Effect of silica coating combined to a MDP-based primer on the resin bond to Y-TZP ceramic

The aim of this study was to evaluate the influence of silica coating and 10‐methacryloyloxydecyl dihydrogen phosphate (MDP)‐based primer applications upon the bonding durability of a MDP‐based resin cement to a yttrium stabilized tetragonal zirconia (Y‐TZP) ceramic. Ninety‐six Y‐TZP tabs were embedded in an acrylic resin (free surface for adhesion: 5 × 5 mm2), ground finished and randomly divided into four groups (N = 24) according to the ceramic surface conditioning: (1) cleaning with isopropanol (ALC); (2) ALC + phosphoric acid etching + MDP‐based primer application (MDP‐primer); (3) silica coating + 3‐methacryloyloxypropyl trimethoxysilane (MPS)‐based coupling agent application (SiO2 + MPS‐Sil); and (4) SiO2 + MDP‐primer. The MDP‐based resin cement was applied on the treated surface using a cylindrical mold (diameter= 3 mm). Half of the specimens from each surface conditioning were stored in distilled water (37°C, 24 h) before testing. Another half of the specimens were stored (90 days) and thermo‐cycled (12,000×) during this period (90d/TC) before testing. A shear bond strength (SBS) test was performed at a crosshead speed of 0.5 mm/min. Two factors composed the experimental design: ceramic conditioning strategy (in four levels) and storage condition (in two levels), totaling eight groups. After 90d/TC (Tukey; p < 0.05), SiO2 + MDP‐primer (24.40 MPa) promoted the highest SBS. The ALC and MDP‐primer groups debonded spontaneously during 90d/TC. Bonding values were higher and more stable in the SiO2 groups. The use of MDP‐primer after silica coating increased the bond strength. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.