Wettability of elastomeric impression materials and voids in gypsum casts

Numerous factors are involved in making an accurate void-free dental artificial stone cast or die. The relationship of the wettability of an elastomeric impression material and its interaction with the gypsum slurry is an important factor. This study examined the relative "pourability" of several impression materials by counting the number of resultant voids in artificial stone casts containing 48 point angles. Those elastomers that exhibited the lowest contact angle with water produced artificial stone casts with the fewest voids. Surfactants applied to the impression material significantly reduced the number of voids in artificial stone casts, as did modified elastomers designated by the manufacturer as hydrophilic.