Dentin/Adhesive Interface in Teeth

Clinical studies have demonstrated an alarmingly high failure rate for posterior composite dental restorations. The premature failure of moderate-to-large composite restorations can be traced to a breakdown of the bond at the tooth surface/composite material interface and increased levels of cariogenic bacteria at the perimeter of these materials. In this chapter, we discuss the dentin/adhesive bond, with a focus on the failure of current adhesives to consistently seal and adhere to the dentin. The concept of forming a resin-reinforced hybrid layer for improved adhesion is presented. The complex role of water in dentin/adhesive bonding is then described. Finally, mechanisms leading to mechanical property changes at the interface are discussed.