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 mm 2 ), 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), SiO 2 + 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 SiO 2 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.