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The devil is in the validation and design; managing the risk from opportunistic pathogens in the dental unit. J Hosp Infect 2021; 114:61-62. [PMID: 34087260 DOI: 10.1016/j.jhin.2021.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 05/25/2021] [Indexed: 11/21/2022]
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Zemouri C, Laheij AMGA, Volgenant CMC, Brandt BW, Crielaard W, Buijs MJ, Zaura E, de Soet JJ. Chlorine-based DUWL disinfectant leads to a different microbial composition of water derived biofilms compared to H 2O 2-based chemical disinfectants in vitro. PeerJ 2020; 8:e9503. [PMID: 32742792 PMCID: PMC7368430 DOI: 10.7717/peerj.9503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/17/2020] [Indexed: 02/06/2023] Open
Abstract
Background Biofilm formation in dental unit waterlines (DUWL) may lead to health risks for dental staff and patients. Therefore, dental unit waterlines need to be disinfected, for instance by using chemical disinfectants. However, the application of chemical disinfectants may lead to the selection of specific microorganisms. Therefore, the aim of our study was to assess the microbial composition of water-derived biofilms, after a continuous exposure to maintenance doses of commercially available chemical disinfectants, in vitro. Methods The AAA-model was used to grow water derived biofilms. The biofilms were subjected to the maintenance dose of each disinfectant. To determine the microbial composition, the V4 hypervariable region of the 16S rRNA gene was sequenced. The sequences were clustered in operational taxonomic units (OTUs). Results The bacterial composition of biofilms in all treatment groups differed significantly (PERMANOVA F = 4.441, p = 0.001). Pairwise comparisons revealed Anoxyl treated biofilms were significantly different from all groups (p = 0.0001). In the Anoxyl-treated biofilms, the relative abundance of Comamonadaceae and Sphingopyxis was high compared to the Dentosept, Green and Clean and Oxygenal groups. Conclusion We concluded that exposure to low doses of the chlorine-based chemical disinfectant Anoxyl led to a substantially different composition of water derived biofilms compared to biofilms exposed to H2O2-based chemical disinfectants.
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Affiliation(s)
- Charifa Zemouri
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
| | - Alexa M G A Laheij
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
| | - Catherine M C Volgenant
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
| | - Bernd W Brandt
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
| | - Wim Crielaard
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
| | - Mark J Buijs
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
| | - Egija Zaura
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
| | - Johannes J de Soet
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
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Zemouri C, Awad SF, Volgenant CMC, Crielaard W, Laheij AMGA, de Soet JJ. Modeling of the Transmission of Coronaviruses, Measles Virus, Influenza Virus, Mycobacterium tuberculosis, and Legionella pneumophila in Dental Clinics. J Dent Res 2020; 99:1192-1198. [PMID: 32614681 PMCID: PMC7444020 DOI: 10.1177/0022034520940288] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Dental health care workers are in close contact to their patients and are therefore at higher risk for contracting airborne infectious diseases. The transmission rates of airborne pathogens from patient to dental health care workers are unknown. With the outbreaks of infectious diseases, such as seasonal influenza, occasional outbreaks of measles and tuberculosis, and the current pandemic of the coronavirus disease COVID-19, it is important to estimate the risks for dental health care workers. Therefore, the transmission probability of these airborne infectious diseases was estimated via mathematical modeling. The transmission probability was modeled for Mycobacterium tuberculosis, Legionella pneumophila, measles virus, influenza virus, and coronaviruses per a modified version of the Wells-Riley equation. This equation incorporated the indoor air quality by using carbon dioxide as a proxy and added the respiratory protection rate from medical face masks and N95 respirators. Scenario-specific analyses, uncertainty analyses, and sensitivity analyses were run to produce probability rates. A high transmission probability was characterized by high patient infectiousness, the absence of respiratory protection, and poor indoor air quality. The highest transmission probabilities were estimated for measles virus (100%), coronaviruses (99.4%), influenza virus (89.4%), and M. tuberculosis (84.0%). The low-risk scenario leads to transmission probabilities of 4.5% for measles virus and 0% for the other pathogens. From the sensitivity analysis, it shows that the transmission probability is strongly driven by indoor air quality, followed by patient infectiousness, and the least by respiratory protection from medical face mask use. Airborne infection transmission of pathogens such as measles virus and coronaviruses is likely to occur in the dental practice. The risk magnitude, however, is highly dependent on specific conditions in each dental clinic. Improved indoor air quality by ventilation, which reduces carbon dioxide, is the most important factor that will either strongly increase or decrease the probability of the transmission of a pathogen.
