A patient had fillings placed in teeth #28 and #29, both of which were sensitive afterward. The work was well done. The patient has controlled periodontal disease, gum recession of 3mm, and bone loss. Why did the patient experience sensitivity in tooth #28?

Correct answer: C. Referred pain from tooth #29

• A. INCORRECT — Gum recession is present (3mm), but this alone does not explain why #28 specifically became sensitive after #29 was restored.
• B. INCORRECT — Galvanic current occurs when dissimilar metals are in contact via saliva and can cause brief metallic taste or sensitivity, but the clinical scenario points to referred pain.
• C. CORRECT — When adjacent teeth are restored and one has pulpal involvement or significant sensitivity, referred pain is a well-documented phenomenon. Tooth #29 is likely the symptomatic tooth, and the dental pulp's convergence of nerve fibers (via the trigeminal nerve) can cause pain to be 'referred' to the adjacent tooth #28.
• D. INCORRECT — Cracked tooth syndrome presents with sharp pain on biting/release of biting; this scenario describes post-operative sensitivity after new fillings.