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Dental Abscess

Written by Ada’s Medical Knowledge Team

Updated on

What is a dental abscess?

An abscess is a pocket of pus that forms within body tissues. 1 Abscesses are the result of an infection, generally bacterial, localized 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.

Each tooth is made up of several layers. The outermost layer is the enamel, which covers a softer layer, the dentin. The 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.

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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 of dental abscesses is usually carried out by dentists, and often involves taking an antibiotic 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

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

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 abscesses: affecting the inside of the tooth

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, including inadequate brushing or flossing, can cause 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, as 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

Periodontal abscesses: affecting the gums

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. ref1

Signs and symptoms of a dental abscess

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: 5 6

  • Feel tender
  • Feel loose in the jaw
  • Be sensitive to heat and/or cold in the mouth
  • Be sensitive to pressure on the tooth, or to being tapped
  • Be slightly raised

People with a dental abscess may experience pain in the affected area. If you are concerned that you may have a dental abscess, you can do a free symptom check with the Ada app or find out more about how it works.

Other symptoms of dental abscesses include: 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 in the area. 9 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.

Rarely, in severe cases of dental abscess, the affected person may also experience: 5

  • Cellulitis, a bacterial infection of skin and subcutaneous tissues
  • Lockjaw (trismus)
  • Difficulty swallowing, due to pain and swelling
  • Difficulty breathing, due to swelling
  • 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 38 C / 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 such as.

If any of these symptoms occur, the affected person should seek emergency dental care from a dentist or, if no dental care is available, visit a hospital emergency department or see another doctor as soon as possible. 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.

Causes of dental abscesses

Dental abscesses are the result of bacterial infection. When the gum tissue surrounding a tooth becomes damaged or the tooth itself is damaged, bacteria that are already in the mouth and, under usual circumstances not harmful, may enter the area and cause infection.

One of the most common causes of damage to the teeth and gums is poor dental hygiene, such as inadequate brushing and flossing, high sugar or carbohydrate consumption, and lack of regular checkups at the dentist. These factors may lead to dental caries or cavities, gingivitis and periodontitis, which can admit bacteria to the inside of the tooth or the gum. 10 Maintaining healthy teeth and gums is therefore one of the best ways of reducing the risk of developing dental abscesses, as it removes one of the main causes of abscesses.

Diagnosing 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 usually be very sensitive to pressure or tapping (percussion), and may often be painful. 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 11 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

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. 12 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. 13 In a few months time, an X-ray and dental checkup will be done to check that the site is healing properly.

Pain management and antibiotics

As abscesses are painful, people may need acetaminophen or 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 may 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.

Home treatment of dental abscesses

Although essential oil of cloves can be used to manage the pain and sensitivity associated with dental abscesses, it will not cure the abscess. Abscesses will not go away on their own and cannot be treated at home. Untreated abscesses can develop secondary infections and other serious complications that are extremely hazardous to health (see below). It is possible for an untreated abscess to become a medical emergency requiring urgent care from a doctor or dentist. It may also lead to jaw bone loss.

Only a qualified medical or dental professional is properly equipped to administer treatment for an abscess safely and effectively. 14 It is strongly advised that people affected by abscesses, or who suspect they may have a dental abscess, seek out the advice of a dentist as soon as they can. It is not safe to try to drain an abscess at home or to leave an abscess untreated.

When to seek emergency treatment for dental abscesses

Ideally, a person affected by a dental abscess, or who suspects that they may have a dental abscess, should visit the dentist as soon as possible. Because it is not always possible to see a dentist in time, some people may need to be treated for their abscesses in a hospital emergency department. Medical doctors are not specifically trained to handle dental issues, but will be able to stabilize the affected person, providing antibiotics and pain relief, until they can see the dentist.

Good to know: Dentists do not form part of the regular staff in most hospital emergency departments. Treatment by a doctor at a hospital will not replace seeing a dentist. Doctors are not trained to deal with dental problems but will be able to assist with managing infection and pain.

If a person with an abscess or a suspected abscess shows any of the signs listed below, they should seek urgent medical care as soon as possible. 15 16 17 Danger signs for tooth abscesses include:

  • An abscess of more than 1cm in diameter, or which feels large
  • Severe swelling or hard lumps on the gums or the face
  • Bleeding on the gums or in the mouth
  • Fever or a body temperature of more than 38 C / 101.4 F
  • Tender lymph nodes in the neck area

If a person shows the symptoms listed below, they should immediately be seen by a hospital emergency department: 18 19 20

  • Severe pain that cannot be controlled with painkillers
  • Shortness of breath or other difficulty breathing
  • Difficulty swallowing due to swelling, or difficulty taking in liquids leading to dehydration
  • Severe difficulty opening the mouth
  • Swelling of the neck or around the eyes, or severe swelling of the face in general
  • Secretions in the mouth they can’t handle due to difficulty swallowing, opening the mouth or others

Complications of dental abscess

In rare cases, complications do arise. These can include: 1 5 21 22

  • Cellulitis, an infection of the skin and subcutaneous tissues.
  • Ludwig’s 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.
  • Sepsis

These conditions require very urgent medical attention and are best evaluated via a hospital emergency department. 18 19 20

Cellulitis and facial cellulitis

Cellulitis is an infection of the skin. Facial cellulitis, for example, can be caused by infections of the upper respiratory tract, middle ear infections or tooth abscesses. Although these conditions can increase the risk of facial cellulitis, they do not directly cause it; the condition results when an infection spreads to the skin. Symptoms of facial cellulitis include: 23

  • Swollen, red skin on the face, especially the cheek
  • Itching and burning of the affected skin
  • A painful, possibly swollen, tongue
  • Fever

If you are concerned that you or a loved one may have cellulitis or a tooth abscess, you can start a free symptom assessment right now using the Ada app.

