Evaluation of microbial contamination of pumice in dental laboratories of Tabriz in 2010-2011

Abstract

In polishing process of dental prostheses using contaminated pumice may result in a cross_ contamination involving dentists, laboratory technicians and patients. The aim of this study was to determine the presence and level of microbial contaminates in pumice powder and pumice slurry used in dental laboratories of Tabriz. Materials and Methods: This study was a descriptive analytical investigation. In the same controlled and sterilized condition, the used pumice samples were controlled from 24 dental laboratories operating in Tabriz. Isolated fungi and bacteria were identified by using gram stain and deferential diagnostic tests. Results: Among the 24 laboratories, in two laboratories there was no contamination of pumice. The results showed that the frequency of infection in dental laboratories was 91/7%. Bacterial was 54/1% in the used Pumice of gram- and 45/9% of gram+. Organisms detected in pumice powders included Staphylococcus Epidermis(21/4%), Acinetobacter(19%), Bacillus(11/9%), Proteus(7/1%), Diphtheroisd and Citrobacter(4/8%), Staphylococcus aureus(2/4%) and Streptococus and E.coli bacteria in were not found in cultured samples. Conclusion: According to this study, it could be concluded that pumice used in dental laboratories of Tabriz were frequently contaminated with microorganisms. Therefore, personnel should be aware of the hazards posed by the presence of pathogens in dental laboratories, and received instruction on contamination control.