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

• A. Enamel chisel
• B. Gingival Margin Trimmer
• C. Right angle probe
• D. Burnisher

Answer: (B)

The task is about shaping and refining the margin so that there’s a clean, supported edge after preparation. The gingival margin trimmer is designed for this exact job: its curved blade is oriented to access the gingival margin and trim away any enamel that is unsupported or any softened dentine right at the margin. This creates a proper bevel and a solid cavosurface margin that will seal well when a restoration is placed.

Enamel chisels can cut enamel, but they aren’t as well suited for finishing the gingival margin or removing marginal enamel precisely where it’s most prone to being unsupported. The right-angle probe is used to check margins and depths, not to cut, and the burnisher is used to smooth or burnish surfaces, not to cut.