Purpose: The bond strength and bond durability of two high-viscosity dual-curing resin luting agents with different surface treatments of ceramic were investigated. Materials and Methods: GN-I machinable ceramic surfaces were treated with 37% phosphoric acid for 30 s (PA), 5% hydrofluoric acid for 5 s (HF-5), 10 s (HF-10), or 30 s (HF-30), or blasting with 50-μm Al2O3 for 10 s (AB). The roughness of the ceramic surface was measured. Treated ceramic surfaces were bonded with three resin bonding systems (RBS): Ceramic Primer/LinkmaxHV (CP/LMHV), Monobond S/VariolinkIIHV (MBS/VLIIHV), or MBS/Heliobond/VLIIHV (MBS/HB/VLIIHV). A microshear test was used to measure the bond strength after 24 h (TC 0) and subsequent thermocycling (TC 10,000 at 4°C and 60°C). ANOVA was performed for statistical analysis, with significance set at p < 0.05. Results: For three RBSs, bond strength at TC 0 was not affected, regardless of ceramic surface treatment (p > 0.05). All combined groups of ceramic surface treatment and resin bonding system decreased after 10,000 thermal cycles, especially groups treated with alumina blasting and bonded with each of three RBSs (p < 0.05). MBS/HB/VLIIHV with each surface treatment did not improve the bond strength and durability compared with MBS/VLIIHV. Conclusion: CP/LMHV and MBS/VLIIHV obtained sufficient bond strength and bond durability to GN-I machinable ceramic by only cleaning with PA; the application of HB may not be necessary.

Keywords: resin luting agent, machinable ceramic, surface treatment, silane coupling agent, microshear bond strength