-threatening. Treatment often involves antibiotics and root canal treatment. In rare cases, however, the infection can spread, and the condition may become very severe and possibly life-threatening in extremely rare cases.[5]

There are two major subtypes of dental abscess: periapical and periodontal.

Good to know: A third type, pericoronitis, is much less common. In pericoronitis, the infection affects the gum flap, known as the operculum which covers a tooth that has not yet erupted through the gum. This article deals with periapical and periodontal abscesses. For more information on pericoronitis, please see the FAQs.

Periapical abscess

Periapical abscesses usually occur near the tip of the root of the tooth. They are more common among children than among adults. Children with poor dental hygiene are particularly at risk of periapical abscesses.[5]

Poor dental hygiene causes caries, also known as cavities, which erode the enamel and dentin, admitting bacteria to the pulp. As a result of this, the pulp becomes inflamed, and this can lead to the death of nerves in the tooth. Because dead tissue is more vulnerable to infection, this puts the tooth at high risk of an abscess.[1]

In periapical abscesses, damage to the enamel and dentin like in the case of later stage cavities admits bacteria to the pulp, leading to an inflammatory condition known as pulpitis. Periapical abscesses are a common complication of severe, long-term pulpitis.[6] They can cause swelling in the jaw, cheeks and the floor of the mouth.[2]

Treatment for dental abscesses involves draining the pus from the tooth and filling or removing the tooth to prevent re-infection.

Periodontal abscess

Periodontal abscesses are more common among adults than children and are often a complication of gum disease.[1] They tend to originate in the alveolar bone[7] and periodontium.[8] Gum disease or injury can cause teeth to become loose and/or inflamed, including the surrounding area. The resulting pocket that forms between the tissue and the tooth is vulnerable to infection by bacteria which can then form a periodontal abscess.[1]

Symptoms of a dental abscesses

Dental abscesses are usually painful. The pain may be situated in the tooth itself, the surrounding gum or be more generalized, including the jaw, cheeks, or even neck or face, depending on the location of the abscess.[1] The affected tooth may feel tender, loose in the jaw, sensitive to heat and/or cold in the mouth and pressure on the tooth, or to being tapped,[5] and/or slightly raised.[6] The Ada app can help you check your symptoms. Download the free app or find out more about how it works.

Some other symptoms of dental abscesses are:[1][5]

  • Swelling in the gums or face
  • Redness of the skin over the affected part of the gum
  • Bleeding in the gums
  • Swollen lymph glands in the neck
  • Generally feeling unwell (malaise)
  • Loss of appetite or inability to eat
  • Fever

Dental examination may also reveal swelling and redness around the tooth in the mouth and a fluctuant (movable/shiftable) mass[9] in the area. Periodontal abscesses may also present with a gum boil. A gum boil, also known as a parulis, is a soft red papule that appears where a sinus or channel from an abscess reaches the outside of the gum, between the gum and the inside of the cheek. It is the result of an abscess, so it is a definite sign that an abscess is present, but it is not itself an abscess.

In severe, rare cases of dental abscess, the affected person may also experience:[5]

  • Cellulitis, a bacterial infection of skin and subcutaneous tissues
  • Lockjaw (trismus)
  • Difficulty swallowing
  • Difficulty breathing
  • Difficulty speaking
  • Dehydration

Generally, a spreading dental infection as a result of an abscess may cause the affected person to feel very unwell. They may have a fever (a body temperature of 100.4 F or higher), swelling in the floor of the mouth, the face or the jaw and severe pain that does not respond to maximum doses of over-the-counter painkillers.

If any of these symptoms occur, the affected person should seek emergency dental care or, if no dental care is available, visit a hospital emergency department. While doctors are not trained to handle dental procedures, they will be able to assist with antibiotics and painkillers to control the infection and pain until dental care is accessed.

Diagnosis of dental abscesses

If a dental abscess is suspected, the affected person should visit the dentist as soon as possible. The dentist will perform an examination of the affected area. They may test the affected tooth by pressing on it or tapping it with an instrument.[6] If the tooth is infected, it will be very sensitive to pressure or tapping (percussion). Further, if the abscess is periapical, the swelling at the root will push the tooth upwards in its socket, and it will feel higher than the surrounding teeth.

