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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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Sasaki JI, Imazato S. Autoclave sterilization of dental handpieces: A literature review. J Prosthodont Res 2019; 64:239-242. [PMID: 31416709 DOI: 10.1016/j.jpor.2019.07.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/20/2019] [Accepted: 07/26/2019] [Indexed: 11/17/2022]
Abstract
PURPOSE The present review aimed to investigate autoclave sterilization of dental handpieces based on available studies. STUDY SELECTION The sterilizing efficiency of dental handpieces with autoclave is mainly affected by the types of apparatus (N, B, and S), the packaging with sterilizing pouch, cleaning, and lubrication. These subjects were reviewed based on the in vitro experimental studies. RESULTS Dental handpieces can be sterilized, including inactivation of heat-resistant bacterial spores, with type B or type S sterilizers, regardless of the use of a sterilization pouch. In contrast, although type N autoclaves are capable of sterilization of general bacteria such as Streptococcus salivarius even in a sterilization pouch if instruments are washed beforehand, complete sterilization of the wrapped handpiece is not always achieved. Therefore, to achieve sterilization efficiency with type N autoclaves, processing without any packaging is recommended. As regards cleaning of handpiece, although contamination decreases with irrigation and wiping of handpieces, all reports concluded that these treatments alone do not achieve complete decontamination of reusable handpieces. CONCLUSION Although type B and type S autoclaves allow us to sterilize the dental handpieces, it is important to realize that complete sterilization of the handpiece is not always achieved by type N autoclave. Understanding autoclave processing of handpieces is essential for dental practice to deliver the safe dental care.
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Affiliation(s)
- Jun-Ichi Sasaki
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry, Japan
| | - Satoshi Imazato
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry, Japan.
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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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Pouralibaba F, Balaei E, Kashefimehr A. Evaluation of gram negative bacterial contamination in dental unit water supplies in a university clinic in tabriz, iran. J Dent Res Dent Clin Dent Prospects 2011; 5:94-7. [PMID: 22991613 PMCID: PMC3442454 DOI: 10.5681/joddd.2011.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 05/11/2011] [Indexed: 11/17/2022] Open
Abstract
Background and aims
Bacterial contamination of dental unit water supplies (DUWS) has attracted a lot of attention in recent years due to the emergence of serious infectionsin susceptible dental patients. The aim of the present study was to evaluate the presence of gram-negative bacterial contamination in DUWS at Tabriz University of Medical Sciences Faculty of Dentistry.
Materials and methods
This descriptive study was carried out on 51 active dental units in different departments. Con-tamination was determined by taking samples from the unit's water supply before dental procedures and the use of specific culture media. The cultures were evaluated after 48 hours.
Results
Gram-negative bacterial contamination was identical in all the departments. In the departments on the ground floor, namely Departments of Periodontics and Oral and Maxillofacial Surgery, Pseudomonas contamination was observed in 71% of units; in the departments on the first floor, namely Departments of Prosthodontics, Orthodontics and Pedodon-tics, 46.8% of the units had Pseudomonas contamination; and in the departments on the second floor, namely Departments of Operative Dentistry and Endodontics, 37.7% of the units demonstrated Pseudomonas contamination.
Conclusion Gram-negative bacterial contamination was evident in the evaluated DUWS. The contamination type was identical but the number of contaminated units decreased with the increase in the height of the floors.