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Affiliation(s)
- C Zemouri
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - S F Awad
- Infectious Disease Epidemiology Group, Weill Cornell Medicine-Qatar, Cornell University, Qatar Foundation, Doha, Qatar
| | - C M C Volgenant
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - W Crielaard
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - A M G A Laheij
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - J J de Soet
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
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Zemouri C, de Soet JJ, Volgenant CMC, Crielaard W, Laheij AMGA. Heterogeneity in the efficacy of dental chemical disinfectants on water-derived biofilms in vitro. BIOFOULING 2020; 36:587-596. [PMID: 32580580 DOI: 10.1080/08927014.2020.1782894] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/29/2020] [Accepted: 06/08/2020] [Indexed: 06/11/2023]
Abstract
Conditions in dental unit waterlines are favourable for biofilm growth and contamination of dental unit water. The aim of this study was to assess the effect of several chemical disinfectants on bacteria in a biofilm model. Water-derived biofilms were grown in a static biofilm model (Amsterdam Active Attachment model), using two growth media. Biofilms were challenged with Alpron/Bilpron, Anoxyl, Citrisil, Dentosept, Green & Clean, ICX and Oxygenal in shock dose and maintenance doses. The concentration and the composition of the chemical disinfectants influenced the number of culturable bacteria in the biofilms. The application of a single shock dose followed by a low dose of the same chemical disinfectants resulted in the greatest suppression of viable bacteria in the biofilms. Exposure to Citrisil and ICX consistently resulted in failure to control the biofilms, while Alpron/Bilpron had a substantial and relevant effect on the number of bacteria in the biofilms.
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Affiliation(s)
- C Zemouri
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
| | - J J de Soet
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
| | - C M C Volgenant
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
| | - W Crielaard
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
| | - A M G A Laheij
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
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Key determinants of health and wellbeing of dentists within the UK: a rapid review of over two decades of research. Br Dent J 2019; 227:127-136. [PMID: 31350498 DOI: 10.1038/s41415-019-0485-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Aim To review the key determinants of health and wellbeing among dentists working in the UK.Methods Rapid review of the literature (1996-2018) across seven health and social science databases through OVID and the Cochrane Library, professional and health system sources. Records were screened according to agreed inclusion and exclusion criteria by title, abstract and full text. Data extraction and qualitative synthesis of the included studies were performed. Quality assessments for risk of bias were made using a mixed methods appraisal tool.Results Thirty-eight studies met the criteria for inclusion. Fourteen were assessed as high, 22 as medium and two of low quality, most involving cross-sectional research in the form of questionnaire surveys. Whereas overall, the health and wellbeing of dentists within the UK is reported as 'good', recently published evidence suggests a less positive view may be emerging. The health and wellbeing of dentists is associated with a wide range of factors: personal, professional career, relationships, job specification, workplace and system. Emerging evidence suggests additional concerns about the regulation of dentistry. Workplace characteristics were most often explored among researchers and reported as being a key issue.Conclusion Evidence highlights multiple determinants of health and wellbeing, most notably related to workplace characteristics; however, while there is a relative lack of well-founded prospective research investigating the nature and direction of the relationships and comparison across UK health systems, there is increasing evidence of health and wellbeing concerns that require further investigation.
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Pankhurst CL, Scully C, Samaranayake L. Dental Unit Water Lines and their Disinfection and Management: A Review. ACTA ACUST UNITED AC 2017; 44:284-5, 289-92. [PMID: 29172350 DOI: 10.12968/denu.2017.44.4.284] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The perceived threat to public health from dental unit water line (DUWL) contamination comes from opportunistic and respiratory pathogens such as Legionella spp, Nontuberculous Mycobacteria (NTM) and pseudomonads. These organisms can grow and multiply in the DUWL biofilm to reach infective concentrations, with the potential for inhalation leading to respiratory infections or direct contamination of surgical wounds. In this paper we discuss current legislation and practical methods for delivering water within the DUWL that meets the standards for safety. Clinical relevance: Understanding the clinical relevance and methods for decontaminating DUWL is essential to create a safe working environment in dentistry.
