Abstract
It was intended to develop the composite resin with desirable characters.Compostite resins containing colloidal silica were prepared for this purpose and their properties were examind.The experimental composite resins were prepared from the comonomers of Bis-GMA and TEDMA and the following fillers:1)MF, surface-treated 0.05μ AEROSIL, 2)CF, crushed resin composite containing 50% of MF, and 3)the mixture of MF and CF.It was found that although the smaller filler, the greater the compressive strength, there was little influence of the filler size on other physical properties of the cured resin containing 50% of CF.The experimental resins improved the physical properties in proportion to the silica contents.The rise rate of physical properties divided by the silica contents were defined as the composite effects.The composite effect of the compressive strength was 3.7, that of the elastic modulus was 2.3, and those of the Rockwell hardness, the coefficient of thermal expansion and the diametral tensile strength were 1.The viscosity of the experimental resin containing MF measured by a cone-plate viscometer was decreased inversely to the shear rate, showing thixotropy.There was little influence of the shear rate on the viscosity of the resin containing CF and there was an intermediate tendency to the composite resin containing MF+CF.
