November/December 2013, Volume 34, Issue 10
Published by AEGIS Communications
Do bib clips pose a cross-contamination risk at the dental clinic?
Although multiple-use dental napkin holders have a relatively low risk of transmitting infection, they do require disinfection between patients. This study sought to: 1) determine the presence of bacterial load on two types of clips of reusable bib chains after dental procedures at the Endodontics and Orthodontics clinics at Tufts University School of Dental Medicine; and 2) evaluate the effectiveness of disinfecting the clips. These specialty clinics represent a wide spectrum of patients, procedures, and appointment times. Bacterial load on the bib clips was determined immediately following dental treatments—both before and after their disinfection—during morning and afternoon sessions. The results revealed that, after treatments, there was a statistically significant difference when comparing the two clinics for bacterial burden on the clips. Furthermore, there was a statistically significant difference in bacterial load on the two types of clips. Disinfection of the bib clips was highly effective in both clinics. Clinically, the results suggest that due to the nature of the treatment, the demographic population, and the type of bib clips used, patients in different clinics may be exposed to varying bacterial concentrations on the bib clips, and thus to different possible cross-contamination risks.
Microbiological evaluation of ultrasonic nebulization for disinfecting dental impressions
Disinfecting dental impressions is necessary to decrease the risk of cross-contamination in dental offices. Ultrasonic nebulization has been mentioned as a microbicidal technique that can be used to disinfect contaminated dental impressions. This study compared the microbicidal effect of 2% glutaraldehyde and 0.2% peracetic acid for the disinfection of dental impressions made with vinyl polysiloxane, using two disinfection methods: immersion and ultrasonic nebulization. Bactericial efficacy was examined using Staphylococcus aureus and Bacillus atrophaeus as indicators. Thirty impressions were obtained and distributed randomly in 5 groups (n = 6). Group 1 was immersed in 2% glutaraldehyde immersion for 10 minutes, Group 2 was immersed in 0.2% peracetic acid for 10 minutes, Group 3 underwent ultrasonic nebulization for 10 minutes in 2% glutaraldehyde solution, Group 4 underwent ultrasonic nebulization for 10 minutes in 0.2% peracetic acid solution, and Group 5 was a control group that received no disinfectant. Both solutions experienced a 100% reduction in microorganisms following ultrasonic nebulization, as did peracetic acid following immersion; however, immersion in glutaraldehyde demonstrated lower values of reduction in B. atrophaeus group, with a statistically significant difference compared with the other experimental groups.
Disinfection protocols to prevent cross-contamination between dental offices and prosthetic laboratories
Control of cross-contamination between dental offices and prosthetic laboratories is critical to maintaining 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. Results 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.