Mechanical Properties of Elastomeric Impression Materials: An In Vitro Comparison

Area of Science:

• Dental Materials Science
• Polymer Engineering

Background:

• New elastomeric impression materials are continuously introduced.
• Limited data exists on their mechanical properties, particularly tensile characteristics.

Purpose of the Study:

• To compare the tensile properties of various hydrophilic elastomeric impression materials.
• To evaluate mechanical features like tensile strength and strain at break.

Main Methods:

• Tested 17 hydrophilic impression materials (12 vinylpolysiloxane, 2 polyether, 3 hybrid vinylpolyether silicone).
• Fabricated dumbbell-shaped specimens (n=10) per ISO 37:2005.
• Performed tensile testing to failure, analyzing tensile strength, yield strength, and strain at break/yield.

Main Results:

• Vinylpolysiloxanes demonstrated higher tensile strength than polyethers.
• Heavy-body materials showed greater tensile strength than light-body variants from the same manufacturer.
• Hybrid vinylpolyether silicone light-body achieved the highest yield strength (2.70 MPa); polyethers had the lowest tensile (1.44 MPa) and yield (0.94 MPa) strengths.

Conclusions:

• Material selection should consider specific elastomer physical behavior.
• Light-body hybrid vinylpolyether silicone's high tensile and yield strengths may minimize tearing in thin interproximal and crevicular areas.