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Statement of Problem: Indirect composite resins (ICRs) have been suggested as veneering materials for implant-supported zirconia-based fixed dental prostheses; however, obtaining a durable bond between the zirconia ceramic and the ICR is a challenge., Purpose: The purpose of this in vitro study was to evaluate the influence of airborne-particle abrasion conditions on the bond strength between 2 kinds of zirconia (yttria-stabilized tetragonal zirconia polycrystal [Y-TZP] and ceria-stabilized tetragonal zirconia/alumina nanocomposite [Ce-TZP/A]) and an ICR., Material and Methods: Zirconia disks were prepared by using computer-aided design and computer-aided manufacturing (CAD-CAM) systems. Specimens were airborne-particle abraded with different particle sizes (25, 50, 90, 125 μm) and jet pressures (0.1, 0.2, 0.3, 0.4 MPa). The control group (CO) was not subjected to airborne-particle abrasion. The surface roughness (Ra) of the specimens was measured. Subsequently, the specimens were treated with a primer and bonded with a light-activated composite resin, and the shear bond strength (SBS) was tested. The obtained data were analyzed by using multivariate analysis of variance, the Spearman rank-order correlation, and the Mann-Whitney U test (α=.05). After the SBS test, the interface failure modes were observed by scanning electron microscopy, and X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical changes of the zirconia surface., Results: The Ra values increased significantly (P<.05) after airborne-particle abrasion with a positive correlation with both particle size and jet pressure. The airborne-particle abraded specimens exhibited significantly higher bond strength after thermocycling (P<.05) than the CO. Nevertheless, the bond strength was not significantly different among different airborne-particle abrasion treatments (P>.05). Additionally, Y-TZP had higher mean bond strength values than Ce-TZP/A. The XPS results revealed that after airborne-particle abrasion, the alumina particles mechanically adhered to the zirconia surface., Conclusions: Within the limitations of this in vitro study, airborne-particle abrasion improved the bond strength between zirconia and ICR; however, particle size or jet pressure were not influencing factors., (Copyright © 2019 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

We investigated the chemical interaction between zirconia surfaces and functional monomers using X-ray photoelectron spectroscopy (XPS). Two types of zirconia disks cleaned with piranha solution were treated with one of two phosphate primers (Alloy Primer, Clearfil Ceramic Primer) or a carboxylic primer (Super-Bond C&B Monomer), and rinsed 3 times with acetone. XPS analysis revealed that phosphorus was incorporated into zirconia when the surface was treated with a primer containing phosphate monomer (10-methacryloyloxydecyl dihydrogen phosphate; MDP). However, the S 2p peak of a triazine dithiol monomer (6-[N-(4-vinylbenzyl)-n-propylamino]-1,3,5-triazine-2,4-dithione; VTD) and Si 2p peak of silane (3-trimethoxysilylpropyl methacrylate; TMSPMA) were not detected in the spectra of the primed surface. The [C]/[Zr] ratio for the surface treated with a carboxylic anhydride (4-methacryloyloxyethyl trimellitate anhydride; 4-META) primer was smaller than that treated with MDP. These results demonstrated that 4-META and MDP adsorbed to zirconia, whereas the VTD and TMSPMA did not.