Dental Unit Water Lines and Risk of Pathogenic Parasitic Contamination

Main Article Content

Wafaa M. Hikal
Hussein A. H. Said-Al Ahl


Mouth care is of great importance for patients in dental care units, for provision of oral health care, and there is great concern about the levels of oral diseases associated with inappropriate and unhygienic oral care practices, the most important of which is the contamination of water with microbes. Oral health is at risk due to systemic diseases transmitted to patients due to microbial contamination of the dental unit waterlines (DUWLs) with pathogenic microbes. Reports of cases infected with pathogenic microbes were published of patients receiving treatment in dental unit waterlines. The quality of water is of considerable importance because both patients and dental team are regularly exposed to water and aero-sols generated by dental equipment. Studies have demonstrated that DUWLs provide a favorable environment for microbial proliferation and biofilm formation, and that water is consequently often contaminated with high densities of various microorganisms (bacteria, fungi, protozoa, viruses). The presence of high levels of microbial contamination may be a health problem for dentists and patients, especially those who are immuno-compromised. The current status of knowledge on microbial contamination of DUWLs is presented, with an emphasis on the infectious risk associated with DUWLs. It is essential that a high standard of mouth care combined with adequate and water quality, and preventive dental units in order to maintain oral comfort and prevent a deterioration and public health.

Microorganisms, water, dental unit waterlines, biofilm, health

Article Details

How to Cite
Hikal, W. M., & Ahl, H. A. H. S.-A. (2021). Dental Unit Water Lines and Risk of Pathogenic Parasitic Contamination. Asian Basic and Applied Research Journal, 3(4), 1-13. Retrieved from
Review Article


Barbot V, Robert A, Rodier M, Imbert C. Update on infectious risks associated with dental unit waterlines. FEMS Immunology and Medical Microbiology. 2012;65:196-204.

Hikal WM, Hussein AH, Said-Al Ahl HAH. Cysticidal activity of Trachyspermum ammi essential oil against Acanthamoeba isolates from dental clinic and hospital water networks. Pakistan Journal of Zoology. 2019;51(5): 1799-1806.

Centers for Disease Control and Prevention (CDC): Dental Unit Water Quality. Content source: Division of Oral Health, National Center for Chronic Disease Prevention and Health Promotion; 2018.

Kumar S, Atray D, Paiwal D, Balasubramanyam G, Duraiswamy P, Kulkarni S. Dental unit waterlines: Source of contaminationand cross-infection. Journal of Hospital Infection. 2010;74:99e111.

Figueiredo-Filho AO, Bem JSP, Sobrinho CRW, Souza FB. Microbiological water evaluation from biofilm adhered to dental unit waterlines. International Journal of Odontostomatology. 2019;(3):357-362.

Garg SK, Mittal S, Kaur P. Dental unit waterline management: Historical perspectives and current trends. Journal of investigative and clinical dentistry. 2012;3(4):247-52.

O’Donnell MJ, Shore AC, Coleman DC. A novel automatedwaterline cleaning system that facilitates effective and consistentcontrol of microbial biofilm contamination of dental chair unit waterlines: a one-year study. Journal of Dentistry. 2006;34(9):648-61.

Ajami B, Ghazvini K, Movahhed T, Ariaee N, Shakeri M, Makarem S. Contamination of a dental unit water line systemby legionella pneumophila in the mashhad school of dentistry in 2009. Iranian Red Crescent Medical Journal. 2012;14(6):376-8.

Walker JT, Brandshaw DJ, Fulford MR, Marsh PD. Microbiological evaluation of a range of disinfectant products tocontrol mixed-species biofilm contamination in a laboratory model of a dental unit water system. Applied and Environmental Microbiology Journal. 2003;69(6):3327-32.

Walker JT, Marsh PD. A review of biofilms and their role inmicrobial contamination of dental unit water systems (DUWS). International Biodeterioration and Biodegradation. 2004;54(2):87-98.

Walker JT, Marsh PD. Microbial biofilm formation in DUWS and their control using disinfectants. Journal of Dentistry. 2007;35(9):721-30.

Szymanska J, Sitkowska J. Bacterial contamination of dentalunit waterlines. Environmental Monitoring and Assessment. 2012;185(5):3603-11.

