Microstructure Evaluation of the Interface between Dental Zirconia Ceramics and Veneering Porcelain

The application of zirconia ceramics for the dental restorations and dental implants has increased. However the weak performance of the veneering porcelains and low adhesion to the zirconia framework were reported. In this study, the micro-structure, elemental distribution and crystal phase around the interface between zirconia and veneering porcelain were estimated using SEM-EDS (energy dispersed spectrometry) and micro-XRD (X-ray diffraction). The specimen fired at 940oC for 1 minute showed clear interface in the SEM and the elemental distribution im-ages of Zr and Si. With extending firing period up to 384 hours, slight diffusions of Zr and Si, which are the major components of zirconia and porcelain ware suggested. In micro-XRD, no phase transformation was observed in the zirconia and porcelain, thus extension of firing period would not affect the crystal phase around the zirconia/porcelain interface. Therefore, the extension of firing period was expected to slightly improve the zirconia/porcelain bonding.