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Gitipour A, Al-Abed SR, Thiel SW, Scheckel KG, Tolaymat T. Nanosilver as a disinfectant in dental unit waterlines: Assessment of the physicochemical transformations of the AgNPs. CHEMOSPHERE 2017; 173:245-252. [PMID: 28110014 PMCID: PMC6143180 DOI: 10.1016/j.chemosphere.2017.01.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 01/06/2017] [Accepted: 01/08/2017] [Indexed: 05/29/2023]
Abstract
Dental unit water lines (DUWL) are susceptible to biofilm development and bacterial growth leading to water contamination, causing health and ecological effects. This study monitors the interactions between a commonly used nanosilver disinfectant (ASAP-AGX-32, an antimicrobial cleaner for dental units, 0.0032% Ag) and biofilm development in DUWL. To simulate the disinfection scenario, an in-house DUWL model was assembled and biofilm accumulation was allowed. Subsequent to biofilm development, the disinfection process was performed according to the manufacturer's instructions. The pristine nanosilver particles in the cleaner measured between 3 and 5 nm in diameter and were surrounded by a stabilizing polymer. However, the polymeric stabilizing agent diminished over the disinfection process, initiating partial AgNPs aggregation. Furthermore, surface speciation of the pristine AgNPs were identified as primarily AgO, and after the disinfection process, transformations to AgCl were observed. The physicochemical characteristics of AgNPs are known to govern their fate, transport and environmental implications. Hence, knowledge of the AgNPs characteristics after the disinfection process (usage scenario) is of significance. This study demonstrates the adsorption of AgNPs onto biofilm surfaces and, therefore, will assist in illustration of the toxicity mechanisms of AgNPs to bacteria and biofilms. This work can be an initial step in better understanding how AgNPs transform depending on the conditions they are exposed to during their lifetime. Until this date, most research has been focused on assessing the impacts of pristine (lab synthesized) nanomaterials on various systems. However, it is our belief that nanoparticles may undergo transformations during usage, which must be taken into consideration. Furthermore, this experiment is unique as it was conducted with a commonly used, commercially available nanosilver suspension leading to more realistic and applicable findings.
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Affiliation(s)
- Alireza Gitipour
- Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Souhail R Al-Abed
- US EPA, Office of Research and Development, National Risk Management Laboratory, Cincinnati, OH, USA.
| | - Stephen W Thiel
- Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Kirk G Scheckel
- US EPA, Office of Research and Development, National Risk Management Laboratory, Cincinnati, OH, USA
| | - Thabet Tolaymat
- US EPA, Office of Research and Development, National Risk Management Laboratory, Cincinnati, OH, USA
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Lal S, Singhrao SK, Bricknell M, Pearce M, Morton LHG, Ahmed W, Crean SJ. Monitoring Dental-Unit-Water-Line Output Water by Current In-office Test Kits. Curr Microbiol 2014; 69:135-42. [DOI: 10.1007/s00284-014-0569-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 02/04/2014] [Indexed: 10/25/2022]
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Effect of different disinfection protocols on microbial and biofilm contamination of dental unit waterlines in community dental practices. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:2064-76. [PMID: 24552789 PMCID: PMC3945585 DOI: 10.3390/ijerph110202064] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 01/20/2014] [Accepted: 01/28/2014] [Indexed: 11/17/2022]
Abstract
Output water from dental unit waterlines (DUWLs) may be a potential source of infection for both dental healthcare staff and patients. This study compared the efficacy of different disinfection methods with regard to the water quality and the presence of biofilm in DUWLs. Five dental units operating in a public dental health care setting were selected. The control dental unit had no disinfection system; two were disinfected intermittently with peracetic acid/hydrogen peroxide 0.26% and two underwent continuous disinfection with hydrogen peroxide/silver ions (0.02%) and stabilized chlorine dioxide (0.22%), respectively. After three months of applying the disinfection protocols, continuous disinfection systems were more effective than intermittent systems in reducing the microbial contamination of the water, allowing compliance with the CDC guidelines and the European Council regulatory thresholds for drinking water. P. aeruginosa, Legionella spp, sulphite-reducing Clostridium spores, S. aureus and β-haemolytic streptococci were also absent from units treated with continuous disinfection. The biofilm covering the DUWLs was more extensive, thicker and more friable in the intermittent disinfection dental units than in those with continuous disinfection. Overall, the findings showed that the products used for continuous disinfection of dental unit waterlines showed statistically better results than the intermittent treatment products under the study conditions.
