Effect of immediate dentin sealing applications on bonding of CAD/CAM ceramic onlay restoration.

The effects of immediate dentin sealing (IDS) applications on the bonding of computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic onlay restorations after cyclic loading were examined. Standardized mesial-distal-occlusal-palatal cavities in 32 extracted human molars were prepared. The cavities were divided into four groups: those receiving thin-layered (T), slope-shaped (S), and base-shaped (B) sealing, and the non-sealing group (N) as a control. The intra-cavity dentin walls of the T, S, and B groups were sealed with an all-in-one adhesive and a flowable composite. All cavities were scanned; hence, CAD/CAM onlays were fabricated using ceramic blocks and bonded with a resin cement system. Cyclic loading was applied and the microtensile bond strength (μ-TBS) was measured. It was found that IDS application improved not only the μ-TBS, but also the bonding reliability and durability of the CAD/CAM restoration. In particular, the S restoration exhibited the highest-performance as regards both robust bond strength and stable bonding.