A patient who underwent radiotherapy for oral cancer is given a cold (thermal) test. What happens?

Correct answer: C. Feels LESS pain (reduced response)

• A. Incorrect. Radiation tends to reduce, not heighten, pulpal sensory response over time.
• B. Incorrect. Studies show a progressive CHANGE (decrease) in pulp sensibility, not unchanged responses.
• C. Correct. Head/neck radiotherapy progressively decreases pulpal microvascular/sensory response, so teeth respond LESS to cold (with some showing no response by 6–12 months).
• D. Incorrect. Response decreases progressively; complete absence is not universal early on, so 'less' is the better general answer.