| 초록 |
Polymer infiltrated ceramic networks (PICNs) are considered to be the main material of dental prostheses. Because of their approximately 50% lower elastic modulus compared to dental porcelains, PICNs are easier to mill and adjust, and have higher damage tolerance. CAD-CAM systems in dentistry that are used exponentially because of high productivity and aesthetic impression use PICNs actively. PICNs are based on initial sintering of a ceramic powder to 70~75% of its theoretical density, followed by infiltration with polymer systems. The polymer channels are formed randomly depending on the shape of the pore and change the mechanical properties of the PICNs. Freeze casting is a fabrication technique used to make porous ceramics. If slurry used for freeze casting is cooled in specific direction, ice crystals grow continuously along the cooling direction, finally provide lamellar pore channels. Lamellar structure has a high mechanical strength because of the slow crack propagation. In this study, th achieve high mechanical strength, porous yttria-stabilized zirconia was fabricated to have lamellar pore channels by using freeze casting. The optimum condition of polymer infiltration behavior was determined by changing curing temperature and sintering temperature of yttria-stabilized zirconia. The morphology of fabricated PICNs are characterized by using scanning electron microscopy (SEM). The mechanical strength of the composites is measured by using 3-point bending test. |
