What Is a Tooth Infection?
A tooth infection is a buildup of bacteria and pus inside or around a tooth, typically caused by untreated decay or injury. It requires professional treatment to resolve.
Dentists classify dental abscesses into two main types. A periapical abscess forms at the tip of the tooth root when bacteria invade the pulp, which is the soft tissue containing nerves and blood vessels inside the tooth. A periodontal abscess forms in the gums next to the root, usually as a result of advanced gum disease. [1] Both types cause pain and swelling, and both can become dangerous if left untreated.
The infection begins when bacteria break through the hard outer layers of a tooth, the enamel and dentin, and reach the pulp chamber. Once inside, bacteria multiply rapidly. The body sends white blood cells to fight the infection, and the resulting battle produces pus. This pus builds pressure inside the tooth or surrounding tissues, which is a major reason tooth infections cause such intense pain. [7]
A dental abscess is classified as a dental emergency. [1] The infection can spread beyond the tooth into the jawbone, the soft tissues of the face and neck, or in rare cases the bloodstream. Early recognition of symptoms is the key to getting treatment before complications develop.
What Causes a Tooth Infection?
Tooth infections are caused by bacteria entering the tooth or gum tissue through decay, cracks, or deep periodontal pockets.
Tooth Decay and Trauma
Untreated cavities are the most common pathway for bacteria to reach the pulp. As decay eats through enamel and dentin, it eventually exposes the pulp to oral bacteria. A 2014 study in the Journal of Endodontics examined 40 extracted teeth and found that clinical signs of irreversible pulpitis, which is painful inflammation of the pulp, strongly correlated with histologic evidence of bacteria deep within the pulp tissue. [9]
Trauma is another common cause. A cracked or chipped tooth can give bacteria a direct route to the pulp, even if no cavity is present. Teeth that have had multiple dental procedures can also become vulnerable over time, as each procedure brings instruments closer to the pulp chamber.
Gum Disease and Periodontal Abscesses
Advanced gum disease, known as periodontitis, creates deep pockets between the teeth and gums. Bacteria colonize these pockets and can form a periodontal abscess. [3] The abscess may drain on its own temporarily, giving the impression that it has healed, but the infection typically returns until the underlying gum disease is treated.
Acute periodontal lesions can appear suddenly, even in patients who did not realize they had chronic gum disease. [10] These lesions cause rapid swelling, pain, and sometimes fever. Certain systemic conditions and medications can increase the risk of periodontal infections. [6]
Spread to Nearby Structures
Upper back teeth have roots that sit close to the maxillary sinuses. An infection in these teeth can spread into the sinus cavity, causing a condition called odontogenic sinusitis. Symptoms include nasal congestion, facial pressure, and a foul-smelling nasal discharge, typically on one side only. [2] This is one reason a dental evaluation may be recommended for patients with recurring sinus infections that do not respond to standard medical treatment.
When to See a Dentist or Visit the Emergency Room
Any toothache lasting more than one to two days warrants a dental visit. Certain symptoms require immediate emergency care.
Schedule a dental appointment as soon as possible if you notice a persistent throbbing toothache, sensitivity to hot or cold foods, a small pimple-like bump on the gums (called a fistula or sinus tract), a foul taste or salty liquid draining in your mouth, or mild swelling near the affected tooth. These signs suggest an active infection that needs professional evaluation. [1]
Go to an emergency room or call 911 if you experience any of the following red flags. Difficulty breathing or swallowing is the most urgent sign, as it can mean the infection is blocking the airway. Rapid swelling that spreads to the eye, the area under the tongue (the floor of the mouth), or down the neck is also a medical emergency. A fever above 101°F (38.3°C) combined with facial swelling suggests the infection is advancing. Chest pain or a rapid heartbeat may indicate that the infection is affecting the cardiovascular system. [7]
These complications are uncommon but serious. Odontogenic infections rank among the most common reasons patients visit emergency departments for dental problems. [1] Getting timely care from a dentist or the endodontics page specialist typically prevents the infection from reaching this stage.
How a Tooth Infection Is Diagnosed
Diagnosis involves a clinical exam, specific dental tests, and usually an X-ray to locate the source and extent of the infection.
Your dentist or endodontist will begin with a visual exam of the affected area. They will look for swelling, redness, a draining fistula, and any visible decay or cracks. They will also press gently on the tooth and surrounding gums. An infected tooth is typically tender when tapped or when pressure is applied to the gum near the root tip. [9]
Pulp vitality testing helps determine whether the nerve inside the tooth is alive or dead. The dentist may place a cold stimulus, such as a refrigerant spray on a cotton pellet, on the tooth. A healthy tooth responds with brief, mild sensitivity. A tooth with irreversible pulpitis often produces a sharp, lingering pain. A tooth with a dead (necrotic) pulp may produce no response at all. [9]
X-Rays and Advanced Imaging
A periapical X-ray shows the tooth root and the bone around it. A dark area at the tip of the root typically indicates a periapical abscess. Widening of the periodontal ligament space, which is the thin gap between the root and the bone, is another sign of infection.
