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Microbiological evaluation of dental unit water systems in general dental practice in Europe
Author(s) -
Walker J. T.,
Bradshaw D. J.,
Finney M.,
Fulford M. R.,
Frandsen E.,
Østergaard E.,
Ten Cate J. M.,
Moorer W. R.,
Schel A. J.,
Mavridou A.,
Kamma J. J.,
Mandilara G.,
Stösser L.,
Kneist S.,
Araujo R.,
Contreras N.,
GoroncyBermes P.,
O'Mullane D.,
Burke F.,
Forde A.,
O'Sullivan M.,
Marsh P. D.
Publication year - 2004
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/j.1600-0722.2004.00151.x
Subject(s) - dental practice , biofilm , legionella , water contamination , microbiology and biotechnology , dental plaque , colony forming unit , medicine , veterinary medicine , contamination , biology , bacteria , dentistry , ecology , genetics
A range of opportunistic pathogens have been associated with dental unit water systems (DUWS), particularly in the biofilms that can line the tubing. This study therefore aimed to assess the microbiology of DUWS and biofilms in general dental practices across seven European countries, including the United Kingdom (UK), Ireland (IRL), Greece (GR), Spain (ES), Germany (D), Denmark (DK) and the Netherlands (NL). Water supplied by 51% of 237 dental unit water lines exceeded current American Dental Association recommendations of ≤ 200 colony‐forming units (CFU) ml −1 . Microbiological loading of the source waters was between 0 (Denmark, the Netherlands and Spain) and 4.67 (IRL) log CFU ml −1 ; water line samples from the DUWS ranged from 1.52 (ES) to 2.79 (GR) log CFU ml −1 ; and biofilm counts ranged from 1.49 (GR) to 3.22 (DK) log CFU.cm −2 . Opportunistic pathogens such as legionellae (DK and ES), including Legionella pneumophila SG1 (DK and GR), and Mycobacterium spp. (DK, NL, GR, D and ES) were recovered occasionally. Presumptive oral streptococci (ES and NL), oral anaerobes (GR), Candida spp. (UK, NL and ES) and blood (GR and IRL) were detected at relatively low frequencies, but their presence indicated a failure of the 3‐in‐1 antiretraction valve, leading to back siphonage of oral fluids into the water and biofilm phase. These findings confirm that a substantial proportion of DUWS have high levels of microbial contamination, irrespective of country, type of equipment and source water. The study emphasizes the need for effective mechanisms to reduce the microbial burden within DUWS, and highlights the risk of occupational exposure and cross‐infection in general dental practice.