Perioontal scalers are dental instruments used primarily in the prophylactic and periodontal care of human teeth. The working ends come in a variety of shapes and sizes, but they are always sharp at the tip, so as to allow for access to narrow embrasure spaces between teeth. They differ from curettes, which possess a rounded tip to access subgingival calculus below the gum line. Subgingival use of a scaler would prove too traumatic to the gingiva for subgingival cleaning.