Parapharyngeal abscesses and Ludwig’s angina

Parapharyngeal abscesses and Ludwig’s angina can both cause swelling severe enough to obstruct the airways and cause difficulty breathing. Parapharyngeal abscesses require a and needle aspiration to diagnose. Ludwig’s angina is diagnosed by, needle aspiration and X-rays.

Treatment for Ludwig’s 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. People affected by Ludwig’s angina, if untreated, may require a tracheostomy to open their airways and thereby help them breathe if the swelling obstructs the windpipe. 14

Spreading infection

A spreading untreated infection from a dental abscess can cause pain around the eyes, ear pain, nose pain and swelling in the eyes or face. Severe dental infections can spread to other parts of the body, causing potentially serious medical conditions such as bacterial meningitis and infective endocarditis.

An untreated dental abscess or one that does not respond to treatment can very rarely cause sepsis, which is potentially life-threatening.

Read more about Sepsis »

Dental abscess FAQs

Q: Can a dental abscess be dangerous?
A: Dental abscesses, especially if they are properly treated, typically do not cause severe or long-term problems. However, if it is left untreated or if improperly treated, a severe dental abscess can potentially cause complications, possibly even serious ones.

Q: Are dental abscesses contagious?
A: No, they are not. Dental abscesses cannot be spread from one person to another.

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, 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. 24 25 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.

People who are immunocompromised may be at higher risk of dental abscesses because their immune systems cannot always 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 best to eat soft, bland foods after treatment for a dental abscess, as there may be some mouth pain. 26 Foods such as milkshakes, bananas, applesauce, yogurt, cooked cereals, scrambled eggs, mashed potato and custard or soft pudding may be suitable. 27 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. 28

Acute cases of pericoronitis can have symptoms such as pain in the jaw and pain when the affected person opens their mouth, as well as swelling and fever. Bad breath may also be a symptom. 29 Abscesses can also occur. Chronic pericoronitis may present with mild inflammation that comes and goes. 30 Pericoronitis will require the treatment and care of a dentist.

Pericoronitis can be treated with warm salt-water rinses and antibiotics such as metronidazole, phenoxymethylpenicillin, or erythromycin. 31

Q: Can dental abscesses affect wisdom teeth?
A: Wisdom teeth, also known as third molars, usually erupt into the mouth in late adolescence. Occasionally, due to the position of the other teeth in the mouth, there is not enough space for them and as a result impaction may occur. Impaction can occur at any age and means that the teeth cannot erupt properly and get stuck completely or partly below the surface of the gum. Although this does not always cause problems, 32 it can cause pericoronitis, an inflammation (see above), which may then develop into an abscess. 33

Q: Can a dental abscess cause swelling but no pain?
A: Yes. However, this is a cause for concern: if an abscessed tooth that has been painful initially stops being painful, it generally means that the affected tooth has died. Pain may also lessen considerably if the abscess ruptures and drains. It does not mean that the abscess is gone, however. 34 Infection can still spread and become very serious even if the tooth is not painful, and the affected person should see a dentist as soon as they can.

Q: Are all dental abscesses visible?
A: No. Those dental abscesses that develop a fistula or a gum-boil are visible, but it is possible for there to be no visible sign that an abscess has formed. If someone is experiencing mouth pain and/or any of the symptoms listed above, they should see a dentist to determine what is causing the pain, even if they cannot see anything obviously wrong in the mouth.

Q: Can a dental abscess be hard?
A: While most abscesses are usually soft and warm to the touch, occasionally they can feel firm or even hard to the touch. 35 Anyone with a suspected abscess, jaw swelling, jaw pain or tooth pain who feels a hard lump in the mouth should see a dentist as soon as possible.

Q: Can dental abscesses develop next to or underneath a crown, dentures, dental implant or a dental bridge?
A: Yes. Dental work such as crowns or implants can cause dental abscesses, but only if they are improperly done, damaged or broken. Crowns are often used to help preserve a tooth after a root canal has been done, meaning that they are attached to a tooth that is already compromised. 36 Although it is rare for abscesses to affect crowns, it is possible. Dentures can cause injury to the gums beneath them if they do not fit properly; 37 an injured gum is vulnerable to infection. It is important to make sure that dentures fit properly, and it is necessary to replace any denture that does not fit properly to reduce the risk of infection, injury and poor dental hygiene. Dental implants are used to replace missing teeth and are not natural teeth. They are a little more susceptible to mechanical stress and therefore to colonization by bacteria that may lead to abscesses. However, most dental implants are successful. 38 Dental bridges do not have roots and cannot themselves become abscessed, but it is possible for one of the supporting teeth on either side of the bridged tooth to become abscessed.

Q: Can trauma or an injury to the mouth cause a dental abscess?
A: Yes. A trauma like a blow to a tooth, or, over the longer term, increased wear and tear, such as might result from chronically grinding or clenching teeth, can damage structures of the tooth and therefore increase the risk of a dental abscess developing by bacteria having easier access to this tooth’s sensitive areas. 39

Q: Can dental abscesses appear under the tongue?
A: An abscess under the tongue is not a dental abscess, but it could possibly be the result of a dental abscess that has led to Ludwig’s angina, a form of cellulitis that affects the tissue below the tongue, below the lower jaw, and the floor of the mouth. Ludwig’s angina is a medical emergency, and the affected person should seek medical help in a hospital without delay.