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Affiliation(s)
- Firoz Pouralibaba
- Assistant Professor, Department of Oral Medicine, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
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Büchter A, Kruse-Loesler B. Development of a validated process for manual preparation of dental transmission instruments. Clin Oral Investig 2010; 15:605-8. [PMID: 20490580 DOI: 10.1007/s00784-010-0425-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Accepted: 04/28/2010] [Indexed: 11/24/2022]
Abstract
The goal of the study was to develop a validated manual preparation process that conforms to the requirements of validation guidelines. Twelve dental transmission devices from various manufacturers (turbines, handpieces, and contra-angle handpieces) were artificially contaminated with bovine hemoglobin for the test. Ten microliters (corresponding to 800 μg) of bovine hemoglobin solution (concentration 80 mg/ml) was pipetted into the spray water and spray air channels. The manual preparation was conducted by blowing air through the spray channels of the transmission instruments through an attachment to a treatment unit (model 1060T, KaVo, Biberach, Germany) for 5 s. The spray channels were cleaned with WL-Clean (Alpro, Georgen, Germany) as directed by the manufacturer. The spray channels were disinfected with WL-Cid (Alpro) and the spray channels were blow-dried with WL-Dry (Alpro) at the end of the exposure time as directed by the manufacturer. To determine the protein content (protein residue analysis) in the channels of the transmission instruments, 2 ml of an alkaline SDS solution (1%; pH 11) was flushed through the channels. For the quantitative protein residue analysis, the Biuret method was used as described in DIN EN 15883-1:2006. After the application of this method, all results of the protein residue analysis were within the acceptance criteria of the validation guideline. The newly developed manual preparation process is therefore confirmed as suitable from a hygienic viewpoint for preparation of transmission instruments in the dental practice.
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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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Ma’ayeh SY, Al-Hiyasat AS, Hindiyeh MY, Khader YS. Legionella pneumophila contamination of a dental unit water line system in a dental teaching centre. Int J Dent Hyg 2008; 6:48-55. [DOI: 10.1111/j.1601-5037.2007.00280.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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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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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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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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Weightman NC, Lines LD. Problems with the decontamination of dental handpieces and other intra-oral dental equipment in hospitals. J Hosp Infect 2004; 56:1-5. [PMID: 14706263 DOI: 10.1016/j.jhin.2003.09.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Dental departments within district general hospitals contain items of equipment that require decontamination between patients. Some of these items are complex and expensive, and in busy clinics, may be required in large numbers if a sterile services department (SSD) were to be used. This may result in local manual cleaning of these instruments and sterilization in non-vacuum downward displacement autoclaves within dental departments, despite some items having narrow lumens, deep recesses and cavities, which will not adequately sterilize these instruments. Infection control teams should be aware of these difficulties particularly when arranging satisfactory infection control and decontamination procedures in hospital dental departments.
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Affiliation(s)
- N C Weightman
- Department of Microbiology, Friarage Hospital, Northallerton, North Yorkshire DL6 1JG, UK.
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Smith AJ, McHugh S, McCormick L, Stansfield R, McMillan A, Hood J. A cross sectional study of water quality from dental unit water lines in dental practices in the West of Scotland. Br Dent J 2002; 193:645-8; discussion 641. [PMID: 12607622 DOI: 10.1038/sj.bdj.4801651] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To determine the microbiological quality of water from dental units in a general practice setting and current practice for disinfection of units. DESIGN A cross-sectional study of the water quality from 40 dental units in 39 general practices and a questionnaire of the disinfection protocols used in those practices. SETTING NHS practices in primarydental care. SUBJECTS Thirty-nine general practices from the West of Scotland. METHODS Water samples were collected on two separate occasions from dental units and analysed for microbiological quality by the total viable count (TVC) method. Water specimens were collected from the triple syringe, high speed outlet, cup filler and surgery tap. Each participating practitioner was asked to complete a questionnaire. Results Microbial contamination was highest from the high speed outlet followed by the triple syringe and cup filler. On average, the TVC counts from the high speed water lines at 37 degrees C and for the high speed lines, triple syringe and cup filler at 22 degrees C were significantly higher than that from the control tap water specimens. The study included units from 11 different manufacturers with ages ranging from under one year to over eight years. The age of the dental unit analysed did not appear to influence the level of microbial contamination. Five of the practices surveyed used disinfectants to clean the dental units but these had no significant effect on the microbiological quality of the water. The majority of dental units (25 out of 40) were never flushed with water between patients. A number of different non-sterile irrigants were used for surgical procedures. CONCLUSION The microbiological quality of water from dental units in general dental practice is poor compared with that from drinking water sources. Suitable sterile irrigants should be used for surgical procedures in dental practice. Further work is required for pragmatic decontamination regimens of dental unit water lines in a general dental practice setting
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Affiliation(s)
- A J Smith
- Infection Research Group, Glasgow Dental Hospital & School, Glasgow G2 3JZ.
