The four generations of dentin bonding.

The achievement of an adhesive bond between enamel and dentin and restorative materials has been an objective for generations of dental research workers. Dentin bonding agents have been classified into generations, with earliest generations showing unreliable bond strengths. Some currently available systems show in vitro shear bond strengths to dentin which are similar to the bond strength to enamel, this being considered an ideal property. Alongside other previously recognized ideal properties, appropriate criteria for state-of-the-art dentin bonding systems at the present time may be considered to include the ability of systems to operate in moist environments and be technique insensitive.