Explorer on one side: The dental explorer is used with its sharp point to enhance tactile sensation and to determine the presence of tooth decay on tooth enamel. William Probe on other side: Laser Markings mm1-2-3-5-7-8-9-10 to measure pocket depths around a tooth in order to establish the state of health of the periodontium with its long, thin, and blunted tip.There are markings inscribed onto the head of the instrument for accuracy and readability.