In Vitro Shear Bond Strength of Three Self-adhesive Resin Cements and a Resin-Modified Glass lonomer Cement to Various Prosthodontic Substrates

Objective: To evaluate the shear bond strength (SBS) of three self-adhesive resin cements and a resin-modified glass ionomer cement (RMGIC) to different prosthodontic substrates. Materials and Methods: The substrates base metal, noble metal, zirconia, ceramic, and resin composite were used for bonding with different cements (n=12). Specimens were placed in a bonding jig, which was filled with one of four cements (RelyX Unicem, Multilink Automix, Maxcem Elite, and FujiCEM Automix). Both light-polymerizing (LP) and self-polymerizing (SP) setting reactions were tested. Shear bond strength was measured at 15 minutes and 24 hours in a testing device at a test speed of 1 mm/min and expressed in MPa. A Student t-test and a one-way analysis of variance (ANOVA) were used to evaluate differences between setting reactions, between testing times, and among cements irrespective of other factors. Generalized linear regression model and Tukey tests were used for multifactorial analysis. Results: Significantly higher mean SBS were demonstrated for LP mode relative to SP mode (p<0.001) and for 24 hours relative to 15 minutes (p<0.001). Multifactorial analysis revealed that all factors (cement, substrate, and setting reaction) and all their interactions had a significant effect on the bond strength (p<0.001). Resin showed significantly higher SBS than other substrates when bonded to RelyX Unicem and Multi link Automix in LP mode (p<0.05). Overall, FujiCEM demonstrated significantly lower SBS than the three self-adhesive resin cements (p<0.05). Conclusions: Overall, higher bond strengths were demonstrated for LP relative to SP mode, 24 hours relative to 15 minutes and self-adhesive resin cements compared to the RMGICs. Bond strengths also varied depending on the substrate, indicating that selection of luting cement should be partially dictated by the substrate and the setting reaction.