How does exposure to air affect the alginate material?

Exposure to air can cause syneresis in alginate materials. Syneresis is a phenomenon where gel-like materials expel liquid when exposed to certain conditions, resulting in a loss of water content that can lead to shrinkage. In the context of alginate impressions, when they are left exposed to air, moisture may evaporate from the surface, causing the impression to dry out and potentially distort. This underscores the importance of proper handling and storage of alginate impressions after they are taken, as protection from air exposure is necessary to maintain their dimensional stability and accuracy for dental work. Preventing syneresis is crucial for achieving high-quality results in dental impressions.