An elderly patient has a zirconia crown on tooth #18. A carious lesion has developed cervically below the crown margin, extending subgingivally. What is the most appropriate management?

Correct answer: B. Silver diamine fluoride (SDF) application to arrest the carious lesion

• A. A Class V composite requires adequate access and dry field control — subgingival extension makes this extremely challenging in an elderly patient.
• B. CORRECT. For an elderly patient with a subgingival carious lesion that is difficult to access for conventional restoration, silver diamine fluoride (SDF) is an appropriate non-invasive, palliative caries management strategy. SDF arrests active carious lesions and is especially valuable in elderly, medically compromised, or patients where invasive treatment is high-risk or impractical.
• C. Crown lengthening may ultimately be needed, but SDF as an immediate conservative measure to arrest the lesion is the most appropriate first step before planning more complex treatment.
• D. Removing and replacing the zirconia crown is invasive, expensive, and may not be appropriate without addressing the carious lesion and access issues first.