Effect of Different Primers on the Peel Bond Strength between Silicone Elastomer and Acrylic Resins

Introduction: Implant-supported extra-oral prostheses often require a retentive matrix to hold gold alloy clips and magnets, which act as retentive means. Silicone elastomers have a different structure to acrylic resins. Hence, primers are used to increase the bonding between silicone and acrylic resin.
Aim of Study: To investigate the effect of new platinum primers on the peel bond strength of silicone elastomer to acrylic resins.
Materials and Methods: Peel bond strength of Cosmesil 2004 to two acrylic resins was assessed using two primers (MED6-161 and MED160) and no primer (control group). Sixty samples were prepared and divided into six groups according to the combination of acrylic resin, silicone, primer and no primer. All samples were then exposed to load in a universal testing machine with a cross head speed of 25 mm/min until failure. Data was analysed using STATA 12.1 software. Values of mean peel force between light and auto-polymerising acrylic resins were compared using two-way ANOVA and tukey HSD test.
Results: The interaction between primers and acrylic resins had a significant effect on peel bond strength between Cosmesil 2004 and acrylic resins. MED6-161 primer significantly improved peel bond strength of Cosmesil 2004 to light-polymerising acrylic resin. However, MED-160 primer enhanced peel bond strength between Cosmesil 2004 and auto-polymerising acrylic resin.
Conclusion: The combination of primer and acrylic is important in improving the bond strength. However, further investigation of different primers, silicones and different surface treatments to achieve the optimum bonding is need.