In some cases, a cone beam computed tomography (CBCT) scan may be ordered. This three-dimensional image gives a more detailed view of the infection and helps the clinician see exactly which root or roots are involved. CBCT is especially useful when the standard X-ray is inconclusive or when the infection may have spread to nearby structures such as the sinus. [2]
Periodontal Evaluation
If gum disease is suspected, the dentist will use a small probe to measure pocket depths around the tooth. Healthy pockets are typically 1 to 3 millimeters deep. Pockets deeper than 4 millimeters suggest periodontal disease, and very deep pockets with pus (suppuration) point to a periodontal abscess. [3] The results help distinguish between an infection originating from inside the tooth and one originating from the gum tissue, which affects the treatment plan.
Treatment Options for a Tooth Infection
Treatment focuses on removing the source of infection and draining any accumulated pus. The specific approach depends on the cause.
Root Canal Treatment
Root canal treatment is the standard approach for saving a tooth with a periapical abscess. An endodontist, a dentist who specializes in treating the inside of teeth, removes the infected pulp tissue, cleans and disinfects the root canal system, and then fills and seals it. A crown is usually placed afterward to protect the tooth. [11]
In many cases, the endodontist will open the tooth and place a medicated dressing inside during the first visit. This allows the infection to drain and begin to resolve before the root canal is completed. Pain relief is often significant within 24 to 48 hours of this initial treatment.
Incision and Drainage
When a large collection of pus has formed in the soft tissue, the dentist may make a small incision to drain it. This procedure provides rapid pressure relief and helps antibiotics work more effectively. Incision and drainage is typically performed alongside other treatment, such as starting a root canal or extracting the tooth. [7]
Antibiotics and Pain Management
Antibiotics are prescribed when the infection shows signs of spreading, such as fever, facial swelling, or involvement of the lymph nodes. They help control the bacterial load but cannot eliminate the source of infection by themselves. The infected pulp or periodontal pocket must still be treated directly. [7]
For pain management, a combination of ibuprofen (a nonsteroidal anti-inflammatory drug) and acetaminophen is typically more effective than opioid-based pain relievers for acute dental pain. A 2021 review in the journal Drugs found that this over-the-counter combination provided pain relief comparable to or better than prescription opioids for endodontic pain, with fewer side effects. [5] Your dentist will recommend specific doses based on your medical history.
Extraction
If the tooth is too damaged by decay, fracture, or advanced gum disease, extraction may be the only option. Removing the tooth eliminates the source of infection. After healing, the missing tooth can be replaced with a dental implant, bridge, or removable partial denture. Your dentist will discuss which replacement option fits your situation.
Periodontal Abscess Treatment
A periodontal abscess is treated by draining the pus from the gum pocket and cleaning out the bacteria and debris. This is called scaling and root planing, sometimes referred to as a deep cleaning. [10] In severe cases, periodontal surgery may be needed to access and clean deep pockets. Ongoing management of the underlying gum disease is essential to prevent the abscess from returning. [8]
Cost Factors for Diagnosis and Treatment
The cost of treating a tooth infection depends on the type of treatment needed, the tooth's location, and your geographic area.
A dental exam and periapical X-ray, which are the first steps in diagnosing an infection, typically range from $50 to $250. If a CBCT scan is needed, costs generally range from $150 to $500. Costs vary by location, provider, and case complexity.
Root canal treatment costs vary widely depending on which tooth is involved. Front teeth, which have a single root canal, are less complex and typically less expensive. Molars, which can have three or four canals, require more time and skill. Root canal treatment generally ranges from $700 to $1,500 or more per tooth, not including the crown that usually follows. An endodontist may charge more than a general dentist for this procedure, but endodontists handle complex cases routinely. [11]
Extraction costs typically range from $150 to $400 for a simple extraction and $200 to $800 or more for a surgical extraction. Tooth replacement costs, if applicable, are additional. Antibiotics, if prescribed, are generally inexpensive, ranging from $10 to $50 for a standard course. Costs vary by location, provider, and case complexity. Dental insurance often covers a significant portion of these procedures. Check with your insurance plan before scheduling treatment.
Find a Dental Specialist Near You
If you have symptoms of a tooth infection, an endodontist can evaluate the tooth and start treatment, often on the same day. Endodontists complete two to three years of advanced training beyond dental school, focusing entirely on diagnosing and treating problems inside the tooth. [11] You can search for an endodontist in your area on the endodontics page to find a specialist who can help.
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