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Smith AJ, McHugh S, Aitken I, Hood J. Evaluation of the efficacy of Alpron disinfectant for dental unit water lines. Br Dent J 2002; 193:593-6; discussion 584. [PMID: 12481185 DOI: 10.1038/sj.bdj.4801635] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2002] [Accepted: 07/17/2002] [Indexed: 11/08/2022]
Abstract
AIMS To assess the efficacy of a disinfectant, Alpron, for controlling microbial contamination within dental unit water lines. METHODS The microbiological quality of water emerging from the triple syringe, high speed handpiece, cup filler and surgery hand wash basin from six dental units was assessed for microbiological total viable counts at 22 degrees C and 37 degrees C before and after treatment with Alpron solutions. RESULTS The study found that the use of Alpron disinfectant solutions could reduce microbial counts in dental unit water lines to similar levels for drinking water. This effect was maintained in all units for up to six weeks following one course of treatment. In four out of six units the low microbial counts were maintained for 13 weeks. CONCLUSIONS Disinfectants may have a short term role to play in controlling microbial contamination of dental unit water lines to drinking water quality. However, in the longer term attention must be paid to redesigning dental units to discourage the build up of microbial biofilms.
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Affiliation(s)
- A J Smith
- Infection Research Group, Glasgow Dental Hospital and School.
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Abstract
This paper describes a trial of chlorine dioxide in dental unit waterlines to produce potable quality water. Four treatment protocols using 50 ppm activated chlorine dioxide solution were tested. Each caused a short-term (<48 h) decline in total viable counts but did not provide potable quality water. Intermittent use of chloride dioxide is thus not suitable for long-term decontamination of dental unit waterlines. Units should be redesigned to discourage biofilm formation, and more research into practical methods of achieving potable water is required in the interim.
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Affiliation(s)
- A J Smith
- Infection Research Group, Glasgow Dental Hospital and School, Glasgow, UK.
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Wirthlin MR, Marshall GW JR. Evaluation of ultrasonic scaling unit waterline contamination after use of chlorine dioxide mouthrinse lavage. J Periodontol 2001; 72:401-10. [PMID: 11327069 DOI: 10.1902/jop.2001.72.3.401] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND An infection control problem in dental operatories which is not fully controlled is waterline contamination by heterotrophic mesophilic bacteria. These bacteria are present in water supplies as a planktonic phase and adhere to the lumen of tubings as a biofilm comprised of their external cell surface glycocalyx and by production of extracellular carbohydrate polymers. The adherent film is most difficult to remove. The accumulated planktonic phase can be reduced significantly by flushing water from the lines before use in patient treatment, but will return when the equipment is idle through the accumulation of more planktonic phase and by slough of the biofilm surface-adsorbed phase not yet enmeshed in the carbohydrate matrix. Chlorine dioxide has antimicrobial activity against many bacteria, spores, and viruses. It is used in water supply treatment as a disinfectant and slime preventive and has an advantage over chlorine in that carcinogenic trihalomethanes are not generated. METHODS This study compared use of phosphate buffer-stabilized chlorine dioxide (0.1%) mouthrinse as a lavage in ultrasonic dental scaler units with the use of tap water as a control. Sterile water flushed through the units onto heterotrophic plate count (HPC) sampler plates was cultured 7 days at room temperature and colonies were counted at 12x. One test and one control unit were used for biopsy of internal tubing and scanning electron microscopy imaging. RESULTS The HPC counts, in colony forming units (CFU)/ml, were reduced 3- to 5-fold by flushing tap water through the units, but they returned after units were idle overnight. When phosphate-buffered chlorine dioxide mouthrinse was used as a lavage, CFU/ml were reduced 12- to 20-fold. Holding chlorine dioxide in waterlines overnight reduced recurrent buildup compared to water (P <0.05). Scanning electron microscopy images indicated a significant reduction of biofilm coverage by chlorine dioxide as compared to water (P<0.001). CONCLUSIONS Phosphate-buffered chlorine dioxide mouthrinse was effective in these short-term trials for control of waterline contamination in ultrasonic dental scaling units. It should prove as useful in dental professional waterline applications as it has in industrial uses for biofilm control.
