Skip to main content

Advertisement

SpringerLink
Log in

Monitoring Dental-Unit-Water-Line Output Water by Current In-office Test Kits

  • Published:
Current Microbiology Aims and scope Submit manuscript

Abstract

The importance of monitoring contamination levels in the output water of dental-unit-water-lines (DUWLs) is essential as they are prone to developing biofilms that may contaminate water that is used to treat patients, with opportunistic pathogens such as species of Legionella, Pseudomonas and others. Dentists and practice staff are also at risk of being infected by means of cross-infection due to aerosols generated from DUWL water. The unit of measurement for the microbial contamination of water by aerobic mesophilic heterotrophic bacteria is the colony-forming unit per millilitre (cfu/ml) of water. The UK has its own guidelines set by the Department of Health for water discharged from DUWL to be between 100 and 200 cfu/ml of water. The benchmark or accepted standard laboratory test is by microbiological culture on R2A agar plates. However, this is costly and not convenient for routine testing in dental practices. A number of commercial indicator tests are used in dental surgeries, but they were not developed for the dental market and serve only to indicate gross levels of contamination when used outside of the manufacturer’s recommended incubation period. The aim of this article is to briefly review the universal problem of DUWL contamination with microbial biofilms and to update dental professionals on the availability of currently available commercial in-office monitoring systems for aerobic mesophilic heterotrophic bacteria and to discuss their limitations for testing water samples in assuring compliance with recommended guidelines.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Al Shorman H, Nabaa LA, Coulter WA, Pankhurst CL, Lynch E (2002) Management of dental unit water lines. Dent Update 29:292–298

    PubMed  Google Scholar 

  2. Anonymous (1993) Council Directive 93/42/EEC of 14 June 1993 concerning medical devices. OJEU L169:1–43

    Google Scholar 

  3. Anonymous (2012) The Microbiology of Drinking Water (2012)—Part 7—methods for the enumeration of heterotrophic bacteria, Methods for the Examination of Waters and Associated Materials, Environment Agency. http://cdn.environment-agency.gov.uk/geho0812bwwk-e-e.pdf. Accessed 25 Oct 2013

  4. Artini M, Scarughi GL, Papa R, Dolci M, De Luca G, Orsini S, Pappalardo S, Costerton JW, Serlan L (2008) Specific anti cross-infection measures may help to prevent viral contamination of dental unit waterlines. Infection 36:467–471

    Article  CAS  PubMed  Google Scholar 

  5. Atlas RM, Williams JF, Huntington MK (1995) Legionella contamination of dental-unit waters. Appl Environ Microbiol 61:1208–1213

    CAS  PubMed Central  PubMed  Google Scholar 

  6. Barbeau J (2007) Lawsuit against a dentist related to serious ocular infection possibly linked to water from a dental handpiece. J Can Dent Assoc 73:618–622

    PubMed  Google Scholar 

  7. Barbeau J, Tanguay R, Faucher E, Avezard C, Trudel L, Cote L, Prevost AP (1996) Multiparametric analysis of waterline contamination in dental units. Appl Environ Microbiol 62:3954–3959

    CAS  PubMed Central  PubMed  Google Scholar 

  8. Barbot V, Robert A, Rodier M, Imbert C (2012) Update on infectious risks associated with dental unit waterlines. FEMS Immunol Med Microbiol 65:196–204

    Article  CAS  PubMed  Google Scholar 

  9. Blake GC (1963) Incidence and control of bacterial infection in dental spray reservoirs. Br Dent J 115:413–416

    Google Scholar 

  10. Chate RA (2010) An audit improves the quality of water within the dental unit water lines of general dental practices across the East of England. Br Dent J 209(7):E11

    Article  CAS  PubMed  Google Scholar 

  11. Clark A (1974) Bacterial colonization of dental units and the nasal flora of dental personnel. Proc R Soc Med 67:1269–1270

    CAS  PubMed Central  PubMed  Google Scholar 

  12. Coleman DC, O’Donnell MJ, Shore AC, Swan J, Russell RJ (2007) The role of manufacturers in reducing biofilms in dental chair waterlines. J Dent 35:701–711

