Which instrument is primarily used to remove calculus from subgingival surfaces?

• A. Scaler
• B. Curette
• C. Explorer
• D. Hoe

Answer: (B)

When calculus is below the gum line, you need an instrument that can safely adapt to the root surface and access deep pockets without harming soft tissue. A curette fits this need because its blade is curved and smooth, and the instrument is designed to work along the root surfaces in subgingival areas. It allows you to remove calculus progressively with controlled strokes and to debride the root surface, often using area-specific Gracey configurations that match different parts of the mouth. This design minimizes tissue trauma while effectively cleaning deposits from beneath the gingival margin.

Scalers, with their sharp, pointed blades, are best for supragingival calculus and can cause tissue trauma or root gouging if used under the gum line. An explorer is mainly for detecting calculus and evaluating the tooth surface, not for removing deposits. A hoe is heavier and used more for planing larger, accessible surfaces rather than precise subgingival debridement.