Researchers have carried out a varity of investigations to determine the properties of available dentin bonding system. The test methods and variables used in 50 published investigations of bone strength were analyzed. Among the studies analyzed, shear tests predominated, being used in 80% of the studies; dentin from human molar teeth was used most often (in 88% of investigations); and the most prevalent time of testing was 24 hours postcuring. However, a number of potential varialbes were not recorded in a high proportion of articles, among these the film thickness, the type of dentin tested, and the surface condition (moist or dry). The mode of failure was reco rded in only 42% of the investigations assessed. It was found that htere is little standardization of test methods in studies of dentin bond strength and that a number of variables are often either not recorded or reporte