Distribution of Bacteria in Dental Offices and the Impact of Hydrogen Peroxide Disinfecting Wipes.

The purpose of this study was to characterize the occurrence of heterotrophic plate count bacteria (HPCs), fecal bacterial indicators, and methicillin-resistant Staphylococcus aureus (MRSA) on hard, nonporous surfaces (fomites) commonly found in dental offices, and to assess the impact of a hygienic disinfection intervention on the reduction of these bacteria in the office setting. Samples of various fomites were collected from dental offices located in Arizona (6) and Illinois (4) and assayed for HPCs, total coliforms, Escherichia coli, and MRSA in order to establish baseline bacterial levels. Dental office personnel were then provided with disposable disinfectant wipes containing hydrogen peroxide to use in the office, and the surfaces were subsequently resampled to assess their impact on the specified bacterial populations. The greatest numbers of HPCs were found on the patients' arm rest and office phones, with dental tool handles and the dentist examination lights yielding the lowest levels. Coliform bacteria and E. coli were also detected on those surfaces demonstrating the highest HPCs, and were cultured from other fomites as well. MRSA was also isolated from 5% of the fomites tested. The use of disinfectant wipes significantly reduced the numbers of HPC bacteria detected on fomites (p=0.002). No total coliforms, E. coli, or MRSA were cultured from disinfected fomites following the hygienic intervention. The use of hydrogen peroxide-impregnated towelettes reduced total bacterial numbers on fomites commonly located in dental offices. Total coliforms, E. coli, and MRSA were reduced to levels below detection.