    Article  CAS  PubMed  Google Scholar 

  13. Coleman DC, O’Donnell MJ, Shore AC, Russell RJ (2009) Biofilm problems in dental unit water systems and its practical control. J Appl Microbiol 106:1424–1437

    Article  CAS  PubMed  Google Scholar 

  14. D’Ovidio C, Carnevale A, Pantaleone G, Piattelli A, Di Bonaventura G (2011) First report of an acute purulent maxillary sinusitis caused by Pseudomonas aeruginosa secondary to dental implant placement in an immunocompetent patient. Br Dent J 211:205–207

    Article  PubMed  Google Scholar 

  15. Decraene V, Ready D, Pratten J, Wilson M (2008) Air-borne microbial contamination of surfaces in a UK dental clinic. J Gen Appl Microbiol 54:195–203

    Article  CAS  PubMed  Google Scholar 

  16. Dillon A, Achilles-Day U, Singhrao SK, Pearce M, Morton LHG, Crean S (2014) Biocide sensitivity of Vermamoeba vermiformis isolated from dental-unit-water-line systems. Int Biodeterior Biodegrad 88:97–105

    Google Scholar 

  17. Donlan RM, Costerton JW (2002) Biofilms: survival mechanisms of clinically relevant microorganisms. Clin Microbiol Rev 15:167–193

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  18. Dutil S, Veillette M, Meriaux A, Lazure L, Barbeau J, Duchaine C (2007) Aerosolization of Mycobacteria and Legionellae during dental treatment: low exposure despite dental unit contamination. Environ Microbiol 9:2836–2843

    Article  CAS  PubMed  Google Scholar 

  19. Falkinham JO (2003) The changing pattern of nontuberous mycobacterial disease. Can J Infect Dis 14:281–286

    PubMed Central  PubMed  Google Scholar 

  20. Fitzgeorge RB, Baskerville A, Broster M, Hambleton P, Dennis PJ (1983) Aerosol infection of animals with strains of Legionella pneumophila of different virulence: comparison with intraperitoneal and intranasal routes of infection. J Hyg 90:81–90

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  21. Fotos PG, Westfall HN, Snyder IS, Miller RW, Mutchler BM (1985) Prevalence of Legionella-specific IgG and IgM antibody in a dental clinic population. J Dent Res 64:1382–1385

    Article  CAS  PubMed  Google Scholar 

  22. Fulford MR, Walker JT, Martin MV, Marsh PD (2004) Total viable counts, ATP, and endotoxin levels as potential markers of microbial contamination of dental unit water systems. Br Dent J 196:157–159

    Article  CAS  PubMed  Google Scholar 

  23. Goksay D, Cotuk A, Zeybek Z (2008) Microbial contamination of dental unit waterlines in Istanbul, Turkey. Environ Monit Assess 147:265–269

    Article  PubMed  Google Scholar 

  24. Gross KB, Overman PR, Cobb C, Brockmann S (1992) Aerosol generation by two ultrasonic scalers and one sonic scaler: a comparative study. J Dent Hyg 66:314–318

    CAS  PubMed  Google Scholar 

  25. Harrel SK, Molinari J (2004) Aerosols and splatter in dentistry: a brief review of the literature and infection control implications. J Am Dent Assoc 135:429–437

    Article  PubMed  Google Scholar 

  26. Karpay RI, Plamondon TJ, Mills SE, Dove SB (1998) Validation of an in-office dental unit water monitoring technique. J Am Dent Assoc 129:207–211

    Article  CAS  PubMed  Google Scholar 

  27. Karpay RI, Plamondon TJ, Mills SE, Dove SB (1999) Combining periodic and continuous sodium hypochlorite treatment to control biofilms in dental unit water systems. J Am Dent Assoc 130(7):957–965

    Article  CAS  PubMed  Google Scholar 

  28. Kemp GK, Schneider KR (2000) Validation of thiosulfate for neutralization of acidified sodium chlorite in microbiological testing. Poult Sci 79(12):1857–1860

