Evaluation of Elastomeric Impression Materials' Hydrophilicity: An in vitro Study

Area of Science:

• Dental Materials Science
• Surface Chemistry

Background:

• Hydrophilicity of dental impression materials is critical for accurate impressions and well-fitting restorations.
• Contact angle measurement is the standard method for assessing material hydrophilicity.
• Understanding material wettability is essential for selecting optimal impression materials.

Purpose of the Study:

• To compare the water contact angles of four different elastomeric dental impression materials.
• To evaluate the hydrophilicity of these materials before and during their setting phase.
• To determine the influence of material type on initial and developing hydrophilicity.

Main Methods:

• Flattened specimens of four impression material groups were prepared using a Teflon mold.
• A 5μl droplet of deionized water was applied to each specimen.
• Water contact angles were measured using digital photography at specific time points during setting.

Main Results:

• CAD/CAM impression material exhibited the highest contact angles, indicating hydrophobic behavior.
• Polyvinylsiloxane (PVS), polyether (PE), and vinylsiloxanether materials showed comparable and lower contact angles initially.
• A significant reduction in contact angles (increased hydrophilicity) was observed over time for PVS, PE, and vinylsiloxanether materials, most notably for light-body PVS.

Conclusions:

• CAD/CAM impression materials are the most hydrophobic among those tested.
• PVS materials demonstrate excellent hydrophilicity, crucial for detailed impression capture.
• Polyether and vinylsiloxanether materials offer superior hydrophilicity compared to others, especially during the setting process.
• All tested materials show a progressive increase in hydrophilicity as they set.