Analysis of fungi in aerosols dispersed by high speed pens in dental clinics from Teresina, Piaui, Brazil

Abstract

This quantitative and qualitative study aimed to evaluate the level of fungal contamination in aerosols dispersed by high rotation pens in dental clinics from Teresina, Piaui, Brazil. The data were collected during the attendance at two dental clinics. Petri dishes containing Sabouraud agar with chloramphenicol were opened for 15 min in the following places: in front of the chair, on the partitions to the right and left of the chair, and in the neighboring workbench. The plates were incubated at room temperature to allow the fungal growth and subsequent species identification. Colonies were formed in 100% of the plaques, accounting for 49 isolates belonging to 19 species, where the most frequent were: Curvularia clavata, Aspergillus niger, Phialemonium obovatum, Curvularia geniculata, and Scopulariopsis koningii. All identified species are pathogenic, and may develop allergic respiratory tract infections and even systemic infections in the patient and the dental surgeon. Our results indicate that the minimum safety distance between the dental chairs defended by the National Sanitary Surveillance Agency is insufficient and that the boxes are an efficient variable to minimize the dispersion of fungal aerosols in the dental environment. Based on these findings, we recommend the adoption of a minimum safety distance of more than 2 m and the use of boxes between the dental chairs, as well as a biweekly cleaning of the air-conditioned system and water lines as viable and efficient measures for reduction of the formation and dispersion of fungal aerosols in these environments.