Tooth Infection and Abscess

A dental abscess is a pocket of pus caused by bacteria that have reached the inside of a tooth, through deep decay or a crack, or the bottom of a deep gum pocket. It causes a deep throbbing ache, a tooth that feels raised and tender, and often swelling. It does not resolve on its own, antibiotics alone do not cure it, and swelling that spreads toward the eye or down the neck is a medical emergency. Treatment removes the source: a root canal, gum treatment, or extraction.

How to recognize it

• A deep, throbbing ache that builds, often worse lying down, sometimes radiating to the ear or jaw
• A tooth that feels raised in the bite and is tender to touch or tap
• Swelling of the gum beside the tooth, or a pimple-like bump that may release a salty or foul taste
• Swelling of the cheek or face on that side
• Sensitivity to heat more than cold, or a tooth that has gone from very sensitive to numb
• Fever, feeling unwell, or tender lymph nodes under the jaw
• Bad breath or a bad taste that brushing does not fix

Not every abscess hurts. Some drain through a bump on the gum and are found on an X-ray at a routine visit, while the infection continues to destroy bone around the root.

Two kinds

A periapical abscess starts inside the tooth. Decay, a crack or a blow lets bacteria reach the nerve, the nerve dies, and the infection collects at the tip of the root. A periodontal abscess starts in the gum, at the bottom of a deep pocket where bacteria and debris are trapped, sometimes after food packs into the pocket.

Why antibiotics alone are not the answer

Antibiotics reduce the spread of infection and are the right call when there is fever, swelling extending into the face or a patient whose health demands caution, and we prescribe them in those situations. What they cannot do is reach the dead tissue inside a tooth or the debris in a pocket, where the bacteria live. Until that source is cleaned out or removed, the infection returns. Antibiotics control the infection until the source can be treated.

What we do

• The first priority is relief: numbing the area and, where there is a collection of pus, draining it, which usually brings immediate improvement.
• For an infection inside the tooth, a root canal removes the dead tissue, disinfects the canals and seals them, saving the tooth in most cases. An emergency visit may begin that process and relieve the pressure, with the treatment completed at a later visit.
• For an infection in the gum, the pocket is cleaned and periodontal treatment follows.
• When a tooth cannot be saved, because it is cracked below the gum, too decayed to restore, or has lost its bone support, it is removed, and the replacement is planned at the same time.

What to do until you are seen

• Call us as soon as you can; infections do not improve with waiting.
• Take an over-the-counter pain reliever as the label directs, if your doctor allows.
• Rinse gently with warm salt water.
• A cold compress on the cheek, twenty minutes on and off, eases swelling.
• Do not apply heat to the face and do not put anything on the gum.
• If you have antibiotics already prescribed, keep taking them as directed and bring the bottle.

Afterward

• Once the source is treated, the swelling and pain settle over a few days.
• Finish any antibiotics as prescribed.
• Complete the planned treatment.

Most infections we see began as a cavity or a crack that had been painless for a long time, and regular examinations are how those are caught before they reach the nerve.

Frequently asked questions

Can a tooth infection go away by itself?

The pain can ease when the abscess finds a way to drain, through a bump on the gum for example, but the infection remains until its source is treated. Left alone it can flare again, spread, and cost the tooth and the bone around it.

Will antibiotics cure it?

No. Antibiotics can calm an infection that is spreading or causing fever, and we prescribe them when they are needed, but the source inside the tooth or the pocket has to be cleaned out or removed. A prescription without treatment only delays the problem.

Is swelling in my face an emergency?

Swelling that is spreading quickly, closing the eye, extending down the neck, or accompanied by difficulty breathing or swallowing or a high fever is a medical emergency; go to an emergency room. Localized swelling of the gum or a mild puffiness of the cheek needs to be seen promptly, by us.

Will I lose the tooth?

Often not. Many infected teeth are saved with a root canal once the infection is controlled. A tooth that is too damaged, cracked below the gum, or has lost its bone support is removed, and we plan the replacement at the same time.

Why does the bump on my gum keep coming back?

That bump is a drainage point for an infection at the root. It comes and goes because the pressure builds and releases, but the infection underneath stays until the tooth is treated.

Sources

Professional guidelines and peer-reviewed reviews this page draws on.

1. Lockhart PB, Tampi MP, Abt E, et al. Evidence-based clinical practice guideline on antibiotic use for the urgent management of pulpal- and periapical-related dental pain and intraoral swelling. Journal of the American Dental Association. 2019;150(11):906-921. DOI