A patient has a 6-to-11 fixed bridge. The edentulous area under the bridge shows significant erythema on clinical examination. The most likely cause is:

Correct answer: D. Poor pontic design with excessive tissue contact

• A. Incorrect. While oral hygiene contributes, erythema localized specifically under the pontic strongly implicates the pontic design rather than hygiene alone.
• B. Incorrect. Metal allergy causing gingival erythema is possible but rare and less common than pontic design issues.
• C. Incorrect. Recurrent caries occurs at abutment tooth margins, not under a pontic where there is no tooth structure.
• D. CORRECT. Poor pontic design — particularly a ridge-lap or modified ridge-lap pontic with excessive tissue contact — traps plaque and causes chronic irritation of the underlying mucosa, leading to erythema. The appropriate fix is to revise the pontic design or switch to a hygienic/ovate pontic form with minimal tissue contact.