The Fabrication and Properties of Biscuit-Sintered Y-TZP Ceramics for Dental Applications
Moderately porous Y-TZP dental ceramics were designed to combine the high strength and fracture toughness of densely sintered Y-TZP and the relatively low elastic modulus of porous Y-TZP ceramics. The materials were produced by biscuit-sintering dry-pressed pellets at different temperatures in an ambient air atmosphere. The flexural strength progressively increased with the fractional density, starting from 150–200 MPa at 55–60 % of theoretical density (TD), and exceeding 500 MPa at >80 % TD. The elastic modulus of the early-stage sintered material was matched with that of dentine, but the flexural strength was too low for a practical application. Strength values equal to or higher than those of the existing dental glass-ceramics and glass-infiltrated ceramic materials were achieved with specimens sintered to 8085 % TD, but the elastic modulus of these ceramics (100130 GPa) was about two times higher than that of dentine. Soft grinding of the biscuit-sintered samples resulted in a noticeable increase in the surface roughness, also leading to a significant strength reduction.
J. Dusza, R. Danzer, R. Morrell and G.D. Quinn
T. Kosmač et al., "The Fabrication and Properties of Biscuit-Sintered Y-TZP Ceramics for Dental Applications", Key Engineering Materials, Vol. 409, pp. 342-345, 2009