A tooth infection, or an abscessed tooth, generally occurs as a result of tooth decay. However, it can also develop due to previous dental work or traumatic injury.

One of the first things a dentist will likely recommend to treat a tooth infection is an antibiotic.

When an infection occurs, it causes a pocket of pus to form in the mouth as a result of an overgrowth of bacteria. This infection often causes swelling, pain, and sensitivity in the area.

While some over-the-counter (OTC) pain medications can help with the pain, antibiotics are necessary to target the bacteria that is causing the infection. Some antibiotics work better than others for tooth infections. Without treatment, the infection spread to other areas of the jaw or even the brain.

Treating tooth decay early is also important to prevent the development of tooth infections. Dental decay is very common. As one article notes, up to 91% of adults aged 20–64 have cavities. Also, around 27% of people in the same age group have untreated tooth decay.

A dentist may sometimes prescribe antibiotics as a precaution to prevent the development of infection. Anyone who experiences dental symptoms should see a dentist right away.

Dentists may prescribe antibiotics in two cases:

  1. To prevent oral bacteria from spreading outside of the oral cavity during a dental procedure. Bacteria from the mouth can spread and trigger certain diseases, especially endocarditis.
  2. To treat infections in the oral cavity that other treatments are not able to clear.

Most often, dentists will typically prescribe antibiotics for tooth infections. However, not all infected teeth require antibiotics.

In some cases, a dentist may simply be able to drain the infected area, remove the infected tooth, or perform a root canal to fix the issue.

In large part due to growing antibiotic resistance, doctors tend to avoid recommending antibiotics unless they are absolutely necessary. This includes instances when the infection is severe or spreading or if a person has a weakened immune system.

There are more than 150 different strains of bacteria that occur in the mouth. Many of these bacteria have the potential to grow and cause an infection.

Although antibiotics can help clear a tooth infection, it is important to use the appropriate antibiotic in each situation.

Treatment may change depending on the bacteria causing the infection, though much of the time, dentists simply recommend an antibiotic that works against many types.

Penicillin class

Penicillin-type drugs are common forms of antibiotics for tooth infections. This includes penicillin and amoxicillin.

Some dentists may also recommend amoxicillin with clavulanic acid, which a person can get under the brand name Augmentin. This combination may help eliminate more stubborn bacteria.

Typical dosages of amoxicillin for tooth infections are either 500 milligrams (mg) every 8 hours or 1,000 mg every 12 hours.

Typical dosages of amoxicillin with clavulanic acid are around 500–2,000 mg every 8 hours or 2,000 mg every 12 hours, depending on the minimum effective dosage.

However, since some bacteria may resist these drugs, many doctors now choose other antibiotics as their first line of treatment.

Also, some people may be allergic to these types of antibiotics. Anyone who has had an allergic reaction to similar medications should tell their dentist before receiving their treatment recommendation.

Clindamycin

Clindamycin is effective against a wide range of infectious bacteria.

As a 2015 study notes, some researchers recommend clindamycin as the drug of choice to treat dental infections, as bacteria may be less likely to resist this drug than penicillin-class drugs.

A typical dosage of clindamycin is either 300 mg or 600 mg every 8 hours, depending on which dosage will be effective.

Azithromycin

Azithromycin works against a wide variety of bacteria, halting their growth.

It may be effective in treating some tooth infections. However, dentists may only recommend it to people who are allergic to penicillin-class drugs or who do not respond to them or other drugs such as clindamycin.

The typical dosage of azithromycin is 500 mg every 24 hours for 3 consecutive days.

Metronidazole

Metronidazole is an antibiotic that doctors and dentists use to treat a number of infections.

However, it may not be suitable for everyone and is typically not the first choice of treatment.

The dosage for metronidazole is around 500–750 mg every 8 hours.

Although antibiotics can help clear up an infection or to prevent an infection from developing after dental work, these drugs do have some possible side effects.

Common side effects from antibiotics include:

More serious side effects include:

However, these side effects can vary with each type of antibiotic. It is important to discuss any possible side effects of taking a drug with a doctor before moving forward with that particular treatment.

How long each antibiotic takes to work varies depending on many factors, such as the severity of the infection and how effectively the drug eliminates the infectious bacteria.

It is important for people to complete a full round of antibiotics, taking all of the prescribed medication exactly how the dentist says to take it.

Although a person may begin to notice their symptoms go away after a couple of doses, completing the full round of antibiotics helps prevent the infection from coming back or getting stronger.

According to research, the majority of acute infections resolve in 3–7 days.

Antibiotics may help clear the active infection. However, the tooth will need work to keep the infection at bay. This typically means undergoing one or more procedures in the area, such as:

  • draining the abscess
  • filling in any cavities
  • performing a root canal
  • extracting the tooth

Antibiotic treatment for a tooth infection is just one part of the solution. In reality, most tooth infections require work on the actual tooth itself to clear up completely.

There may also be some helpful practices a person can try at home to help ease symptoms, such as:

  • gently rinsing the mouth with warm saltwater
  • gently rinsing the mouth with baking soda in water
  • avoiding very hot or very cold foods to prevent sensitivity
  • chewing with the opposite side of the mouth to reduce additional injury to the area
  • brushing with a very soft toothbrush around the sensitive area
  • avoiding very sharp, hard-to-chew foods that may bump into the sensitive area or become stuck in the teeth

Adopting good oral hygiene practices, such as brushing and flossing each day and seeing a dentist for regular checkups, may help prevent tooth infections and their complications.

Although antibiotics may help clear up a tooth infection, they are only one part of the solution. Most tooth infections require a dental procedure, such as a root canal or tooth extraction, to completely clear up.

Prompt treatment is important to keep the infection from spreading. Some helpful home remedies may help keep swelling down or ease the pain while taking antibiotics and preparing for the dental procedure.

What is the best antibiotic for a tooth infection?

There is no one antibiotic that is best for treating a tooth infection. The type of antibiotic a dentist recommends will vary depending on the bacteria causing the infection.

This is because different antibiotics work in different ways to eliminate different strains of bacteria. However, doctors will often choose amoxicillin as the first-line treatment.

How long does it take for a tooth infection to go away with antibiotics?

After a person begins to take antibiotics, it should take 2-3 days for the infection to begin to clear. A person should finish the entire course of the medication as prescribed by their doctor even if they begin to feel better sooner. A common treatment period is 7 days.

Will antibiotics stop tooth pain?

Research shows that when a person begins to take antibiotics for a tooth infection, they begin to feel some pain relief within 24 hours. After 24 hours, the pain intensity may increase slightly. After 7 days, it may reduce slightly again.

While taking antibiotics, a person can manage pain with OTC pain relievers such as ibuprofen (Advil) and acetaminophen (Tylenol).