ABSTRACT
Control of cross-contamination between dental offices and prosthetic laboratories is of utmost importance to maintain the health of patients and dental office staff. The purpose of this study was to evaluate disinfection protocols, considering antimicrobial effectiveness and damage to the structures of prostheses. Solutions of 1% sodium hypochlorite, 2% chlorhexidine digluconate, 50% vinegar and sodium perborate were evaluated. Specimens were contaminated in vitro with standardized suspensions of Candida albicans, Streptococcus mutans, Escherichia coli, Staphylococcus aureus and Bacillus subtilis spores. Disinfection by immersion for 10 min was performed. Final counts of microorganisms were obtained using the plating method. were statistically compared by Kruskal-Wallis ANOVA and Dunn's test. The surface roughness of 40 specimens was analyzed before and after 10 disinfection cycles, and results were compared statistically using Student's t test. The solution of 50% vinegar was as effective as 1% sodium hypochlorite and 2% chlorhexidine against C. albicans, E. coli and S. mutans. The sodium perborate solution showed the lowest antimicrobial effectiveness. Superficial roughness increased after cycles in 1% sodium hypochlorite [p = 0.02]. Solutions of 1% sodium hypochlorite, 2% chlorhexidine and 50% vinegar were effective for the disinfection of heat-polymerized acrylic specimens. Sodium hypochlorite increased the superficial roughness
ABSTRACT
Ozone has been used as an alternative method for the decontamination of water, food, equipment and instruments. The objective of this study was to evaluate the antimicrobial effects of ozonated water on the sanitization of dental instruments that were contaminated by Escherichia coli, Staphylococcus aureus, Candida albicans and the spores of Bacillus atrophaeus. A total of one hundred and twenty standardized samples of diamond dental burs were experimentally contaminated with E. coli [ATCC 25922], S. aureus [ATCC 6538] and C. albicans [ATCC 18804] and the spores of B. atrophaeus [ATCC 6633] for 30 min. After the contamination, the samples were exposed to ozonated water [10 mg/L O3] for 10 or 30 min. The control group was composed of samples that were exposed to distilled water for 30 min. After the exposure to the ozonated water, 0.1 mL aliquots were seeded onto BHI agar to count the colony-forming units per milliliter [CFU/mL] of E. coli, S. aureus, and B. atrophaeus. Sabouraud dextrose agar was used to count the CFU/mL of C. albicans. The results were subjected to an analysis of variance and the Tukey test. For all of the microorganisms studied, the ozonated water reduced the number of CFU/mL after 10 and 30 min of sanitization, and this microbial reduction was dependent on the duration of the exposure to the ozonated water. E. coliexhibited the greatest reduction in CFU/mL [2.72-3.78 log] followed by S. aureus [2.14-3.19 log], C. albicans [1.44-2.14 log] and the spores of B. atrophaeus [1.01-1.98 log]. The ozonated water was effective in reducing the CFU of E. coli, S. aureus, C. albicans and B. atrophaeus spores, suggesting that ozonated water can be used for the sanitization of dental instruments