Patterns of cell death induced by eluates from denture base acrylic resinsin U-937 human monoblastoid cells

The purpose of this study was to investigate in vitro the apoptosis- and ne crosis-inducing potential of eluates from three heat-polymerized and foul a utopolymerized poly(methyl methacrylate)-based denture base resins. Our hyp othesis was that the rate of cell death by apoptosis and/or necrosis induce d by such denture base resins could be an important indicator of their cyto toxicity degree. U-937 human monoblastoid cells were exposed for 24 h and 4 8 h to eluates of 0.1 g/ml, 0.2 g/ml, 0.4 g/ml, and 0.8 g/ml extracted for 24 h and 48 h. The characteristics of apoptosis and necrosis were evaluated by flow cytometry and light and electron microscopy. Eluates from all resi ns enhanced cell death by apoptosis and necrosis in U-937 cells in a dose- and time-dependent fashion. Eluates from autopolymerized resins yielded hig her percentages of apoptosis and necrosis than the heat-polymerized ones. T he results support our hypothesis that eluates of poly(methyl methacrylate) -based denture base acrylic resins activate death-signaling pathways, and t hat the extent of this process reflects their biocompatibility degree.