    Article  CAS  PubMed  Google Scholar 

  29. Kohn W, Collins A, Cleveland J, Harte J, Eklund K, Malvitz D (2003) Guidelines for infection control in dental health-care settings. MMWR Recomm Rep 52(RR-17):1–61

    Google Scholar 

  30. Larsen T, Fiehn NE (2003) The effect of Sterilex Ultra for disinfection of dental unit waterlines. Int Dent J 53(4):249–254

    Article  CAS  PubMed  Google Scholar 

  31. Lazar V (2011) Quorum sensing in biofilms—how to destroy the bacterial citadels or their cohesion/power? Anaerobe 17:280–285

    Article  PubMed  Google Scholar 

  32. Lohr DC, Goeken JA, Doty DB, Donta ST (1978) Mycobacterium gordonae infection of a prosthetic aortic valve. JAMA 239:1528–1530

    Article  CAS  PubMed  Google Scholar 

  33. Martin M (1987) The significance of the bacterial contamination of dental unit water systems. Br Dent J 163:152–154

    Article  CAS  PubMed  Google Scholar 

  34. McDade JE, Shepard CC, Fraser DW, Tsai TR, Redus MA, Dowdle WR (1977) Legionnaires’ disease. Isolation of a bacterium and demonstration of its role in other respiratory disease. N Engl J Med 297:1197–1203

    Article  CAS  PubMed  Google Scholar 

  35. McEntegart MG, Clark A (1973) Colonisation of dental units by water bacteria. Br Dent J 34:140–142

    Article  Google Scholar 

  36. Michel O, Kips J, Duchateau J, Vertongen F, Robert L, Collet H, Pauwels R, Sergysels R (1996) Severity of asthma is related to endotoxin in house dust. Am J Respir Crit Care Med 154:1641–1646

    Article  CAS  PubMed  Google Scholar 

  37. Mills SE (2003) Waterborne pathogens and dental waterlines. Dent Clin N Am 47:545–557

    Article  PubMed  Google Scholar 

  38. Mills SE, Karpay RI (2002) Dental waterlines and biofilm—searching for solutions. Compend Contin Educ Dent 23(3):237–240

    PubMed  Google Scholar 

  39. Momeni SS, Tomlin N, Ruby JD, Dasanayake AP (2012) Evaluation of in-office dental unit waterline testing. Gen Dent 60:e142–e147

    PubMed  Google Scholar 

  40. Morris BF, Vandewalle KS, Hensley DM, Bartoloni JA (2010) Comparison of in-office dental unit waterline kits. Mil Med 175:901–906

    Article  PubMed  Google Scholar 

  41. O’Donnell MJ, Shore AC, Russell RJ, Coleman DC (2007) Optimisation of the long-term efficacy of dental chair waterline disinfection by the identification and rectification of factors associated with waterline disinfection failure. J Dent 35(5):438–451

    Article  PubMed  Google Scholar 

  42. Pankhurst CL (2003) Risk assessment of dental unit waterline contamination. Prim Dent Care 10:5–10

    Article  PubMed  Google Scholar 

  43. Pankhurst CL, Coulter WA (2007) Do contaminated dental unit waterlines pose a risk of infection? J Dent Res 35:712–720

    Article  Google Scholar 

  44. Pankhurst CL, Philpott-Howard JN (1993) The microbiological quality of water in dental chair units. J Hosp Infect 23:167–174

    Article  CAS  PubMed  Google Scholar 

  45. Pankhurst CL, Johnson NW, Woods RG (1998) Microbial contamination of dental unit waterlines: the scientific argument. Int Dent J 48:359–368

    Article  CAS  PubMed  Google Scholar 

  46. Pankhurst CL, Coulter W, Philpott-Howard JN, Surman-Lee S, Warburton F, Challacombe S (2005) Evaluation of the potential risk of occupational asthma in dentists exposed to contaminated dental unit waterlines. Prim Dent Care 12:53–59

    Article  PubMed  Google Scholar 

  47. Pearce M, O’Donnell H, Singhrao SK, St. Crean J (2013) Assessing water discharged from dental units using Dip Slides™. The British Society for Oral and Dental Research (BSODR) abstract number 181571

