Mechanical properties of elastomeric impression materials

Dental elastomeric impression materials of different consistencies, representing addition and condensation silicones, polysulphides and a polyether, were studied to determine their mechanical properties in terms of tearing energy, tensile properties and modulus determined at high strain rates. Whilst the polysulphides had the greatest resistance to tearing, they were more extensible, had lower moduli of elasticity and lower tensile strengths than the silicones. The polyether resembled the silicones in many respects.