Effects of chemical disinfectant solutions on the stability and accuracy of the dental impression complex

Currently available impression materials were not designed for disinfection or sterilization, and it is conceivable that disinfectants may adversely affect impressions. This study evaluated the accuracy and dimensional stability of polyether (Permadyne/Impregum) and polyvinyl siloxane (Express) impression materials retained by their adhesives in two different acrylic resin tray designs (perforated and nonperforated) when the materials were immersed for either 30 or 60 minutes in three high-level disinfectants. Distilled water and no solution served as controls. A stainless steel test analog similar to ADA specification No. 19 was used. A total of 400 impressions were made with all combinations of impression materials, tray designs, disinfectant, and soaking times. Samples were evaluated microscopically before and after immersion and 48 hours after soaking. Results indicated that these two impression materials were dimensionally stable. Because the results emphasized the stability and accuracy of the impression complex under various conditions, dentists can perform disinfection procedures similar to the protocol of this study without concern for clinically significant distortion of the impression.