Effect Of Si-Zr Coating On The Bond Strength Between Zirconia And Decorative

Objective The all-ceramic system of zirconia and porcelain in clinic has the problem of porcelain disintegration.In recent years,how to reduce the occurrence of clinical collapse porcelain and enhance the combination of veneer porcelain and zirconia substrate is one of the hotspots of research by experts and scholars at home and abroad.In this experiment,silica and zirconia two materials were mixed into a slurry,and the coating was coated on the surface of zirconia substrate.The effect of the coating on the bond strength between the zirconia substrate and the veneer porcelain was detected to find a new teratment method to reduce the rate of clinical avalanche porcelain.Methods The unsintered standard zirconia tiles produced by CAM were divided equally into two groups,12 specimens in each groups.One group of zirconium oxide was only placed after the step of sintering,which set to the A group.The other group was treated with the same sintering process after the zirconium-zirconium coating,and the surface was treated with hydrofluoric acid,which set to the B group.Two specimens from each group were sprayed with gold and observed under an electron microscope,and the surface was analyzed under an energy dispersive spectrometer.The surface of the 10 pieces remaining in the two groups of A and B were piled up with the same veneer porcelain and sinterde again to complete the standard shear test.Test the shear bond strength between the two groups of zirconia and veneer by universal testing machine.According to the formula,the combined strength was obtained,and performed statistical analysis.The fractured A and B specimens were placed under a stereomicroscope to observe the fracture pattern.Results 1.Scanning electron microscopy results: The SEM images showed that the surface of the group A was smooth and there were a few scratches.The surface of the coating of group B showed a clear and distinct island structure.2.Energy spectrum analysis results: It could be seen from the spectrograms and the EDS stratification graphs that the surface of the coating group had Si elements,and the elements were distributed in an island shape.3.Stereomicroscopy results: No veneer porcelain residue on the surface of group A.On the surface of each specomen in group B,there was a residue of veneer porcelain.The surface of zirconia was still coverde with coating after fracture.4 The bonding strength results: The bond strength in group A was(25.26±1.35)MPa,and the group B was(29.63±1.59)MPa.The analysis of independent sample test shows that the strength difference between the two groups is significant(P <0.01).Conclusions 1.The preparation of zirconium-zirconium coating increases the Si element and roughness on the surface of the zirconia substrate,confirming the feasibility of the zirconium zirconium coating method technology route.2.From the shear strength test and the interface analysis after fracture,it is shown that the zirconium-zirconium coating can enhance the bonding strength between the veneer ceramic and the zirconia-based ceramic.