Dental Abscess: Types and Treatment

How a dental abscess forms

Bacteria live in everyone's mouth. An abscess forms when they get past the tooth's or gum's defenses and the body walls off the infection with pus. Pressure from trapped pus causes the typical intense, throbbing pain.

For general symptoms and danger signs, see tooth abscess. This page focuses on the different types and what treatment involves.

Types of dental abscess

A periapical abscess may drain itself through a small pimple on the gum (a sinus tract). The pain then eases, but the infection is still there and will flare again.

Symptoms

• Severe, throbbing pain in a tooth or the gum that can spread to the ear, jaw or neck.
• Pain when biting or chewing, or a tooth that feels "high".
• Swelling of the gum, face or jaw.
• A red, shiny, tender lump on the gum.
• A sudden salty, foul taste if the abscess bursts.
• Bad breath.
• Tender, swollen lymph nodes under the jaw.
• Fever and feeling unwell if infection spreads.

Risk factors

• Untreated cavities, broken or cracked teeth and large old fillings.
• Gum disease.
• Poor oral hygiene and frequent sugary food and drink.
• Dry mouth from medicines or radiotherapy.
• Diabetes, smoking and a weakened immune system.

What your dentist will do

Diagnosis

The dentist asks about your pain and examines the teeth and gums. They tap the teeth, check for looseness, test whether the nerve responds to cold, and measure gum pockets. A dental X-ray shows decay, bone loss at the root tip, or a periodontal pocket.

Treatment options

1. Drainage: the dentist makes a small cut in the swollen gum, or opens the tooth, to let the pus out. Pain usually eases quickly afterward.
2. Root canal treatment: for a periapical abscess when the tooth can be saved. The infected pulp is removed, the canals are cleaned and sealed, and the tooth is usually crowned later.
3. Extraction: removing the tooth when it is too damaged to restore or you prefer not to keep it.
4. Deep cleaning: for a periodontal abscess, the pocket is drained and cleaned below the gumline.
5. Wisdom tooth care: cleaning under the gum flap, and often later removal of the wisdom tooth.

When antibiotics are needed

Antibiotics do not cure a dental abscess by themselves, because they cannot reach pus in a closed space well. Current dental guidelines advise against antibiotics for a localized abscess that can be drained. They are added when there is spreading facial swelling, fever, swollen glands, difficulty opening the mouth, or a weakened immune system, and when treatment has to be delayed.

What to do until you see a dentist

• Take an over-the-counter pain reliever such as ibuprofen or acetaminophen (paracetamol), following the label dose. Ibuprofen works well for dental pain if you can take NSAIDs. Avoid it with kidney disease, stomach ulcers or blood thinners.
• Rinse with warm salt water several times a day.
• Chew on the other side and avoid very hot, cold or sweet foods.
• Do not place aspirin on the gum; it burns the tissue.
• Do not apply heat to the outside of the face, which can draw infection outward.
• Do not try to pop the swelling yourself.

Complications

Most abscesses stay local. Without treatment, infection can spread to:

• The soft tissues of the face (cellulitis).
• The floor of the mouth and neck, causing Ludwig's angina, which can block the airway.
• The jawbone (osteomyelitis) or sinuses.
• The bloodstream (sepsis).
• Rarely, the veins behind the eye (cavernous sinus thrombosis) or the brain.

Prevention

• Brush twice daily with fluoride toothpaste and clean between teeth daily.
• Limit sugary snacks and drinks between meals.
• See a dentist regularly so decay and gum disease are treated early.
• Get chipped or cracked teeth checked promptly.
• Wear a mouthguard for contact sports.

Frequently asked questions

Will a dental abscess go away on its own?

No. The pain may ease if the abscess bursts and drains, but the source of infection remains inside the tooth or gum, and it will usually return. A dentist needs to drain it and either treat the root canal, clean the gum pocket or remove the tooth.

Can antibiotics alone cure a dental abscess?

No. Antibiotics may calm spreading infection, but they cannot clear trapped pus or the infected pulp inside a tooth. Without drainage and root canal treatment or extraction, the abscess comes back. Antibiotics are added mainly when there is facial swelling, fever or a weak immune system.

What is the difference between a periapical and a periodontal abscess?

A periapical abscess forms at the tip of the root after the tooth's nerve dies, usually from deep decay or a crack. A periodontal abscess forms in the gum pocket beside a tooth with gum disease, and the tooth's nerve may still be healthy. Treatment differs: root canal versus gum cleaning.

How long does dental abscess swelling last after treatment?

Once the abscess is drained, pain usually improves within a day and swelling within 2 to 5 days. If swelling increases, you develop a fever, or you have trouble swallowing or opening your mouth after treatment, contact your dentist or seek urgent care.

Is a dental abscess an emergency?

It becomes an emergency if swelling spreads under the jaw, tongue or into the neck or eye, or if you have trouble breathing or swallowing, a high fever or feel very unwell. Otherwise, see a dentist within a day or two. Do not wait for it to settle.