Bond strengths of silicoated and acrylic resin bonding systems to metal

Statement of problem. The Kevloc bonding system is based on the bond of acr ylic resin with the metal surface, in contrast to the Silicoater system, wh ich covers the metal surface with a SiOx-C layer. Bonding prevents the occu rrence of the marginal gap between the metal and the resin, which causes we aker bond strengths and discoloration. Purpose. This investigation examined the bond strength values achieved by u sing the Kevloc technique on Ag-Pd and Co-Cr alloys, and compared them with those obtained by the Silicoater technique. After artificial aging, shear testing of the specimens was performed. Material and methods. A microscope image analyzer measured the thickness of bonding layers to reveal any marginal gap. Results. No marginal gap was noticed for either technique. The Kevloc techn ique provided better results than Silicoater regardless of alloy used. Imme rsion in water (7.64 to 8.05 MPa) and thermocycling (6.12 to 6.95 MPa) redu ced the initial bond strength Values (12.52 to 12.94 MPa), but the breakdow n occurred between the opaque layers or between the opaque and the resin, t hus giving a cohesive type of failure. Conclusion. The dental alloy used did not affect bond strengths and artific ial aging caused reduction in bond strengths. The Kevloc bonding system exh ibited higher bond strengths than Silicoater, but the marginal gap was not seen for either bonding system.