Which instrument is used to measure the depth of the gingival sulcus?

The instrument used to measure the depth of the gingival sulcus is a periodontal probe. This specialized tool is designed with a calibrated, tapered tip that allows the dental professional to gently insert it into the sulcus, which is the space between the tooth and the surrounding gum tissue. The calibrated markings on the probe allow for accurate measurement of the depth, which is crucial for diagnosing periodontal disease and assessing the health of the patient's gums.

Other instruments, such as the cowhorn explorer, right-angle explorer, and shepherd's hook, serve different purposes in the dental examination process. The cowhorn explorer is primarily used to detect carious lesions or abnormalities in the tooth structure. The right-angle explorer helps in examining hard-to-reach areas for decay or calculus. The shepherd's hook is mainly utilized for checking pits and fissures on teeth but does not provide the measurement capability necessary for assessing the sulcus depth. Thus, the periodontal probe stands out as the appropriate instrument for this specific task.