Erties of miracle mixtures were far inferior to amalgam, and it was not well received as a retorative material. In part, the problem with the admixture was that the matrix would not strongly adhere to the Ag-Sn alloy particles.
To circumvent this difficulty, silver-palladium (Ag-Pd) was substituted. Ag-Pd generates a passivating oxide film of PdO that is chemically reactive by chelation with polyacrylic acid. These mixtures. Termed caramic-metal polyacrylic acid. These mixtures, termed ceramic-metal (cermets) mixtures (see Fig.4-83,B) were much stronger than unmokified glass-ionomer cements, but had poor esthetics and could not e higly modified, or else they would not set as well.