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Affiliation(s)
- M R Wirthlin
- Department of Stomatology, University of California San Francisco, 94143-0762, USA
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Pratt LH, Smith DG, Thornton RH, Simmons JB, Depta BB, Johnson RB. The effectiveness of two sterilization methods when different precleaning techniques are employed. J Dent 1999; 27:247-8. [PMID: 10079632 DOI: 10.1016/s0300-5712(98)00053-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The effectiveness was investigated of methods for the preparation of dental handpieces prior to sterilization procedures utilizing ethylene oxide (ETO) gas. The handpieces were cleaned using either a forced-air purging unit (group 1) or by flushing with air and water from the dental unit (group 2). They were inoculated with either Bacillus subtilis or Streptococcus mutans. After exposure to either steam or ETO gas, the handpieces were flushed with saline and the viability of recovered bacteria assessed. No viable bacteria were recovered from group 1 handpieces treated with either ETO gas or steam. However, viable S. mutans were recovered from group 2 handpieces following exposure to ETO gas. Thus, the use of a high-pressure forced-air purging unit may be required for the reliable sterilization of dental handpieces by ETO gas, as viable S. mutans could be recovered from untreated handpieces exposed to ETO gas.
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Affiliation(s)
- L H Pratt
- Department of Diagnostic Sciences, University of Mississippi School of Dentistry, Jackson 39216-4505, USA
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18
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Abstract
Biofilms are emerging as an increasing problem as medical technology advances. Dental practice is no exception and interest in the role of biofilms within dental units as a possible source of cross-infection is intensifying. It is difficult to quantitate the risks associated with aerosolised bacteria for the majority of patients seen in general practice. However, it seems prudent to eliminate this source of infection during treatment of compromised patients. This article attempts to provide a brief overview of current concepts and problems in this area of infection control.
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Affiliation(s)
- A J Smith
- Infection Research Group, Glasgow Dental Hospital & School
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19
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Abstract
Ethylene oxide gas has been utilized as an alternative method for sterilization of dental handpieces, as it is less corrosive than steam. However, its effectiveness for sterilization of the internal components of dental handpieces has not been established. The objective of this study was to compare the effectiveness of ethylene oxide and steam for sterilization of dental handpieces. Unused handpieces and handpieces which had been exposed to clinical dental procedures ('clinical') were contaminated with Streptococcus mutans, exposed to steam or ethylene oxide, and flushed with sterile saline. Washings were plated on mitis-salivarius agar, and colonies identified and counted. No viable colonies could be established from washings from 'clinical' or 'unused' handpieces exposed to steam. However, viable colonies could be established from 'clinical' handpieces exposed to ethylene oxide. This data suggests that a substance entrapped within 'clinical' handpieces (possibly the biofilm) may protect bacteria from ethylene oxide gas, preventing adequate sterilization.
