Shear Bond Strengths of Different Substrates Bonded to Lithium Disilicate Ceramics

The aim of this study was to evaluate the shear bond strengths of pre- and untreated resin core materials to lithium disilicate ceramics. Bond strengths to dental hard tissues served as controls. Ceramic cubes (IPS-Empress II) were luted either with a one-step (Variolink II/ Excite DSC) or multiple-step total etching bonding system (Tetric Flow/ Syntac Classic) to ground surfaces of human enamel, dentin, and resin core materials (Clearfil Core, Multicore). Resin core materials were additionally pretreated with hydrofluoric acid (HF) or were silica-coated (CoJet System). Shear bond strengths were determined after 24-hour water storage (n=10) and thermocycling (TC) (n=10; 2000 cycles, 5-55°C, 30 seconds). Bond strengths to enamel, dentin, and silica-coated composites were significantly higher compared to untreated and HF-pretreated composites (p