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10
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Singh T, Bello B, Jeebhay MF. Risk factors associated with asthma phenotypes in dental healthcare workers. Am J Ind Med 2013; 56:90-9. [PMID: 22473580 PMCID: PMC4289708 DOI: 10.1002/ajim.22041] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2012] [Indexed: 11/06/2022]
Abstract
BACKGROUND Exposure in the dental environment can increase the risk of respiratory disease in dental healthcare workers (HCWs). This study investigated the prevalence of asthma phenotypes in dental HCWs and associated risk factors. METHODS A cross-sectional study of 454 dental HCWs in five dental institutions in South Africa was conducted. A self-administered questionnaire elicited the health and employment history of subjects. Sera was analyzed for atopic status and latex sensitization. Pre- and post-bronchodilator spirometry was performed. RESULTS The prevalence of atopic asthma was 6.9%, non-atopic asthma 5.9% and work-exacerbated asthma (WEA) 4.0%. Atopy and work-related ocular-nasal symptoms were strong predictors of WEA (OR: 3.4; 95% CI: 1.07-10.8; OR: 6.7, 95% CI: 2.4-19.1), respectively. Regular use of personal protective equipment (PPE) was associated with a protective affect (OR: 0.23, 95% CI: 0.1-0.7) among non-atopic asthmatics, while glove use and respiratory protection was protective among atopic asthmatics (OR: 0.39, 95% CI: 0.17-0.89). CONCLUSION Identification of risk factors associated with specific asthma phenotypes in dental HCWs can be used to focus preventive strategies for asthmatics.
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Affiliation(s)
- Tanusha Singh
- National Institute for Occupational Health, National Health Laboratory Services, Johannesburg, South Africa.
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11
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Murthy BS, Manjula K, George JV, Shruthi N. Evaluation of effect of three different dental unit waterline antimicrobials on the shear bond strength to dentin - An ex vivo study. J Conserv Dent 2012; 15:289-92. [PMID: 22876021 PMCID: PMC3410344 DOI: 10.4103/0972-0707.97963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 11/14/2011] [Accepted: 01/13/2012] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND In restorative treatment dental unit water is used while irrigating the cavity and also in the use of composite restorations to flush away the etchant to place bonding agent. These antimicrobials may influence the bond strength of the dentine bonding agent to the dentine. AIM AND OBJECTIVE To evaluate the effect of three different dental units waterline antimicrobials on the shear bond strength of dentin. MATERIALS AND METHODS Sixty freshly extracted human teeth were taken and the occlusal surfaces were sectioned to obtain a flat dentin surface. Then the teeth were randomized into 4 groups depending on the antimicrobial used: Group 1(Distilled water), Group 2 (Alpron), Group 3 (CitriSil), and Group 4 (Chlorhexidine). The dentine surface was prepared for bonding and composite resin was placed in two increments of 2 mm each. The specimens were stored in distilled water, thermo cycled after 7 days shear test was performed by using the universal testing machine. RESULT No significant difference between Group 1 and Group 2 with regard to shear bond strength. There was a significant difference in the SBS of Group 1 and Group 3 and Group 4. The SBS of group 2 was higher than Group 3 and Group 4 and the difference was statistically significant. CONCLUSION Citrisil and Chlorhexidine groups showed affected bond strength whereas Alpron did not vary with bond strength.
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Affiliation(s)
- Bv Sreenivasa Murthy
- Department of Conservative Dentistry and Endodontics, M.S. Ramaiah Dental College and Hospital, M.S. Ramaiah Nagar, MSRIT Post, Bangalore, Karnataka, India
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Corrao CRN, Mazzotta A, La Torre G, De Giusti M. Biological risk and occupational health. INDUSTRIAL HEALTH 2012; 50:326-337. [PMID: 22785422 DOI: 10.2486/indhealth.ms1324] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Many work activities include hazards to workers, and among these biological risk is particularly important, mostly because of different types of exposure, contact with highly dangerous agents, lack of limit values able to compare all exposures, presence of workers with defective immune systems and therefore more susceptible to the risk. Bioaerosols and dust are considered important vehicles of microganisms at workplaces and interaction with other occupational agents is assumed. Moreover, biological risk can be significant in countries with increasing economic development or particular habits and some biological agents are also classified as carcinogenic to human. Specific emerging biological risks have been recently pointed out by Risk Observatory of the European Agency for Safety and Health at work, and we must consider the worker's attitude and behaviour, influenced by his own perception of risk more than his real knowledge, that could over-underestimate the risk itself. Therefore, biological risk at work requires a complex approach in relation to risk assessment and risk management, made more difficult due to the wide variety of biological agents, working environments and working techniques that can determine the exposures.
