A tooth has lingering pain to cold and spontaneous, throbbing aching but no periapical radiolucency. The pulpal diagnosis is:

Correct answer: A. Symptomatic irreversible pulpitis

• A. Correct. Lingering pain to thermal stimulus plus spontaneous pain indicates symptomatic irreversible pulpitis — the pulp is inflamed beyond recovery and requires endodontic treatment or extraction.
• B. Reversible pulpitis causes brief pain that resolves quickly after the stimulus is removed (no lingering/spontaneous pain).
• C. A necrotic pulp typically does not respond to cold (no vital response).
• D. A normal pulp responds briefly to cold with no lingering or spontaneous pain.