Abstract: In a dental prosthetic casting-on process, in which a secondary part made of metal is cast-on to a primary part made of metal, a primary part made from an oxide-forming metal alloy may be used if the latter's casting-on surface is alloyed, prior to casting-on, with a reducing metalloid. In this regard, boron, silicon or phosphorus, for example, can be made to diffuse into the surface lattice of the primary part. A primary part made from an oxide-forming dental alloy and suitable for such a casting-on process exhibits in its casting-on surface an enhanced boron or silicon or phosphorus content.