Which instrument is described as curved and not sharp?

• A. Scaler
• B. Ultrasonic
• C. Probe
• D. Curette

Answer: (D)

Understanding instrument design helps explain why this one fits the description. In dental instrumentation, the way the blade or working end is shaped determines how it interacts with calculus and tissue. A curved instrument with a rounded toe and a more blunt edge is designed to scooping remove deposits from around the tooth roots while minimizing tissue injury; that describes a curette. Curettes are built with a curved, often semicurved blade and a rounded toe so you can reach subgingival surfaces without gouging the gingiva.

Scalers, by contrast, have sharp edges and pointed or triangular blades intended for removing supragingival calculus, which makes them sharp and less suited to gentle subgingival use. Probes and ultrasonic tips aren’t cutting instruments in the same way—they’re used for measurement or for vibrating to disrupt deposits, not for the curved, rounded cutting action described here. So the instrument described as curved and not sharp is a curette.