Dental explorer
A dental explorer or sickle probe is an instrument in dentistry commonly used in the dental armamentarium. A sharp point at the end of the explorer is used to enhance tactile sensation. In the past it was usual for dentists to use the explorer to probe teeth for the presence of cavities. Some dental professionals have questioned this practice in the first decade of the twenty-first century. The use of a sharp explorer to diagnose caries in pit and fissure sites is no longer recommended and clinicians instead should rely on "sharp eyes and a blunt explorer  or probe." Penetration by a sharp explorer can actually cause cavitation in areas that are remineralizing or could be remineralized. Dental lesions initially develop as a subsurface lesion. Early lesions may be reversed - with meticulous patient self-care and application of fluoride - as long as the thin surface layer remains intact. The use of a dental explorer with firm pressure to probe suspicious areas may result in the rupture of the surface layer covering early lesions. Instead, they argue that fluoride and oral hygiene should be used to remineralize the enamel and prevent it from decaying further. This debate still  continues because sometimes decay can be difficult to diagnose without tactile verification. Additionally, radiographs and other products designed to identify decay (such as measuring fluorescence from a laser) help the dental professional make a final diagnosis of tooth decay. There are various types of explorers, though the most common one is the No. 23 explorer, which is also known as a "shepherd's hook". Other types include the 3CH (also known as "cowhorn" or "pigtail") and No. 17 explorers, which are useful for the interproximal areas between teeth.