The combination 'mandrel and pop-on sandpaper disc' is used for which purpose?

• A. Holding amalgam
• B. Polishing and finishing restorations
• C. Matrix for composite
• D. Storage of burs

Answer: (B)

The main idea is finishing and polishing restorations. A mandrel acts as the holder that fits into the handpiece, and pop-on sandpaper discs attach to it to create a controllable abrasive surface. By using these discs, you can progressively smooth and polish the surface of a restoration—removing minor scratches, blending margins, and bringing the surface to a high-gloss finish. This is especially useful on composite restorations, where you want a smooth, esthetically pleasing finish that resists plaque buildup.

Why this fits best: finishing and polishing steps come after shaping a restoration, and the mandrel with pop-on discs provides a convenient, conformable way to polish contours efficiently. The other tasks—holding amalgam, acting as a matrix for composite, or storing burs—use different tools and setups, not this polishing combination.