The diameter of the tip of a periodontal probe is:

 # The diameter of the tip of a periodontal probe is:

A. 0.25 mm

B. 0.5 mm

C. 0.75 mm

D. 1 mm

The correct answer is B. 0.5 mm.

Periodontal probes are used to measure the depth of pockets and to determine their configuration. The typical probe is a tapered, rodlike instrument calibrated in millimeters, with a blunt, rounded tip. There are several other designs with various millimeter calibrations. The World Health Organization (WHO) probe has millimeter markings and a small, round ball at the tip. Ideally, these probes are thin, and the shank is angled to allow easy insertion into the pocket. Furcation areas can best be evaluated with the curved, blunt Nabers probe. When measuring a pocket, the probe is inserted with a firm, gentle pressure to the bottom of the pocket. The shank should be aligned with the long axis of the tooth surface to be probed. Several measurements are made to determine the level of attachment along the surface of the tooth.

Reference: Carranza's Clinical Periodontology 12th edition.