1. A method for creating a shaded ceramic including the steps of:
creating three or more uniquely shaded zirconia pigment powders, each having their own characteristic hue, by combining zirconia powder with a chemical component selected from the group consisting of Fe, Er, Co, Pr, Tb, Cr, Nd, Ce, V, Eu, Ho, Ni, and Cu salts, oxides, inorganic, organic, organo-metallic compounds thereof, and combinations thereof;
mixing together unpigmented zirconia powder with one or more of said pigment powders to achieve a predetermined shade powder;
pressing said predetermined shade powder to form a green block;
drying said green block;
pre-sintering said green block.
2. A method for creating a dental ceramic comprising the method of claim 1, wherein zirconia powder comprises yttria stabilized tetragonal zirconia polycrystal (YTZP) powder.
3. A method for creating a dental ceramic comprising the method of claim 1, with the further steps of milling the block to create a desired form, and sintering said form.
4. A method for creating a dental ceramic comprising the method of claim 1, wherein the chemical component is added in the form of an aqueous or nonaqueous solution, emulsion, dispersion, gel or particulate.
5. A method for creating a dental ceramic comprising the method of claim 1, wherein three uniquely shaded pigment powders each have their own characteristic hue in the yellow, pink and gray ranges.
6. A shaded ceramic created by the method set forth in claim 1.
7. A dental ceramic prosthesis created by the method set forth in claim 1.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A discharger for a powder, the discharger comprising a hopper and an outlet, the hopper comprising a discharging surface over which, in use, a powder flows, and means for lowering the angle of internal friction of the powder or for lowering the angle of sliding friction between the powder and the full discharger surface, wherein the discharging surface comprises surfaces at of at least two angles that are progressively shallower towards the outlet and in which a steeper part of the discharging surface in use is steeper than 40\xb0 from the horizontal.
2. A discharger according to claim 1, in which the discharger surface is steeper than 45\xb0 from the horizontal.
3. A discharger according to claim 2, in which the discharger surface is steeper than 50\xb0 from the horizontal.
4. A discharger according to claim 3, in which the discharger surface is steeper than 60\xb0 from the horizontal.
5. A discharger according to claim 1, in which the width of the discharger surface is less than 30% of its length.
6. A discharger according to claim 1, in which the discharger surface is curved from the back to the outlet.
7. A discharger according to claim 1, In which there is provided means for lowering the angle of internal friction and for lowering the angle of sliding friction between the powder and the discharger surface, in which means the discharger surface comprises a gas permeable membrane and means for passing a gas through the gas permeable membrane.
8. A discharger according to claim 7, in which the gas permeable member comprises a flexible bag.
9. A discharger according to claim 7, in which means is provided to pass a gas through a powder from beneath.
10. A discharger according to claim 9, in which the discharger is adopted to pass gas through a powder adjacent to the outlet.
11. A discharger according to claim 1, in which there is provided means for lowering the angle of internal friction and for lowering the angle of sliding friction between the powder and the discharger surface, which comprises a vibrator for vibrating the discharger surface.
12. A discharger according to claim 1, in which the discharger further comprises a front wall adjacent the outlet, which front wall slopes inwardly towards the hopper as it extends to the outlet.
13. A discharger according to claim 12, in which the inward slope is substantially 10\xb0 from the vertical.
14. A discharger according to claim 1, in which the discharger surface is curved across the discharger surface.
15. A discharge according to claim 14, in which the curve is generally a U-shape.
16. A discharger according to claim 1, in which the discharger comprises side walls at least one of which diverges as it approaches the outlet.
17. A discharger according to claim 1, in which at least one internal ridge is provided extending from a side wall.
18. A discharger according to claim 17, in which the at least one ridge extends in a direction toward the outlet.
19. A discharger according to claim 1, in which the outlet is at the side of the discharger.
20. A method of use of a discharger according to claim 1, the method comprising discharging a powder through the outlet.