Abstract: A melting trough made of ceramic material is used for melting small amounts of metal by means of a flame including at least one trough channel which is not closed during operation. A thermosensor having a protective cover extends into the trough which is filled with melt during operation through an aperture in the wall of the trough. The aperture as well as the thermosensor are located below the level of the melt.

Abstract: Positive wax models are disposed on carriers in a casting frame so that the widest cross sections are in a common plane, vertical fitting pins are provided, and the frame is filled with silicone to the level of the plane to form a first model. The surface is then coated with silver, electroplated with copper, and reinforced with synthetic resin to form a first electrode, which is removed from the first model. The first model is likewise removed from the frame and oriented by means of the fitting pins in a casting frame filled with hardening carrier mass to the plane of the widest cross sections. The carriers and molding mass are then removed to form a second model. The surface of the second model is then coated with silver, electroplated with copper, and reinforced with synthetic resin to form a second electrode, which is removed from the second model. The electrodes are then used to erode respective opposite sides of an erosion body to form the spare parts.

Abstract: An improved method for preparing a dental prosthetic construction such as a crown or bridge is described by applying a dental ceramic composition to a base of a precious metal silver-containing alloy, drying it and firing the same. In accordance with the improvement, the firing is conducted in a reducing atmosphere.