Merck Manual

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Bernard J. Hennessy

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

Reviewed/Revised Jan 2023

Pulpitis is inflammation of the dental pulp resulting from untreated caries, trauma, or multiple restorations. Its principal symptom is pain. Diagnosis is based on clinical findings, and results of x-rays and pulp vitality tests. Treatment involves removing decay, restoring the damaged tooth, and sometimes doing root canal therapy or extracting the tooth.

Pulpitis can occur when

Pulpitis is designated as

  • Reversible: Pulpitis begins as limited inflammation, and the tooth can be saved by a simple filling.

  • Irreversible: Swelling inside the rigid encasement of the dentin compromises circulation, making the pulp necrotic, which predisposes to infection.


Infectious sequelae of pulpitis include apical periodontitis Periodontitis Periodontitis is a chronic inflammatory oral disease that progressively destroys the tooth-supporting apparatus. It usually manifests as a worsening of gingivitis and then, if untreated, with... read more Periodontitis , periapical abscess, cellulitis Cellulitis Cellulitis is acute bacterial infection of the skin and subcutaneous tissue most often caused by streptococci or staphylococci. Symptoms and signs are pain, warmth, rapidly spreading erythema... read more Cellulitis , and (rarely) osteomyelitis Osteomyelitis Osteomyelitis is inflammation and destruction of bone caused by bacteria, mycobacteria, or fungi. Common symptoms are localized bone pain and tenderness with constitutional symptoms (in acute... read more Osteomyelitis of the jaw. Spread from maxillary teeth may cause purulent sinusitis Sinusitis Sinusitis is inflammation of the paranasal sinuses due to viral, bacterial, or fungal infections or allergic reactions. Symptoms include nasal obstruction and congestion, purulent rhinorrhea... read more Sinusitis , meningitis Overview of Meningitis Meningitis is inflammation of the meninges and subarachnoid space. It may result from infections, other disorders, or reactions to drugs. Severity and acuity vary. Findings typically include... read more , brain abscess Brain Abscess A brain abscess is an intracerebral collection of pus. Symptoms may include headache, lethargy, fever, and focal neurologic deficits. Diagnosis is by contrast-enhanced MRI or CT. Treatment is... read more Brain Abscess , orbital cellulitis Preseptal and Orbital Cellulitis Preseptal cellulitis (periorbital cellulitis) is infection of the eyelid and surrounding skin anterior to the orbital septum. Orbital cellulitis is infection of the orbital tissues posterior... read more Preseptal and Orbital Cellulitis , and cavernous sinus thrombosis Cavernous Sinus Thrombosis Cavernous sinus thrombosis is a very rare, typically septic thrombosis of the cavernous sinus, usually caused by nasal furuncles or bacterial sinusitis. Symptoms and signs include pain, proptosis... read more .

Symptoms and Signs of Pulpitis

In reversible pulpitis, pain occurs when a stimulus (usually cold or sweet) is applied to the tooth. When the stimulus is removed, the pain ceases within 1 to 2 seconds.

In irreversible pulpitis, pain occurs spontaneously or lingers minutes after the stimulus (usually heat, less frequently cold) is removed. A patient may have difficulty locating the tooth from which the pain originates, even confusing the maxillary and mandibular arches (but not the left and right sides of the mouth). The pain may then cease for several days because of pulpal necrosis. When pulpal necrosis is complete, the pulp no longer responds to hot or cold but often responds to percussion. As infection develops and extends through the apical foramen, the tooth becomes exquisitely sensitive to pressure and percussion. A periapical (dentoalveolar) abscess elevates the tooth from its socket, and the tooth feels “high” when the patient bites down.

Diagnosis of Pulpitis

  • Clinical evaluation

  • Sometimes dental x-rays

Diagnosis is based on the history and physical examination, which makes use of provoking stimuli (application of heat, cold, and/or percussion). Dentists may also use an electric pulp tester, which indicates whether the pulp is alive but not whether it is healthy. If the patient feels the small electrical charge delivered to the tooth, the pulp is alive.

