Bond strength of ceramic or resin CAD-CAM laminate veneers

Purpose: To compare the bond strength of ceramic or resin laminate veneers produced using computer assisted design/computer assisted machining (CAD-CAM). Methods: 80 teeth were prepared for laminate veneer, and divided into eight groups of different CAD-CAM blocks in each group. Each group was restored with the manufacturers' recommended procedures. After cementation of the veneers, all samples were thermocycled (1,000 cycles); the crowns of the teeth were embedded vertically into acrylic blocks and subjected to shear bond strength in a universal tester. Shear bond strength was determined in Newtons (N). Results: The tests showed 52.5% cohesive failure, 30% adhesive failure, and 17.5% adhesive-cohesive failure (mixed). Lava Ultimate had the highest bond strength average and the Cerec blocks had the lowest with 82.2N. Lava Ultimate, Cerasmart, and E-Max's shear bond strength values were statistically different compared to Vitablocs Mark II, Cerec Blocs, GC Initial LRF Blocks (P< 0.05). The difference between the Vitablocs Mark II and Cerec Blocs and the Vita Enamic block was statistically significant. There was no statistically significant difference among the other groups. The selected CAD-CAM material affected the shear bond strength of the laminate veneers.