2012 Volume 55 Issue 1 Pages 38-45
When repairing restored cast-metal teeth using an adhesive metal primer, it is difficult to apply the primer to a metal surface alone. For this reason, the metal surfaces will frequently become stained by adhesive dentin and/or ceramic primers. The purpose of the present study has been to investigate 1) the influence of a combined application of an adhesive metal primer and a silane coupling agent on the bond strength between a resin composite and a gold-silver-palladium alloy, and 2) the influence that a metal surface grinding condition will have on this bond strength. Gold-silver-palladium alloy castings were fabricated in a conventional manner. The surfaces of the castings were ground using either a 600-grit SiC paper or a carborundum point, or were blasted with 50-μm alumina particles. The metal surfaces were primed using one of three adhesive metal primers (Alloy Primer® ; Kuraray Medical, Metal Primer II® ; GC and V-Primer® ; Sun Medical). A silane coupling agent (Clearfil Porcelain Bond Activator® ; Kuraray Medical) was used and applied with Clearfil Mega Bond® (Kuraray Medical), Clearfil ST Opaquer®(Kuraray Medical) and Clearfil AP-X® (Kuraray Medical) were then bonded to the treated surfaces. The bonded specimens were subjected to tensile bond strength tests after being stored in water for 48 h at 37℃. The results of this study indicated that the adhesive metal primers increased the bond strength between the resin composite and the alloy castings, whereas the silane coupling agent had no influence on the bond strength. The results also indicated that the bond strength also depended on the grinding condition of the casting surfaces, with the highest bond strength found for an alumina blasted surface. No difference in bond strength was found among the three adhesive metal primers.