Bond strengths of ceramics to biocompatible dental metals : substitutes for gold alloys

Abstract

Objectives: This study evaluated the bond strengths of ceramics to 3 biocompatible dental metals that may substitute for gold alloys and compared them with the bond strengths of ceramics to a conventional gold alloy. Methods: Four groups of dental metals (conventional gold alloy, milled titanium alloy, cast commercially pure titanium, and milled palladium-silver alloy fabricated into discs with dimensions of 9  3 mm were included in this study (n = 40). All specimens were air-abraded with 50-m alumina. Before application of porcelain discs with a dimension of 5  2 mm at the center of the metal specimens, the metal surfaces were surface-treated according to the manufacturers’ suggestions. The specimens were embedded in an acrylic resin matrix, and bonding strengths were tested using the parallel shear bond test. The load at fracture was recorded, and the fractured surfaces were observed under a scanning electron microscope. One-way ANOVA and Tukey’s tests were used to analyze the data at a 5% probability level.Results: The average bond strengths were 25.9, 18.86, 21.95, and 20.33 MPa for groups PG, TP, CT, and IN, respectively. Significant differences in bond strengths were only seen between groups PG and TP (p < 0.05). The fractured surfaces showed a combination of cohesive and adhesive failures for all testing groups with the exception of group PG, which showed mainly cohesive fractures within the porcelain body.