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Wu M, Shi Z, Yu X, Xu Y, Jin X, Zhang L, Fu B. Disinfection methods of dental unit waterlines contamination: a systematic review. J Med Microbiol 2022; 71. [PMID: 35670283 DOI: 10.1099/jmm.0.001540] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Background. Severe contamination of dental unit waterlines was found in healthcare settings. The benefits of decontamination methods are controversial. The aim of this review was to systematically evaluate disinfection methods in contamination control of dental unit waterlines.Methods. The terms 'dental unit waterline(s) or DUWL(s) or dental unit water line(s)' were searched through PubMed, Cochrane Library, Embase, Web of Science and Scopusup to 31 May 2021. The DUWLs' output water was incubated on R2A agar at 20-28 °C for 5-7 days to evaluate heterotrophic mesophilic bacteria. The risk of bias was evaluated by a modified Newcastle-Ottawa quality assessment scale.Results. Eighteen papers from the literature were included. One study indicated that water supply played a crucial role in disinfecting DUWLs. Three studies indicated that flushing decreased bacteria counts but did not meet the American CDC standard (500 c.f.u. ml-1). All chlorine- and peroxide-containing disinfectants except sodium hypochlorite in one of 15 studies as well as three mouthrinses and citrus botanical extract achieved the standard (≤500 c.f.u. ml-1). The included studies were of low (1/18), moderate (6/18) and high (11/18) quality.Conclusion. Independent water reservoirs are recommended for disinfecting DUWLs using distilled water. Flushing DUWLs should be combined with disinfections. Nearly all the chlorine-, chlorhexidine- and peroxide-containing disinfectants, mouthrinses and citrus botanical extract meet the standard for disinfecting DUWLs. Alkaline peroxide would lead to tube blockage in the DUWLs. Regularly changing disinfectants can reduce the risk of occurrence of disinfectant-resistant strains of microbes.
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Affiliation(s)
- Mengting Wu
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou 310006, PR China
| | - Zhiwei Shi
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou 310006, PR China
| | - Xuefen Yu
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou 310006, PR China
| | - Yuedan Xu
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou 310006, PR China
| | - Xinyang Jin
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou 310006, PR China
| | - Ling Zhang
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou 310006, PR China
| | - Baiping Fu
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou 310006, PR China
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Ji XY, Fei CN, Zhang Y, Liu J, Liu H, Song J. Three key factors influencing the bacterial contamination of dental unit waterlines: a 6-year survey from 2012 to 2017. Int Dent J 2018; 69:192-199. [PMID: 30565215 DOI: 10.1111/idj.12456] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The contaminated output water from dental unit waterlines (DUWLs) is a potential risk to both patients and dental personnel who are frequently exposed to this water or aerosols. AIM The purpose was to evaluate the contamination level and prevalence of bacteria in the output water of DUWLs, and to identify key factors to provide technical support for formulating relevant policies. METHODS We developed a special sampling connector designed for collecting dental handpiece output water and a measurement device to assess retraction of a dental chair unit (DCU). Output water from dental handpieces and air/water syringes were collected as representative of DUWLs. Water samples were tested with reference to China's national standard. FINDINGS From 2012 to 2017, 318 DCUs were randomly selected from 64 hospitals in Tianjin, China. Of these DCUs, 78.93% had no disinfection to prevent DUWL contamination. Three-hundred and forty-three (56.14%) samples complied with the guidelines on DUWL output water. The highest concentration of bacteria was 1.8 × 106 colony-forming units (CFUs)/mL. The three key factors of influence were as follows: daily or weekly disinfection of DUWLs; water supply source being hospital self-made purified water or purchased purified bottled water; and DCU with a valid anti-retraction valve. Potential infectious agents, including Bacillus cereus, Burkholderia cepacia and Pseudomonas aeruginosa, were isolated. CONCLUSION There was a high rate of contamination in DUWLs. This highlights the need to develop national standards. There is a need to disinfect the DUWLs periodically and use a cleaner source of water; more attention should be paid to the efficacy of DCU anti-retraction valves.
