BONDING OF A COBALT-CHROMIUM ALLOY WITH ACIDIC PRIMERS AND TRI-N-BUTYLBORANE-INITIATED LUTING AGENTS

Limited information is available about chemical bonding of cobalt-chro mium alloys for resin-retained fixed partial dentures. This study eval uated the effect of acidic primers on the bonding of luting agents joi ned to a cobalt-chromium alloy. Disk alloy specimens were bonded with eight combinations of five primers and two luting agents. Shear bond s trengths were determined before and after thermocycling. The effect of priming on bond strength varied among the combinations of primer and luting agent. In particular, after thermocycling three groups demonstr ated greater bond strengths than the other groups did. These were (1) specimens treated with a phosphate-methacrylate primer (Cesead Opaque Primer), (2) specimens bonded with an adhesive resin (Super-Bond Opaqu e), or (3) a combination of both.