Hydrophilicity of unset and set elastomeric impression materials

Area of Science:

• Materials Science
• Dental Materials Science
• Surface Chemistry

Background:

• Elastomeric impression materials are crucial in dentistry for accurate prosthodontic and orthodontic restorations.
• The hydrophilicity of impression materials influences their wetting characteristics and accuracy, particularly in moist oral environments.
• Understanding the surface properties of both unset and set impression materials is essential for clinical success.

Purpose of the Study:

• To compare the initial hydrophilicity of unset and set elastomeric impression materials.
• To investigate the wetting behavior and hydrophilicity kinetics of polyether and polyvinyl siloxane (PVS) impression materials.

Main Methods:

• High-resolution drop shape analysis was employed to measure initial water contact angles.
• Thin films of one polyether and six PVS impression materials were tested in both unset and set states.
• Contact angle measurements were recorded at specific drop ages (1 and 3 seconds) to assess hydrophilicity kinetics.

Main Results:

• All unset polyvinyl siloxane (PVS) materials exhibited initial hydrophobicity but demonstrated varying rates of hydrophilization.
• The unset polyether material was initially more hydrophilic but showed limited hydrophilization kinetics.
• Statistically significant differences in contact angles were observed between unset and set surfaces for all materials (P < .05).
• Two PVS materials achieved or surpassed the hydrophilicity of the polyether material, depending on the drop age.

Conclusions:

• The hydrophilicity of elastomeric impression materials differs significantly between their unset and set states.
• The choice of drop age in contact angle measurements is critical for accurately assessing wetting behavior.
• Clinical evaluation of impression material performance should consider both the material type and its surface state (unset vs. set).