A tooth abscess is a pocket of pus caused by a bacterial infection in or around a tooth. It typically produces throbbing pain that can radiate to your ear, jaw, or neck, and it will not resolve on its own. Left untreated, the infection can spread beyond the tooth into the jaw, sinuses, or bloodstream.
Types of Tooth Abscesses
There are two main types, and they differ by where the infection starts.
A periapical abscess forms at the tip of the tooth’s root. It begins inside the tooth itself, usually because bacteria have worked their way through decay, a crack, or a chip in the enamel to reach the soft tissue (pulp) and nerve deep inside. This is the most common type.
A periodontal abscess forms in the gum tissue alongside the root. It typically results from gum disease or an injury to the gums. Pockets of infected tissue develop between the gum and the tooth, trapping bacteria below the gumline. You can also develop a periodontal abscess if food gets forced deep into a gum pocket and can’t work its way back out.
What Causes the Infection
Your mouth contains hundreds of bacterial species, and most of them are harmless. When bacteria gain access to the inner tooth or deep gum tissue, though, certain species take over and cause infection. The bacteria most commonly involved include several types of streptococcus (the same family behind strep throat), along with various oxygen-hating species that thrive in the sealed, low-oxygen environment inside a tooth or deep gum pocket.
The most common entry point is an untreated cavity. As decay eats through enamel and then the softer layer beneath it, bacteria eventually reach the pulp chamber where the nerve and blood vessels live. A cracked or chipped tooth creates a similar shortcut. Previous dental work that has broken down, like an old filling with a gap around its edges, can also let bacteria in.
Symptoms to Recognize
The hallmark symptom is pain. It can feel sharp, throbbing, or shooting, and it often worsens when you chew or press on the tooth. The pain may be constant or come in waves, and it frequently radiates into the ear, jaw, or neck on the same side. Some people describe it as keeping them awake at night.
Beyond pain, common signs include:
- Swelling in the gums, face, or jaw
- A bad taste or bad breath from pus draining into the mouth
- Sensitivity to hot or cold food and drinks
- Red, puffy gums near the affected tooth
- A visible bump on the gums that may look like a small pimple and can ooze when pressed
- Swollen lymph nodes under the jaw or in the neck
- Fever
- A loose-feeling tooth
Not every abscess is painful. In some cases, the pulp inside the tooth has already died, which can dull the nerve. You might notice swelling or a draining sore on the gum without much pain. The infection is still active and still needs treatment.
How Dentists Diagnose It
A dentist will usually start by tapping on the tooth and pressing on the surrounding gum. A tooth with an abscess at its root is generally sensitive to touch or pressure, and that response helps pinpoint which tooth is involved. You may also be asked to bite down on something to check for pain.
An X-ray is the primary imaging tool. It can reveal a dark area at the root tip where bone has been destroyed by the abscess, confirming the diagnosis and showing how far the infection extends. If the infection appears to have spread into the neck or deeper tissues, a CT scan may be ordered to assess the full extent.
Treatment Options
The core goal of treatment is to eliminate the infection and drain the trapped pus. Antibiotics alone cannot cure a tooth abscess because they can’t penetrate well into a sealed pocket of pus. A physical procedure is almost always needed.
Drainage
Your dentist may make a small incision in the swollen gum tissue to let the pus drain. This often brings rapid pain relief because it releases the pressure that has been building up. The area is flushed with saline to clear out bacteria. After drainage, you still need a follow-up procedure to address the source of the infection.
Root Canal
A root canal removes the infected pulp from inside the tooth, then cleans, disinfects, and seals the internal space. The major advantage is that it preserves your natural tooth. You’ll typically get a crown placed over the tooth afterward to restore its strength. This is generally the preferred option when enough healthy tooth structure remains.
Extraction
If the tooth is too damaged to save, extraction removes the tooth and its root entirely. This eliminates the source of infection, but it leaves a gap. Replacing the tooth later with an implant or bridge adds time and cost, which is one reason dentists generally recommend a root canal when it’s feasible. According to the American Association of Endodontists, choosing a root canal over extraction is often less expensive overall once you factor in the cost of replacing the missing tooth.
Antibiotics
Antibiotics are prescribed when the infection has spread beyond the tooth itself, for example into the lymph nodes, jaw, or surrounding tissue. They’re also used when you have a fever or other signs of systemic infection. They are not a substitute for drainage or a root canal but rather a support measure. The current first-line choice is a type of penicillin, typically prescribed for up to five days with a review at three days.
Recovery After Treatment
Once the abscess is drained, the intense throbbing pain usually drops significantly within a day or two. Residual soreness in the gum and surrounding area is normal for several days, especially after an incision. If you’ve had a root canal, mild tenderness around the tooth for a week or so is expected as the tissues heal.
Full soft tissue healing after drainage or a root canal typically takes one to two weeks, though deeper infections can take longer. During recovery, you can manage discomfort with over-the-counter pain relievers and by eating soft foods on the opposite side of your mouth. If you were prescribed antibiotics, finishing the full course matters even if you feel better after a couple of days.
What Happens If You Don’t Treat It
A tooth abscess does not heal on its own, and ignoring it carries real risks. If the abscess doesn’t drain, the infection can spread into the jawbone and then into the soft tissues of the head and neck. When infection spreads into the floor of the mouth, it can cause enough swelling to make breathing or swallowing difficult.
If the affected tooth sits near the sinuses (common with upper back teeth), the abscess can create an opening between the tooth root and the sinus cavity, leading to a sinus infection. In the most serious cases, bacteria enter the bloodstream and trigger sepsis, a life-threatening condition that affects the whole body.
Certain symptoms signal that an abscess has become a medical emergency requiring an emergency room, not just a dentist’s office: difficulty breathing, swallowing, or speaking; swelling or pain around the eye or sudden vision problems; significant swelling in the mouth or face; trouble opening your mouth; a fever of 100.4°F (38°C) or higher; confusion; or a rapid heart rate.
Preventing Tooth Abscesses
Because most abscesses start with tooth decay, the same habits that prevent cavities prevent abscesses. Brush twice a day with a fluoride toothpaste containing at least 1,000 ppm fluoride (most standard toothpastes meet this threshold). Floss daily to clear bacteria from between teeth where your brush can’t reach. Limit sugary foods and drinks, especially between meals, since sugar feeds the bacteria that produce acid and erode enamel.
Regular dental checkups catch small cavities and early gum disease before they progress to the point where an abscess can form. If you crack or chip a tooth, getting it repaired promptly seals off the pathway bacteria would otherwise use to reach the pulp. The same applies to old fillings or crowns that feel loose or rough. These are not cosmetic concerns; they’re open doors for infection.