Which instrument is used to cut enamel and ensure no unsupported enamel or soft dentine remains?

• A. Burnisher
• B. Mouth mirror
• C. Amalgam plugger
• D. Gingival Margin Trimmer

Answer: (D)

The instrument used to cut enamel and remove any unsupported enamel or softened dentine at the margins is the gingival margin trimmer. Its curved cutting edge is designed to bevel and trim the gingival margin precisely, allowing you to eliminate thin, undermined enamel and any softened dentine so the margin is strong and well-sealed. This helps create a proper cavosurface bevel and prevents marginal breakage or leakage.

Other tools have different roles: a burnisher smooths and shapes restorations after placement, a mouth mirror aids vision and retraction, and an amalgam plugger condenses amalgam. None of these are intended to cut enamel or remove unsupported margin enamel like the gingival margin trimmer.