While laboratory testing is not usually needed to establish whether or not an abscess is present, dentists will usually do an X-ray of the affected tooth and the mouth as a whole to establish the exact location and the size of the abscess.[5]

The abscess may be aspirated[10] and the pus cultured to determine which strains of bacteria are involved. This helps to guide antibiotic therapy if it is needed.[5]

Treatment of dental abscesses

The usual treatment for a dental abscess is to drain pus as soon as it is possible to do so. This will be done surgically, either by a dentist or a maxillofacial surgeon, a surgeon that has trained as a dentist as well as a doctor and handles complex jaw, tooth and mouth conditions.[5] They may make an incision in the gum or drill a hole in the tooth to allow the pus to drain.[1]

Once the pus has drained away, the area will be cleaned. In periapical abscesses, all dead pulpal tissue will be removed to prevent infection recurring.[1] In periodontal abscesses, a very deep cleaning of the teeth and specifically the gum and roots will be done. A root canal may also be necessary if the whole tooth is compromised. If the decay is severe, the tooth may be removed.

Root canal treatment is the standard treatment for the removal of pulpal tissue in cases where the tooth will be retained and not extracted, and it may also be an option in cases where pain is ongoing even after the abscess is resolved.[11] The person undergoing a root canal will be given a local anesthetic injection to numb the parts of the jaw and mouth affected by the abscess. During the procedure, the dead or infected pulp is removed, the inside of the pulp canals are smoothed, and the pulp is replaced with a filling, often gutta percha.[12] In a few months time, an X-ray and dental checkup will be done to check that the site is healing properly.

As abscesses are painful, affected people may need acetaminophen or ibuprofen to control the pain. Essential oil of cloves has topical anesthetic properties and can be applied to the painful area, although it is very important to maintain strict hygiene while doing this. Home remedies like the above mentioned oil may provide some pain relief, but will not cure an abscess or prevent further infection.

In uncomplicated abscesses, antibiotics will not be necessary.

If the infection is severe or has spread or if the abscess cannot be drained, antibiotics will be prescribed to help bring the infection under control. Antibiotics commonly prescribed for dental abscesses include:[5]

  • Penicillin
  • Amoxicillin, alone or in combination with clavulanate
  • Azithromycin
  • Metronidazole
  • Cefoxitin

If the patient is allergic to amoxicillin and/or penicillin, clindamycin may be prescribed. Penicillin is the usual antibiotic used to treat mild or moderate infections. Because antibiotics alone don’t always penetrate the abscess very well, the abscess may also be surgically drained.[5]

Most dental abscesses are straightforward to treat and resolve completely after they are drained.

Complications of dental abscess

In some rare cases, complications do arise. These can include:[1][5][13][14]

  • Cellulitis, an infection of the skin and subcutaneous tissues.
  • Ludwig angina, which occurs when cellulitis spreads into the tissues under the tongue, in the lower jaw and under the chin. It is also known as submandibular cellulitis/submandibular space infection.
  • Osteomyelitis, an infection of underlying bone.
  • Parapharyngeal abscess, an abscess at the back of the mouth, near the throat. It is caused by staphylococcal and/or streptococcal bacteria. It is most common in children aged five years or younger.
  • Cavernous sinus thrombosis, which can occur when the infection spreads into the blood vessels in the sinuses of the head.

These conditions require very urgent medical attention.

Parapharyngeal abscesses and Ludwig angina can both cause swelling severe enough to obstruct the airways and cause difficulty breathing. Parapharyngeal abscesses require a CT scan and needle aspiration to diagnose. Ludwig angina is diagnosed by CT scan, needle aspiration and X-rays. Treatment for Ludwig angina, parapharyngeal abscess, osteomyelitis, cellulitis and cavernous sinus thrombosis involves drainage of any pus that is present, possibly via surgery and antibiotics and possibly intravenous antibiotics.


**Q: How can dental abscesses be prevented? **
A: As dental abscesses are most often the result of dental caries or gum disease admitting bacteria to the vulnerable pulp of the tooth or into a gum pocket, the first line of prevention is preventing caries and gum disease. This involves maintaining good dental hygiene, including:

  • Regular, twice daily brushing
  • Regular, daily flossing and use of mouthwash
  • Eating a healthy diet with limited sugar and particularly limiting or avoiding sugary drinks
  • Avoiding smoking

**Q: Are there any factors which predispose people to dental abscesses? **
A: Some medications, such as anticholinergics, protease inhibitors, SSRI antidepressants and SNRI antidepressants can cause xerostomia, meaning dry mouth.[15][16] Dry mouth results from a decrease in the amount of saliva, which causes the amount of bacteria in the mouth to increase and can therefore worsen tooth decay. This can be prevented by taking especially good care of proper dental hygiene, drinking plenty of water and possibly talking to a doctor for further treatment options for the xerostomia itself.[15]

