Apparatus and method for manufacturing a dental milling block with a graduated color and/or translucency profile

A process of manufacturing a dental milling block having a translucency and/or color gradient, the process comprising:

• providing a mold with a cavity having a z-direction and defining an area in a x/y-plane;
• providing a comb having a base extending in the x/y plane and a multiplicity of tines projecting vertically from the base in the z-direction;
• partially filling the cavity with a first zirconia powder to form a first layer having a top surface;
• reciprocating the comb into the mold in the z-direction to penetrate the top surface of the first layer and create a textured pattern in the top surface of the first layer;
• introducing into the mold a second zirconia powder on top of the first layer of first zirconia powder to form a second layer having a top surface and a bottom surface, the textured pattern in the top surface of the first layer creating a complimentary textured pattern in the bottom surface of the second layer, the textured pattern in the top surface of the first layer and the complimentary textured pattern in the bottom surface of the second layer together forming a first interface;
• and
• compacting the first and second layers in the mold and optionally applying heat to the compacted first and second layers, wherein the first zirconia powder has different chemical composition and/or color than the second zirconia powder.