Which tool is used to measure the pocket depth in periodontal assessments?

The tool specifically designed to measure pocket depth during periodontal assessments is the periodontal probe. This instrument is characterized by its calibrated, slender design, which allows for precise measurements of the depth of the sulcus or periodontal pockets around each tooth.

The periodontal probe features markings along its length, usually in millimeter increments, enabling dental professionals to accurately record the depth of gum pockets, which is crucial for diagnosing periodontal health. This measurement helps in determining the presence and severity of periodontal disease, guiding appropriate treatment decisions.

Other tools listed, such as the dental mirror, are used for visual examination, the sickle scaler is primarily for scaling and removing calculus, and the exploratory probe is used for assessing tooth surfaces for caries and irregularities, but none are specifically designed for measuring pocket depth in the way that a periodontal probe is intended. Therefore, the periodontal probe is the correct and most appropriate choice for this assessment.