Effect of Filler Incorporation on the Fracture Toughness Properties of Denture Base Poly(Methyl Methacrylate)

Abstract: Poly(methyl methacrylate) (PMMA) is the material of choice for denture base construction. In spite of its many good qualities, the application of PMMA as an ideal dental base material is still restricted by a few limitations. One of these is the difficulty in achieving intrinsic radiopacity in the material. The aim of the present study is to investigate the possibility of using barium titanate (BaTiO3) as a radiopacifier in PMMA. The formulation used in this study composed of PMMA 89.5 wt%, BaTiO3 10 wt % and benzoyl peroxide (BPO) 0.5 wt % as an initiator, methyl methacrylate (MMA) 90 wt % as a monomer and ethylene glycol dimethyl acrylate (EGDMA) 10 wt % as a cross-linking agent. The BaTiO3 was treated by a silane coupling agent, 3-trimethoxysilylpropyl methacrylate (γ-MPS), prior to incorporation in the solid components (PMMA, BPO). The curing was carried out using a water bath at 78°C for 1.5 h. The samples were tested for fracture toughness before and after soaking for 28 days in simulated body fluid (SBF). Moreover, the morphology of the specimens was investigated by scanning electron microscope (SEM). The results showed that the neat PMMA possessed slightly higher fracture toughness properties than the PMMA composite, and after 28 days of immersion, the fracture toughness values were reduced by 4.8 % and 3.4 % for neat PMMA and PMMA composite, respectively