Fungal contamination and disinfection of dental chairs, Teresina, Piaui, Brazil.

The aim of this study was to analyze fungal contamination on dental chairs at the clinic of a Higher Education Institution in TeresinaPI, Brazil, and to evaluate the effectiveness of different disinfectants: 70% alcohol and 1% sodium hypochlorite. We selected the five sites with most contact between patient and chair: headrest, backrest, armrests, seat and foot rest. Samples were collected from these sites on 14 chairs and inoculated in agar Sabouraud culture medium containing chloramphenicol. Pathogenic fungi were isolated from all sampling sites on the chairs. Highest frequencies were found on footrest, followed in decreasing order by seat, backrest, armrests and headrest. Fourteen species of filamentous fungi were identified, belonging to the genera Alternaria, Aspergillus, Cladosporium, Curvularia, Drechslera, Fusarium, Penicillium and Paecillomyces. After sampling, seven chairs were disinfected with 70% alcohol and seven with 1% sodium hypochlorite, and samples were taken again using the same procedure. No fungal growth was detected following disinfection with sodium hypochlorite, which was clearly more effective than alcohol, after which there was still fungal growth. This study highlights the need for the biosafety protocol to include cleaning and disinfection of dental chairs with 1% sodium hypochlorite after each attendance in order to prevent crossinfection.