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Laheij AMGA, Kistler JO, Belibasakis GN, Välimaa H, de Soet JJ. Healthcare-associated viral and bacterial infections in dentistry. J Oral Microbiol 2012; 4:JOM-4-17659. [PMID: 22701774 PMCID: PMC3375115 DOI: 10.3402/jom.v4i0.17659] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 05/11/2012] [Accepted: 05/11/2012] [Indexed: 12/19/2022] Open
Abstract
Infection prevention in dentistry is an important topic that has gained more interest in recent years and guidelines for the prevention of cross-transmission are common practice in many countries. However, little is known about the real risks of cross-transmission, specifically in the dental healthcare setting. This paper evaluated the literature to determine the risk of cross-transmission and infection of viruses and bacteria that are of particular relevance in the dental practice environment. Facts from the literature on HSV, VZV, HIV, Hepatitis B, C and D viruses, Mycobacterium spp., Pseudomonas spp., Legionella spp. and multi-resistant bacteria are presented. There is evidence that Hepatitis B virus is a real threat for cross-infection in dentistry. Data for the transmission of, and infection with, other viruses or bacteria in dental practice are scarce. However, a number of cases are probably not acknowledged by patients, healthcare workers and authorities. Furthermore, cross-transmission in dentistry is under-reported in the literature. For the above reasons, the real risks of cross-transmission are likely to be higher. There is therefore a need for prospective longitudinal research in this area, to determine the real risks of cross-infection in dentistry. This will assist the adoption of effective hygiene procedures in dental practice.
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Affiliation(s)
- A M G A Laheij
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands
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Su J, Deng XH, Sun Z. A 10-year survey of compliance with recommended procedures for infection control by dentists in Beijing. Int Dent J 2012; 62:148-53. [PMID: 22568740 DOI: 10.1111/j.1875-595x.2011.00107.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVES This study aimed to survey changes in practices of infection control (IC) procedures by dentists in Beijing between 2000 and 2010. METHODS Data were based on the feedback of 592 and 769 dentists surveyed in 2000 and 2010, respectively. Statistical analysis was conducted using Pearson's chi-squared test. RESULTS Response rates of 95% (2000) and 94% (2010) were achieved. The percentages of dentists who had received training in IC were 62.96% (2000) and 76.21% (2010). Improvements in practices in 2010 over those in 2000 included increases in: the percentage of vaccination for hepatitis B virus from 32.66% to 68.14%; the routine use of gloves from 73.31% to 99.73%; the use of face shields or eyewear as protection against splatter during dental treatment from 13.94% to 95.45%; the use of protective gowns from 14.51% to 54.23%; the use of high-volume suction from 11.19% to 74.34%; routine changing of gloves between patients from 63.25% to 99.22%; pressured steam sterilisation of dental handpieces between patients from 41.24% to 96.10%, and the flushing of dental unit waterlines after each treatment from 42.01% to 73.49%. CONCLUSIONS Although compliance with recommended IC practices by dentists in Beijing improved between 2000 and 2010, not all dentists are properly familiar with IC procedures. Education in IC in dental schools and in continuing training in hospitals, and mandatory regulations are needed to improve IC practices in dental health care settings.
