PREPOLYMERIZED ORGANIC-INORGANIC HYBRID NANOPARTICLES AS FILLERS FOR LIGHT-CURED METHACRYLATE MONOMERS

V. L. MUCCI; G. ARENAS; C. J. PÉREZ; C. I. VALLO

Praga

Congreso; 7th International Conference on NANOSTRUCTURED POLYMERS AND NANOCOMPOSITES; 2012

Light-cured dental materials consist of free-radicalpolymerizable methacrylate monomers filled with a mixture of different inorganic fillers. The polymerization of the methacrylate monomers is initiated by radical forming photoinitiators, which decompose under irradiation with visible light in the region of 450-480 nm(blue light). The inorganic fillers are incorporated to reduce the polymerization  shrinkage; which contributes tothe development of contraction stresses that often lead to bond failure and recurrent caries. According to a recent review by Ferracane, the most important changes in resin-based dental composites have involved the reinforcing filler, which has been purposelyreduced in size to produce materials that are more easily and effectively polished. Due to the small particle size, i.e. large specific surface area, the interaction betweenthe matrix and the surfaceofthe particlesis dramaticallyincreased . This raises the viscosity of the filled resins and reduces the attainable filler load. Thus, it is important to devise methodologies to introduce high amounts of inorganic fillers into resin composites. In thiscontext, the preparation of silica nanoparticles in organic liquid media is especiallyinteresting. The present studywas carried out in order to explore the possibilityofincorporating high amounts ofinorganic filler into an organic monomer bythe sol-gel process.