What does syneresis in alginates refer to?

Syneresis in alginates refers to the process by which a gel or a colloidal system shrinks and releases liquid, often leading to a distortion of the initial structure. This occurs when the gel, under certain conditions, expels water or other exudates from its matrix. In the context of dental alginates, syneresis can affect the accuracy of impressions taken for dental work, as the release of fluid can change the dimensions of the set material, leading to a less precise reproduction of the dental anatomy.

The other options describe different phenomena that do not align with the definition of syneresis. For instance, swelling due to absorbing water or gases pertains to different processes entirely, which do not involve the release or distortion of the gel structure that characterizes syneresis. Therefore, understanding that syneresis specifically relates to the distortion resulting from the release of exudates helps clarify its impact on alginate impression materials.