  48. Popat R, Crusz SA, Messina M, Williams P, West SA, Diggle SP (2012) Quorum-sensing and cheating in bacterial biofilms. Proc R Soc 279:4765–4771

    Article  CAS  Google Scholar 

  49. Porteous NB, Redding SW, Jorgensen JH (2004) Isolation of non-tuberculosis Mycobacteria in treated dental unit waterlines. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 98:40–44

    Article  CAS  PubMed  Google Scholar 

  50. Putnins EE, Di Giovanni D, Bhullar AS (2001) Dental unit waterline contamination and its possible implications during periodontal surgery. J Periodontol 72:393–400

    Article  CAS  PubMed  Google Scholar 

  51. Reinthaler FF, Mascher F, Stunzner D (1988) Serological examinations for antibodies against Legionella species in dental personnel. J Dent Res 67:942–943

    Article  CAS  PubMed  Google Scholar 

  52. Ricci ML, Fontana S, Pinci F, Fiumana E, Pedna MF, Farolfi P, Sabattini MA, Scaturro M (2012) Pneumonia associated with a dental unit waterline. Lancet 379:684

    Article  PubMed  Google Scholar 

  53. Rowbotham TJ (1986) Current views of the relationships between amoebae, Legionella and man. Isr J Med Sci 22:678–689

    CAS  PubMed  Google Scholar 

  54. Rusin PA, Rose JB, Haas CN, Gerba CP (1997) Risk assessment of opportunistic bacterial pathogens in drinking water. Rev Environ Contam Toxicol 152:57–83

    CAS  PubMed  Google Scholar 

  55. Schel AJ, Marsh PD, Bradshaw DJ, Finney M, Fulford MR, Frandsen E, Østergaard E, ten Cate JM, Moorer WR, Mavridou A, Kamma JJ, Mandilara G, Stösser L, Kneist S, Araujo R, Contreras N, Goroncy-Bermes P, O’Mullane D, Burke F, O’Reilly P, Hourigan G, O’Sullivan M, Holman R, Walker JT (2006) Comparison of the efficacies of disinfectants to control microbial contamination in dental unit water systems in general dental practices across the European Union. Appl Environ Microbiol 72(2):1380–1387

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  56. Schulze-Robbecke R, Feldman C, Fischeder R (1995) Dental units: an environmental study of sources of potentially pathogenic Mycobacteria. Tuber Lung Dis 76:318–323

    Article  CAS  PubMed  Google Scholar 

  57. Singh T, Coogan MM (2005) Isolation of pathogenic Legionella species and Legionella-laden amoebae in dental unit waterlines. J Hosp Infect 61:257–262

    Article  CAS  PubMed  Google Scholar 

  58. Strauss WL, Plouffe JF, File TM Jr (1996) Risk factors for domestic acquisition of Legionnaires disease. Arch Intern Med 156:1685–1692

    Article  Google Scholar 

  59. Szymanska J (2004) Risk of exposure to Legionella in dental practice. AAEM 11:9–12

    PubMed  Google Scholar 

  60. Szymanska J (2005) Evaluation of mycological contamination of dental unit waterlines. AAEM 12:153–155

    PubMed  Google Scholar 

  61. Toté K, Horemans T, Vanden Berghe D, Maes L, Cos P (2010) Inhibitory effect of biocides on the viable masses and matrices of Staphylococcus aureus and Pseudomonas aeruginosa biofilms. Appl Environ Microbiol 76(10):3135–3142

    Article  PubMed Central  PubMed  Google Scholar 

  62. Tuttlebee CM, O’Donnell MJ, Keane CT, Russell RJ, Sullivan DJ, Falkiner F, Coleman DC (2002) Effective control of dental chair unit waterline biofilm and marked reduction of bacterial contamination of output water using two peroxide-based disinfectants. J Hosp Infect 52:192–205

    Article  CAS  PubMed  Google Scholar 

  63. USDHHS (1987) Guidelines on validation of the Limulus amebocyte lysate test as an end-product endotoxin test for human and animal parenteral drugs, biological products, and medical devices. US Department of Health and Human Services, Food and Drug Administration, Washington, DC