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Affiliation(s)
- Jing Su
- Department of Nosocomial Infection Control, Capital Medical University School of Stomatology, Beijing, China
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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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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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Smith AJ, Lockhart DEA, McDonald E, Creanor S, Hurrell D, Bagg J. Design of dental surgeries in relation to instrument decontamination. J Hosp Infect 2010; 76:340-4. [PMID: 20888669 DOI: 10.1016/j.jhin.2010.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2009] [Accepted: 06/02/2010] [Indexed: 10/19/2022]
Abstract
Recent guidelines advise that the decontamination of dental instruments should be undertaken outwith the treatment area. The aim of this study was to determine the physical area of rooms in dental surgeries that decontaminate instruments within and outwith the treatment area respectively, and other factors relating to practice layout and ventilation. Data were collected by interview and observation of dental healthcare workers in dental practice in Scotland, UK. Room layouts were recorded and measured at floor, benchtop and above benchtop heights. Thirteen surgeries with instrument decontamination processes occurring in the treatment area and seven surgeries with instrument decontamination outwith the treatment area were selected at random for detailed analysis of room dimensions. Of the 179 dental surgeries surveyed, 55% were located in converted residential premises and most practitioners (91%) did not share premises with other healthcare providers. The median number of rooms in the practices was 8 (range: 2-21) and the median number of surgeries present was 3 (range: 1-6). Regardless of whether instrument decontamination facilities were housed within the treatment area or not, the average treatment area room size for both was 15.8m(2) (range: 7.3-23.9) (P=0.862), with 20% of the room area available as work surfaces. The median size of the seven instrument decontamination rooms (local decontamination units) was 7.6m(2) (range: 2.9-16.0), with, on average, 63% of the room used for work surfaces. This survey suggests that the historical location of dental surgeries in converted residential properties places many restrictions on appropriate design for healthcare premises.
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Affiliation(s)
- A J Smith
- Infection & Immunity Research Group, Glasgow Dental Hospital and School, Faculty of Medicine, University of Glasgow, Glasgow, UK.
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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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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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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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23
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Percival RS, Devine DA, Nattress B, Kite P, Marsh PD. Control of microbial contamination in dental unit water systems using tetra-sodium EDTA. J Appl Microbiol 2009; 107:1081-8. [PMID: 19486406 DOI: 10.1111/j.1365-2672.2009.04299.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM To examine the efficacy of tetra-sodium EDTA in controlling microbial contamination of dental unit water systems (DUWS). METHODS AND RESULTS Ten dental units were treated once a week with either 4% or 8% tetra-sodium EDTA for four or two consecutive weeks, respectively. Before treatment, 43% and 60% of the water samples from the air/water triple syringe and high-speed hand-pieces, respectively, exceeded the American Dental Association (ADA) guidelines of 200 CFU ml(-1) water during a 6-week baseline period. After each weekend treatment, the levels of microbial contamination in all DUWS fell significantly (P < 0.001) to below the ADA guideline. By the end of the week, microbial counts in the outflowing water had returned to baseline levels indicating a transient effect of single doses of tetra-sodium EDTA, and the need for multiple applications. The biofilms were virtually eliminated after a single weekend treatment. CONCLUSIONS Tetra-sodium EDTA is effective in controlling microbial contamination in DUWS. SIGNIFICANCE AND IMPACT OF THE STUDY Inexpensive, effective and safe products for reducing the microbial load of water from DUWS are needed to meet ADA and other national guidelines. Tetra-sodium EDTA can significantly reduce microbial biofilms and bacterial counts in outflowing water, and is compatible for use in DUWS.
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Affiliation(s)
- R S Percival
- Department of Oral Biology, Leeds Dental Institute, Clarendon Way, Leeds LS2 9LU, UK.
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24
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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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25
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Huntington MK, Williams JF, Mackenzie CD. Endotoxin contamination in the dental surgery. J Med Microbiol 2007; 56:1230-1234. [PMID: 17761488 DOI: 10.1099/jmm.0.47231-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dental waterlines contain large numbers of Gram-negative bacteria. Endotoxin, a component of such organisms, has significant health implications. Paired samples of dental unit water and the aerosols generated during dental procedures were collected, and assayed for bacteria and endotoxin levels, using heterotrophic plate counts and the Limulus amoebocyte lysate test. Consistent with published studies, the extent of bacterial contamination in the dental waters sampled for this investigation surpassed the levels associated with potable water, with counts in excess of 2.0x10(6) c.f.u. ml(-1) in some samples. Correspondingly high concentrations of endotoxin [up to 15 000 endotoxin units (EU) ml(-1)] were present in the water. A statistically significant Spearman correlation coefficient of rho=0.94 between endotoxin (EU ml(-1)) and bacterial load (c.f.u. ml(-1)) was demonstrated. All of the aerosol samples contained detectable endotoxin. Further studies of the consequences of dental endotoxin exposure, and evaluation of means to prevent exposure, are warranted.
