Based SOLELY on a sharp, transient response of the pulp to a hot stimulus, what periradicular diagnosis can be made?

Correct answer: B. No periradicular diagnosis can be made from this information

• A. An acute apical abscess requires swelling and a necrotic pulp — a pulp responding sharply to heat is vital, not necrotic.
• B. CORRECT. This tests whether you understand that PULPAL and PERIRADICULAR diagnoses are made from different data. A thermal response describes the state of the PULP. Periradicular status is established by PERCUSSION, PALPATION, probing and radiographs — none of which is given here. Without that information no periradicular diagnosis is possible.
• C. Acute apical periodontitis is diagnosed from tenderness to PERCUSSION, which has not been tested.
• D. Irreversible pulpitis is a PULPAL diagnosis, and in any case a SHARP TRANSIENT response that resolves on removal of the stimulus indicates a normal or reversibly inflamed pulp — lingering pain is what signals irreversibility.

Note: Every endodontic diagnosis has two halves: a pulpal diagnosis and a periradicular diagnosis. Thermal and electric tests give you the first; percussion, palpation and radiographs give you the second.