Verification and maintenance of dental explorer sharpness.

An ongoing study of the relationship between different chewing gums, remineralization, and caries rates was started in 1989 in Belize, Central America. Initially 1277 children, age 10 years, were assigned in equal randomized groups to four dentists who had been trained to identify a standard of caries diagnosis. The same children were examined according to a modified WHO caries code by the same dentist in each of the three subsequent years. To eliminate one possible variable, all 200 dental explorers used were examined under a X20 binocular Bausch and Lomb dissecting microscope initially and at each exam period. Any explorer not comparable to an explorer that was originally marked and kept unused as a standard was sharpened by hand on an Arkansas oilstone wetted with engine oil for lubrication. Explorers that could not be restored to a condition comparable at X20 to the standard were discarded. Approximately 10% of the explorers needed correction at each exam period and about 1% were discarded. In any study related to dental caries evaluation with dental explorers or comparison of explorer use versus nonuse, verification and maintenance of sharpness of used and even new dental explorers should be addressed to remove that factor as a possible variable.