The metals used in the prosthetic restorations, addition to pure gold are the alloys that can be easily melted with conventional casting techniques, have sufficient physical properties, adequate marginal fit, resistance to corrosion and tarnish. Also they are economic. In the result of introducing of metal-ceramic restorations to the prosthetic dentistry, also the physical and chemical compatibility with ceramic have been joined to those properties. The investigations that are concerning to find the unique alloy are still continuing and compared to the precious alloys that have unique properties about marginal fit, castability, manipulation, corrosion and tarnish resistance, nonprecious are found to be insufficient yet.