[Homogeneity and corrosion resistance of cast dental precious metal alloys compared with uncast alloys].

60 cast crowns were manufactured in 6 different dental laboratories using 3 different alloys. The relative areas of cavities at the crown margins and the palatal crown surfaces were measured. Subsequently the crowns and uncast alloy plates were stored in artificial saliva and 1nHCl. After 30 days the dissolved amounts of Cu or, respectively, Ag were measured. All crowns exhibited cavities and porosities. The area of cavities at the crown margins was twice as high as that at the palatal surfaces. The copper ion concentrations measured for cast crowns of the PdCuGaIn-type Pd base alloy were increased by a factor of 20 (maximum) when compared to the uncast alloy. The solubility of the cast PdAgSnIn alloys was characterized by an only slight increase in the amount of dissolved silver. The results suggest that, in view of the inadequacies of dental casting, the use of alloys that may release toxic metal ions should be abandoned.