How should elastomeric impression materials be stored to maintain dimensional stability?

• A. In the sun
• B. In a metal box
• C. Sealed container away from heat and moisture; pour within time window
• D. In a humid area

Answer: (C)

Dimensional stability of elastomeric impressions hinges on keeping environmental factors like temperature and moisture from altering the material after removal. Heat can cause expansion or creep, while exposure to moisture or evaporation can lead to imbibition or syneresis, both changing the impression’s size. The best practice is to store the impression in a sealed container that protects it from heat and moisture, and to pour within the manufacturer’s recommended time window while the material remains within its specified accuracy range. Storing in the sun or a humid area promotes distortion, and simply using a metal box doesn’t guarantee a proper seal or temperature/moisture control. This approach most effectively preserves the impression’s dimensions.