Periodontal scaler

Periodontal scalers have sharp tips to access tight embrasure spaces between teeth and are triangular in cross-section.
A posterior scaler shown in relation to a posterior tooth on a typodont.

Periodontal scalers are dental instruments used in the prophylactic and periodontal care of teeth (most often human teeth), including scaling and root planing. The working ends come in a variety of shapes and sizes, but they are always narrow at the tip, so as to allow for access to narrow embrasure spaces between teeth. They differ from periodontal curettes, which possess a blunt tip.

Use

Together with periodontal curettes, periodontal scalers are used to remove calculus from teeth. Scalers are used above the gum line, and curettes are used below it. Use of a scaler below the gum line is likely to damage the gingiva (gums).

The anterior scaler (yellow ring) is straight, while the posterior scaler (orange ring) has an angled terminal shank (highlighted in red) to allow for easy access to the surfaces of posterior teeth.

Scalers are universal and have scraping edges on both sides of their blades, and are thus fit for both mesial and distal surfaces of any tooth in the area in which they are being used.

Scalers are best used when their terminal shanks, namely, the last portions of the handle attached to the blades, are held parallel to the long axis of the tooth. To facilitate proper usage, instruments often come with posterior analogs which possess angled terminal shanks.