For amalgam restorations with less than 0.5 mm remaining dentin thickness, what is used?

• A. Sealer
• B. Liner, base, and sealer
• C. Liner
• D. Base

Answer: (B)

When there is very little dentin left, pulp protection and a good seal become crucial before placing amalgam. A liner is placed first to protect the pulp and help form reparative dentin. Then a base provides necessary thermal insulation and mechanical support so the amalgam doesn’t irritate the pulp. Finally, a sealer (cavity varnish) seals the tubules and reduces microleakage at the dentin–amalgam interface. Taken together, liner, base, and sealer address both pulp protection and a secure seal, which is why this combination is used when remaining dentin thickness is under 0.5 mm. Using only a liner or only a base wouldn’t provide all these protective and sealing benefits, and omitting the sealer leaves tubules unsealed, increasing leakage risk.