What is the term for when an alginate impression takes up water due to soaking or wrapping in a wet towel?

The term that describes the process where an alginate impression absorbs water, typically due to being wrapped in a wet towel or soaking in water, is imbibition. This phenomenon occurs when hydrophilic materials like alginate attract and absorb moisture from their surroundings.

Imbibition can affect the accuracy and integrity of the impression by causing it to expand, which may lead to dimensional changes that compromise the fit of the final dental restoration or appliance. This is particularly important for dental assistants and practitioners to understand, as proper handling and storage of alginate impressions are essential to maintain their quality and ensure precise results in dental procedures.

In contrast, other terms related to the behavior of materials do not describe this specific process. Contraction refers to a reduction in size, which occurs when an impression loses moisture. Syneresis is the process of moisture loss from the impression material, leading to shrinkage. Solvation pertains to the interaction between solute and solvent but is not specific to the water absorption of alginate impressions.