DIMETHACRYLATE RESINS MODIFIED WITH METHACRYLATE FUNCTIONALIZED SILSESQUIOXANES

SILVANA V. ASMUSSEN; CLAUDIA I. VALLO

Mar del Plata

Encuentro; III Encuentro Nacional de Materia Blanda; 2010

Light-cured dental composites have been available for over four decades. In general, they shown relatively satisfactory clinical results. However, one major limitation of composite resins is their relatively high volumetric shrinkage during polymerization. Therefore, the main efforts to improve the performance of composites for dental fillings centre on reducing the volumetric shrinkage without sacrificing other useful properties. Nanocomposite materials based on polyhedral oligomeric silsesquioxanes (POSS) are receiving increasing attention because of the unique features derived from their hybrid nanometer-scale architecture. The purpose of the present study was the synthesis and characterization of methacrylate-functionalized silsesquioxanes (SSQO), which were incorporated to methacrylate monomers commonly used in dental restorative resins. The SSQO were characterized by Size exclusion chromatography (SEC), Matrix-assisted ultraviolet laser desorption ionization time of flight mass spectra (UV-MALDI-TOF MS) and 29Si NMR spectroscopy.The methacrylate monomers modified with SSQO were photopolymerized and the performance of the resulting nanocomposites was assessed by measuring the volumetric shrinkage during polymerization, the flexural modulus and the compressive yield strength.