Tensile bond strengths of Comspan^® to electrolytically etched metal with and without enamel bonding agent

When cementing a resin-bonded etched metal "Maryland" bridge, the clinician applies unfilled resin bonding agent to the etched metal prior to placing the filled resin cement. This study evaluated whether or not it was necessary to place the unfilled resin bonding agent on the metal. Twenty rods were cast in Rexillium III and machined so their ends could be etched and bonded together, first with filled resin alone, then with filled resin plus unfilled resin yielded an average tensile bond strength of 39.24 MPa, while the filled resin alone had an average of 32.21 MPa. At p≤.05, this was statistically insignificant, suggesting that elimination of unfilled Comspan^® resin application to Rexillium III is possible without loss of bond strength.