A comparison of three wetting agents used to facilitate the pouring of dies.

This study compared the effect of a clinical surfactant and one of three laboratory surfactants used before pouring dies from elastomeric impression materials. A total of 154 impressions were recorded. Hydrosystem surfactant was used before the recording of 78 of these impressions. A total of 154 dies were poured with Wax-mate, Tensilab, or Hydrosystem surfactants and examined for surface voids by an examiner who was unaware which wetting agent was used. Six dies were grossly defective and discarded. When the Hydrosystem surfactant had not been used during impression recording there was no significant difference between Hydrosystem (mean 10.2 +/- 8.8 voids, n 25), Wax-mate (mean 13.1 +/- 14.4 voids, n 25), and Tensilab (mean 14.9 +/- 11.6 voids, n 21) surfactants when the dies were poured. When Hydrosystem surfactant was used during impression recording, there was no significant difference between the number of voids on dies produced with Hydrosystem (mean 3.8 +/- 3.9 voids, n 26), Wax-mate (3.9 +/- 3.3 voids, n 25), or Tensilab (3.7 +/- 4.9 voids, n 26) surfactants. However, each of the groups in which Hydrosystem surfactant was used before impression recording resulted in dies with significantly fewer voids than when it had not been used, independent of the surface wetting agent used in the pouring of dies (p < 0.05). To reduce the number of voids in laboratory dies, this in vitro study suggested that a topical surfactant should be used before an impression is recorded.