title: Aerosolization of mycobacteria and legionellae during dental treatment: low exposure despite dental unit contamination.
abstract: Dental unit waterlines (DUWL) support growth of a dense microbial population that includes pathogens and hypersensitivity-inducing bacteria, such as Legionella spp. and non-tuberculous mycobacteria (NTM). Dynamic dental instruments connected to DUWL generate aerosols in the work environment, which could allow waterborne pathogens to be aerosolized. The use of the real-time quantitative polymerase chain reaction (qPCR) provides a more accurate estimation of exposure levels compared with the traditional culture approach. Bioaerosol sampling was performed 13 times in an isolated dental treatment room according to a standardized protocol that included four dental prophylaxis treatments. Inhalable dust samples were taken at the breathing zone of both the hygienist and patient and outside the treatment room (control). Total bacteria as well as Legionella spp. and NTM were quantified by qPCR in bioaerosol and DUWL water samples. Dental staff and patients are exposed to bacteria generated during dental treatments (up to 4.3 E + 05 bacteria per m(3) of air). Because DUWL water studied was weakly contaminated by Legionella spp. and NTM, their aerosolization during dental treatment was not significant. As a result, infectious and sensitization risks associated with legionellae and NTM should be minimal.
authors.affiliation: Institut universitaire de cardiologie et de pneumologie de l'Université Laval, Hôpital Laval, Québec, Québec, Canada.
authors.forename: Steve
authors.initials: S
authors.lastname: Dutil
authors.forename: Marc
authors.initials: M
authors.lastname: Veillette
authors.forename: Anne
authors.initials: A
authors.lastname: Mériaux
authors.forename: Louis
authors.initials: L
authors.lastname: Lazure
authors.forename: Jean
authors.initials: J
authors.lastname: Barbeau
authors.forename: Caroline
authors.initials: C
authors.lastname: Duchaine
mesh_terms: D000336:Aerosols; D003729:Dental Care / Q000009:adverse effects*; D019551:Dental Disinfectants; D003748:Dental Equipment / Q000382:microbiology*; D004866:Equipment Contamination; D006801:Humans; D019552:Infection Control, Dental; D007875:Legionella / Q000378:metabolism* / Q000472:pathogenicity; D009161:Mycobacterium / Q000378:metabolism* / Q000472:pathogenicity; D014871:Water Microbiology
chemical_list: D000336:Aerosols; D019551:Dental Disinfectants