Antibacterial Effect of Sanosil ۲% and ۶% and Sodium Hypochlorite ۰.۵% on Impressions of Irreversible Hydrocolloid (Alginate) and Condensational Silicone (Speedex)

Background: Dental impressions often carry microorganisms that may cause cross-infection from patients to dental staff. Impressions should be disinfected to eliminate the risk of cross-contamination. Objectives: The aim of this study was to determine the effectiveness of three different disinfectant solutions on two commonly used impression materials. Material and Methods: Seventy-two impressions were taken from dentate arches of nine dental staff from the school of dentistry, Hamadan University of Medical Sciences. Eight successive impressions were recorded in two different impression materials for each participant as four alginate and four condensational silicones (Speedex). For each impression material, specimens were exposed to four different regimens; one was immersed in sterile water as control, and the remaining specimens were exposed to three different disinfection treatments (۰.۵% sodium hypochlorite, ۲% Sanosil, and ۶% Sanosil) for ۱۰ minutes. The impressions were washed with distilled water for ۱۵ seconds, were inserted into sterilized tubes, and covered with Tryptic soy broth media (TSB). The tubes were incubated at ۳۵۰ ºC for ۲۴ hours. In total, ۰.۰۱ milliliter was obtained from each tube, and inoculated on blood agar medium. Gram staining and biochemical tests were performed for bacterial detection. Data was analyzed by SPSS software using Fisher exact test. Results: Bacterial growth was observed in all impressions immersed in sterile water for ۱۰ minutes (control group). Disinfected alginate impressions were not contaminated withany microorganisms. None of the solutions under examination were completely effective for condensational Silicone impressions. Antibacterial effects on condensational silicone impressions ranked in a decreasing order as ۰.۵% sodium hypochlorite, ۶% Sanosil and ۲% Sanosil. Conclusion: Within the limitations of this study, disinfectants were able to completely eliminate microorganisms carried by the alginate impressions. However, more efficient disinfection methods are needed to eliminate the risk of cross contamination by condensational silicone impressions.