ABSTRACT
Currently, most polymethyl methacrylate (PMMA) denture materials are radiolucent, and it is difficult to remove the fragments of dentures aspirated during accidents. The aim of this study was to investigate the possibility of using barium titanate (BaTiO3) as a radiopacifier in PMMA. The formulation used in this study was composed of PMMA, BaTiO3 (5,10, 15 and 20 wt%) and 0.5 wt% benzoyl peroxide (BPO) as an initiator, 90 wt% methyl methacrylate (MMA) as a monomer, and 10 wt% ethylene glycol dimethyl acrylate (EGDMA) as a cross-linking agent. The BaTiO3 was treated by a silane coupling agent, (γ-MPS) prior to incorporation into the solid components (PMMA, BPO). Curing was carried out using a water bath at 78°C for 1.5 h. The thermal properties of the PMMA composite were evaluated using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). It could be observed that the density of the PMMA composite increased slightly after the filler was incorporated. In addition, filled samples showed slightly lower Tg valuesthan the Tg value of the pure PMMA sample. The sample containing 20 wt% filler showed a higher degradation temperature than did the sample containing 5 wt% filler, which indicates that the former was more thermally stable than the latter. The TGA curves demonstrated that the degradation ratio increased more rapidly above 300°C. The storage modulus, E’, was higher for the filled samples than for the pure PMMA sample.
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