While it’s difficult to completely eradicate waterborne pathogens from healthcare water systems, infections caused by these microorganisms are preventable.
News reports and clinical articles documenting microbial infections traced back to contaminated public and healthcare water sources have increased at an alarming rate within the last decade (Table 1). Four incidents in dental practices have also been reported during this period.1-4 Localized cutaneous infections, bacteremias, and even disseminated, life-threatening diseases have been diagnosed, especially when they develop in immune compromised and/or critically ill patients.
Clinicians are asked to devote more attention to understanding possible treatment sequelae for the increasing number of compromised patients, while also minimizing microbial exposure for all patients using established infection prevention practices.
Efforts to prevent contamination of water sources in healthcare settings have improved at a rapid pace. With specific regard to dentistry, colonization of dental treatment water can be greatly reduced by appropriate application of a number of direct and indirect antimicrobial technologies. Progress aimed at addressing this emerging issue has led to the development and availability of a number of products for use in dental settings. Unfortunately, clinicians may become confused by competing and conflicting efficacy claims. In such cases, resultant dental unit waterline (DUWL) infection control procedures can be compromised and/or ineffective due to lack of following proper instructions.
In order to maximize infection prevention efforts, dental professionals should be aware of a few basic guidelines when selecting and using products.
Advances in microbial identification techniques and epidemiological investigations of waterborne outbreaks have allowed improvement in documentation of infections caused by a variety of bacteria. While it is difficult to eliminate waterborne pathogens as natural inhabitants in healthcare water systems, infections caused by these microorganisms are preventable.5
Multiple choices are available for controlling and monitoring colonization of water delivery systems and reservoirs, and other technologies continue to be developed. With specific regard to dentistry, the keys for accomplishing DUWL asepsis goals remain the same as for other infection control areas: One, application of basic infection prevention principles; and Two, compliance with use of approved products.
Colonized waterlines should be cleaned first to remove accumulated microbial and extracellular material prior to implementation of routine treatment procedures. Subsequent compliance with step-by-step IFUs is essential for controlling and maintaining low microbial levels in potable (<500 CFU/mL) treatment water. Periodic testing of water quality can also ensure that ongoing water treatment procedures are effective.
When monitoring is performed as a component of a practice’s DUWL infection prevention routine, it can assist in identifying compliance problems and also provide documentation of water quality.
1. Ricci MI, Fontana S, Pinci F, et al. Pneumonia associated with a dental unit waterline. Lancet 2012;379:684
2. Peralta G, Tobin-D’Angelo M, Parham A, et al. Notes from the field: Mycobacterium abscessus infections among patients of a pediatric dentistry practice – Georgia, 2015. Morbid Mortal Wkly Rpt 2016;65:355-356
3. Hatzenbuehler LA, Tobin-D’Angelo M, Drenzek C, et al. Pediatric dental clinic-associated outbreak of Mycobacterium abscessus infection. J Pediat Dent 2017;6:e116-122
4. Schonning C, Jernberg C, Klingenberg D, et al. Legionellosis acquired through a dent unit: a case study. J Hosp Infect 2017;96:89-92
5. Kanamori H, Weber DJ, Rutala WA. Healthcare outbreaks associated with a water reservoir and infection prevention strategies. Clin Infect Dis 2016;62:1423-1435
6. Molinari JA. The ongoing challenge of waterborne infections. Inside Dent. August 2017;52-58
7. Molinari JA. Dental waterline infection control: a work in progress. Dent Econ. February 2017;2
8. Mills SE, Porteous N, Zawada J. Dental unit water quality: Organization for Safety, Asepsis, and Prevention White Paper Recommendations – 2018. J Dent Infect Control Safety 2018;1:1-27