Synthesis, characterization and evaluation of new fluorene-based dimethacrylates for formulating dental composites

This study focused on the preparation and evaluation of several new fluoren e-based dimethacrylates, as possible intermediates to formulate improved de ntal composites. As the first step towards modification of the composite fo rmulation, the new monomers and unfilled resin matrix were prepared. The fo rmulated and visible light-cured materials were found to be more hydrophobi c, along with having higher wet (water saturated) glass transition temperat ures (T-g) than the commonly used matrix resins based on 2,2-bis(4(2-hydrox y-3-methacryloxy-propyloxy))-phenylpropane (Bis GMA). In addition, the new matrix resins exhibited greater compressive strength along with greater res istant to creep and fracture. Finally, the results suggested a correlation may exist between creep and the homologous temperature (T/T-g) of the light -cured neat resins, where the T/T-g may be used to compare the mechanical p roperties of different materials at various temperature. Copyright (C) 1999 John Wiley & Sons, Ltd.