The effect of tribochemical silica treatment on the shear bond strength of dental composite resin to gold electroformed surface

Gold electroforming restoration (GER) may be used as an alterative to the currently available porcelain-fused-to-metal and all ceramic dental restoration system. However, the quality and strength of bonding between the gold coping and composite resin need to be further investigated. The purpose of this study was to evaluate the effect of surface treatment between resin composite veneering materials and gold electroforming coping. In this study, the shear bond test was performed to measure the bond strength of composite resin and GER of which surfaces have been treated by sandblasting only (control), by methods of tribochemical silica coating (Rocatec) or by painting with a primer (Metaltite). Shear bond strengths were measured at a cross-head speed of 1.0 mm/minute with Instron and determined after thermocycling (1,200 cycles). ANOVA showed differences among the surface treatment groups (P < 0.05). The GER with Metaltite treatments resulted in the highest bond strengths. Values for Metaltite-treated group were higher than those for Rocatec-treated group. The control specimens showed the lowest bond strength value. The results suggest that both Metaltite primer and Rocatec system represent useful methods to improve the bond between the GER and composite resin veneering.