ABSTRACT
PURPOSE: The aim of this study is to evaluate the effects of various primers on the microtensile bond strength (µTBS) of resin cements to cobalt-chromium (Co-Cr) dental casting alloy. MATERIALS AND METHODS: Four adhesive primers (Universal primer, Metal primer II, Alloy primer, and Metal/Zirconia primer) and two resin cements (Panavia F2.0, G-CEM LinkAce) were tested. One hundred fifty Co-Cr beams were prepared from Co-Cr ingots via casting (6 mm length × 1 mm width × 1 mm thick). The metal beams were randomly divided into ten groups according to the adhesive primers and resin cements used; the no-primer groups served as the control (n = 15). After sandblasting with aluminum oxide (125 µm grain), the metal and resin cements were bonded together using a silicone mold. Prior to testing, all metal-resin beams were examined under stereomicroscope, and subjected to the µTBS test. The mean value of each group was analyzed via one-way ANOVA with Tukey's test as post hoc (α = .05) using SPSS software. RESULTS: The mean µTBS of all groups was ranged from 20 to 28 MPa. There is no statistically significant difference between groups (P > .05). Mixed failure, which is the combination of adhesive and cohesive failures, is the most prevalent failure mode in both the Panavia F2.0 and G-Cem LinkAce groups. CONCLUSION: The µTBS of all tested groups are relatively high; however, the primers used in this study result in no favorable effect in the µTBS of Panavia F2.0 and G-Cem LinkAce resin cement to Co-Cr alloy.