Effect of a glaze layer on adhesion energy between resin cements to zirconia ceramic

Abstract

PurposeTo evaluate the effect of an etched and silanized glazed porcelain layer on the interfacial fracture toughness between a zirconia ceramic and resin cements. Materials and methodsForty rectangular-shaped yttrium stabilised zirconia ceramic plates were sintered and sandblasted with 100 µm Al2O3. Twenty specimens were glazed with Akzent Glaze Spray and then etched with 9% hydrofluoric acid for 3 min prior to being silanized with Monobond-S. Glazed and non-glazed specimens were further divided into two groups (n = 10) and allocated to one of two resin bonding systems, Variolink II and Multilink-Automix (Ivoclar Vivadent). The Multilink-Automix groups were treated with Metal/Zirconia Primer. Glass rods (12 mm) were bonded to each prepared zirconia plate, using the two bonding systems and were loaded to failure using a universal testing machine. Strain energy release rate (bond) values were calculated and de-bonded specimens were examined using SEM to determine the modes of failure. Data were analysed using two-tailed T-test and Dunnett-T3 post-hoc tests with statistical significance set at p < 0.05. ResultsGlazed zirconia surface significantly improved the mean bond values in the Variolink II group (p < 0.05), with no significant change (p > 0.05) in the Multilink-Automix Metal/Zirconia Primer group; the Multilink – Automix group, produced significantly higher bond values in the non-glazed group (p < 0.05). Fractographic analysis showed predominantly cohesive failure for the glazed groups and adhesive failure in the non-glazed groups. ConclusionGlazed zirconia surfaces produced higher resin cement bond strength than unglazed zirconia, however the combination of silanised phosphate monomer and metal/zirconia primer produced weaker bond on glazed zirconia.