[Retention or adhesion?].

One of the reasons for immediate or late failure of restorations is the detachment of the restoration from the tooth. Retention for the restoration could be achieved from axial walls (macromechanical retention) or from adhesion of the restoration to the remaining tooth structure. Adhesion relies on bonding of resin cement to enamel or dentin on one side and to the restorative material on the other side. Bonding to enamel is predictable. Good bonding to dentin is more of a challenge especially with indirect restorations. In those cases the restoration is delivered usually a few days after the tooth was prepared during this time the exposed dentin might be contaminated or damaged. The question is whether you can rely on adhesion when cementing indirect restorations? In order to achieve the maximal bonding strength to dentin, the hybrid layer on the dentin must be built immediately after tooth preparation. This procedure is called Immediate Dentin Sealing. In vitro and clinical studies have shown better performance of restorations cemented following the IDS procedure. The article discusses the rational and the protocol of this procedure. A clinical case is presented as an example for the possibilities following this philosophy.