Dynamic viscoelastic properties of models composed of posterior denture teeth and denture base resin

The purpose of this investigation was to compare the dynamic viscoelastic properties of various models composed of denture teeth and heat-cured denture base resin. The specimens were porcelain and resin teeth mounted in denture base resin. Compressive dynamic stiffness and phase differences were measured with a viscoelastic spectrometer. Measurements of the viscoelastic frequency spectrum based on the fast Fourier transform of displacement to applied random forces were analyzed with a spectrum analyzer. The stiffness of the specimens was independent of the frequency. The stiffness of the porcelain specimens was higher than that of the resin ones measured under the same conditions. The phase lag of the specimens was dependent on the frequency. The phase lag of the porcelain specimens was lower than that of the resin ones measured under the same conditions. This study suggested that the acrylic resin teeth had greater toughness and higher shock-absorbing ability than the porcelain teeth, and that the porcelain teeth were more brittle than the acrylic resin ones, whether the teeth were isolated or in dentures.