A patient reports pain to hot that is relieved by cold, has a positive response on electric pulp testing, and the pain lingers for minutes. What is the most likely diagnosis?

Pain to hot that is relieved by cold is a classic sign of advanced (late-stage) symptomatic irreversible pulpitis. In this stage, the inflamed pulp has increased interstitial pressure; cold (which causes vasoconstriction and reduces pulp pressure) provides temporary relief. Lingering pain after stimulus is the hallmark of irreversible pulpitis. A positive EPT response confirms pulp vitality (the pulp is still alive, just irreversibly inflamed). Reversible pulpitis causes sharp transient pain that resolves quickly. Pulp necrosis would typically show no response to cold or EPT. This presentation requires root canal treatment.