Rheological studies of photopolymerized dental composites

An oscillating rheometer was constructed to study the polymerization of light-cured dental composites. The instrument is based on the forced harmonic oscillator, where the polymerization of the sample leads to a reduction of amplitude of oscillations. The polymerization time as determined for different materials seemed to be influenced by the filler particle size. The results obtained for the viscosity and shear modulus for a class of samples agreed with values published using other instruments and methods.