X-rays help determine whether inflammation has extended beyond the tooth apex and help exclude other conditions.

Treatment of Pulpitis

  • Drilling and filling for reversible pulpitis

  • Root canal and crown or extraction for irreversible pulpitis

  • Antibiotics (eg, amoxicillin or clindamycin) for infection that cannot be resolved with local measures

In reversible pulpitis, pulp vitality can be maintained if the tooth is treated, usually by caries removal, and then restored.

In irreversible pulpitis, the pulpitis and its sequelae require endodontic (root canal) therapy or tooth extraction. In endodontic therapy, an opening is made in the tooth and the pulp is removed. The root canal system is thoroughly debrided, shaped, and then filled with gutta-percha. After root canal therapy, adequate healing is manifested clinically by resolution of symptoms and radiographically by bone filling in the radiolucent area at the root apex over a period of months. If patients have systemic signs of infection (eg, fever), an oral antibiotic is prescribed (amoxicillin 500 mg every 8 hours; alternatives for patients allergic to penicillin include cephalexin or another first- or second-generation cephalosporin, azithromycin, clarithromycin, or doxycycline) (1 Treatment reference Pulpitis is inflammation of the dental pulp resulting from untreated caries, trauma, or multiple restorations. Its principal symptom is pain. Diagnosis is based on clinical findings, and results... read more ). If symptoms persist or worsen, root canal therapy is usually repeated in case a root canal was missed, but alternative diagnoses (eg, temporomandibular disorder, occult tooth fracture, neurologic disorder) should be considered.

Very rarely, subcutaneous or mediastinal emphysema develops after compressed air or a high-speed air turbine dental drill has been used during root canal therapy or extraction. These devices can force air into the tissues around the tooth socket that dissects along fascial planes. Acute onset of jaw and cervical swelling with characteristic crepitus of the swollen skin on palpation is diagnostic. Treatment usually is not required, although prophylactic antibiotics are sometimes given.

Treatment reference

  • 1. Wilson WW, Gewitz M, Lockhart PB, et al: Prevention of viridans group streptococcal infective endocarditis: A scientific statement from the American Heart Association. Circulation 18;143(20):e963-e978, 2021. doi: 10.1161/CIR.0000000000000969

Key Points

  • Pulpitis is inflammation of the dental pulp due to deep cavities, trauma, or extensive dental repair.

  • Sometimes infection develops (eg, periapical abscess, cellulitis, osteomyelitis).

  • Pulpitis may be reversible or irreversible.

  • In reversible pulpitis, the pulp is not necrotic, a cold or sweet stimulus causes pain that typically lasts 1 or 2 seconds, and repair requires only drilling and filling.

  • In irreversible pulpitis, the pulp is becoming necrotic, the stimulus (often heat) causes pain that typically lasts minutes, and root canal or extraction is needed.

  • Pulpal necrosis is a later stage of irreversible pulpitis; the pulp does not respond to hot or cold but often responds to percussion, and root canal or extraction is needed.

Drugs Mentioned In This Article

Drug Name Select Trade
Amoxil, Dispermox, Moxatag, Moxilin , Sumox, Trimox
Cleocin, Cleocin Ovules, Cleocin Pediatric, Cleocin T, CLIN, Clindacin ETZ, Clindacin-P, Clinda-Derm , Clindagel, ClindaMax, ClindaReach, Clindesse, Clindets, Evoclin, PledgaClin, XACIATO
Biocef, Daxbia , Keflex, Keftab, Panixine
Azasite, Zithromax, Zithromax Powder, Zithromax Single-Dose , Zithromax Tri-Pak, Zithromax Z-Pak, Zmax, Zmax Pediatric
Biaxin, Biaxin XL
Acticlate, Adoxa, Adoxa Pak, Avidoxy, Doryx, Doxal, Doxy 100, LYMEPAK, Mondoxyne NL, Monodox, Morgidox 1x, Morgidox 2x , Okebo, Oracea, Oraxyl, Periostat, TARGADOX, Vibramycin, Vibra-Tabs
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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