| Research Abstract |
Six alloy compositions (Ag:30-50%, Pd:20-30%, Cu:10-20%) were selected, out of the organization that developed the multi-function alloy. Eighteen alloys that added 0,2,4% of Sn to these alloys were used for the adhesion test. The specimens were prepared using an ordinary dental casting procedure. The surface of the specimen was finished with #800 SiC paper. The adhesive cement, Superbond C&B was applied to the specimen following the manufacturer's instruction. The measurement of the bond strength was carried out for three times for each alloy composition. Many of the tested alloys had higher bond strength (more than 40MPa) than commercially available silver-based palladium gold alloys.
Either 0,2,4% Sn, Ga or In was added to nine alloy compositions (20%Au,20,30 or 40%Pd,10,15 or 20%Cu and Ag as balance) and a total of 63 alloys were prepared. Superbond was used as an adhesive cement and the bond strength was measured for these alloys. The bond strength of the mother composition alloys, that of Sn-added alloys, that of Ga-added alloys and that of In-added alloys were in the range of 33.1-42.5 MPa, 35.9-45.9 MPa, 38.4-44.1 MPa and 42.2-47.3 MPa, respectively.
Panavua21EX with alloy primer was used as an adhesive cement and the bond strength was measured for these alloys. The bond strength of the mother composition alloys, that of Sn-added alloys, that of Ga-added alloys and that of In-added alloys were was in the range of 21.8-41.6 MPa, 19.4-43.2 MPa, 18.1-33.9 MPa and 18.6-42.9 MPa, respectively.
The elemental analysis using XPS showed that Ag, Pd, Cu, Sn, Ga and In in the alloy were oxidized for all 63 alloys tested. In the alloys added with either Sn, Ga or In, the oxidation of Ag, Pd and Cu was limited and the additives were selectively oxidized.
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