- The primary role of surfactant in alginate impression materials is to improve wettability.
- Alginate is a hydrophilic material, but the presence of a surfactant further reduces the surface tension of the mix.
- This enhances the ability of the alginate to flow over and adapt closely to the moist dental tissues, capturing detailed impressions accurately.
- Improved wettability ensures that the material can displace fluids like saliva and blood, leading to a more precise and detailed impression model.

Other options like enhancing setting time, increasing dimensional stability, or strengthening mechanical properties are influenced by different components or factors in the formulation, but surfactants specifically target the surface interactions to improve flow and adaptation.

Reference: Craig’s Restorative Dental Materials, 13th Edition, Chapter 6 - Impression Materials, Page 163