Dimensional change of elastomeric materials after immersion in disinfectant solutions for different times

The aim of this study was to evaluate the influence of immersion period in two disinfectant solutions on dimensional change of four elastomeric impression materials.

Four representative materials of each class of elastomers: Xantopren (polydimethylsiloxane-PDS), Express (polyvinyl siloxane-PVS); Permlastic (polysulfide- PS) and Soft Impregum (polyether-EP) were mixed according to manufacturers' instructions and then inserted into a metal matrix prepared according to the specification of ISO 4823. The molds were removed from the matrix after 7 minutes and immersed in disinfectant solutions (sodium hypochlorite 0.5 and 2% glutaraldehyde) for 5, 10, 20, 30 and 60 minutes (n = 7), except the control group, which was not immersed. Once removed from solutions, the test samples were washed in water for 15 seconds, dried and measured three times, using a comparative optical microscope, with accuracy of 0.0005 mm. The analysis of variance with three criteria and Tukey's test with significance level of 5% showed that differences in linear dimensions of the materials analyzed were not statistically significant (p > 0.05) after soaking in sodium hypochlorite 0.5 and 2% glutaraldehyde, for the tested periods of time.

Combinations of molding material and disinfecting solution can be used in the dental clinic for infection control, without changing the dimensional molds, for immersion periods not longer than 20 minutes.