Abstract

Dental unit waterlines (DUWLs) represent a complex environment able to promote microbial contamination, due to functional, mechanical and practical risk factors. According to a water safety plan approach, the main goal is to preserve the health of dentists, dental staff and patients.

The aim of this study is to develop a DUWLs water safety plan that is able to support correct and effective maintenance and disinfection procedures.

Three different water systems serve 60 dental chairs: (i) water that comes directly from municipal water (Type A), (ii) water supplied by municipal water and water bottles (Type B) and (iii) water supplied only via water bottles (Type C). For each type, Legionella and Pseudomonas aeruginosa contamination was studied, by applying a new sampling scheme, based on separate sampling from water bottles, cup filler and handpieces. Type B DUWL is the only type of DUWL contaminated by L. pneumophila (ST 59) and L. anisa (mean contamination: 608.33 ± 253.33 cfu/L) detected in cup filler and handpieces, as well as the high presence of P. aeruginosa (44.42 ± 13.25 cfu/100 mL). Two subsequent shock treatments and resampling procedures were performed by increasing disinfectant dosage and contact time and removing some DUWL components linked to biofilm growth in DUWLs. A significant reduction of contamination was obtained for both microorganisms (Legionella spp.: −100%, p < 0.001 and P. aeruginosa: −99.86%, p = 0.006). The sampling strategy proposed allows us to identify the source of contamination and better focus on the maintenance and disinfection procedures. DUWLs represent an environment that requires a multidisciplinary approach, combining the knowledge of all DUWL components to correct procedures that are able to preserve the health of personnel and patients, as well as guaranteeing DUWLs’ safe functionality.

Details

Title
First water safety plan approach applied to a Dental Clinic complex: identification of new risk factors associated with Legionella and P. aeruginosa contamination, using a novel sampling, maintenance and management program
Author
Marino, Federica 1   VIAFID ORCID Logo  ; Mazzotta, Marta 1   VIAFID ORCID Logo  ; Pascale, Maria Rosaria 2   VIAFID ORCID Logo  ; Derelitto, Carlo 1   VIAFID ORCID Logo  ; Luna Girolamini 3   VIAFID ORCID Logo  ; Cristino, Sandra 3 

 Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy 
 Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy; Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Bologna, Italy 
 Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy; European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Legionella Infections (ESGLI), Basel, Switzerland 
Publication year
2023
Publication date
Dec 2023
Publisher
Taylor & Francis Ltd.
e-ISSN
20002297
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2894309884
Copyright
© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This work is licensed under the Creative Commons  Attribution – Non-Commercial License http://creativecommons.org/licenses/by-nc/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.