Alginate impressions should be poured within what time frame to prevent distortion?

Alginate impressions should ideally be poured within 1 hour to prevent distortion. This time frame is crucial because alginate impressions are made from a material that begins to undergo changes in dimension and consistency shortly after they are removed from the mouth. After about an hour, the water content in the alginate can begin to evaporate, and the material can start to set or deform due to environmental factors such as humidity and temperature.

This means that pouring the impression within this time frame helps to ensure that the negative reproduction of the teeth and surrounding structures retains its accuracy and detail. If the impression is poured too late, it may not provide a reliable representation for the dental cast, leading to poor-fitting restorations or appliances, which can ultimately affect patient care and treatment outcomes.