This study aimed to evaluate the bonding behaviors of a gold alloy and a titanium-aluminum-niobium (Ti-6Al-7Nb) alloy after priming with three metal conditioners. Cast alloy disks were ground and divided into the following four conditions: (1) unprimed control versus priming with (2) Alloy Primer, (3) Estenia Opaque Primer, or (4) V-Primer. The disks were bonded with tri-n-butylborane (TBB) initiated methacrylic resin, and shear bond strengths were determined both before and after 20,000 times of thermocycling. Alloy Primer and V-Primer—which contained a vinyl-thione monomer—were effective for bonding the Au-Pt-Pd alloy. As for the hydrophobic phosphate monomer contained in Alloy Primer and Estenia Opaque Primer, it was effective for bonding the Ti-6Al-7Nb alloy. Further, when specimens were primed with Alloy Primer that contained both functional monomers, bond strength to Ti-6Al-7Nb alloy was greater than that to Au-Pt-Pd alloy.