Antibiotics for Tooth Infection: What You Should Know

A tooth infection is a pocket of pus (abscess) caused by the proliferation of bacteria. Usually, an abscess appears in the pulp—the soft, living tissue inside a tooth.

A periapical abscess develops from an infection in the pulp that forms an abscess at the root of a tooth, while a periodontal abscess develops between the tooth and the surrounding gum tissue.

Symptoms of a tooth infection may include a severe toothache, sensitivity to heat and cold, swollen glands, swelling in the gums, foul-smelling breath, and pain while chewing. If the infection spreads to the surrounding bones, it may become life-threatening. 

Your dentist may prescribe antibiotics to clear up your tooth infection. Learn more about antibiotics for tooth infections, including why they are used and how fast they work.

When Are Antibiotics Used for a Tooth Infection?

Tooth infections don’t always require antibiotics. In many cases, they may clear up on their own. Rinsing with warm saltwater or taking over-the-counter medicines, such as non-steroidal anti-inflammatory drugs (NSAIDs), may help to reduce tooth pain and swelling.

The American Dental Association (ADA) recommends that dentists avoid prescribing antibiotics for most tooth infections due to potential side effects. Dental treatments, such as drainage, deep cleaning, or a root canal (removing the infected pulp from the tooth), may sometimes be necessary.

However, your dentist may prescribe antibiotics if you are immunocompromised (have a weakened immune system) or if your tooth infection is spreading. Some of the signs that your tooth infection is getting worse may include:

• Fever
• Fatigue
• Malaise (a general “ill feeling”)
• Swelling in the jaw or neck
• Intense pain or swelling that does not go away

If left untreated, a tooth infection may spread to the surrounding bones and tissues. This can lead to serious health complications, including:

• Tooth loss
• Blood infection
• Pneumonia (lung infection)
• Brain infection
• Endocarditis (infection in the heart)

If you have a severe tooth infection, your dentist may prescribe a course of antibiotics to prevent it from spreading. Antibiotics may prevent tooth loss and other serious health complications.

Taking Antibiotics

Your dentist can diagnose you with a tooth infection with a thorough physical examination. Your healthcare provider may tap your teeth or ask you to bite down to assess your level of pain. They may also perform imaging tests, such as dental X-rays. 

If your tooth infection is severe or persistent, your dentist may prescribe antibiotics. The goals of taking antibiotics for a tooth infection are to prevent tooth loss and other serious health complications. 

According to the ADA, the first-line antibiotics for a tooth infection include: 

• Oral amoxicillin
• Oral penicillin V potassium

Amoxicillin and penicillin V potassium are both in a class of antibiotics known as penicillin-type drugs. They work to fight infections by killing bacteria or stopping its growth. Penicillin-type drugs won’t work to treat viral infections. 

If you are allergic to penicillin-type drugs, your dentist may prescribe one of the following antibiotics instead:

• Oral azithromycin
• Oral clindamycin
• Oral cephalexin

Azithromycin, clindamycin, and cephalexin are all commonly used to treat bacterial infections.

Dosage

The current ADA recommendations for antibiotic dosage for tooth infections are as follows:

• Oral amoxicillin: 500 milligrams (mg), three times per day
• Oral penicillin V potassium: 500 milligrams, four times per day
• Oral azithromycin: 500 milligrams on the first day, followed by 250 milligrams for four days
• Oral clindamycin: 300 milligrams, four times per day
• Oral cephalexin: 500 milligrams, four times per day

Duration

These are the current ADA recommendations for the duration of a course of antibiotics for a tooth infection:

• Oral amoxicillin: Three to seven days
• Oral penicillin V potassium: Three to seven days
• Oral azithromycin: Five days
• Oral clindamycin: Three to seven days
• Oral cephalexin: Three to seven days

Some of your tooth infection symptoms should begin to clear up after two to three days. However, it’s important to take the full course of antibiotics as your dentist prescribes.

Common Antibiotics Used for a Tooth Infection

Penicillin-type drugs, such as amoxicillin and penicillin V potassium, are typically the first-line antibiotics that dentists prescribe to treat a tooth infection.

However, allergic reactions to penicillins are common. If you have a history of allergy symptoms (such as hives, swelling, or low blood pressure) after taking penicillin-type drugs, let your dentist know. They may prescribe a macrolide antibiotic, such as clindamycin, to clear up your infection. 

In some cases, your dentist may prescribe another type of antibiotic, such as:

• Augmentin (amoxicillin with clavulanate)
• Flagyl (metronidazole)

These drugs are typically prescribed if other antibiotics don’t work to treat your symptoms or if your tooth infection begins to spread.

Side Effects

Some of the most common side effects of antibiotics may include:

• Nausea
• Headache
• Diarrhea
• Yeast infection
• Changes in taste 

Seek immediate medical help if you experience any serious side effects while taking antibiotics, such as:

• Rash
• Difficulty breathing
• Wheezing
• Hives
• Peeling skin or blisters
• Swelling in the face, eyes, or mouth 
• Stomach cramps
• Joint pain
• Worsening signs of a tooth infection
• Fever

Prevention

A tooth abscess may sometimes be caused by a cracked or chipped tooth, an injury, or failed dental work. However, in most cases, tooth infections are caused by tooth decay. 

The best way to prevent a tooth infection is to practice good oral hygiene. Here are some ways to protect your teeth from cavities and gum disease: 

• Brush your teeth at least twice a day with fluoride toothpaste.
• Floss or use interdental brushes regularly to remove hard-to-reach plaque from between your teeth.
• Limit your sugar intake, especially between meals.
• Visit your dentist regularly for cleanings and check-ups.

Summary

A tooth infection is a pocket of pus that develops inside a tooth's pulp due to the multiplication of bacteria. Tooth infections are usually caused by tooth decay, failed dental work, broken or chipped teeth, or injury.

Not all tooth infections require treatment with antibiotics. However, a dentist may sometimes prescribe antibiotics to save the tooth and prevent the infection from spreading. 

The most common antibiotics used to treat tooth infections are penicillin-type drugs (such as amoxicillin and penicillin V potassium). Clindamycin, azithromycin, and cephalexin are options for people who have a history of allergies to penicillin. If first-line drugs don't work, metronidazole may be prescribed.

Possible side effects of antibiotics for tooth infections may include nausea, diarrhea, yeast infection, changes in taste, and headache. More serious side effects, such as rash, hives, swelling, joint pain, and fever, require immediate medical attention.

A Word From Verywell

When tooth pain starts you may be tempted to delay calling a dentist. But a tooth infection can lead to serious health complications if left untreated. Talk to your dentist right away if you suspect that you have a tooth abscess.