the effect of disinfection by spray atomization on dimensional accuracy of condensation silicone impressions

background and aims. the condensation silicone impression materials are available, but there is little knowledge of their accuracy after disinfection. the objective of this study was to evaluate the effect of the disinfection by spray atomization on dimensional accuracy of condensation silicone impressions. materials and methods. impressions were made on a stainless steel master model containing a simulated two complete crown preparation with an edentulous space interposed using spidex® and rapid® impression materials. 44 impressions were made with each material, of which 16 were disinfected with 5.25% sodium hypochlorite, 16 were disinfected with 10% iodophor and 12 were not disinfected. three dimensional measurements of working casts, including interpreparation distance, height, and diameter, were calculated using a measuring microscope graduated at 0.001 mm. dimensional changes (mm) between the disinfected and non-disinfected working casts were compared. one-way analysis of variance (anova) was employed to analyze the data (α=0.05). results. disinfection of each condensation silicone material by spraying atomization with two different disinfectant material resulted in significant change in interpreparation distance (p< 0.05). changes in height and diameter were only significant in spidex® impressions (p< 0.05). conclusion. significant changes in the mean dimensions were seen as a result of disinfection by spraying; however, the dimensional changes do not seem great enough to cause critical positional distortion of teeth when fixed partial denture restorations are made.