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Affiliation(s)
- M K Huntington
- Department of Microbiology, B514 West Fee Hall, Michigan State University, East Lansing, MI 48824, USA
| | - J F Williams
- Department of Microbiology, B514 West Fee Hall, Michigan State University, East Lansing, MI 48824, USA
| | - C D Mackenzie
- Department of Pathology, B514 West Fee Hall, Michigan State University, East Lansing, MI 48824, 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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Walker JT, Marsh PD. Microbial biofilm formation in DUWS and their control using disinfectants. J Dent 2007; 35:721-30. [PMID: 17714847 DOI: 10.1016/j.jdent.2007.07.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 07/03/2007] [Accepted: 07/03/2007] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVES Due to the presence of extended narrow bore tubing and long periods of stagnation, dental unit water systems (DUWs) can be prone to relatively high levels of microbial contamination, including the formation of biofilm and the presence of opportunistic pathogens, irrespective of the source and quality of the inflowing water. Whilst the European Union (EU) has yet to set a definitive microbiological guideline, the American Dental Association (ADA) has set a maximum of <200 colony forming units (cfu)/ml for DUWs water in the USA. The objective of this review is to discuss why microbial contamination and biofilms are so prevalent in DUWs, as well as the role of disinfectants and their potential for achieving microbial water quality levels recommended by the ADA. STUDY SELECTION The review outlines the principal factors responsible for biofilm formation in DUWs and a number of mechanisms used for microbial control. SOURCES The source material contained in this review is taken from the peer-reviewed literature. DATA A variety of disinfectants are available for use, but controlled laboratory and clinical studies have shown that they can vary markedly in their efficacy and suitability for use. Some products have been shown to successfully remove biofilm and consistently reduce the microbial load of out-flowing water to <200 cfu/ml. CONCLUSIONS The effective delivery of approved disinfectants can control the level of microorganisms in DUWs at acceptable levels.
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Affiliation(s)
- J T Walker
- Centre for Emergency Preparedness and Response, HPA Porton Down, Salisbury, United Kingdom
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28
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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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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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Schel AJ, Marsh PD, Bradshaw DJ, Finney M, Fulford MR, Frandsen E, Østergaard E, ten Cate JM, Moorer WR, Mavridou A, Kamma JJ, Mandilara G, Stösser L, Kneist S, Araujo R, Contreras N, Goroncy-Bermes P, O'Mullane D, Burke F, O'Reilly P, Hourigan G, O'Sullivan M, Holman R, Walker JT. Comparison of the efficacies of disinfectants to control microbial contamination in dental unit water systems in general dental practices across the European Union. Appl Environ Microbiol 2006; 72:1380-7. [PMID: 16461690 PMCID: PMC1392914 DOI: 10.1128/aem.72.2.1380-1387.2006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Accepted: 11/28/2005] [Indexed: 11/20/2022] Open
Abstract
Water delivered by dental unit water systems (DUWS) in general dental practices can harbor high numbers of bacteria, including opportunistic pathogens. Biofilms on tubing within DUWS provide a reservoir for microorganisms and should be controlled. This study compared disinfection products for their ability to meet the American Dental Association's guideline of <200 CFU x ml(-1) for DUWS water. Alpron, BioBlue, Dentosept, Oxygenal, Sanosil, Sterilex Ultra, and Ster4Spray were tested in DUWS (n = 134) in Denmark, Germany, Greece, Ireland, The Netherlands, Spain, and the United Kingdom. Weekly water samples were tested for total viable counts (TVCs) on yeast extract agar, and, where possible, the effects of products on established biofilm (TVCs) were measured. A 4- to 5-week baseline measurement period was followed by 6 to 8 weeks of disinfection (intermittent or continuous product application). DUWS water TVCs before disinfection ranged from 0 to 5.41 log CFU x ml(-1). Disinfectants achieved reductions in the median water TVC ranging from 0.69 (Ster4Spray) to 3.11 (Dentosept) log CFU x ml(-1), although occasional high values (up to 4.88 log CFU x ml(-1)) occurred with all products. Before treatment, 64% of all baseline samples exceeded American Dental Association guidelines, compared to only 17% following commencement of treatment; where tested, biofilm TVCs were reduced to below detectable levels. The antimicrobial efficacies of products varied (e.g., 91% of water samples from DUWS treated with Dentosept or Oxygenal met American Dental Association guidelines, compared to 60% of those treated with Ster4Spray). Overall, the continuously applied products performed better than those applied intermittently. The most effective products were Dentosept and Oxygenal, although Dentosept gave the most consistent and sustained antimicrobial effect over time.
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Affiliation(s)
- A J Schel
- Department of Medical Microbiology, Academic Medical Centre, Amsterdam, The Netherlands
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