Merck Manual

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Bernard J. Hennessy

, DDS, Texas A&M University, College of Dentistry

Reviewed/Revised Feb 2023
Topic Resources

Pulpitis is painful inflammation of the tooth pulp, the innermost part of the tooth that contains the nerves and blood supply.

The most common cause of pulpitis is tooth decay, and the second most common cause is injury. Mild inflammation, if relieved, may not damage the pulp permanently. Severe inflammation may cause the pulp to die.

Pulpitis may lead to infection, in which a pocket of pus (periapical abscess Periapical Abscess A periapical abscess is a collection of pus at the root of a tooth, usually caused by an infection that has spread from a tooth to the surrounding tissues. (See also Overview of Tooth Disorders... read more ) develops at the root of the tooth. An untreated infection in a tooth may spread to the jaw or to other areas of the body (such as the brain or sinuses).

A Look Inside a Tooth


Symptoms of Pulpitis

Pulpitis causes intense tooth pain. If an abscess is present, the tooth becomes extremely sensitive to pressure and tapping with a dental instrument.

Diagnosis of Pulpitis

  • Testing tooth for sensitivity

  • Testing pulp for vitality with an electric pulp tester

To determine whether the pulp is healthy enough to save, dentists can do certain tests. For example, dentists can apply a hot, sweet, or cold stimulus. If the pain goes away within 1 to 2 seconds after the stimulus is removed, the pulp may be healthy enough to be saved (called reversible pulpitis). If pain persists after the stimulus is removed or if pain occurs spontaneously, the pulp may not be healthy enough to save (called irreversible pulpitis).

Dentists may also use an electric pulp tester, which indicates whether the pulp is alive but not whether it is healthy. If the person feels the small electrical charge delivered to the tooth, the pulp is alive. Sensitivity to tapping on a tooth often means that inflammation has spread to the surrounding tissues. Doctors sometimes do x-rays to evaluate the bone around the tooth for changes related to inflammation of the pulp such as a cyst or inflammation of the bone itself.

Treatment of Pulpitis

  • Removal of cavities

  • Restoration of tooth

  • Sometimes root canal treatment

  • Sometimes antibiotics

The inflammation stops when the cause is treated.

In reversible pulpitis, pain and inflammation go away after dentists remove any decay (cavities Cavities Cavities are decayed areas in the teeth, the result of a process that gradually dissolves a tooth’s hard outer surface (enamel) and progresses toward the interior. (See also Overview of Tooth... read more Cavities ) and then restore the tooth. When pulpitis is detected early, dentists sometimes place a temporary filling containing a sedative that can eliminate the pain. This filling can be left in place for 6 to 8 weeks and then replaced with a permanent filling. Most often, dentists place a permanent filling immediately.

In irreversible pulpitis, pulp damage is extensive and cannot be reversed. The only way dentists can stop the pain is by removing the pulp via root canal treatment Root canal treatment and tooth extraction Cavities are decayed areas in the teeth, the result of a process that gradually dissolves a tooth’s hard outer surface (enamel) and progresses toward the interior. (See also Overview of Tooth... read more Root canal treatment and tooth extraction or tooth removal (extraction). If people have other signs of infection (such as a fever), dentists may give antibiotics taken by mouth. Sometimes root canal treatment is repeated if the symptoms do not go away or worsen.

More Information

The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

  • Mouth Healthy: This general resource provides information on oral health, including nutrition and guidance on selecting products that carry the American Dental Association's seal of approval. There is also advice on finding a dentist and how and when to see one.

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