Preliminary investigation of a disinfected gypsum die stone.

The setting time, comprehensive strength, diametral tensile strength, expansion, and fine detail reproduction of disinfectant-containing die stones (Steri-Die A and Steri-Die B) were compared to two commonly used die materials (Vel-Mix and Die-Keen). Six samples of each die material were formed from polysulfide rubber, condensation silicone, polyether, and poly(vinyl siloxane) impression materials. The disinfected die stones compared favorably to the controls in all tests with the following exceptions: Steri-Die B was weaker in both compressive and tensile strength and deficient in detail reproduction, especially with condensation polymerizing silicone.