Effect of Silica-coating on the Bond Strength to Zirconium

Objectives: The purpose of this study was to examine the effect of two silica-coating methods on the shear bond strength to zirconium with an adhesive resin cement.

Methods: This study used zirconia ceramic disks (yttria-stabilized zirconia) with a 15 mm diameter and 10 mm thickness and stainless steel rods with a 5 mm diameter and 3 mm thickness. The ceramic samples were embedded in epoxy resin and the surface of the ceramic material was wet-ground sequentially to 600 grit using SiC and paper. All samples were ultrasonically cleaned in water for five minutes. The surface of the zirconia ceramic disks was treated in one of four different ways ; (a) ground to 600 grit, (b): (a) + air-abraded with 150 µm alumina at 2.8 bar pressure at a distance 10 mm for 10 seconds, (c) : (a) + (b) + tribochemically silica-coated using the Rocatec system (3M ESPE), (d) : (a) + (b) + silica-coated using the Silano-Pen (Bredent). After ultrasonically cleaning in water for five minutes, zirconia ceramic disks and stainless steel rods were bonded with Linkmax (GC), GC ceramic primer (GC) and Metal primer (GC). All specimens were stored in 37 °C water for 24 before shear bond strength test (n=6). The bonded specimens were subjected to shear testing using a Universal testing machine with a notched shear blade and a crosshead speed of 0.5 mm/min. Load at failure was recorded in Newtons and converted into shear bond strength in MPa. Data were analyzed by one-way ANOVA and Turkey-Kramer post-hoc test at p<0.05.

Results: Shear bond results were : (a); 7.7(4.5)a, (b); 20.5(1.4)b, (c); 32.9(2.8)c, (d); 40.5(5.8)d.

There were significant differences among four groups.

Conclusion: These results suggest that the application of silica-coting to zirconia ceramic appears to be effective for bonding between zirconia ceramic and an adhesive resin cement.