Endodontic diagnosis: naming pulp and apical disease

What it is

Endodontic diagnosis names two things separately: the pulp (inside the tooth) and the apical tissues (bone and ligament around the root tip). The pulp diagnosis comes mainly from the history and the response to cold; the apical diagnosis from percussion, palpation, swelling and the radiograph. Standard terms make treatment decisions and records consistent.

Findings and interpretation

• Pulp: normal; reversible pulpitis (short pain to cold that stops); symptomatic irreversible pulpitis (lingering or spontaneous pain); asymptomatic irreversible pulpitis (deep caries reaching the pulp, no pain).
• Pulp: necrosis (no response to tests); previously treated (root filled); previously initiated therapy (partly treated).
• Apical: normal; symptomatic apical periodontitis (pain to bite or percussion); asymptomatic apical periodontitis (radiolucency, no symptoms).
• Apical: acute apical abscess (rapid onset, pain, swelling); chronic apical abscess (little pain, a draining sinus tract).
• Condensing osteitis: a diffuse radiopaque area around the apex from low-grade inflammation.

How it is done

1. Take the pain history: what starts it, how long it lasts after the stimulus, whether it is spontaneous or wakes the patient, and pain on biting.
2. Look for caries, deep or leaking fillings, cracks, swelling and sinus tracts; probe the gums around the tooth.
3. Test the suspect tooth and its neighbours and the same tooth on the other side with cold; note whether pain lingers.
4. Percuss and palpate over the root tips.
5. Take a periapical radiograph (and CBCT only when it will change management).
6. Write a pulp diagnosis and an apical diagnosis.

Common mistakes

• A single test can mislead: necrotic multirooted teeth, calcified canals and recent trauma give false results.
• Referred pain is common: the painful tooth may be in the other jaw on the same side.
• Radiographs miss early apical periodontitis until bone has been lost.

Next step / Initial management

• Record a pulp diagnosis and an apical diagnosis for every tooth before treatment.
• Reversible pulpitis: remove the cause and restore; irreversible pulpitis or necrosis: refer to the dentist for pulpotomy, root canal treatment or extraction.
• Acute apical abscess with spreading swelling, fever or trismus: urgent drainage; refer the same day.

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Educational content; it does not replace assessment by a dentist or doctor and is not a clinical instruction. For facial or neck swelling with difficulty swallowing or breathing, a knocked-out tooth or bleeding that will not stop, go to an emergency department at once.

Sources: Diagnosis consensus among endodontic specialists and general practitioners: An international survey and a proposed modification to the current diagnostic terminology (International Endodontic Journal (PMC open access), 2022); Apical Periodontitis (StatPearls Publishing (NCBI Bookshelf), 2023); Endodontic Periapical Lesion: An Overview on the Etiology, Diagnosis and Current Treatment Modalities (European Endodontic Journal (PMC open access), 2020); Anatomy, Head and Neck, Dental Pulp (StatPearls Publishing (NCBI Bookshelf), 2025).

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