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Affiliation(s)
- Xue-Yue Ji
- Department of Infectious Disease, Tianjin Centers for Disease Control and Prevention, Tianjin, China
| | - Chun-Nan Fei
- Department of Infectious Disease, Tianjin Centers for Disease Control and Prevention, Tianjin, China
| | - Ying Zhang
- Department of Infectious Disease, Tianjin Centers for Disease Control and Prevention, Tianjin, China
| | - Jun Liu
- Department of Infectious Disease, Tianjin Centers for Disease Control and Prevention, Tianjin, China
| | - He Liu
- Department of Infectious Disease, Tianjin Centers for Disease Control and Prevention, Tianjin, China
| | - Jia Song
- Department of Infectious Disease, Tianjin Centers for Disease Control and Prevention, Tianjin, China
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Pankhurst CL, Scully C, Samaranayake L. Dental Unit Water Lines and their Disinfection and Management: A Review. ACTA ACUST UNITED AC 2017; 44:284-5, 289-92. [PMID: 29172350 DOI: 10.12968/denu.2017.44.4.284] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The perceived threat to public health from dental unit water line (DUWL) contamination comes from opportunistic and respiratory pathogens such as Legionella spp, Nontuberculous Mycobacteria (NTM) and pseudomonads. These organisms can grow and multiply in the DUWL biofilm to reach infective concentrations, with the potential for inhalation leading to respiratory infections or direct contamination of surgical wounds. In this paper we discuss current legislation and practical methods for delivering water within the DUWL that meets the standards for safety. Clinical relevance: Understanding the clinical relevance and methods for decontaminating DUWL is essential to create a safe working environment in dentistry.
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Ditommaso S, Giacomuzzi M, Ricciardi E, Zotti CM. Efficacy of a Low Dose of Hydrogen Peroxide (Peroxy Ag⁺) for Continuous Treatment of Dental Unit Water Lines: Challenge Test with Legionella pneumophila Serogroup 1 in a Simulated Dental Unit Waterline. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:E745. [PMID: 27455299 PMCID: PMC4962286 DOI: 10.3390/ijerph13070745] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/11/2016] [Accepted: 07/19/2016] [Indexed: 11/29/2022]
Abstract
This study was designed to examine the in vitro bactericidal activity of hydrogen peroxide against Legionella. We tested hydrogen peroxide (Peroxy Ag⁺) at 600 ppm to evaluate Legionella survival in a simulated dental treatment water system equipped with Water Hygienization Equipment (W.H.E.) device that was artificially contaminated. When Legionella pneumophila serogroup (sg) 1 was exposed to Peroxy Ag⁺ for 60 min we obtained a two decimal log reduction. High antimicrobial efficacy was obtained with extended periods of exposure: four decimal log reduction at 75 min and five decimal log reduction at 15 h of exposure. Involving a simulation device (Peroxy Ag⁺ is flushed into the simulation dental unit waterlines (DUWL)) we obtained an average reduction of 85% of Legionella load. The product is effective in reducing the number of Legionella cells after 75 min of contact time (99.997%) in the simulator device under test conditions. The Peroxy Ag⁺ treatment is safe for continuous use in the dental water supply system (i.e., it is safe for patient contact), so it could be used as a preventive option, and it may be useful in long-term treatments, alone or coupled with a daily or periodic shock treatment.
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Affiliation(s)
- Savina Ditommaso
- Department of Public Health and Pediatrics, University of Turin, Turin 10126, Italy.
| | - Monica Giacomuzzi
- Department of Public Health and Pediatrics, University of Turin, Turin 10126, Italy.
| | - Elisa Ricciardi
- Department of Public Health and Pediatrics, University of Turin, Turin 10126, Italy.
| | - Carla M Zotti
- Department of Public Health and Pediatrics, University of Turin, Turin 10126, Italy.