Also, people who are immunocompromised may be at higher risk of dental abscesses because their immune systems cannot adequately handle bacterial invasions. People at risk include:[1]

  • People who are HIV positive or have AIDS
  • People who are undergoing chemotherapy
  • People who have sickle cell anemia
  • People who use steroids
  • People who have had a splenectomy
  • People taking immunosuppressive medication after transplantation
  • People with severe autoimmune diseases, taking immunosuppressive medication

It is recommended that most people have a dental checkup at least once a year. Children and people who are at risk, or who have a history of dental problems, should go more often, at least twice per year. If a dental abscess is suspected, dental help should be sought immediately.

Q: What foods are safe to eat and drink after treatment for a dental abscess?
A: Many people find it better to eat soft, bland foods after treatment for a dental abscess, as there may be some mouth pain.[17] Foods such as milkshakes, bananas, applesauce, yogurt, cooked cereals, scrambled eggs, mashed potato and custard or soft pudding.[18] It is important to ensure that the affected person stays well hydrated.

Q: What is pericoronitis?
A: Pericoronitis is a condition involving infection in the gum that covers an unerupted tooth, the operculum. It is particularly associated with wisdom teeth, especially impacted wisdom teeth. Sometimes the gum above the unerupted tooth breaks, and bacteria lodge in the damaged tissue, causing infection.[19]

Acute cases of pericoronitis can have symptoms such as pain in the jaw and when the affected person opens their mouth, swelling and fever. Bad breath may also be a symptom.[20] Abscesses can also occur. Chronic pericoronitis may present with mild inflammation that comes and goes.[21] Pericoronitis will require the treatment and care of a dentist.

Pericoronitis can be treated with antibiotics such as metronidazole or phenoxymethylpenicillin, or erythromycin[22].

  1. Patient.info “Dental Abscess”. 4 June 2015. Accessed 23 April 2018.

  2. Plaque: a sticky film that forms on the teeth. Plaque is home to many bacteria, which contribute to tooth decay if the plaque is not regularly removed.

  3. Gingivitis: inflammation of the gums, a mild form of gum disease.

  4. MSD Manuals Consumer Version. “Periapical Abscess”. Accessed 24 April.

  5. Medscape. “Dental Abscess”. 20 December 2017. Accessed 23 April 2018.

  6. MSD Manuals Professional Version. “Pulpitis”. January 2018. Accessed 23 April 2018.

  7. Alveolar bone: the thickened ridge of bone in the mandible (lower jaw) or maxilla (upper jaw) that holds the teeth.

  8. Periodontium: specialized tissues that surround the tooth, and hold it in place in the gum.

  9. Fluctuant mass: a mass capable of being moved or palpated.

  10. Needle aspiration: a procedure in which a thin hypodermic needle attached to a syringe is inserted into the abscess, and a few drops of pus withdrawn. This sample is then cultured in a laboratory to determine which species of bacteria are present.

  11. MSD Manuals Consumer Version. “Cavities”. Accessed 24 April 2018.

  12. Gutta percha: a natural bioinert latex derived from trees of the genus Palaquium.

  13. UpToDate. “Complications, diagnosis, and treatment of odontogenic infections”. Accessed 24 April 2018.

  14. Amboss. “Deep Neck Infections.”. 18 March 2018. Accessed 24 April 2018.

  15. MSD Manuals Consumer Version. “Dry Mouth”. Accessed 23 April 2018.

  16. Oral Diseases. “Drug effects on salivary glands: dry mouth.”. July 2003. Accessed 24 April 2018.

  17. Medscape. “Dental Abscess Treatment & Management”. 20 December 2017. Accessed 15 May 2018.

  18. National Caregivers Library. “Eating tips for oral discomfort”. Accessed 15 May 2018.

  19. American Family Physician. “Common Dental Infections in the Primary Care Setting”. March 2008. Accessed 15 May 2018.

  20. John P Gallardo. “What is Pericoronitis?”. Accessed 15 May 2018.

  21. Hawaii Family Dental. “Pericoronitis: Definition, Types, Causes, Signs, Symptoms And Treatment”. 23 March 2015. Accessed 15 May 2018.

  22. Journal of the Irish Dental Association. “Pericoronitis: treatment and a clinical dilemma”. June/July 2009. Accessed 15 May 2018.