Poly(methyl methacrylate) denture base composites enhancement by various combinations of nitrile butadiene rubber/treated ceramic fillers

Nitrile butadiene rubber (NBR) particles as impact modifier mixed with treated ceramic fillers (aluminum oxide, yttria-stabilized zirconia, and silicon dioxide) were used to reinforce poly(methyl methacrylate) (PMMA) denture base material. The powder components are PMMA, benzoyl peroxide, NBR (5, 7.5, and 10 wt%), and ceramic fillers (5 wt%) treated with silane. The liquid components are 90% methyl methacrylate and 10% ethylene glycol dimethacryate. Fourier transform infrared spectroscopy and energy dispersive X-ray spectroscopy analyses confirmed that the ceramic fillers were successful. The morphology of fracture surfaces of specimens was characterized using field emission scanning electron microscopy. The impact strength (IS) and fracture toughness (K-IC) improved significantly. IS increased to 56% (8.26 kJ m(-2)) and 73% (2.77 MPa m(1/2)) for K-IC when compared with unreinforced PMMA matrix. Statistical analyses of data results were significantly improved (p < 0.005). PMMA denture base reinforced by NBR particles mixed with treated ceramic fillers are ideally suited for dentistry applications with the ability to withstand high mastication forces.