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Petti S, Tarsitani G. Detection and Quantification of Dental Unit Water Line Contamination by Oral Streptococci. Infect Control Hosp Epidemiol 2016; 27:504-9. [PMID: 16671033 DOI: 10.1086/504500] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2003] [Accepted: 06/21/2004] [Indexed: 11/03/2022]
Abstract
Objective.(1) To investigate the prevalence of oral streptococci (OS) and biological indicators of water contamination by oral fluids in water from dental unit water lines (DUWs) by detection and quantification and of saprophytes indigenous to the oral cavity. (2) To test whether measurement of the total cultivable mesophilic flora (TCF), the parameter commonly used to monitor water quality in DUWs, is an effective predictor for OS contamination.Design.Survey of 21 dental units equipped with antiretraction devices. Water samples were collected from air-water syringes, cup fillers, tap water, and before and during the working day.Setting.Units were from 7 public dental offices selected for convenience from among those in proximity of the microbiological laboratory.Methods.For detection of OS, samples were plated on an enriched medium, to revitalize the organisms. Colonies were subcultured on a selective medium and biochemically identified (lower detection limit, 1 cfu/mL). For measurement of the TCF, samples were plated on a nutrient-poor medium. Cultures with colony counts greater than 200 cfu/mL were considered to be TCF positive. The sensitivity and specificity of TCF positivity in predicting OS detection was calculated.Results.Prevalence rates for OS contamination and for TCF positivity were, respectively, 34.4% (11 of 32 samples) and 25.0% (8 of 32 samples) for syringes, 27.8% (10 of 36 samples) and 8.3% (3 of 36 samples) for cup fillers, and 0.0% (0 of 7 samples) for tap water. OS contamination levels ranged from 1 to 6 cfu/mL. No statistically significant differences were found between samples obtained before and during the working day. TCF positivity did not predict OS contamination effectively, because of low sensitivity.Conclusions.Given the absence of OS in tap water, the reported prevalence of OS contamination suggests that oral fluids are aspirated during dental therapy with relatively high frequency and that DUWs can potentially expose successive patients to bloodborne cross-infections.
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Affiliation(s)
- Stefano Petti
- Department of Public Health Sciences G. Sanarelli, University La Sapienza, Piazzale Aldo Moro 5, Rome 00185, Italy.
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Narayana TV, Mohanty L, Sreenath G, Vidhyadhari P. Role of preprocedural rinse and high volume evacuator in reducing bacterial contamination in bioaerosols. J Oral Maxillofac Pathol 2016; 20:59-65. [PMID: 27194863 PMCID: PMC4860938 DOI: 10.4103/0973-029x.180931] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Context: Microbial contamination, which occurs during dental procedures, has been a potential threat to dental professionals and individuals. There has been a growing concern over the role of bioaerosols in spread of various airborne infections and also to reduce the risk of bioaerosol contamination. Aims: This study was to analyze the number of colony forming units (CFUs) in bioaerosols generated during ultrasonic scaling procedure as well as to evaluate the efficacy of chlorhexidine 0.12% (CHX) preprocedural mouth rinse and high volume evacuator (HVE) in minimizing the bioaerosol contamination. Methods: About 45 individuals were divided into three Groups A, B and C. These groups underwent ultrasonic scaling before and after the use of CHX (0.12%), HVE and combination of CHX (0.12%) and HVE. Bioaerosols were collected on blood agar plates which were incubated at 37°C for 48 h, and the CFUs were counted with manual colony counting device. A comparison was also done between A versus B, B versus C and A versus C groups. Statistical Analysis Used: Student's t-test. Results: We found a significant reduction in the CFUs when CHX (0.12%) preprocedural rinse (P < 0), or HVE (P < 0.001) or combination of both CHX (0.12%) and HVE were employed (P < 0.001). Maximum reduction in CFUs was observed when CHX (0.12%) and HVE were used in combination as compared to their individual use. A moderate significance was seen between A versus C groups but not with B versus C groups and A versus B groups. Conclusion: From our study, we conclude that individual methods such as CHX (0.12%) and HVE were useful to reduce the dental bioaerosols; however, combination of both CHX (0.12%) and HVE is more efficient to reduce dental bioaerosols than individual method.
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Affiliation(s)
- T V Narayana
- Head of Oral and Maxillofacial Pathology, Independent Dental Practitioner, Impressions Dental Car, Elegant Desire Building No 1, Coles Road, Frazer Town, Bangalore, India
| | - Leeky Mohanty
- Department of Oral and Maxillofacial Pathology, The Oxford Dental College, Bangalore, India
| | - G Sreenath
- Department of Oral and Maxillofacial Pathology, G Pulla Reddy Dental College, Kurnool, Andhra Pradesh, India
| | - Pavani Vidhyadhari
- Department of Oral and Maxillofacial Pathology, G Pulla Reddy Dental College, Kurnool, Andhra Pradesh, India
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Ji XY, Fei CN, Zhang Y, Zhang W, Liu J, Dong J. Evaluation of bacterial contamination of dental unit waterlines and use of a newly designed measurement device to assess retraction of a dental chair unit. Int Dent J 2016; 66:208-14. [PMID: 27000421 DOI: 10.1111/idj.12225] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
INTRODUCTION Dental unit waterline (DUWL) output water is delivered through instruments of a dental chair unit (DCU) to irrigate and cool teeth. However, these waterlines can be heavily contaminated with bacteria. AIM The purpose of the present study was to assess retraction and investigate the contamination level and prevalence of bacteria in DUWL output water. METHODS Fifty-eight DCUs were randomly selected from 30 hospitals in 10 districts of Tianjin, one of the four special municipalities of China. A unique sampling connector was used in place of the dental handpiece to collect water samples. Evaluation of retraction was accomplished using a retraction measurement device designed in accordance with the International Standard ISO 7494-2:2015(E). RESULTS A total of 263 water samples were collected, and the highest concentration of bacteria [1.8 × 10(6) colony-forming units (CFU)/mL] was found in the handpiece group. Thirty (51.72%) water samples in the handpiece group and 21 (36.21%) in the air/water syringe groups were cultured, yielding colony counts of > 500 CFU/mL. Potential infectious agents, such as Bacillus cereus, Kocuria kristinae and Pseudomonas fluorescens, were isolated from the water samples. Thirty (51.72%) DCUs failed the retraction evaluation. There was a significant, positive correlation (P < 0.05) between the concentration of bacteria in the water sample and the retracted volume. CONCLUSION It is of paramount importance to increase compliance with the standards for controlling DUWL contamination. Routine microbial monitoring and evaluation of retraction are necessary to provide high-quality water for use in dental treatment.
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Affiliation(s)
- Xue-Yue Ji
- Tianjin Centers for Disease Control and Prevention, Tianjin, China
| | - Chun-Nan Fei
- Tianjin Centers for Disease Control and Prevention, Tianjin, China
| | - Ying Zhang
- Tianjin Centers for Disease Control and Prevention, Tianjin, China
| | - Wei Zhang
- Tianjin Centers for Disease Control and Prevention, Tianjin, China
| | - Jun Liu
- Tianjin Centers for Disease Control and Prevention, Tianjin, China
| | - Jie Dong
- Tianjin Centers for Disease Control and Prevention, Tianjin, China
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Pseudomonas aeruginosa and Achromobacter sp. clonal selection leads to successive waves of contamination of water in dental care units. Appl Environ Microbiol 2015; 81:7509-24. [PMID: 26296724 DOI: 10.1128/aem.01279-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/12/2015] [Indexed: 01/30/2023] Open
Abstract
Dental care unit waterlines (DCUWs) consist of complex networks of thin tubes that facilitate the formation of microbial biofilms. Due to the predilection toward a wet environment, strong adhesion, biofilm formation, and resistance to biocides, Pseudomonas aeruginosa, a major human opportunistic pathogen, is adapted to DCUW colonization. Other nonfermentative Gram-negative bacilli, such as members of the genus Achromobacter, are emerging pathogens found in water networks. We reported the 6.5-year dynamics of bacterial contamination of waterlines in a dental health care center with 61 dental care units (DCUs) connected to the same water supply system. The conditions allowed the selection and the emergence of clones of Achromobacter sp. and P. aeruginosa characterized by multilocus sequence typing, multiplex repetitive elements-based PCR, and restriction fragment length polymorphism in pulsed-field gel electrophoresis, biofilm formation, and antimicrobial susceptibility. One clone of P. aeruginosa and 2 clones of Achromobacter sp. colonized successively all of the DCUWs: the last colonization by P. aeruginosa ST309 led to the closing of the dental care center. Successive dominance of species and clones was linked to biocide treatments. Achromobacter strains were weak biofilm producers compared to P. aeruginosa ST309, but the coculture of P. aeruginosa and Achromobacter enhanced P. aeruginosa ST309 biofilm formation. Intraclonal genomic microevolution was observed in the isolates of P. aeruginosa ST309 collected chronologically and in Achromobacter sp. clone A. The contamination control was achieved by a complete reorganization of the dental health care center by removing the connecting tubes between DCUs.
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Barbot V, Costa D, Deborde M, Imbert C. Efficacy of dental unit disinfectants against Candida spp. and Hartmannella vermiformis. Pathog Dis 2014; 70:289-96. [PMID: 24391018 DOI: 10.1111/2049-632x.12127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 12/19/2013] [Accepted: 12/21/2013] [Indexed: 11/30/2022] Open
Abstract
Human oral commensal Candida yeasts, as well as environmental free-living amoebae (FLA) such as Hartmannella, are known to be direct or indirect human pathogens. These microorganisms may be isolated from dental unit waterlines (DUWL), because of contamination coming from the tap water and/or a patient's mouth. This study compared the efficacy of commonly used DUWL disinfectants (chlorine, H2 O2 , and Oxygenal 6©) against three species of Candida (C. albicans, C. glabrata, and C. parapsilosis) and one FLA species (H. vermiformis), growing either as single or as mixed biofilms in tap water. Results showed variable efficacies: H2 O2 had no significant activity, while chlorine was effective but only at the highest doses tested, probably not compatible with DUWL uses. Oxygenal 6© was the most efficacious in preventing the growth of yeasts in tap water. However, in the presence of FLA, Oxygenal 6© displayed a reduced antimicrobial activity against sessile C. albicans. In conclusion, none of the tested disinfectants could eradicate yeasts or FLA. Moreover, the antiyeast activity of Oxygenal 6© was reduced in the presence of FLA. Both sessile or planktonic and mixed or single-species conditions should be considered when evaluating the activity of disinfectants for DUWL maintenance. This study also highlighted that FLA should be included in the testing protocols.
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Affiliation(s)
- Vanessa Barbot
- Laboratoire d'Ecologie et de Biologie des Interactions, Université de Poitiers, UMR CNRS 7267, Poitiers Cedex, France
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Petti S, Moroni C, Messano GA, Polimeni A. Detection of oral streptococci in dental unit water lines after therapy with air turbine handpiece: biological fluid retraction more frequent than expected. Future Microbiol 2013; 8:413-21. [PMID: 23464376 DOI: 10.2217/fmb.12.151] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM Oral streptococci detected in water from dental unit water lines (DUWLs) are a surrogate marker of patients' biological fluid retraction during therapy. We investigated oral streptococci detection rate in DUWLs in a representative sample of private offices in real-life conditions. MATERIALS & METHODS Samples of nondisinfected water (100 ml) were collected from the DUWL designated for the air turbine handpiece in 81 dental units, immediately after dental treatment of patients with extensive air turbine handpiece use. Water was filtered and plated on a selective medium for oral streptococci and, morphologically, typical colonies of oral streptococci were counted. The lowest detection limit was 0.01 CFU/ml. RESULTS The oral streptococci detection rate was 72% (95% CI: 62-81%), with a mean level of 0.7 CFU/ml. Oral streptococci detection was not affected by handpiece age or dental treatment type, but was associated with dental unit age. CONCLUSION Biological fluid retraction into DUWLs during patient treatment and, possibly, the risk for patient-to-patient blood- or air-borne pathogen transmission are more frequent than expected.
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Affiliation(s)
- Stefano Petti
- Department of Public Health & Infectious Diseases, Sapienza University, Piazzale Aldo Moro 5, 00185 Rome, Italy.
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Barbot V, Robert A, Rodier MH, Imbert C. Update on infectious risks associated with dental unit waterlines. ACTA ACUST UNITED AC 2012; 65:196-204. [PMID: 22469485 DOI: 10.1111/j.1574-695x.2012.00971.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 02/08/2012] [Accepted: 03/22/2012] [Indexed: 11/28/2022]
Abstract
Modern dental chair units consist of a network of interconnected narrow-bore plastic tubes called dental unit waterlines (DUWLs). The water delivered by these DUWLs acts as both a coolant for a range of instruments and an irrigant during dental treatments. The quality of water is of considerable importance because both patients and dental team are regularly exposed to water and aerosols generated by dental equipment. Studies have demonstrated that DUWLs provide a favourable 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 immunocompromised. The current status of knowledge on microbial contamination of DUWLs is presented, with an emphasis on the infectious risk associated with DUWLs and on the various approaches for disinfecting and protecting DUWLs.
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Affiliation(s)
- Vanessa Barbot
- Laboratoire de Chimie et Microbiologie de l'Eau, Université de Poitiers, Poitiers, France.
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O’Donnell MJ, Boyle MA, Russell RJ, Coleman DC. Management of dental unit waterline biofilms in the 21st century. Future Microbiol 2011; 6:1209-26. [DOI: 10.2217/fmb.11.104] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Dental chair units (DCUs) use water to cool and irrigate DCU-supplied instruments and tooth surfaces, and provide rinsewater during dental treatment. A complex network of interconnected plastic dental unit waterlines (DUWLs) supply water to these instruments. DUWLs are universally prone to microbial biofilm contamination seeded predominantly from microorganisms in supply water. Consequently, DUWL output water invariably becomes contaminated by high densities of microorganisms, principally Gram-negative environmental bacteria including Pseudomonas aeruginosa and Legionella species, but sometimes contain human-derived pathogens such as Staphylococcus aureus. Patients and staff are exposed to microorganisms from DUWL output water and to contaminated aerosols generated by DCU instruments. A wide variety of approaches, many unsuccessful, have been proposed to control DUWL biofilm. More recently, advances in biofilm science, chemical DUWL biofilm treatment agents, DCU design, supply water treatment and development of automated DUWL biofilm control systems have provided effective long-term solutions to DUWL biofilm control.
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Affiliation(s)
- Mary J O’Donnell
- Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Dublin 2, Republic of Ireland
| | - Maria A Boyle
- Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Dublin 2, Republic of Ireland
| | - Ronnie J Russell
- The Department of Microbiology, The Moyne Institute of Preventive Medicine, University of Dublin, Trinity College Dublin, Dublin 2, Republic of Ireland
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Coleman DC, O'Donnell MJ, Boyle M, Russell R. Microbial biofilm control within the dental clinic: reducing multiple risks. J Infect Prev 2010. [DOI: 10.1177/1757177410376845] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This short review focuses on biofilms in the dental clinic environment. Microbial biofilms are potentially a significant source of cross-contamination and cross-infection in the dental clinic. Biofilms in dental chair unit waterlines (DUWLs), suction hoses and fittings pose the most significant risk as these may come into contact with the patient during treatment. These can be managed effectively by regular disinfection using chemical disinfectants and procedures that have proven efficacy. As dental chair units (DCUs) are classified as medical devices, there is a requirement for DCU manufacturers to provide detailed guidance for their decontamination. Planned routine preventive maintenance of the dental clinic water network and good quality water will considerably minimise infection risks from microorganisms in tap water and has benefits for the operation of other clinic equipment. Regular and effective cleaning and disinfection of taps, sinks and splash-backs will help to minimise reservoirs and disseminators of potentially pathogenic bacteria from these areas.
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Affiliation(s)
- David C Coleman
- Dublin Dental School and Hospital, Trinity College Dublin, Lincoln Place, Dublin, Ireland,
| | - Mary J O'Donnell
- Dublin Dental School and Hospital, Trinity College Dublin, Lincoln Place, Dublin, Ireland
| | - Maria Boyle
- Dublin Dental School and Hospital, Trinity College Dublin, Lincoln Place, Dublin, Ireland
| | - Ronnie Russell
- Department of Microbiology, Trinity College Dublin, Dublin, Ireland
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Coleman DC, O'Donnell MJ, Shore AC, Russell RJ. Biofilm problems in dental unit water systems and its practical control. J Appl Microbiol 2009; 106:1424-37. [PMID: 19187140 DOI: 10.1111/j.1365-2672.2008.04100.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- D C Coleman
- Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental School & Hospital, University of Dublin, Trinity College Dublin, Lincoln Place, Dublin 2, Ireland.
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Coleman DC, O'Donnell MJ, Shore AC, Swan J, Russell RJ. The role of manufacturers in reducing biofilms in dental chair waterlines. J Dent 2007; 35:701-11. [PMID: 17576035 DOI: 10.1016/j.jdent.2007.05.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2007] [Revised: 05/03/2007] [Accepted: 05/08/2007] [Indexed: 01/23/2023] Open
Abstract
OBJECTIVES This paper reviews how dental chair unit (DCU) manufacturers can contribute practically to resolving the problem of biofilm formation in dental unit waterlines (DUWs). STUDY SELECTION The review concentrates on how novel developments and changes in a range of specific areas have, and might contribute to DUW biofilm control. These include (i) DCU engineering and design changes; (ii) improvements to DCU supply water quality; (iii) development of automated DUW treatment procedures that are effective at controlling biofilm in the long-term, safe for patients and dental staff, environmentally friendly and which do not exhibit adverse effects on DCU components after prolonged use. SOURCES The majority of the material contained in this review is based on, or supported by the peer-reviewed literature. DATA The current consensus from the literature reveals that the emphasis on DUW biofilm and its control has focused on describing the problem and its control using a range of periodic and residual DUW treatment agents. Unfortunately, until recently, DCU manufacturers have provided very little specific guidance in this regard. Indeed, ensuring that DCUs provide good quality output water has generally been regarded to be the responsibility of dental practitioners. Some recent studies have shown that novel DCUs with integral semi-automated or automated DUW cleaning systems can effectively control DUW biofilm in the long-term. However, there are other potential DCU engineering and design changes that DCU manufacturers could undertake to further improve DUW biofilm control. CONCLUSIONS DCU manufacturers can significantly contribute to controlling the problem of DUW biofilm.
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Affiliation(s)
- D C Coleman
- Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental School & Hospital, University of Dublin, Trinity College Dublin, Lincoln Place, Dublin 2, Ireland.
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Abstract
AIM The purpose of the present study was to evaluate the effect of an ultrafiltration system on the bacteriological water quality in dental units. DESIGN A BIN-X UF-45R ultrafiltration system with a pore membrane of 0.03 microm was mounted at the water supply of six older dental units while six control units were disinfected with sodium hypochlorite according to a standard procedure. As the water quality in the test units deteriorated in spite of ultrafiltration the test units were subjected to chlorination at different concentrations several times during the test period. OUTCOME MEASURE The number of colony forming units (cfu)/ml in water was determined according to European Standards on water quality. RESULTS While the median number of cfu/ml in control units never exceeded 7.6x10(1) the median cfu/ml in test units increased up to >1x10(5) in 3-4 days every time chlorination of the units was interrupted. CONCLUSION The ultrafiltration system mounted at the water supply for six dental units was not able to control the bacteria originating from the existing biofilm in the water lines and deliver water of an acceptable quality.
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Affiliation(s)
- T Larsen Copenhagen
- Department of Oral Microbiology, School of Dentistry, University of Copenhagen, Denmark.
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Lindsay D, von Holy A. Bacterial biofilms within the clinical setting: what healthcare professionals should know. J Hosp Infect 2006; 64:313-25. [PMID: 17046102 DOI: 10.1016/j.jhin.2006.06.028] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Accepted: 06/15/2006] [Indexed: 10/23/2022]
Abstract
Bacterial biofilm formation is the prevailing microbial lifestyle in natural and manmade environments and occurs on all surface types. Biofilm formation develops in several phases and is influenced by various parameters, both environmental and inherent to the attaching cell. Biofilms also serve as protective niches for particular pathogens when outside a host. Although it is accepted that biofilms are ubiquitous in nature, the significance of biofilms in clinical settings, especially with regard to their role in medical-related infections, is often underestimated. It has been found that several aspects of human pathogenesis within a clinical context are directly related to biofilm development. Various types of surfaces in clinical settings are prone to biofilm development and an increased risk of disease may be a direct consequence of their formation. This review describes the process of biofilm formation, highlights the importance of bacterial associations with surfaces in clinical settings and describes various methods for biofilm visualization and control.
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Affiliation(s)
- D Lindsay
- School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa.
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Montebugnoli L, Chersoni S, Prati C, Dolci G. A between-patient disinfection method to control water line contamination and biofilm inside dental units. J Hosp Infect 2004; 56:297-304. [PMID: 15066741 DOI: 10.1016/j.jhin.2004.01.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2003] [Accepted: 12/16/2003] [Indexed: 11/23/2022]
Abstract
The aim of the present study was to evaluate the efficacy of a between-patient disinfection procedures to maintain low bacterial counts in dental unit water line (DUWL) effluents, and control dental water line biofilms. Six dental units already in use, that had never been cleaned, were monitored for three weeks. During the first week only baseline contamination levels were assessed with no treatment of the system. In the second week lines were flushed with water for 30 s before treating each patient. During the third week, a disinfection procedure with 0.26% peracetic acid, followed by a water flush, was implemented before treating each patient. DUWL samples were collected both at the beginning and at the end of 216 dental procedures (72 during each period), plated on R2A agar and incubated at room temperature for seven days to obtain total bacterial counts in colony forming units per millilitre. To assess biofilm control, nine dental units (five never used and four old dental units with established biofilm) were used for 30 days in routine dental practice undergoing five between-patient DUWL disinfecting cycles every day. Water line samples were removed at baseline and at the end of the study and examined by scanning electron microscopy to determine the presence or absence of biofilms. A significant difference (P < 0.01) in mean DUWL bacterial counts was found between the three sets of observations. Biofilms were not present in any of the new dental units and a demonstrable reduction in the biofilms from the four dental units with previous presence of established biofilms was observed at the end of the study. In this study, a between-patient disinfection procedure consisting of flushing DUWL with peracetic acid with use of water was efficacious in the control of both microbial contamination of dental treatment water and dental water line biofilms.
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Affiliation(s)
- L Montebugnoli
- Department of Oral Science, University of Bologna, Via S. Vitale 59, 40125 Bologna, Italy.
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