Blocks of material are prepared in a variety of shapes and sizes to be used in the fabrication of models for dental restorations. The material comprises a partially sintered ceramic material. The blocks are used to manufacture molds using CAD / CAM methods and equipment. The molds are useful in the manufacture of dental restorations using ceramics, metals, alloys, or powders thereof, and composite materials. The models milled from the blanks may be used to manufacture a variety of dental restorations including, but not limited to, crowns, bridges, space maintainers, tooth replacement appliances, orthodontic retainers, dentures, posts, jackets, inlays, onlays, facings, veneers, facets, implants, abutments, splints, partial crowns, teeth, cylinders, pins, and connectors.