Pre-Clinic II Practice Test

The key idea here is the instrument geometry that lets you work beneath the gumline. Gracey curettes are designed with a 70-degree offset between the blade and the shank, which positions the cutting edge so you can adapt the blade to the root surface while your handle remains comfortably aligned. This offset lets the tip of the blade follow the contour of the root and access narrow periodontal pockets without traumatizing soft tissue, making them ideal for subgingival scaling and root planing. Other tools don’t have this combination: a sickle scaler is mainly for supragingival deposits, the air polisher is a cleaning device rather than a periodontal instrument, and a universal curette has no such offset and isn’t optimized for subgingival access.