Detail reproduction of soft tissue: a comparison of impression materials.

The extent to which an impression material reproduces detail is influenced by factors such as viscosity, wettability, handling properties, and voids. This clinical study compared the ability of several impression materials to register soft tissue without creating voids and produce detailed gypsum casts. Thirty impressions of the hard palate of a single subject were made by use of a custom-cast metal framework serving as an impression tray. Six impression materials commonly used in clinical practice were tested. Die stone casts made from the impressions were evaluated and ranked by five judges. Polyether and hydrophilic addition silicone were judged best in terms of detail reproduction and zinc oxide-eugenol and polysulfide low-viscosity materials were judged worst in this regard. Impression voids were minimized with low-viscosity polysulfide and zinc oxide-eugenol when compared with addition silicones (low and medium viscosities).