Desenvolvimento de um método simplificado para obtenção de adesão à zircônia

Abstract

The aim of this study was to develop a simplified method for bonding to yttriastabilized zirconia ceramic. The method was based on deposition of a reactive silica layer on the ceramic surface followed by heat treatment. The study comprised six steps: (i) preparation of solutions using four concentrations of tetraethyl orthosilicate (TEOS) and zirconium tert-butoxide (ZTB) diluted in hexane; (ii) cutting and polishing of the zirconia substrate; (iii) organic silica-based treatment before (infiltration, INF) or after (coating, COA) zirconia sintering; (iv) analysis by scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS); (v) G-Raman confocal spectroscopy analysis; (vi) shear bond strength to zirconia tested after 24-h and failure analysis. An untreated (control) and a commercial reference (Rocatec Plus, 3M ESPE) groups were tested. Quantitative data were analyzed using ANOVA and Tukey s post hoc test (P < 0.05). SEM micrographs showed that zirconia surface was covered by silica nanoparticle clusters. EDS and G-Raman analyses confirmed composition of this layer. The bond strength results showed that most groups that received coating (COA) and infiltration (INF) presented higher bonding potential than the untreated (control) group. Almost all experimental groups were similar to commercial reference. Mixed failures were predominant. In conclusion, the present study introduces a novel, simple, and cost-effective method to provide adhesion to yttria-stabilized zirconia ceramic. Both the method of silica deposition (if before or after zirconia sintering) and concentration of organic silica precursors have a significant impact on the adhesion of methacrylates to the treated zirconia