Microbial contamination of dental unit waterlines in dental practices in Hesse, Germany: A cross-sectional study

Abstract

The quality of water from dental units is of considerable importance since patients and dental staff are regularly exposed to water and aerosols generated from the dental unit. This study analyzed the microbial quality of water obtained for periodical monitoring from 56 dental units in different dental practices in Hesse. Contamination by Legionella spp., Pseudomonas aeruginosa, and increased total colony counts were detected in 27.8%, 3.5%, and 17% of samples. Legionella pneumophila serogroup 1 accounted for 28% of Legionella isolates. The Legionella concentration was >100 cfu/100 ml in 84% of contaminated samples. Samples collected from an instrument channel were more frequently contaminated by Legionella than those from cup filler (41.7% vs. 18.6%, p = 0.02).After release of these results, decontamination measures were performed in units that had revealed unsatisfactory results. The outcome of the intervention was followed-up by microbiological analysis. At follow-up, 65.2% and 72.7% of waterlines that had previously been contaminated by Legionella or had shown increased total colony counts were free of contamination.Our results show a high rate of contamination of water from dental units in dental practices in Hesse. They highlight the risk of exposure for patients and personnel and the need for effective strategies to reduce microbial contamination.

Pyrosequencing analysis of bacterial diversity in dental unit waterlines

“…Microbial contamination levels up to standard recommendations had previously been reported in other studies focusing on DUWL microbial contamination (Arvand and Hack, 2013;Barbeau et al, 1996;Santiago et al, 1994;Szyma nska et al, 2008). In our study, microorganisms were clearly detected in the three water groups (IW, OWS and OWA).…”

“…Dental Unit Waterlines (DUWL) appear to be regularly contaminated with microorganisms, ranging from 10 2 to 10 8 CFU (colony forming units)/mL of water (Arvand and Hack, 2013;Barbeau et al, 1996;Barbot et al, 2012;O'Donnell et al, 2011;Szyma nska et al, 2008). This type of DUWL contamination is associated with a wide variety of microorganisms ranging from non-pathogenic to pathogenic bacteria, fungi, viruses and protozoa such as free-living amoebae (Puttaiah et al, 2012;Szyma nska, 2005;Szyma nska et al, 2008;Walker et al, 2000).…”

Assessment of volatile organic compounds and particulate matter in a dental clinic and health risks to clinic personnel

“…Microbial factors associated with indoor air quality in a dental environment have been studied extensively. [1][2][3] Nonetheless, limited attempts have been made to assess chemical hazards in aerosols, gases, and vapors in the dental clinic setting. Dental materials commonly contain resins and solvents, which could emit gas-phase contaminants into the indoor air.…”

Comparing Efficiency Between Conventional and Molecular Methods for Detecting Legionella pneumophilia in Dental Unit Waterline Systems

“…Aerosols produced during dental treatments are the most important pathway for the migration of Legionella via dental practices. DUWL S that are contaminated with Legionella may contribute to respiratory diseases among dentists, dental nurses, and patients [4]. The high prevalence of Legionella seropositivity in dental personnel supports the notion that dental healthcare staff are at a high level of risk infection [5].…”