Influence of Adhesive on Shear Bond Strength Between Denture Base Materials and Self-Cured Silicon Soft Liner

Abstract

Background: Soft lining materials play an important role in modern prosthodontics because of their capability of restoring health of inflamed and distorted mucosa. Gradual changes of oral tissues require that complete or partial dentures be relined to improve their adaptation to the supporting tissue. This study aimed to evaluate the shear bond strength (SBS) of heat cured acrylic and injection-molded ValplastTM denture base materials to silicone self-cure soft lining materials, with and without adhesive, after storage in two different times in artificial saliva. Materials and Methods: 40 rectangularspecimens were prepared from two types of self-cured silicone soft lining material,one with adhesive and the other without adhesive were applied to two types of denture base materials ( heat polymerized Polymethyl methacrylate and injection-molded nylon denture base materials). Shear bond strength of the specimens was measured, after immersionin artificial saliva for different periods (72 hours or 10 weeks), using Lloyd universal testing machine. Results: Acrylic denture base bonded to soft liner with adhesive at 72 hours of immersion in artificial saliva showed the highest shear bond strength. Comparing SBS values of the tested soft lining materials revealed significant differences between adhesively bonded and non-adhesively bonded types. Conclusions: This study concluded that the bond strength of the silicone soft lining materials with denture base materials increased with adhesive. Silicone soft lining materials are affected by artificial saliva storage.