The purpose of this study was to evaluate the effect of dental metal primers on the bond strength between
oxidation heat-treated gold-silver-palladium alloy and MMA-TBBO resin. Adherends were fabricated with pure
metal of Au, Ag, Cu, Pd or gold-silver-palladium alloy (MC12). Three different dental metal primers, namely Alloy
Primer (AP), V-Primer (VP) and Epricode Opaque Primer (OP), were used. Also, two different resin cements,
including Super-Bond C&B (Normal) or resin cement in which monomer liquid was replaced by pure MMA from
4-META-MMA of Normal, were used. On pure metal specimens, a total of sixteen groups including four pure
metals, four surface treatments and Normal, were prepared (n = 5). On MC12 specimens, a total of 32 groups,
including four heat treatment times, four surface treatments and two resin cements, were prepared (n = 7). After
subjecting the specimens to 2,000 times of thermo-cycling, shear bond strengths were measured. As a result,
specimens using VP demonstrated significantly higher bond strength than Ag and Cu in the presence of 4-META.
Also, Cu specimens were easily oxidized by oxidation heat treatment, and increased in reactivity to non-noble
metal primer. On the other hand, it was difficult for VBATDT to react unoxidized area through metal oxide film.
Within the limitations of this study, it is concluded that oxidation heat treatment of MC12 restorations improves
bond durability.
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