The Effects of Surface Roughness on Bond Strengths With Hybrid Ceramics

Objectives: To evaluate the effects of surface treatments of various hybrid ceramics and silane treatment on shear bond strength to resin cement.
Methods: Four brands of hybrid ceramic blanks (MAZIC Duro, VERICOM; Block HC, SHOFU; Lava Ultimate, 3M ESPE; VITA Enamic, VITA) for CAD/CAM system were tested. Hybrid ceramic blanks were grinded with 600 grit SiC papers. The hybrid ceramic specimens were divided each groups (n=6/group) according to each surface treatment and used silane primer (table 1). The surface roughness were analyzed and categorized. All specimens were cemented with resin cement, U-Cem Premium (VERICOM) but was used with/without silane primer(Ceramic primer II, GC). Silane primer was used in treated surface(alumina 50 µm, 1.5 bar, 10sec) and additionally HF-etching(IPS ceramic etching gel) for 60sec. Stub (Ø 3.0mm) of U-Cem premium cement was bonded to the surface and light cured. After 24 hours of storage at 37^oC, a shear bond test was performed using universal testing machine (Shimazu, Japan) at 1.0 mm/min crosshead speed until debonding. Statistical analysis was carried using ANOVA (α= 0.05).
Results: Silane treatment showed higher bond strengths than SiC#600(non-treatment) for MAZIC Duro and Lava Ultimate blanks. A significant increase in mean shear bond strength was measured for combination with surface and silane treatments, but a significant decrease was measured for HF and silane treatment for Lava Ultimate.
Conclusions: Cementation of hybrid ceramic using U-Cem Premium resin cement was affected surface roughness. Therefore surface and silane treatments seem to provide most reliable bonding in the hybrid ceramic restoration.