Methods: Impressions were made from the master model with condensation silicone (Coltène's Speedex) impression material. In four treatment groups the disinfected samples were immersed for 30 minutes with the four disinfectants, respectively. Impressions with no immersion served as controls. A computerized contact-measuring device was used to measure the three-dimensions of the stone casts poured against the treated impressions. The device is precise to a reading of 0.001 mm.
Results: Although statistical evaluation of the measurements of the casts made from condensation silicone impressions showed significant differences (P<0.05) among the treatment groups for the three-dimensional stability, the small differences might be acceptable in dental clinical practice according to ADA specification No. 19. Conclusion:The 30 minutes treatments with the four immersion disinfectants have no adverse effect on the three-dimensional stability of condensation silicones.