Method and composition to produce high translucency dental ceramics
Translucency of a yttria-stabilized zirconia ceramic is improved to achieve even higher translucency than what is currently offered on the market, without greatly altering its mechanical properties. The enhancement is done by incorporating magnesium-containing dopants into the microstructure of yttria-stabilized zirconia ceramic dental ceramics.
1 . A material comprising:
a sintered yttria-stabilized zirconia ceramic, stabilized by 4.5 mol % to 6 mol % yttria, wherein the sintered ceramic has a transmittance of 65% to 70% at 700 nm (when measured on a 1 mm thick fully sintered ceramic body), an average grain size of less than 6 μm, a fracture toughness greater than 1.5 MPa·m 1/2 , and a cubic phase of 40% to 50%, and wherein the sintered ceramic comprises 0.1 wt % to 2 wt % MgO.
2 . The material of claim 1 , wherein the ceramic has an average grain size of less than 4 μm.
3 . The material of claim 1 , wherein the ceramic has a cubic phase of 42% to 50%.
4 . The material of claim 1 , wherein the ceramic has a cubic phase of 44% to 48%.
5 . The material of claim 1 , wherein the ceramic comprises 0.2 wt % to 0.7 wt % MgO.
6 . The material of claim 1 , wherein the ceramic comprises 0.2 wt % to 0.6 wt % MgO.
7 . The material of claim 1 , wherein the ceramic is stabilized by 4.5 mol % to 5.5 mol % yttria.
8 . The material of claim 1 , wherein the ceramic has a flexural strength greater than 500 MPa.
9 . The material of claim 1 , wherein the ceramic comprises 0.2 wt % to 0.6 wt % MgO, and has a transmittance of 65% to 70% at 700 nm (when measured on a 1 mm thick fully sintered ceramic body), a flexural strength greater than 500 MPa, and a cubic phase of 44% to 48%.
10 . The material of claim 9 , wherein the ceramic is stabilized by 4.5 mol % to 5.5 mol % yttria.
11 . The material of claim 1 , wherein the yttria-stabilized zirconia ceramic is shaded by a coloring agent comprising at least one metal selected from Fe, Co, Cu, Pr, Tb, Cr or Er.