Elastomeric impression materials: a comparison of accuracy of multiple pours

Area of Science:

• Materials Science
• Dental Materials Science

Background:

• Elastomeric impression materials are crucial for accurate dental restorations.
• Evaluating dimensional stability over multiple pours is essential for clinical reliability.

Purpose of the Study:

• To compare the accuracy and dimensional stability of different elastomeric impression materials.
• To assess the impact of multiple pours on cast accuracy from a single impression.

Main Methods:

• Three master dies were used to create impressions with three types of elastomeric materials: addition silicones, polyethers, and condensation silicones.
• Impressions were poured multiple times at various intervals.
• Dimensional changes in the resulting casts were measured using a traveling microscope.

Main Results:

• Addition silicones resulted in shorter dies with larger diameters; polyethers yielded shorter dies in both height and diameter.
• Condensation silicones showed minimal changes on the initial pour but degraded with subsequent pours.
• No material demonstrated consistent behavior up to the fourth pour, though deviations were statistically insignificant.

Conclusions:

• Addition and condensation silicones exhibit superior recovery from deformation compared to polyethers.
• None of the tested elastomeric impression materials maintained consistent accuracy across multiple pours.
• Clinical selection should consider the trade-offs in dimensional stability and deformation recovery for specific applications.