A patient reports sensitivity in the first premolar that began after the SECOND premolar was restored. Radiographs show a sound restoration on the second premolar and gingival recession on the first premolar. What is the most likely explanation and next step?

Correct answer: A. Exposed root dentin from recession — manage with desensitizing measures and monitor

• A. CORRECT. Recession-exposed root dentin is by far the most parsimonious explanation for the findings described, and the radiograph confirms it. The temporal association with the neighbouring restoration is coincidental — patients frequently become aware of a pre-existing sensitivity only after attention has been drawn to the area.
• B. The stem states the restoration is sound. Replacing a satisfactory restoration to chase a symptom arising from an adjacent tooth is unnecessary intervention.
• C. Cracked tooth syndrome causes pain on RELEASE of biting pressure and is not supported by the findings given.
• D. Irreversible pulpitis produces spontaneous, lingering, poorly localized pain. Sensitivity attributable to exposed dentin is stimulus-bound and stops when the stimulus is removed.

Note: Two useful principles here. First, dental pain is poorly localized — patients routinely misattribute it to the adjacent tooth or even the opposing arch, so always test the neighbours. Second, temporal association is not causation: 'it started after you did X' is a hypothesis to test, not a diagnosis.