Which statement regarding polyvinyl siloxane (PVS) and polyether impression material is false?

Polyether impression materials are characterized by their hydrophilic nature, which allows them to capture fine details effectively even in the presence of moisture. This property supports their use in situations where saliva or blood might be present, as they can still provide accurate impressions. Storing polyether in a moist environment is acceptable due to its ability to absorb water without compromising its performance.

On the other hand, polyvinyl siloxane (PVS) is an addition silicone that indeed sets without producing by-products, allowing for precise and dimensionally stable impressions. Its accuracy can remain intact even when the impressions are poured a week after they have been taken, making it a preferred material for many dental procedures. Polyether materials also demonstrate good dimensional stability over time, allowing for delayed pouring without significant loss of accuracy. Thus, option D is false because it misrepresents the properties of polyether as hydrophobic rather than hydrophilic.