Influence of 10-MDP Adhesive System on Shear Bond Strength of Zirconia-Composite Interfaces

This in-vitro study investigated the initial 24h bond strength between different composites and zirconia after application of four different adhesive systems. A total of 120 specimens of zirconia (InCoris, Sirona, Germany, Bernsheim) were ground with a 165 µm grit rotating diamond disc. Thirty specimens were each additionally treated with Cimara Zircon “CZ” (VOCO GmbH, Germany, Cuxhaven), Futurabond U “FBU” (VOCO GmbH), Futurabond M+ “FBM” (VOCO GmbH) or Futurabond M+ in combination with the DCA activator “FBMD” (VOCO GmbH). One of three different types of composites – BifixSE (“BS”), BifixQM (“BQ”) or GrandioSO (“G”) (VOCO GmbH) – was bonded to ten specimens each in every group. Shear bond strength (SBS) was determined in a universal testing machine. Statistical analysis was performed with ANOVA and the Tukey test. FBM and FBMD gave higher SBS than CZ and FBU in combination with all tested composites. In comparison to FBU, FBM gave statistically significant increases in SBS with BifixSE (19.4±5.7 MPa) (P<0.013) and with GrandioSO (19.1±4.4 MPa) (P<0.021). None of the other comparisons was statistically significant. The new 10-MDP-containing adhesive systems FBM and FBMD increases initial SBS between composites and zirconia in comparison to CZ and FBU.