The long-term bonding of dental materials to dentin remains an area of great controversy and the results of in vitro testing do not always reflect those found in vivo. The clinician is faced with a large number of dentinal bonding agents that have had limited testing in vivo and are frequently replaced before any long-term clinical testing has been completed. Glass-ionomer cements, although having a longer history of good adhesion to dentin, are not suitable for use in high-stress-bearing areas. The selection of materials for specific clinical situations has become more and more difficult. This paper gives a personal view of the history and evolution of both resin bonding agents and glass-ionomer cements and their potential in clinical use.