The aim of the study is to develop a new interface design between filler particles and resin matrix of restorative composites by the use of different silane agents and oligomers, to reduce the shrinkage stress that is developed during the polymerization process and improve the mechanical properties of these materials. Pilot studies will be conducted to determine the silane to cover the fillers, associating functional and non-functional agents. Oligomeric chains will be tethered at one end to the filler surface with either an aromatic backbone or an aliphatic backbone, to create a transactional area between organic and inorganic phase. Modified particles will be comprehensively characterized including thermogravimetric analysis, gel permeation chromatography, dynamic light scattering and transmission electron microscopy. Experimental composites will be fabricated by mechanical mixing of resin and filler (30 wt% filler loading). The effect of this interfacial variation on composite properties such as degree of conversion and polymerization kinetics, volumetric shrinkage, shrinkage stress measurements, flexural modulus and strength will be studied. The results from each experiment will be statistically analyzed according to the factors under study and the comparison among groups of relevance for this project.
News published in Agência FAPESP Newsletter about the scholarship: