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Vosooghi K, Larypoor M, Sakhaee F, Ghazanfari Jajin M, Moghaddam S, Samieefar N, Rahbari Keramat R, Amiri Sabotki M, Fateh A. Distribution of nontuberculous mycobacteria in dental unit waterlines: A potential health hazard in the dental office. Microb Pathog 2024; 196:106963. [PMID: 39306050 DOI: 10.1016/j.micpath.2024.106963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 09/12/2024] [Accepted: 09/18/2024] [Indexed: 09/27/2024]
Abstract
BACKGROUND It is essential to control the microbiology of dental unit water lines (DUWs) to prevent the spread of nontuberculous mycobacteria (NTM) and associated oral diseases. Therefore, the objective of this study was to quantify the presence of NTM in the water of 112 DUWs from dental centers and 57 DUWs from individual dental offices in Tehran, Iran. METHODS A total of 169 water samples were collected from DUWs. After filtration through a 0.45 μm membrane, the samples were decontaminated with 0.005 % cetylpyridinium chloride and then cultured on two Lowenstein-Jensen media, incubated at 25 °C and 37 °C for 8 weeks. Positive cultures for mycobacteria were analyzed using phenotypic tests, and the NTM species were identified through 16S rDNA, rpoB, and hsp65 genes analysis. Drug resistance was also assessed. RESULTS Of the total isolates, 38 (34.5 %) were classified as slow-growing mycobacteria (SGM), while 72 (65.5 %) were categorized as rapid-growing mycobacteria (RGM). NTM isolates were identified using molecular tests, including M. chelonae, M. abscessus, M. lentiflavum, M. mucogenicum, M. fortuitum, M. kansasii, M. simiae, M. gordonae, M. conceptionense, M. phocaicum, M. porcinum, and M. aurum. The NTM counts ranged from 50 to >500 CFU/500 mL across these 188 samples, with a median of 350 CFU/500 mL. Additionally, we reported two cases of intraoral infection caused by M. abscessus and M. chelonae, where the source of infection was traced to NTM-contaminated DUWs. CONCLUSIONS The study found that most DUWs contained water contaminated with NTM, posing a potential health risk to humans. This research underscores the necessity of stringent quality control and certification of DUW water, with particular emphasis on ensuring the absence of NTM.
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Affiliation(s)
- Kimia Vosooghi
- Biology Department, Faculty of BioSciences, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Mohaddeseh Larypoor
- Department of Biotechnology, Faculty of Biological Sciences, Tehran North Branch, Islamic Azad University, Tehran, Iran
| | - Fatemeh Sakhaee
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
| | | | - Sina Moghaddam
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
| | - Noosha Samieefar
- Network of Interdisciplinarity in Neonates and Infants (NINI), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | | | - Mohsen Amiri Sabotki
- Imam Khomeini Hospital Complex, Tehran University of Medical Science, Tehran, Iran
| | - Abolfazl Fateh
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran; Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran.
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Shuai T, Shao T, Yi L, Han S, Jiménez-Herrera MF, Wang Z, Li X. The effect of different types of water sources on dental unit waterline contamination: A systematic review and meta analysis. Heliyon 2024; 10:e35745. [PMID: 39220891 PMCID: PMC11365326 DOI: 10.1016/j.heliyon.2024.e35745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 07/28/2024] [Accepted: 08/02/2024] [Indexed: 09/04/2024] Open
Abstract
To systematically review the effect of different types of water sources on dental unit waterline (DUWL) contamination. 5 databases were searched from their inception to December 23, 2023. Two reviewers independently extracted the data and assessed the quality of the literature. The risk ratio (RR) was used as measure of effect size in meta-analysis. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for evaluating quality of the evidence. Meta-analysis was completed by RevMan 5.4.5 studies involving 561 water samples were quantified for meta-analysis. The results indicated that no significant differences were found in view of contamination rate (RR = 1.01; 95 % CI, 0.72-1.41; P = 0.96, I 2 = 62 %; GRADE low)and detection rate of Pseudomonas aeruginosa (RR = 0.78; 95 % CI, 0.15-4.13; P = 0.77; I 2 = 83 %; GRADE very low) between using purified water and tap water as water sources of DUWL. The available evidence suggests that there is no significant difference between purified water and tap water in controlling DUWL contamination. However, the conclusions need to be further validated through more randomized controlled trials with robust design and a large sample size.
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Affiliation(s)
- Ting Shuai
- Second Clinical Division, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, 100081, China
| | - Tianyi Shao
- School of Nursing, Peking University, Beijing, 100191, China
| | - Lijuan Yi
- Department of Nursing, Hunan Traditional Chinese Medical College, Zhuzhou, 412000, China
- Nursing Department, Universitat Rovira i Virgili, Tarragona, Spain
| | - Shuyu Han
- School of Nursing, Peking University, Beijing, 100191, China
| | | | - Zhiwen Wang
- School of Nursing, Peking University, Beijing, 100191, China
| | - Xiue Li
- Department of Nursing, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, 100081, China
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Li N, Cai QM, Hu NY, Jiang SL, Chen FQ, Hu QQ, Yang F, He CZ. Pyrosequencing analysis of bacterial community changes in dental unit waterlines after chlorogenic acid treatment. Front Cell Infect Microbiol 2024; 14:1303099. [PMID: 38299116 PMCID: PMC10828043 DOI: 10.3389/fcimb.2024.1303099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/02/2024] [Indexed: 02/02/2024] Open
Abstract
Introduction The contamination of dental unit waterlines (DUWLs) poses a significant risk of cross-infection in dentistry. Although chemical disinfectants have been effective in reducing number of bacteria, they do have limitations. Methods This study aimed to investigate the potential of chlorogenic acid, a natural substance with broadspectrum antibacterial properties, for treating DUWLs. Over a period of three months, we analyzed the microbial communities in 149 DUWLs samples collected from 5 dental units using high-throughput pyrophosphate sequencing. Results The results revealed that chlorogenic acid treatment had a significant impact on the microbial community profile in the DUWLs, with the most significant changes occurring within the first 15 days and stabilization observed in the last 30 days. The predominant genera detected in the samples were Bacteroides, Lactobacillus, Streptococcus, Methylobacterium, and Phreatobacter. Additionally, the relative abundance of certain beneficial bacteria, such as Alloprevotella, Roseburia, and Blautia, increased, while the presence of opportunistic pathogens like Mycobacteria significantly decreased. The functional prediction analysis using the KEGG database indicated a decrease in the pathogenicity of the bacterial community in the DUWLs following chlorogenic acid treatment. Discussion This study introduces a novel approach for the prevention and treatment of infections associated with dental care.
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Affiliation(s)
- Na Li
- Department of Stomatology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, China
- Nursing School, Nanchang University, Nanchang, China
| | - Qin-Ming Cai
- The First Affiliated Hospital of Nanchang University, School of Public Health, Nanchang University, Nanchang, China
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Ni-Ya Hu
- The First Affiliated Hospital of Nanchang University, School of Public Health, Nanchang University, Nanchang, China
| | - Shu-ling Jiang
- Department of Stomatology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, China
- Nursing School, Nanchang University, Nanchang, China
| | - Fu-Qing Chen
- Department of Stomatology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Qiao-Qiao Hu
- Department of Stomatology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Fen Yang
- Department of Stomatology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Chao-Zhu He
- Nursing School, Nanchang University, Nanchang, China
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Patil R, Hindlekar A, Jadhav GR, Mittal P, Humnabad V, Di Blasio M, Cicciù M, Minervini G. Comparative evaluation of effect of sodium hypochlorite and chlorhexidine in dental unit waterline on aerosolized bacteria generated during dental treatment. BMC Oral Health 2023; 23:865. [PMID: 37964280 PMCID: PMC10647182 DOI: 10.1186/s12903-023-03585-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/27/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND In dentistry, nosocomial infection poses a great challenge to clinicians. The microbial contamination of water in dental unit waterlines (DUWLs) is ubiquitous. Such infected DUWLs can transmit oral microbes in the form of aerosols. Previous studies have suggested treating DUWLs with various disinfectants to reduce cross-contamination. The literature lacks a comparative evaluation of the effect of the use of 0.2% chlorhexidine (CHX) and 0.1% sodium hypochlorite (NaOCl) in DUWLs on aerosolized bacteria generated during dental procedures. OBJECTIVE To compare the effect of NaOCl and CHX in DUWLs on aerosolized bacteria generated during restorative and endodontic procedures. MATERIALS AND METHODS A total of 132 patients were equally divided into three groups (n = 44 in each group) according to the content of DUWL as follows. Group I-0.1% NaOCl Group II-0.2% CHX Group III-distilled water (Positive control) One-way ANOVA was performed and the Kruskal-Wallis test was used for intergroup comparison. RESULTS For the restorative procedure, inter-group comparison of mean colony-forming units (CFU) scores showed a statistically significant difference between the groups (p - .001) with the score of group 3 higher than group 2 followed by group 1. For the endodontics, an inter-group comparison of CFU scores showed a statistically significant difference between the groups (p - .003) with the mean score in group 1 being the lowest and group 3 being the highest. CONCLUSION The addition of NaOCl or CHX in DUWLs shows an effective reduction in aerosolized bacteria compared to distilled water.
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Affiliation(s)
- Rutuja Patil
- Department of Conservative Dentistry and Endodontics, Dr D. Y. Patil Dental College & Hospital, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune -18, India
| | - Ajit Hindlekar
- Department of Conservative Dentistry and Endodontics, Dr D. Y. Patil Dental College & Hospital, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune -18, India
| | | | - Priya Mittal
- Department of Conservative Dentistry and Endodontics, Swargiya Dadasaheb Kalmegh Smruti Dental College & Hospital, Nagpur, India
| | - Vamshi Humnabad
- Department of Conservative Dentistry and Endodontics, Dr D. Y. Patil Dental College & Hospital, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune -18, India
| | - Marco Di Blasio
- Department of Medicine and Surgery, University Center of Dentistry, University of Parma, 43126, Parma, Italy.
| | - Marco Cicciù
- Department of Biomedical and Surgical and Biomedical Sciences, Catania University, 95123, Catania, Italy
| | - Giuseppe Minervini
- Saveetha Dental College & Hospitals, Saveetha Institute of Medical & Technical Sciences Saveetha University, Chennai, India.
- Multidisciplinary Department of Medical-Surgical and Odontostomatological Specialties, University of Campania "Luigi Vanvitelli", Naples, Italy.
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Marino F, Mazzotta M, Pascale MR, Derelitto C, Girolamini L, Cristino S. 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. J Oral Microbiol 2023; 15:2223477. [PMID: 37346998 PMCID: PMC10281406 DOI: 10.1080/20002297.2023.2223477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/18/2023] [Accepted: 06/06/2023] [Indexed: 06/23/2023] Open
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.
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Affiliation(s)
- Federica Marino
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy
| | - Marta Mazzotta
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy
| | - Maria Rosaria Pascale
- 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
| | - Carlo Derelitto
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy
| | - Luna Girolamini
- 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
| | - Sandra Cristino
- 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
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Schalli M, Kogler B, Miorini T, Gehrer M, Reinthaler FF. High-Speed Dental Instruments: An Investigation of Protein-Contaminated Dental Handpieces with the Bicinchoninic Acid Assay in Dental Offices in Styria, Austria. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:1670. [PMID: 36767036 PMCID: PMC9914004 DOI: 10.3390/ijerph20031670] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/09/2023] [Accepted: 01/15/2023] [Indexed: 06/18/2023]
Abstract
Due to permanent contact with bodily secretions such as blood and saliva, the dental workplace poses a high risk of infection for patients as well as for personnel. High-speed dental instruments are still considered one of the major hygienic risks, as the high-speed rotation of the attachments leads to the retraction of infectious material from patients' oral cavities. The aim of this study was to investigate the extent to which dental handpieces are contaminated after use. Spray-water samples were taken from different handpieces used in seven dental offices and protein concentrations were measured photometrically. In the first part of the study, samples were collected from each handpiece before and after the treatment of the patients. Additionally, the changes in protein concentration after consecutive treatments in which the same high-speed dental instrument was used were investigated. The results demonstrated measurable protein concentrations in 91.2% of a total of 398 samples, and 96.4% of the spray-water samples taken after treatment showed a discrepancy from the initial measured protein concentration. In 68.4% an increase in protein concentration was observed, whereas in 27.9% a decrease was measured. In conclusion, the internal contamination of high-speed dental instruments frequently occurs in daily usage and consequently may lead to the transmission of infectious agents by flushing the contaminated water out of the spray water tubes. Moreover, it must be pointed out that internal cleansing of handpieces is insufficient and that a final mechanical disinfection is indispensable.
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Affiliation(s)
- Michael Schalli
- Department for Water-Hygiene and Micro-Ecology, D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Birgit Kogler
- Department for Water-Hygiene and Micro-Ecology, D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, 8010 Graz, Austria
| | | | - Michael Gehrer
- Styrian Hospital Corporation KAGes, Hospital Leoben, 8700 Leoben, Austria
| | - Franz F. Reinthaler
- Department for Water-Hygiene and Micro-Ecology, D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, 8010 Graz, Austria
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Khajezadeh M, Mohseni F, Khaledi A, Firoozeh A. Contamination of dental unit water lines (DUWL) with Legionella pneumophila and Pseudomonas aeruginosa; A Middle East systematic review and meta-analysis. Eur J Microbiol Immunol (Bp) 2023; 12:93-99. [PMID: 36626121 PMCID: PMC9869867 DOI: 10.1556/1886.2022.00023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 12/12/2022] [Indexed: 01/11/2023] Open
Abstract
This review aimed to evaluate the contamination rate of dental unit waterlines (DUWL) with Pseudomonas aeruginosa and Legionella pneumophila in several countries in the Middle East.Literature search was conducted in databases such as PubMed, Scopus, Web of Science, and Google Scholar to gather studies published from the beginning of 2000 to 30th April 2020. Medical Subject Headings (MeSH) terms were; "Legionellosis"; "Legionnaire", "Legionellosis", "L. pneumophila", "dent", "dental", "dentistry", "Dental Unit Waterlines", "dental water", "DUWL", "Middle East", "P. aeruginosa", "Iran", "Turkey", "Iraq", and "Jordan". The search was independently conducted by two of the authors. Data was analyzed using Comprehensive Meta-Analysis software.Almost all studies included in this review reported a high rate of bacterial contamination of DUWL, which exceeded the current standard bacterial contamination level of <200 (CFU) mL-1 recommended by the American Dental Association (ADA). The combined prevalence of L. pneumophila from four countries (Iran, Jordan, Turkey, and Iraq) was 23.5% (95% Cl: 6.5-57.7), and the combined prevalence of P. aeruginosa was reported 21.7% (95% Cl: 7.1-50.1%).This study showed a high bacterial contamination rate of DUWL with opportunistic pathogens. So, it is recommended to prevent biofilm formation in DUWL, some measures should be extended by practical approaches allowing for water quality control and improvement on-site in the dental practices such as mobile filtration units, chlorination and disinfection chemicals.
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Affiliation(s)
- Masoud Khajezadeh
- Cellular and Molecular Gerash Research Center, Gerash University of Medical Sciences, Gerash, Iran
| | - Fatemeh Mohseni
- Department of Anesthesiology, Nursing School, Gerash University of Medical Sciences, Gerash, Iran,Department of Medical Education, Medical School, Tehran University of Medical Sciences, Tehran, Iran
| | - Azad Khaledi
- Infectious Diseases Research Center, Kashan University of Medical Sciences, Kashan, Iran,Department of Microbiology and Immunology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran
| | - Arezoo Firoozeh
- Department of Microbiology, Mashhad University of Medical Sciences, Mashhad, Iran,Corresponding author. Tel.: +989304347901. E-mail:
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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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Umer F, Khan M, Khan FR, Tejani K. Managing dental unit waterlines: a quality improvement programme. BMJ Open Qual 2022; 11:bmjoq-2021-001685. [PMID: 35667705 PMCID: PMC9171218 DOI: 10.1136/bmjoq-2021-001685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 05/17/2022] [Indexed: 11/25/2022] Open
Abstract
The presence of bacterial biofilms within dental unit waterlines (DUWLs) can cause secondary bacterial infections in immunocompromised patients. As a result, the management of biofilms within waterlines has always concerned medical and dental professionals. In February 2020, an internal audit identified the high bacterial counts within the DUWLs at the Aga Khan University Hospital, Karachi and this paper discusses a pragmatic approach to improving the water quality of DUWLs. A three-person committee was developed and the area for improvement was identified as the contaminated DUWLs. Distilled water samples from two dental units were first assessed as baseline in July 2020. The process changes were then implemented which included daily flushing of the dental unit waterlines and ‘shock treatment’ using A-dec ICX capsules. Subsequently, the units were tested after intervention on 24 August 2020 and water from all 16 dental units assessed on 20 November 2020 and again on 22 April 2021. The samples from all the dental units assessed showed marked reduction in bacterial counts and compliance with the Centers for Disease Control guidelines after intervention. All the dental units showed minimal bacterial counts; however, a slightly low pH was noted in the final round of water testing. DUWLs are heavily contaminated with microbes and pose potential risk both to the patient as well as the DHCPs. This study suggests that chemical disinfection using A-dec ICX tablets and flushing as an effective method of reducing the bacterial load in DUWLs.
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Affiliation(s)
- Fahad Umer
- Surgery, Operative Dentistry, The Aga Khan University Hospital Main Campus Karachi, Karachi, Sindh, Pakistan
| | - Madiha Khan
- Surgery, The Aga Khan University Hospital Main Campus Karachi, Karachi, Pakistan
| | - Farhan Raza Khan
- Surgery, Operative Dentistry, The Aga Khan University Hospital Main Campus Karachi, Karachi, Sindh, Pakistan
| | - Karim Tejani
- Surgery, The Aga Khan University Hospital Main Campus Karachi, Karachi, Pakistan
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Microbiological Evaluation of Water Used in Dental Units. WATER 2022. [DOI: 10.3390/w14060915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In modern dentistry, dental units are used for the treatment of patients’ teeth, and they need water to operate. Water circulates in a closed vessel system and finally reaches the mucous membranes of the patient as well as the dentist themselves. Therefore, the microbiological safety of this water should be a priority for physicians. This study aims to identify and determine the microbial count, expressed in CFU/mL, in water samples from various parts of the dental unit that are in direct contact with the patient. Thirty-four dental units located in dentistry rooms were analysed. The dentistry rooms were divided into three categories: surgical, conservative, and periodontal. It was found that in surgical rooms, the bacterial count was 1464.76 CFU/mL, and the most common bacterium was Staphylococcus pasteuri—23.88% of the total bacteria identified. In dentistry rooms where conservative treatments were applied, the average bacterial concentration was 8208.35 CFU/mL, and the most common bacterium was Ralsonia pickettii (26.31%). The periodontal rooms were also dominated by R. pickettii (45.13%), and the average bacterial concentration was 8743.08 CFU/mL. Fungi were also detected. Rhodotorula spp., Alternaria spp., and Candida parapsilosis were found to be the most common bacteria which are potentially harmful. This study indicates the need for effective decontamination of the water that is used in dental units and for constant monitoring of the level of contaminants present in the closed vessel system.
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Spagnolo AM, Sartini M, Cristina ML. Microbial Contamination of Dental Unit Waterlines and Potential Risk of Infection: A Narrative Review. Pathogens 2020; 9:E651. [PMID: 32823641 PMCID: PMC7460066 DOI: 10.3390/pathogens9080651] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/09/2020] [Accepted: 08/12/2020] [Indexed: 12/19/2022] Open
Abstract
Several studies have revealed that dental unit waterlines (DUWLs) are often contaminated by large numbers of various micro-organisms (bacteria, fungi, protozoa, viruses). Microbial contamination in DUWLs may originate from the mains water piped into the dental unit, the suck-back of patients' saliva into the line due to the lack of adequate valves, and contamination from bottled water systems. Some of the main determinants of microbial contamination in DUWLs are: a very small lumen size (0.5-2 mm) of the tubing used, high surface-to-volume ratio (6:1), low throughput and the materials of which the tubing is made, water stagnation outside of working hours. The environmental conditions present inside the conduits of the dental unit may facilitate the proliferation of micro-organisms and the consequent formation of biofilm on the interior surface of the pipes of DUWLs. During the use of handpieces, particularly high-speed rotating instruments, a spray is thrown up in the form of aerosols or spatters containing biological material (saliva, blood and dental plaque) and micro-organisms. This means that the health of both dental staff and patients could be at risk of infection. The risk of cross-infections in dental settings can be tackled by implementing combined interventions to prevent the contamination of DUWLs.
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Affiliation(s)
| | - Marina Sartini
- Department of Health Sciences, University of Genova, 16132 Genova, Italy; (A.M.S.); (M.L.C.)
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12
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Tuvo B, Totaro M, Cristina ML, Spagnolo AM, Di Cave D, Profeti S, Baggiani A, Privitera G, Casini B. Prevention and Control of Legionella and Pseudomonas spp. Colonization in Dental Units. Pathogens 2020; 9:E305. [PMID: 32326140 PMCID: PMC7238104 DOI: 10.3390/pathogens9040305] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 11/29/2022] Open
Abstract
Introduction: Dental Unit Waterlines (DUWLs) have shown to be a source of Legionella infection. We report the experience of different dental healthcare settings where a risk management plan was implemented. Materials and methods: In a Hospital Odontostomatology Clinic (HOC) and three Private Dental Clinics (PDCs) housing 13 and six dental units (DUs), respectively, an assessment checklist was applied to evaluate staff compliance with guideline recommendations. DUWLs microbial parameters were investigated before and after the application of corrective actions. Results: In the HOC a poor adherence to good practices was demonstrated, whereas protocols were carefully applied in PDCs. L. pneumophila sg 2-15 was isolated in 31% (4/13) and 33% (2/6) of DUs in HOC and PDCs, respectively, mainly from handpieces (32%, 6/19) with counts >102 colony-forming units per milliliter (CFU/L), often associated with P. aeruginosa (68%, 13/19). The shock disinfection with 3% v/v hydrogen peroxide (HP) showed a limited effect, with a recolonization period of about 4 weeks. Legionella was eradicated only after 6% v/v HP shock disinfection and filters-installation, whilst P. aeruginosa after the third shock disinfection with a solution of 4% v/v HP and biodegradable surfactants. Conclusions: Our data demonstrate the presence and persistence of microbial contamination within the DUWLs, which required strict adherence to control measures and the choice of effective disinfectants.
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Affiliation(s)
- Benedetta Tuvo
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
| | - Michele Totaro
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
| | - Maria Luisa Cristina
- Department of Health Sciences, University of Genova, Via Pastore 1, 16132 Genova, Italy; (M.L.C.); (A.M.S.)
| | - Anna Maria Spagnolo
- Department of Health Sciences, University of Genova, Via Pastore 1, 16132 Genova, Italy; (M.L.C.); (A.M.S.)
| | - David Di Cave
- Department of Clinical Sciences and Translational Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy;
| | - Sara Profeti
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
| | - Angelo Baggiani
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
| | - Gaetano Privitera
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
| | - Beatrice Casini
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
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Castellano Realpe OJ, Gutiérrez JC, Sierra DA, Pazmiño Martínez LA, Prado Palacios YY, Echeverría G, de Waard JH. Dental Unit Waterlines in Quito and Caracas Contaminated with Nontuberculous Mycobacteria: A Potential Health Risk in Dental Practice. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E2348. [PMID: 32244267 PMCID: PMC7177417 DOI: 10.3390/ijerph17072348] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/16/2020] [Accepted: 02/20/2020] [Indexed: 11/17/2022]
Abstract
Three cases of severe odontogenic infections due to nontuberculous mycobacteria (NTM) in Venezuela that were directly associated with dental procedures and the finding of dental unit waterlines (DUWLs) in dental offices that were colonized with mycobacteria species was the reason for assessing the water quality of DUWLs in dental offices in two capital cities in South America, namely, Quito and Caracas. The main water supplies and the water from 143 DUWLs in both cities were sampled and especially checked for contamination with NTM. To measure the overall bacteriological quality of the water also the presence of heterotrophic bacteria, coliform bacteria, and Pseudomonas was determined. Results showed that respectively 3% and 56% of the DUWLs in Quito and Caracas yielded NTM species (up to 1000 colony-forming units (CFU)/mL). Furthermore, high and unacceptable total viable counts of heterotrophic bacteria and/or coliform bacteria and Pseudomonas were detected in 73% of the samples. We conclude that, in both cities, the water in the majority of DUWLs was contaminated with NTM and other potential pathogens, presenting a risk to human health. The detection of NTM in DUWL water with acceptable heterotrophic bacteria counts shows the need to include NTM in water quality testing. Mycobacteria are more resistant to disinfection procedures than other types of vegetative bacteria, and most testing protocols for DUWLs do not assess mycobacteria and thus do not guarantee risk-free water.
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Affiliation(s)
| | - Johanna C. Gutiérrez
- Facultad de Medicina. Escuela de Bioanálisis, Universidad Central de Venezuela, 1053 Caracas, Venezuela
- Instituto de Biomedicina “Dr. Jacinto Convit”, Universidad Central de Venezuela, 1010 Caracas, Venezuela
| | - Deisy A. Sierra
- Facultad de Medicina. Escuela de Bioanálisis, Universidad Central de Venezuela, 1053 Caracas, Venezuela
- Instituto de Biomedicina “Dr. Jacinto Convit”, Universidad Central de Venezuela, 1010 Caracas, Venezuela
| | | | - Yrneh Y. Prado Palacios
- Instituto de Biomedicina “Dr. Jacinto Convit”, Universidad Central de Venezuela, 1010 Caracas, Venezuela
| | - Gustavo Echeverría
- Instituto de Investigación en Salud Pública y Zoonosis CIZ, Universidad Central del Ecuador, 170521 Quito, Ecuador
| | - Jacobus H. de Waard
- Instituto de Biomedicina “Dr. Jacinto Convit”, Universidad Central de Venezuela, 1010 Caracas, Venezuela
- One Health Research Group, Facultad de Ciencias de la Salud, Universidad De Las Américas, 170504 Quito, Ecuador
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14
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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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15
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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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16
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Ávila de Navia SL, Estupiñán Torres SM, Estupiñán Torres DM. Indicadores de calidad bacteriológica del agua en unidades odontológicas. REVISTA DE LA FACULTAD DE MEDICINA 2014. [DOI: 10.15446/revfacmed.v62n1.43766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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17
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Disinfection of dental unit water line using aloe vera: in vitro study. Int J Dent 2013; 2013:618962. [PMID: 24089615 PMCID: PMC3781845 DOI: 10.1155/2013/618962] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 07/11/2013] [Accepted: 07/11/2013] [Indexed: 12/28/2022] Open
Abstract
Context. Dental unit waterlines may be heavily contaminated with microorganisms and are a potential source of infection for both practicing staff and immunocompromised patients particularly. Contamination of dental unit water lines could be inhibited with the use of disinfectants. The present study investigates the effect of aloe-vera-based disinfectant in reducing the microbial growth in dental unit water lines (DUWLs). Aims. To compare the efficacy of aloe vera, hydrogen peroxide (H2O2), and 5% sodium hypochlorite (NaOCl) in controlling microbial contamination of DUWLs. Materials and Methods. After obtaining baseline water samples, the dental unit waterlines were treated with aloe vera, 10% hydrogen peroxide, and 5% sodium hypochlorite. Each of the three disinfectants was used in increasing concentrations and their inhibiting effect was compared. Water samples were analyzed for microbiological quality by the total viable count (TVC) method. Statistical Analysis Used. SPSS 16. Results. There was significant reduction in mean CFU/ml when treated with disinfectants each for a period of one week. Aloe-vera solution was found to be the most effective in reducing the microbial colonies. Conclusions. Improving the water quality from dental unit water lines is of considerable importance; chemical-based disinfectants can be replaced with herbal disinfectants for treating microbial contamination in dental unit waterlines.
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18
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Garg SK, Mittal S, Kaur P. Dental unit waterline management: historical perspectives and current trends. ACTA ACUST UNITED AC 2012; 3:247-52. [DOI: 10.1111/j.2041-1626.2012.00135.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 02/19/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Shushant K. Garg
- Maharishi Markandeshwar College of Dental Sciences and Research; Mullana-Ambala Haryana India
| | - Sanjeev Mittal
- Maharishi Markandeshwar College of Dental Sciences and Research; Mullana-Ambala Haryana India
| | - Prabhmanik Kaur
- Maharishi Markandeshwar College of Dental Sciences and Research; Mullana-Ambala Haryana India
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19
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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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20
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Pasquarella C, Veronesi L, Napoli C, Castiglia P, Liguori G, Rizzetto R, Torre I, Righi E, Farruggia P, Tesauro M, Torregrossa MV, Montagna MT, Colucci ME, Gallè F, Masia MD, Strohmenger L, Bergomi M, Tinteri C, Panico M, Pennino F, Cannova L, Tanzi M. Microbial environmental contamination in Italian dental clinics: A multicenter study yielding recommendations for standardized sampling methods and threshold values. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 420:289-299. [PMID: 22335883 DOI: 10.1016/j.scitotenv.2012.01.030] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 01/06/2012] [Accepted: 01/12/2012] [Indexed: 05/31/2023]
Abstract
A microbiological environmental investigation was carried out in ten dental clinics in Italy. Microbial contamination of water, air and surfaces was assessed in each clinic during the five working days, for one week per month, for a three-month period. Water and surfaces were sampled before and after clinical activity; air was sampled before, after, and during clinical activity. A wide variation was found in microbial environmental contamination, both within the participating clinics and for the different sampling times. Before clinical activity, microbial water contamination in tap water reached 51,200cfu/mL (colony forming units per milliliter), and that in Dental Unit Water Systems (DUWSs) reached 872,000cfu/mL. After clinical activity, there was a significant decrease in the Total Viable Count (TVC) in tap water and in DUWSs. Pseudomonas aeruginosa was found in 2.38% (7/294) of tap water samples and in 20.06% (59/294) of DUWS samples; Legionella spp. was found in 29.96% (89/297) of tap water samples and 15.82% (47/297) of DUWS samples, with no significant difference between pre- and post-clinical activity. Microbial air contamination was highest during dental treatments, and decreased significantly at the end of the working activity (p<0.05). The microbial buildup on surfaces increased significantly during the working hours. This study provides data for the establishment of standardized sampling methods, and threshold values for contamination monitoring in dentistry. Some very critical situations have been observed which require urgent intervention. Furthermore, the study emphasizes the need for research aimed at defining effective managing strategies for dental clinics.
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Affiliation(s)
- Cesira Pasquarella
- Dipartimento di Sanità Pubblica, Università degli Studi di Parma, Italy.
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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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Luo J, Porteous N, Sun Y. Rechargeable biofilm-controlling tubing materials for use in dental unit water lines. ACS APPLIED MATERIALS & INTERFACES 2011; 3:2895-903. [PMID: 21721534 PMCID: PMC3161146 DOI: 10.1021/am200576q] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A simple and practical surface grafting approach was developed to introduce rechargeable N-halamine-based antimicrobial functionality onto the inner surfaces of continuous small-bore polyurethane (PU) dental unit waterline (DUWL) tubing. In this approach, tetrahydrofuran (THF) solution of a free-radical initiator, dicumyl peroxide (DCP), flowed through the PU tubing (inner diameter of 1/16 in., or 1.6 mm) to diffuse DCP into the tubing's inner walls, which was used as initiator in the subsequent grafting polymerization of methacrylamide (MAA) onto the tubing. Upon chlorine bleach treatment, the amide groups of the grafted MAA side chains were transformed into acyclic N-halamines. The reactions were confirmed with attenuated total reflectance infrared (ATR) spectra and iodometric titration. The mechanical properties of the tubing were not significantly affected by the grafting reactions. The biofilm-controlling function of the new N-halamine-based PU tubing was evaluated with Pseudomonas aeruginosa (P. aeruginosa), one of the most isolated water bacteria from DUWLs, in a continuous bacterial flow model. Bacteria culturing and SEM studies showed that the inner surfaces of the new N-halamine-based PU tubing completely prevented bacterial biofilm formation for at least three to four weeks. After that, bacteria began to colonize the tubing surface. However, the lost function was fully regenerated by exposing the tubing inner surfaces to diluted chlorine bleach. The recharging process could be repeated periodically to further extend the biofilm-controlling duration for long-term applications.
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Affiliation(s)
- Jie Luo
- Biomedical Engineering Program, University of South Dakota, Sioux Falls, SD 57107
| | - Nuala Porteous
- Department of Comprehensive Dentistry, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-4404
| | - Yuyu Sun
- Biomedical Engineering Program, University of South Dakota, Sioux Falls, SD 57107
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23
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Boyle M, O’Donnell M, Russell R, Coleman D. Lack of cytotoxicity by Trustwater Ecasol™ used to maintain good quality dental unit waterline output water in keratinocyte monolayer and reconstituted human oral epithelial tissue models. J Dent 2010; 38:930-40. [DOI: 10.1016/j.jdent.2010.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 08/05/2010] [Accepted: 08/06/2010] [Indexed: 11/16/2022] Open
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24
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Chate RAC. 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 2010; 209:E11. [PMID: 20885414 DOI: 10.1038/sj.bdj.2010.885] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2010] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To evaluate and improve upon the quality of water emanating from the dental unit waterlines (DUWLs) which supply irrigation for dental handpieces and triple spray syringes in general practice. DESIGN A prospective clinical audit. SETTING Seventy-two general dental practices in the East of England. METHODS In 2006, 124 dentists initially registered to participate in the audit. By 2007, 72 had begun and by 2008, 68 had completed the project. This involved collecting samples of water discharged from the DUWLs in the dental practices both before the start and mid-way through a morning session. These were tested microbiologically at a United Kingdom Accreditation Service testing laboratory. INTERVENTIONS Before the audit, 56% of the DUWLs were reportedly flushed through for 2 minutes at the start of the day, 29% were purged for 20 seconds in between each patient, 50% were treated with a wide range of different disinfectant solutions, 44% were drained down dry at the end of the day and 9% had no cross-infection control measures applied to them at all. In the audit, 100% used a disinfectant solution alone, predominantly either Alpron or Sterilox. MAIN OUTCOME MEASURES The minimum audit standard set was for the water samples to meet the United States' Centers for Disease Control and Prevention (CDC) guideline on the quality of DUWL water, namely that the United States' Environmental Protection Agency (EPA) regulatory standards for drinking water be adopted, in that no more than 5% of water samples should be contaminated with total coliforms and that they should not have more than 500 colony forming units per ml (cfu/ml) of heterotrophic water bacteria. However, the participating dentists were encouraged to try and achieve the more stringent European Union (EU) standards for potable (drinking) water, namely for the water samples to have neither Escherichia coli nor any other faecal coliforms present and for the aerobic colony count to be less than 100 cfu/ml at 22°C after 72 hours of culturing. RESULTS In the pre-audit survey, none of the 72 DUWL water samples were contaminated with E. coli but in five of them (7%) coliforms were recovered. Only 25% reached the EU potable water standard, of which 11% had zero planktonic bacterial contamination. Three percent were above the EU standard but below the CDC guideline/EPA regulatory drinking water standard, while alarmingly, 72% of them failed to reach this minimum audit standard altogether. However, after the application of a suitable disinfectant for at least a month, the audit revealed that E. coli still remained absent in the water samples taken from the 68 DUWLs that completed the project and in only one (1.5%) were coliforms recovered. Remarkably, nearly 81% reached the EU potable water standard, of which 54% had zero planktonic bacterial contamination, with nearly an additional 6% reaching the American CDC/EPA standard and with only 13% failing outright. CONCLUSIONS Clinical audit using appropriate DUWL disinfectants can result in the improvement of the quality of water that is discharged through DUWLs, thereby minimising both the risk of cross-infection to vulnerable patients as well as to dental staff chronically exposed to contaminated aerosols.
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Affiliation(s)
- R A C Chate
- Orthodontic Department, Essex County Hospital, Lexden Road, Colchester, UK
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25
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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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Orrù G, Del Nero S, Tuveri E, Laura Ciusa M, Pilia F, Erriu M, Orrù G, Liciardi M, Piras V, Denotti G. Evaluation of antimicrobial-antibiofilm activity of a hydrogen peroxide decontaminating system used in dental unit water lines. Open Dent J 2010; 4:140-6. [PMID: 21113279 PMCID: PMC2948419 DOI: 10.2174/1874210601004010140] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 02/15/2010] [Accepted: 02/25/2010] [Indexed: 11/22/2022] Open
Abstract
A dental unit water line (DUWL) equipped with a device designed to automatically and continually flush a bacteriostatic solution of hydrogen peroxide (WHE) and a discontinuous disinfecting system (BIOSTER) was evaluated. In the first instance a preliminary sensitivity test on a large number of microorganisms (bacteria and fungi) was tried with a H2O2 range from 100 to 800 ppm. The bacteria frequently reported in DUWL (including Pseudomonas spp, Streptococcus spp., Staphylococcus spp., E. coli) and some periodontal pathogens showed a minimum inhibitory concentration from 100 to 300 H2O2 ppm (also including M. marinum and C. albicans). However, H2O2 did not show any inhibitory effects against: A. actinomycetemcomitans, C. glabrata C. parapsilos, F. nucleatum, M. micros. In a second step, the DUWL was experimentally infected with S. faecalis, E. coli, P. aeruginosa, S. aureus. After disinfection steps with 3% H2O2, the inhibitory effect on planktonic forms and on sessile biofilm was measured. In a third step, the count of 16S rRNA gene copies by real time PCR at different points of the DUWL described an accrue of bacterial slime in “hot spot” regions characterized by irregular/slow water flux (valves, elbows). However these results suggest that hydrogen peroxide is not only able to inhibit bursts of planktonic bacteria inside the DUWL, but that it could also be effective against sessile biofilm containing heterotrophic microorganisms derived from domestic water line contamination. In addition some oral pathogens could be contaminating and surviving in DUWL.
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Affiliation(s)
- Germano Orrù
- OBL (Oral Biotechnology Laboratory), Dipartimento di Chirurgia e Scienze Odontostomatologiche, Universita' degli Studi di Cagliari, Cagliari, Italy
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O’Donnell M, Boyle M, Swan J, Russell R, Coleman D. A centralised, automated dental hospital water quality and biofilm management system using neutral Ecasol™ maintains dental unit waterline output at better than potable quality: A 2-year longitudinal study. J Dent 2009; 37:748-62. [DOI: 10.1016/j.jdent.2009.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 06/02/2009] [Accepted: 06/03/2009] [Indexed: 10/20/2022] Open
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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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Dutil S, Meriaux A, de Latremoille MC, Lazure L, Barbeau J, Duchaine C. Measurement of airborne bacteria and endotoxin generated during dental cleaning. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2009; 6:121-130. [PMID: 19093289 DOI: 10.1080/15459620802633957] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Dynamic dental instruments generate abundant aerosols in the work environment. Dental unit waterlines (DUWL) support a large microbial population and can be a significant source of bioaerosols generated during dental treatments. This study was conducted to characterize bioaerosol generation during dental treatments performed in standardized conditions. Culture-based method (R2A, and blood agar with and without O2) and fluorescence microscopy were used. Dental cleaning procedures were performed in an isolated treatment room with controlled ventilation rate. Andersen microbial samplers were used to collect culturable bioaerosols generated before (baseline), during, and after 2 hr of dental treatments. Inhalable dust samplers were used to measure total bioaerosols content in dental hygienist's and patients' breathing zones. AGI-30 were used for the collection of the endotoxin. The use of fluorescence microscopy in combination with culture demonstrated that dental staff and patients were exposed to up to 1.86 E+05 bacteria/m(3) generated during treatments. Fortunately, bioaerosols returned to baseline within 2 hr after the dental procedures. The small diameter of the aerosols generated (< 1 microm) suggests that the risk of contact between the aerosolized bacteria and the respiratory system of exposed individuals is likely to occur.
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Affiliation(s)
- Steve Dutil
- Institut Universitaire de Cardiologie et de Pneumologie de l'Universite Laval, Hopital Laval, Quebec City, Quebec, Canada
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Assessment of inhibitory effects of fluoride-coated tubes on biofilm formation by using the in vitro dental unit waterline biofilm model. Appl Environ Microbiol 2008; 74:5958-64. [PMID: 18676694 DOI: 10.1128/aem.00610-08] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study aimed to establish an in vitro model to simulate biofilms formed in dental unit waterlines (DUWLs) and to investigate the ability of polyvinylidene fluoride (PVDF)-coated tubes to inhibit biofilm formation using this model. The water and biofilm samples were obtained from DUWLs which had been clinically used for 2.5 years, and the predominant bacteria were identified. A conventional polyurethane tube was incubated for 24 to 96 h in the mixed flora of isolated bacteria, and the optimal incubation conditions to simulate a clinically formed biofilm were determined by observation with a scanning electron microscope. Biofilm formation on a PVDF-coated tube was observed using this in vitro model, and the adherence of different bacterial species to conventional and PVDF-coated tubes was assessed. Sphingomonas paucimobilis, Acinetobacter haemolytics, and Methylobacterium mesophilicum were predominantly isolated from contaminated DUWLs. Incubation of the polyurethane tube with the mixed flora containing these three species for 96 h resulted in the formation of a mature biofilm similar to the one clinically observed. The PVDF-coated tube was significantly less adhesive to all three bacterial species than the polyurethane tube (P < 0.05 by the Mann-Whitney U test), and the attachment of small amounts of rods was observed even after incubation with the mixed flora for 96 h. In conclusion, an in vitro biofilm model was obtained by using a mixed flora of bacteria isolated from DUWLs, and the PVDF-coated tube was found to be effective in preventing biofilm formation using this model.
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de Oliveira AC, Maluta RP, Stella AE, Rigobelo EC, Marin JM, de Ávila FA. Isolation of Pseudomonas aeruginosa strains from dental office environments and units in Barretos, state of São Paulo, Brazil, and analysis of their susceptibility to antimicrobial drugs. Braz J Microbiol 2008; 39:579-84. [PMID: 24031269 PMCID: PMC3768431 DOI: 10.1590/s1517-838220080003000032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2007] [Revised: 02/22/2008] [Accepted: 07/13/2008] [Indexed: 11/22/2022] Open
Abstract
A wide variety of opportunistic pathogens has been detected in the tubing supplying water to odontological equipment, in special in the biofilm lining of these tubes. Among these pathogens, Pseudomonas aeruginosa, one of the leading causes of nosocomial infections, is frequently found in water lines supplying dental units. In the present work, 160 samples of water, and 200 fomite samples from forty dental units were collected in the city of Barretos, State of São Paulo, Brazil and evaluated between January and July, 2005. Seventy-six P. aeruginosa strains, isolated from the dental environment (5 strains) and water system (71 strains), were tested for susceptibility to six antimicrobial drugs most frequently used against P. aeruginosa infections. Susceptibility to ciprofloxacin, followed by meropenem was the predominant profile. The need for effective means of reducing the microbial burden within dental unit water lines is emphasized, and the risk of exposure and cross-infection in dental practice, in special when caused by opportunistic pathogens like P. aeruginosa, are highlighted.
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Affiliation(s)
- Ana Claudia de Oliveira
- Programa de Microbiologia, Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal, Universidade Estadual Paulista , Jaboticabal, SP , Brasil
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Castiglia P, Liguori G, Montagna MT, Napoli C, Pasquarella C, Bergomi M, Fabiani L, Monarca S, Petti S. Italian multicenter study on infection hazards during dental practice: control of environmental microbial contamination in public dental surgeries. BMC Public Health 2008; 8:187. [PMID: 18644099 PMCID: PMC2430203 DOI: 10.1186/1471-2458-8-187] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Accepted: 05/29/2008] [Indexed: 11/11/2022] Open
Abstract
Background The present study assessed microbial contamination in Italian dental surgeries. Methods An evaluation of water, air and surface microbial contamination in 102 dental units was carried out in eight Italian cities. Results The findings showed water microbial contamination in all the dental surgeries; the proportion of water samples with microbial levels above those recommended decreased during working. With regard to Legionella spp., the proportion of positive samples was 33.3%. During work activity, the index of microbial air contamination (IMA) increased. The level of microbial accumulation on examined surfaces did not change over time. Conclusion These findings confirm that some Italian dental surgeries show high biocontamination, as in other European Countries, which highlights the risk of occupational exposure and the need to apply effective measures to reduce microbial loads.
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Affiliation(s)
- Paolo Castiglia
- Istituto di Igiene e Medicina Preventiva, Università degli Studi di Sassari, Via P, Manzella 4, 07100 Sassari, Italy.
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Dutil S, Veillette M, Mériaux A, Lazure L, Barbeau J, Duchaine C. Aerosolization of mycobacteria and legionellae during dental treatment: low exposure despite dental unit contamination. Environ Microbiol 2008; 9:2836-43. [PMID: 17922766 DOI: 10.1111/j.1462-2920.2007.01395.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dental unit waterlines (DUWL) support growth of a dense microbial population that includes pathogens and hypersensitivity-inducing bacteria, such as Legionella spp. and non-tuberculous mycobacteria (NTM). Dynamic dental instruments connected to DUWL generate aerosols in the work environment, which could allow waterborne pathogens to be aerosolized. The use of the real-time quantitative polymerase chain reaction (qPCR) provides a more accurate estimation of exposure levels compared with the traditional culture approach. Bioaerosol sampling was performed 13 times in an isolated dental treatment room according to a standardized protocol that included four dental prophylaxis treatments. Inhalable dust samples were taken at the breathing zone of both the hygienist and patient and outside the treatment room (control). Total bacteria as well as Legionella spp. and NTM were quantified by qPCR in bioaerosol and DUWL water samples. Dental staff and patients are exposed to bacteria generated during dental treatments (up to 4.3 E + 05 bacteria per m(3) of air). Because DUWL water studied was weakly contaminated by Legionella spp. and NTM, their aerosolization during dental treatment was not significant. As a result, infectious and sensitization risks associated with legionellae and NTM should be minimal.
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Affiliation(s)
- Steve Dutil
- Institut universitaire de cardiologie et de pneumologie de l'Université Laval, Hôpital Laval, Québec, Québec, Canada
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Liaqat I, Sabri AN. Effect of biocides on biofilm bacteria from dental unit water lines. Curr Microbiol 2008; 56:619-24. [PMID: 18322732 DOI: 10.1007/s00284-008-9136-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2007] [Accepted: 01/18/2008] [Indexed: 11/28/2022]
Abstract
Microbial biofilm formation in dental unit water lines (DUWL) is a phenomenon that has been recognized for nearly four decades. Water delivered by DUWL can harbor high numbers of bacteria, including opportunistic pathogens. Biofilms on tubing within DUWL may serve as a reservoir for these microorganisms and should therefore be controlled. In this study, the effects of eight biocides were monitored on DUWL biofilms individually and in combination by epifluorescence microscopy and total viable counts (TVC). The effects of sodium dodecyl sulphate (SDS), hydrogen peroxide (H2O2), sodium hypochlorite (NaOCl), phenol (Phe), Tween 20 (Tw 20), ethylenediaminetetraacetic acid (EDTA), chlorohexidine gluconate (CHX), and povidine iodine (PI) were tested on DUWL biofilms alone and in combination. PI was found to have negligible effects on biofilm removal either applied alone or in combined form with CHX. Applying all biocides simultaneously did not completely eliminate viable bacteria nor did they remove biofilm. Overall, when combined, the biocides performed better than singly applied products. The most effective biocides were NaOCl and Phe (both alone and in combination).
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Affiliation(s)
- I Liaqat
- Department of Microbiology and Molecular Genetics, University of the Punjab, Lahore, 54590, Pakistan.
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35
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Luo J, Sun Y. AcyclicN-halamine-based biocidal tubing: Preparation, characterization, and rechargeable biofilm-controlling functions. J Biomed Mater Res A 2008; 84:631-42. [PMID: 17635013 DOI: 10.1002/jbm.a.31301] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In this study, the surfaces of polypropylene tubing were hydroxylated with potassium persulfate. The resultant tubing surfaces were grafted with methacrylamide (MAA) using ceric(IV) ammonium nitrate as an initiator. Upon chlorination treatment with diluted chlorine bleach, some of the amide groups in the grafted MAA side chains were transformed into stable acyclic N-halamines. The reactions were confirmed with attenuated total reflectance infrared, X-ray photoelectron spectra, and iodimetric titration. The resultant tubing was challenged with Pseudomonas aeruginosa (P. aeruginosa) in a continuous flowing model. Bacteria culturing and scanning electron microscope studies showed that the chlorinated MAA-grafted tubing could provide potent and rechargeable biofilm-controlling functions against the test microorganisms.
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Affiliation(s)
- Jie Luo
- Department of Human Ecology, The University of Texas at Austin, Austin, Texas 78712, USA
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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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Pankhurst CL, Coulter WA. Do contaminated dental unit waterlines pose a risk of infection? J Dent 2007; 35:712-20. [PMID: 17689168 DOI: 10.1016/j.jdent.2007.06.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 06/01/2007] [Accepted: 06/05/2007] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES To review the evidence that the dental unit waterlines are a source of occupational and healthcare acquired infection in the dental surgery. DATA Transmission of infection from contaminated dental unit waterlines (DUWL) is by aerosol droplet inhalation or rarely imbibing or wound contamination in susceptible individuals. Most of the organisms isolated from DUWL are of low pathogenicity. However, data from a small number of studies described infection or colonisation in susceptible hosts with Legionella spp., Pseudomonas spp. and environmental mycobacteria isolated from DUWL. The reported prevalence of legionellae in DUWL varies widely from 0 to 68%. The risk from prolonged occupational exposure to legionellae has been evaluated. Earlier studies measuring surrogate evidence of exposure to legionellae in dental personnel found a significant increase in legionella antibody levels but in recent multicentre studies undertaken in primary dental care legionellae were isolated at very low rate and the corresponding serological titres were not above background levels. Whereas, a case of fatal Legionellosis in a dental surgeon concluded that the DUWL was the likely source of the infection. The dominant species isolated from dental unit waterlines (DUWL) are Gram-negative bacteria, which are a potent source of cell wall endotoxin. A consequence of indoor endotoxin exposure is the triggering or exacerbation of asthma. Data from a single large practice-based cross-sectional study reported a temporal association between occupational exposure to contaminated DUWL with aerobic counts of >200cfu/mL at 37 degrees C and development of asthma in the sub-group of dentists in whom asthma arose following the commencement of dental training. SOURCES Medline 1966 to February 2007 was used to identify studies for this paper. STUDY SELECTION Design criteria included randomised control trials, cohort, and observational studies in English. CONCLUSIONS Although the number of published cases of infection or respiratory symptoms resulting from exposure to water from contaminated DUWL is limited, there is a medico-legal requirement to comply with potable water standards and to conform to public perceptions on water safety.
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Affiliation(s)
- Caroline L Pankhurst
- Department of Oral Medicine, King's College London Dental Institute, Bessemer Road, London, United Kingdom.
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Milward MR, Cooper PR. Competency assessment for infection control in the undergraduate dental curriculum. EUROPEAN JOURNAL OF DENTAL EDUCATION : OFFICIAL JOURNAL OF THE ASSOCIATION FOR DENTAL EDUCATION IN EUROPE 2007; 11:148-54. [PMID: 17640258 PMCID: PMC7194216 DOI: 10.1111/j.1600-0579.2007.00439.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 09/26/2006] [Indexed: 05/16/2023]
Abstract
OBJECTIVES This study aimed at investigating the introduction of an infection control competency assessment on undergraduate dental student's awareness and knowledge of infection control. METHOD A short course, including an introductory lecture and a three component competency based assessment exercise testing student's knowledge and ability in infection control measures was incorporated into the previously established training programme. The assessment exercises included a written test of students' knowledge of the Infection Control Policy, a unit management exercise and a hand hygiene assessment. The infection control competency was initially incorporated into the final term of the second year in 2004 and is now an established part of the 5-year dental undergraduate degree programme. Re-assessments were scheduled (at the start of third year) for students failing to meet the required standard as successful completion of this course was compulsory prior to students being allowed to treat their first patients. Student performance over the last 2 years on this course and during their first year on clinic were analysed to determine potential improvements in student knowledge and application in infection control. Examination results from the year 3, infection control spot test were compared with those of earlier years. In addition, the opinions, as assessed by questionnaire analysis, of dental staff and students on the infection control competency were obtained. RESULTS All students successfully completed the infection control competency (either at first or second attempt) and were subsequently allowed to enter clinical training in year 3. Significant improvements were seen in students passing the course at their initial attempt, 42% and 78%, in the 2004 and 2005 academic years, respectively. Also subsequent testing of these students during their first year on clinic showed marked increases in awareness and knowledge of the infection control protocols. Staff and student feedback on this course was also found to be highly supportive of the introduction of the infection control competency. CONCLUSION Incorporation of additional formal pre-clinical teaching and introduction of an infection competency potentially provides enduring knowledge and clinical application benefits.
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Affiliation(s)
- Mike R Milward
- School of Dentistry, University of Birmingham, St Chads Queensway, Birmingham, UK.
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O'Donnell MJ, Shore AC, Russell RJ, Coleman DC. 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 2007; 35:438-51. [PMID: 17303302 DOI: 10.1016/j.jdent.2007.01.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 12/22/2006] [Accepted: 01/03/2007] [Indexed: 11/18/2022] Open
Abstract
UNLABELLED Although many studies have highlighted the problem of biofilm growth in dental chair unit waterlines (DUWs), no long-term studies on the efficacy of DUW disinfection using a large number of dental chair units (DCUs) have been reported. OBJECTIVES To investigate the long-term (21 months) efficacy of the Planmeca Waterline Cleaning System (WCS) to maintain the quality of DUW output water below the American Dental Association (ADA) recommended standard of < or =200cfu/mL of aerobic heterotrophic bacteria using once weekly disinfection with the hydrogen peroxide-and silver ion-containing disinfectant Planosil. METHODS Microbiological quality of DUW output water was monitored by culture on R2A agar for 10 DCUs fitted with the WCS. The presence of biofilm in DUWs was examined by electron microscopy. RESULTS During the first 9 months a high prevalence (28/300 disinfection cycles; 9.3%) of intermittent DUW disinfection failure occurred in 8/10 DCUs due to operator omission to disinfect all DUWs (10/28 failed cycles), incorrect compressed air pressure failing to distribute the disinfectant properly (4/28 failed cycles) and physical blockage of disinfectant intake valves due to corrosion effects of Planosil (14/28 failed cycles). On rectification of these faults through engineering redesign and procedural changes, no further cases of intermittent DUW disinfection failure were observed. Independently of these factors, a rapid and consistent decline in efficacy of DUW disinfection occurred in 4/10 DCUs following the initial 9 months of once weekly disinfection. There was a highly significant difference (P<0.0001) in the prevalence of strongly catalase-positive Novosphingobium and Sphingomonas bacterial species (mean average prevalence of 37.1%) in DUW output water from these 4 DCUs compared to the other 6 DCUs and DCU supply water (prevalence <1%), which correlated with biofilm presence in the DUWs and indicated selective pressure for maintenance of these species by prolonged disinfectant usage. Planosil was reformulated to a more concentrated form (Planosil Forte) and when used once weekly was found to maintain bacterial density in output water below the ADA standard for all 10 DCUs. CONCLUSIONS A variety of factors can contribute to failure of DUW disinfection in the long-term, including human error, disinfectant corrosion of equipment and natural selection of naturally disinfectant-tolerant bacterial species.
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Affiliation(s)
- M J O'Donnell
- 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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Chate RAC. An audit improves the quality of water within the dental unit water lines of three separate facilities of a United Kingdom NHS Trust. Br Dent J 2007; 201:565-9. [PMID: 17099661 DOI: 10.1038/sj.bdj.4814206] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/09/2006] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To improve the quality of water emanating from dental unit waterlines (DUWLs). DESIGN A prospective clinical audit. SETTING Three geographically separate district dental facilities of a United Kingdom NHS Trust, involving two community clinics and one hospital orthodontic department, which were evaluated between 2002 and 2004. METHODS Samples of water discharged from the DUWLs were collected prior to the start and midway through a morning session. These were tested microbiologically at a United Kingdom Accreditation Service testing laboratory within six hours of sampling. INTERVENTIONS One of the clinics followed the contemporaneous BDA advice of flushing water through its DUWLs while the other two clinics used separate intermittent disinfection purging regimes instead. One of them used a two stage protocol of Ethylene Diamine Tetra-Acetic acid followed by hydrogen peroxide, while the other used Bio 2000 as a single agent, which was subsequently superseded by the continuous use of super-oxidised water (Sterilox). MAIN OUTCOME MEASURE To assess whether the samples either met the American Dental Association's guideline on the quality of DUWL water, or the more stringent European Union standards for potable (drinking) water. RESULTS The two units which used a disinfection regime both complied with the ADA guideline and the EU potable water standard. However, the unit which only flushed through its DUWLs without using a disinfectant failed to comply with either of them. After all three dental facilities subsequently standardised their DUWL disinfection regimes by using Bio 2000, the colony counts from all of the water samples thereafter remained well below the EU recommended level. The unit which progressed to using Sterilox as a continuous disinfectant achieved and maintained zero readings from its water samples. CONCLUSIONS Clinical audit can result in the improvement of the quality of water that is discharged through DUWLs, thereby minimising both the risk of cross infection to vulnerable patients, as well as to dental staff chronically exposed to contaminated aerosols.
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Affiliation(s)
- R A C Chate
- Orthodontic Department, Essex County Hospital, Lexden Road, Colchester, CO3 3NB.
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O'Donnell MJ, Shore AC, Coleman DC. A novel automated waterline cleaning system that facilitates effective and consistent control of microbial biofilm contamination of dental chair unit waterlines: A one-year study. J Dent 2006; 34:648-61. [PMID: 16442201 DOI: 10.1016/j.jdent.2005.12.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2005] [Revised: 12/02/2005] [Accepted: 12/09/2005] [Indexed: 10/25/2022] Open
Abstract
Microbial contamination of dental chair unit (DCU) output water caused by biofilm growth in dental unit waterlines (DUWs) is a universal problem and a potentially significant source of cross-infection. The microbial quality of output water from a Planmeca Compact i DCU equipped with the novel Water Management System (WMS), an integrated and automated DUW cleaning system, was investigated over a 12-month period with the hydrogen peroxide- and silver ion-containing disinfectants Planosil and Planosil Forte. Four weeks after connection to the potable-water quality mains supply the density of aerobic heterotrophic bacteria, rose from the low levels consistently found in the supply water throughout this study (mean average 77 cfu/mL) to 15,400 cfu/mL. Disinfection of DUWs once weekly with Planosil for 10 weeks resulted in a dramatic reduction in bacterial density immediately following disinfection (mean average 26 cfu/mL). Bacterial density rose steadily between disinfections and by 7 days post-disinfection, water quality failed (mean average 384 cfu/mL) the American Dental Association DCU water quality standard of <or=200 cfu/mL. The DCU was then disinfected once weekly for 40 weeks with Planosil Forte. The average bacterial density immediately post-disinfection was 20 cfu/mL and 7 days post-disinfection was 113 cfu/mL. Electron microscopy showed that improved output water quality following disinfection with both disinfectants was associated with marked elimination of DUW biofilm, but deterioration of water quality following disinfection was associated with its regrowth. The most common bacterial species cultured from the mains water and the DCU output water were Microcococcus luteus and Sphingomonas spp., respectively, the latter of which are known opportunistic pathogens. The findings of this study show that the Planmeca Compact i DCU equipped with the easy to use and automated WMS, that requires minimal effort on the part of the operator, consistently provides output water that passes the ADA quality standard of <or=200 cfu/mL for up to 7 days following once-weekly disinfection with Planosil Forte.
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Affiliation(s)
- M J O'Donnell
- Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental School & Hospital, University of Dublin, Trinity College, Lincoln Place, Dublin 2, Republic of Ireland
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Dutil S, Tessier S, Veillette M, Laflamme C, Mériaux A, Leduc A, Barbeau J, Duchaine C. Detection of Legionella spp. by fluorescent in situ hybridization in dental unit waterlines. J Appl Microbiol 2006; 100:955-63. [PMID: 16629996 DOI: 10.1111/j.1365-2672.2006.02845.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To confirm the presence of viable Legionella spp. in dental unit waterlines (DUWL) using fluorescent in situ hybridization (FISH) and compare this method with culture approach and also to validate the utility of an enrichment to increase FISH sensitivity. METHODS AND RESULTS Water samples from 40 dental units were analysed. Three different techniques for detecting Legionella spp. were compared: (i) culture approach, (ii) direct FISH and (iii) FISH with a previous R2A medium enrichment (R2A/FISH). The FISH detection was confirmed by PCR. The use of the direct FISH does not improve significantly the detection of legionellae when compared with the culture. On the contrary, when R2A/FISH was performed, sensitivity was, respectively, two- and threefold higher than that with the direct FISH and culture approach. Using R2A/FISH, 63% of water samples analysed showed a contamination by legionellae. CONCLUSIONS Legionellae detection by direct FISH and R2A/FISH in dental unit water is possible but is more rapid and more sensitive (R2A/FISH) than the culture approach. SIGNIFICANCE AND IMPACT OF THE STUDY R2A/FISH showed that several pathogens present in DUWL are viable but may not be culturable. Unlike PCR, R2A/FISH is designed to detect only metabolically active cells and therefore provides more pertinent information on infectious risk.
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Affiliation(s)
- S Dutil
- Centre de recherche, Hôpital Laval, Institut universitaire de cardiologie et de pneumologie de l'Université Laval, Ste-Foy, Québec, Canada
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Merijohn GK. Advances in Clinical Practice and Continuing Education “The Precautionary Context Clinical Practice Model: A Means to Implement the Evidence-Based Approach”. J Evid Based Dent Pract 2005; 5:115-24. [PMID: 17138349 DOI: 10.1016/j.jebdp.2005.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Yabune T, Imazato S, Ebisu S. Inhibitory effect of PVDF tubes on biofilm formation in dental unit waterlines. Dent Mater 2005; 21:780-6. [PMID: 16026668 DOI: 10.1016/j.dental.2005.01.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Revised: 11/26/2004] [Accepted: 01/11/2005] [Indexed: 11/21/2022]
Abstract
OBJECTIVES It has been reported that dental unit waterlines (DUWLs) are contaminated with bacterial biofilm, and that water discharged from a DUWL contains bacteria that might be opportunistic pathogens. This study aimed to investigate the ability of polyvinylidene fluoride (PVDF) tubing to inhibit bacterial contamination in DUWLs. METHODS Newly installed dental units were equipped with either a conventional polyurethane tube (unit A) or a PVDF tube (unit B), and the numbers of bacteria discharged from high- and low-speed handpiece lines were counted using R2A agar plates. Bacterial attachment on surfaces was observed with a scanning electron microscope (SEM) up to 185 days. Bacterial outflow during 1-day clinical service from a DUWL after 1-year usage was also examined. The surface free energy of each tube was determined based on the measurement of contact angles. RESULTS The number of bacteria discharged from unit B was lower than from unit A at 80 days and thereafter. SEM examination demonstrated that the unit A tube was covered by biofilm constituting rods and filaments after 94 days, while no biofilm was observed in the unit B tube even after 185 days. After 1-year of usage, the unit B released significantly less bacteria than the unit A at every sampling period of 1-day clinic work. Surface free energies, calculated from contact angles measured, of PVDF and polyurethane tubes were 37.7 and 77.8, respectively. SIGNIFICANCE The present results indicate that PVDF tubes, which have lower surface free energy than the conventional tubes, were effective in inhibiting biofilm formation and reducing bacterial outflow from DUWLs.
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Affiliation(s)
- Toshiaki Yabune
- Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
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Walker RJ, Burke FJT, Miller CH, Palenik CJ. An investigation of the microbial contamination of dental unit air and water lines. Int Dent J 2004; 54:438-44. [PMID: 15633500 DOI: 10.1111/j.1875-595x.2004.tb00301.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIM The objective of this study was to measure the microbial contamination released from dental unit air lines (DUAL) and dental unit water lines (DUWL). MATERIALS AND METHODS Emissions from DUAL and DUWL from five dental units supplied by a central water source (tap) and a centralised air supply were sampled three times over a five- week period. Air was forced through sterile water and then plated onto selective agar using apparatus designed to spread the sample solution evenly, and then incubated at room temperature for seven days. Colonies were then counted and the concentration of bacteria present was determined and expressed as colony forming units per millilitre (cfu/ml) per minute. The same procedure was used to evaluate five other dental units, which had attached independent water reservoir (bottle) systems (IWR). Only deionised water was added to the bottles and unit waterlines were cleaned weekly with alkaline peroxide based solution. Values were expressed as cfu/ml. RESULTS Air and water specimens obtained from dental units supplied with tap water had microbial counts significantly (t-test, p < 0.05) greater than IWR dental units. CONCLUSIONS Results indicate that IWR can reduce the numbers of micro-organisms released from DUWL. However, the effectiveness of such systems should be routinely monitored. Emissions from DUAL seems to reflect the levels of microbial contamination present in DUWL.
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Affiliation(s)
- Rachel J Walker
- University of Birmingham Dental School, St. Chad's Queensway, Birmingham B4 6NN, UK
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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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Kohn WG, Harte JA, Malvitz DM, Collins AS, Cleveland JL, Eklund KJ. COVER STORY Guidelines for infection control in dental health care settings—2003. J Am Dent Assoc 2004; 135:33-47. [PMID: 14959873 DOI: 10.14219/jada.archive.2004.0019] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The Centers for Disease Control and Prevention, or CDC, is the lead federal agency for disease prevention in the United States. It has been 10 years since CDC infection control guidelines for dental health care settings were last published. During those 10 years, new technologies and issues have emerged, and other CDC infection control guidelines for health care settings have been updated. RESULTS In light of these developments, CDC collaborated with experts in infection control to revise its infection control recommendations for dental health care settings. Existing guidelines and published research pertinent to dental infection control principles and practices were reviewed. This article provides background information, describes the process used to create these guidelines, and lists the new recommendations. CLINICAL IMPLICATIONS CDC believes that dental offices that follow these new recommendations will strengthen an already admirable record of safe dental practice. Patients and providers alike can be assured that oral health care can be delivered and received in a safe manner.
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Affiliation(s)
- William G Kohn
- Division of Oral Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention , Atlanta, GA 30341, USA.
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Pankhurst CL, Coulter W, Philpott-Howard JJ, Harrison T, Warburton F, Platt S, Surman S, Challacombe S. Prevalence of legionella waterline contamination and Legionella pneumophila antibodies in general dental practitioners in London and rural Northern Ireland. Br Dent J 2003; 195:591-4; discussion 581. [PMID: 14631437 DOI: 10.1038/sj.bdj.4810735] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2002] [Accepted: 03/07/2003] [Indexed: 11/09/2022]
Abstract
OBJECTIVES To determine the prevalence of legionellae in dental unit waterlines (DUWL) in general dental practices in London and rural Northern Ireland and whether the organism occurs at a high enough frequency and magnitude in DUWL to represent a threat to dentists' health. MATERIALS AND METHOD Two hundred and sixty six (166 London, 100 Northern Ireland) randomly selected dental surgeries were recruited. Standardised 250 ml water samples were taken from the DUWL and 1 litre samples from the surgery cold water tap to measure the prevalence of legionellae. The dentists provided a blood sample for legionella serology. RESULTS The prevalence of legionellae was very low (0.37%). Legionellae were not isolated from DUWL or surgery basin taps in Northern Ireland. Legionella spp were isolated from the DUWL and surgery basin of one practice in London and from the cold water supply of a further three practices. The prevalence of Legionella pneumophila antibodies was less than that seen in a comparable group of London blood donors. CONCLUSION The risk to dentists' health from potential exposure to legionellae in this cohort of dentists was very low and this was confirmed by the very low seroprevalence and antibody titres to legionella detected in the dentists.
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Affiliation(s)
- C L Pankhurst
- Division of Oral Medicine, Guy's, King's St Thomas' Dental Institute, Guy's Campus, London SE 9RT.
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Zanetti F, De Luca G, Tarlazzi P, Stampi S. Decontamination of dental unit water systems with hydrogen peroxide. Lett Appl Microbiol 2003; 37:201-6. [PMID: 12904220 DOI: 10.1046/j.1472-765x.2003.01378.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS Transmission of microbial pathogens to patients from water in dental units is a concern. To reduce this risk, the decontaminating efficiency of hydrogen peroxide was evaluated. METHODS AND RESULTS Three percent hydrogen peroxide diluted 1 : 4 in distilled water (contact time 15 min) was used daily to disinfect the waterlines of a pilot unit previously contaminated with Pseudomonas aeruginosa or Staphylococcus aureus. The behaviour of the test bacteria was seen to differ over time. Staph. aureus numbers slowly decreased until only low numbers were recovered, after which the levels remained stable. Ps. aeruginosa abatement was more rapid and the density of the bacteria reached a peak when the circuit was empty. CONCLUSIONS Staph. aureus and Ps. aeruginosa treated with hydrogen peroxide fell from 6 to 4 log. SIGNIFICANCE AND IMPACT OF THE STUDY Treatment of dental unit waterlines with hydrogen peroxide was seen to be able to keep the number of the bacteria under control, as long as the treatment was repeated daily.
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Affiliation(s)
- F Zanetti
- Department of Medicine and Public Health, Division of Hygiene, University of Bologna, Bologna, Italy.
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Abstract
Immunocompromised individuals present a challenge to oral health care providers. As the spectrum of patients with dysfunctional immune responses continues to broaden, practitioners should be able to identify these patients, understand the potential for complications, and manage their dental care safely and effectively. This article reviews various immune deficiencies, addresses complications that may result from an individual's immune status, and discusses dental considerations for these patients.
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Affiliation(s)
- Ernesta Parisi
- Division of Oral Medicine, University of Medicine and Dentistry of New Jersey, 110 Bergen Street, D-860, Newark, NJ 07103, USA.
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