Effects of Veneering Porcelain Type on Bending Strength of Dental Y-TZP/Porcelain Bilayered Structure

The purpose of this study was to investigate the effect of different veneering porcelain types on the flexural strength of dental Y-TZP/porcelain layered structure. KAVO (TM) Everest zirconia ceramics were selected as substructure. To forming Y-TZP/porcelain bilayered structure, a leucite based veneering porcelain was fired on the zirconia substructures by slip-casting technique with dentin washbake, and two nano-fluorapatite based veneering porcelain was fired on the zirconia substructures either by slip-casting or pressed-on technique with or without liner coverage. Bending strength was tested according to ISO 6872 standard, and the veneered surfaces of fracture samples were analyzed by SEM. Experimental results showed that for covering KaVo (TM) zirconia core material, conventionally applied veneering slurry-porcelain combined with liner or wash firing has significant higher bending strength than pressed-on porcelain. SEM showed that the main failure type at the interface was adhesive.