Rodrigues S, Suvarna S, Suvarna J, Saralaya V, Saldanha S, Shenoy VK. Microbial assessment of dental unit waterlines in an institutional setup in Karnataka, South India. Indian Journal of Dental Research. 2017;28(5):555-9.

Sacchetti R, De Luca G, Zanetti F. Influence of material andtube size on DUWLs contamination in a pilot plant. New Microbiologica. 2007;30:29-34.

Barbeau J, Gauthier C, Payment P. Biofilms, infectious agents, and dental unit waterlines: a review. Canadian Journal of Microbiology. 1998;44:1019-1028.

de Oliveira AC, Maluta RP, Stella AE, Rigobelo EC, Marín JM, de Ávila F. A. Isolation of Pseudomonas aeruginosastrains from dental office environments and units in Barretos,state of São Paulo, Brazil, and analysis of their susceptibility toantimicrobial drugs. Brazilian Journal of Microbiology. 2008; 39(3):579-84.

O’Donnell MJ, Shore C, Russell RJ, Coleman DC. Optimisation of the long-term efficacy of dental chair waterlinedisinfection by the identification and rectification of factorsassociated with waterline disinfection failure. Journal of Dentistry. 2007;35(5):438-51.

Göksay D, Çotuk A, Zeybek Z. Microbial contamination ofdental unit waterlines in Istanbul, Turkey. Environmental Monitoring and Assessment. 2008;147:265-269.

Walker JT, Bradshaw DJ, Finney M, Fulford MR, Frandsen E, Qstergaard E, et al. Microbiological evaluation of dental unit water systems in generaldental practice in Europe. European Journal of Oral Sciences. 2004;112:412-418.

Dogruöz N, Ilhan-Sungur E, Göksay D, Türetgen I. Evaluation of microbial contamination and distrubition of sulphate reducing bacteria in dental units. Environmental Monitoring and Assessment. 2012;184:133-139.

Türetgen I, Göksay D, Cotuk A. Comparison of the microbial load of incoming and distal outlet waters from dentalunit water systems in Istanbul. Environmental Monitoring and Assessment. 2009;158:9-14.

Szymanska J. Evaluation of mycological contamination of dental unit waterlines. Annals of Agricultural and Environmental Medicine. 2005;12:153-155.

Genc A, Kadir T, Ercalik S, Erdem H, Demirbas B. The probability of microbial contamination by the internal water/air lines of turbines. Turkish Dental Association IV Inter-national Dental Congress, Istanbul. 1997;131

Walker JT, Bradshaw DJ, Bennett AM, Fulford MR, Martin MV, Marsh PD. Microbial biofilm formation and contamination of dental-unit water systems in general dental practice. Applied and Environmental Microbiology Journal. 2000; 66:3363-3367.

Williams JF, Johnston AM, Johnston B, Hungtington MK, Mac-kenzie CD. Microbial contamination of dental unit waterlines: prevalence, intensity and microbiological char-acteristics. Journal of the American Dental Association. 1993;124:59-65.

Barbeau J, Tanguay R, Faucher E, Avezard C, Trudel L, Cote L, Prevost AP. Multiparametric analysis of water line contamination in dental units. Applied and Environmental Microbiology Journal. 1996; 62:3954-3959.

Wirthlin, MR, Roth, M. Dental unit waterline contamination: A review of research and findings from a clinic setting. Compendium of Continuing Education in Dentistry. 2015; 36(3):216-9.

Davies DG, Parsek MR, Pearson JP, Iglewski BH, Costerton JW Greenberg EP. The involvement of cell-to-cell signals in the development of a bacterial biofilm. Science. 1998;280(5361):295-8.

Sola M, Oliveira A, Feistel J, Minafra C, Rezende C. Mecanismos De Quorum Sensing e sua Relevância na Microbiologiade Alimentos. 8th ed. Goiânia, Enciclopédia Biosfera, Centro Cien-tífico Conhecer; 2012.

Salam N, Mulamoottil VM, George B. Assessment of microbial contamination in dental-unit water lines: An analytical study. Journal of Indian Association of Public Health Dentistry. 2017;15:97-101.