Evaluation of Contamination Reduction on Gypsum Casts from Alginate Impressions Disinfected with Four Different Materials

INTRODUCTION: Infection control is one of the most important aspects in dentistry. According to the special features of dentistry, this profession can have a very important role in transmission of infection. This study was conducted by comparing the effects of four common disinfectants on the microbial contamination of alginate impressions and corresponding gypsum casts.

METHODS & MATERIAL: In this experimental study, eleven patients aged 20-30 years old were selected by convenience sampling method. Six alginate impressions for each patient were formed by 24-hour intervals. These sixty six alginate impressions were divided in six groups (control-no wash, wash with water, Micro10, 2% Glutaraldehyde, 5.25% Sodium hypochlorite and Deconex). Disinfection methods were done by spraying (except for glutaraldehyde group that was done by immersing method) and then the alginate impressions were placed in plastic bags for 10 minutes to prevent the evaporation of disinfectants. Sixty six gypsum casts were made from alginate impressions. Microbial swabs were collected from mid palatal region of alginate impressions and gypsum casts for all groups by dried sterile cotton. The swabs were cultured for bacteria by inoculation on Blood Agar at 37°C for 3 days. The positive cultures were counted and the data was analyzed by software SPSS21.

RESULTS: The counting colonies of gypsum casts and alginate impressions which were disinfected by Micro10, 2% Glutaraldehyde, 5.25% Sodium hypochlorite and Deconex were not statistically significant and meaningful.

CONCLUSION: All disinfectants used in this study, had the same and acceptable effect.