The physical and viscoelastic properties of two resilient denture liners, the polyphosphazine-based Novus and silicone-based Molloplast b, have been characterized. The two materials were found to have comparable tensile strengths and frictional properties but differed in their tear strengths, water sorptions, and solubilities. Novus had a greater tear strength and lower solubility, but greater water sorption, than Molloplast b. Compressibility studies indicated that significantly less force was required to compress 2- and 3-mm thicknesses of Novus by 0.2 and 0.4 mm than for Molloplast b. Dynamic mechanical analysis indicated that Novus should have a greater propensity for energy/impact absorption.