Which impression material is considered the gold standard for fixed prosthodontic impressions due to its dimensional accuracy, excellent detail reproduction, and long-term stability?

Vinyl polysiloxane (VPS), also known as addition silicone or polyvinylsiloxane (PVS), is the most widely used and preferred impression material for fixed prosthodontic impressions. Its advantages include: excellent dimensional accuracy and stability (can be poured multiple times), superb detail reproduction, hydrophilic-modified versions have good behavior in slightly moist environments, no setting byproducts (unlike condensation silicones), and excellent tear resistance. It is used as a two-paste system (base + catalyst) and is available in multiple viscosities for monophase, double-mix, or triple-tray techniques. Alginate is used for diagnostic models and removable prosthodontics but lacks the dimensional stability needed for fixed work.