Abstract The use of tooth-colored dental restorative materials,

along with the adhesive techniques, has become routine

in today’s dental practice. The longevity of adhesive restorations

depends mainly on good bonding between restorative

materials and tooth structure, which should be achieved in

situ, within minutes. While bonding to enamel is reliable

through micromechanical retention, bonding to dentin presents

challenges due to its more complex collagenous structure.

Progressive loss of resin-dentin bond integrity and reduction

in bond strength have been extensively reported. This was

attributed partly to the hydrophilic nature of the contemporary

adhesives systems that causes unwanted water absorption,

phase separation, and resin leaching and also to the endogenous

collagenolytic enzymes that can slowly hydrolyze collagen.

Current research in this field aims at increasing the durability

of resin-dentin bonds by inhibition of the collagenolytic

activity of dentin, as well as implementing bonding strategies

which allow the use of more hydrophobic bonding agents.