    Google Scholar 

  64. Wadowsky RM, Wolford R, McNamara AM, Yee RB (1985) Effect of temperature, pH and oxygen level on the multiplication of naturally occurring Legionella pneumophila in potable water. Appl Environ Microbiol 48:1197–1205

    Google Scholar 

  65. Walker JT, Marsh PD (2004) A review of biofilms and their role in microbial contamination of dental unit water systems (DUWS). Int Biodeterior Biodegrad 54:87–98

    Article  CAS  Google Scholar 

  66. Walker JT, Marsh PD (2007) Microbial biofilm formation in DUWS and their control using disinfectants. J Dent 35:721–730

    Article  CAS  PubMed  Google Scholar 

  67. Walker JT, Bradshaw DJ, Bennett AM, Fulford MR, Martin MV, Marsh PD (2000) Microbial biofilm formation and contamination of Dental-Unit Water Systems in General Practice. Appl Environ Microbiol 66:3363–3367

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  68. Walker JT, Bradshaw DJ, Fulford MR, Marsh PD (2003) Microbiological evaluation of a range of disinfectant products to control mixed-species biofilm contamination in a laboratory model of a dental unit water system. Appl Environ Microbiol 69:3327–3332

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  69. Wallace JR, Swenson JM, Sicox VA, Good RC, Tschen JA, Stone MS (1983) Spectrum of disease due to rapidly growing Mycobacterium. Rev Infect Dis 5:657–679

    Article  PubMed  Google Scholar 

  70. Watnick P, Kolter R (2000) Biofilm, city of microbes. J Bacteriol 18:2675–2679

    Article  Google Scholar 

  71. Williams HN, Kelley J, Folineo D, Williams GC, Hawley CL, Sibiski J (1994) Assessing microbial contamination of clean water dental units and compliance with disinfection protocols. J Am Dent Assoc 125:1205–1211

    CAS  PubMed  Google Scholar 

  72. Wirthlin MR, Marshall GW Jr, Rowland EW (2003) Formation and decontamination of biofilms in dental unit waterlines. J Periodontol 74:1595–1609

    Article  PubMed  Google Scholar 

Download references

Acknowledgments

The lead author (Sham Lal) would like to thank the Shah Abdul Latif University (Pakistan) and Higher Education Commission (HEC) Pakistan, for the award of an overseas scholarship to study at the University of Central Lancashire, UK. Sham Lal is the new privileged recipient of the 2013, Don Claugher Bursary prize awarded by the Committee of the Society of Electron Microscope Technology (www.semt.org.uk).

Conflict of interest

All named authors declare that there is no conflict of interest despite one co-author (Matt Bricknell) being employed by a manufacturing organisation that supplied the in-office test kits. However, this co-author (Matt Bricknell) has not inappropriately influenced or biased the content of the manuscript.

Author information

Authors and Affiliations

  1. Oral & Dental Sciences Research Group, School of Medicine & Dentistry, University of Central Lancashire, Preston, PR1 2HE, UK

    Sham Lal, Sim K. Singhrao, Mark Pearce, L. H. Glyn Morton, Waqar Ahmed & St. John Crean

  2. 3M Food Safety, Leicestershire, LE11 1EP, UK

    Matt Bricknell

  3. Chair of East Lancashire Dental R&D Network Associate Staff, University of Central Lancashire, Quest Dental Care, Burnley, BB11 2AE, UK

    Mark Pearce

Authors
  1. Sham Lal
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Sim K. Singhrao
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Matt Bricknell
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Mark Pearce
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. L. H. Glyn Morton
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Waqar Ahmed
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. St. John Crean
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Sim K. Singhrao.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lal, S., Singhrao, S.K., Bricknell, M. et al. Monitoring Dental-Unit-Water-Line Output Water by Current In-office Test Kits. Curr Microbiol 69, 135–142 (2014). https://doi.org/10.1007/s00284-014-0569-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00284-014-0569-9

Keywords

Search

Navigation