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Affiliation(s)
- H H Parker
- Department of Endodontics, University of Mississippi, School of Dentistry, Jackson, USA
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20
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Abstract
Water samples collected from 28 dental facilities in six U.S. states were examined for the presence of Legionella pneumophila and other Legionella spp. by the PCR-gene probe, fluorescent-antibody microscopic, and viable-plate-count detection methods. The PCR and fluorescent-antibody detection methods, which detect both viable and viable nonculturable Legionella spp., gave higher counts and rates of detection than the plate count method. By the PCR-gene probe detection method, Legionella spp. were detected in 68% of the dental-unit water samples and L. pneumophila was detected in 8%. Concentrations of Legionella spp. in dental-unit water reached 1,000 organisms per ml or more in 36% of the samples, and 19% of the samples were in the category of 10,000/ml or above. L. pneumophila, when present in dental-unit water, never reached concentrations of 1,000/ml or more. Microscopic examination with fluorescent-antibody staining indicated that the contamination was in the dental-unit water lines rather than in the handpieces. Legionella spp. were present in 61% of potable water samples collected for comparative analysis from domestic and institutional faucets and drinking fountains; this percentage was not significantly different from the rate of detection of Legionella spp. in dental-unit water. However, in only 4% of the potable water samples did Legionella spp. reach concentrations of 1,000 organisms per ml, and none was in the 10,000 organisms-per-ml category, and so health-threatening levels of Legionella spp. in potable water were significantly lower than in dental-unit water. L. pneumophila was found in 2% of the potable water samples, but only at the lowest detectable level.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R M Atlas
- Department of Biology, University of Louisville, Kentucky 40292, USA
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21
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Lewis DL, Arens M, Appleton SS, Nakashima K, Ryu J, Boe RK, Patrick JB, Watanabe DT, Suzuki M. Cross-contamination potential with dental equipment. Lancet 1992; 340:1252-4. [PMID: 1359320 DOI: 10.1016/0140-6736(92)92950-k] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Some types of reused dental equipment, especially handpieces and their attachments for drilling and cleaning teeth, might be responsible for cross-contamination if patient material were to lodge temporarily in difficult-to-disinfect internal mechanisms. This possibility is worrisome with respect to transmission of hepatitis B and human immunodeficiency viruses (HBV, HIV). Previous cross-contamination studies have relied on laboratory experiments with bacteria or dye tracers. To assess possible risk more thoroughly, we tested 30 new prophylaxis angles and 12 new high-speed handpieces to see whether they would take up and expel contaminants in laboratory and clinical trials. In treatments of three patients, including two infected with HIV, human-specific DNA (beta-globin, HLA DQ alpha) and HIV proviral DNA were detected inside or coming back from the devices. Similarly, when handpieces were operated in contact with blood pooled from HBV-infected patients, HBV DNA was detected in samples taken from inside the equipment and from their attached air/water hoses. When we used bacteriophage phi X174 as a model virus in laboratory tests, many infective viral particles were recovered from internal mechanisms of handpieces, their connecting air/water hoses, and from water spray expelled when the equipment was reused. We recommend that reused high-speed, air-driven handpieces and prophylaxis angles should be cleaned and heat-treated between patients. Further studies are needed to determine ways of eliminating the risks associated with exhaust hoses and air/water input lines.
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Affiliation(s)
- D L Lewis
- Faculty of Ecology, University of Georgia, Athens 30602
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22
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Lewis DL, Boe RK. Cross-infection risks associated with current procedures for using high-speed dental handpieces. J Clin Microbiol 1992; 30:401-6. [PMID: 1537909 PMCID: PMC265068 DOI: 10.1128/jcm.30.2.401-406.1992] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
When a dye solution used to simulate patient material was either injected into high-speed dental handpiece (drill) waterlines or applied to the equipment externally, internal air turbine chambers became contaminated. These chambers served as a reservoir of the material, which was slowly dislodged by air expelled during subsequent handpiece operation and which was diluted by water spray used for cooling the drilling surface. Considering the fact that patient materials could reside in internal parts of the equipment that are not usually disinfected and that the material may be subsequently sprayed into cuts and abrasions in the oral cavity, the common approach to reprocessing handpieces (external wiping in combination with flushing) may pose unacceptably high risks to those individuals treated soon after infected patients. Therefore, unless reliable data on cross-infection frequencies are obtained and prove it unnecessary, heat-treating high-speed handpieces between each patient should be considered an essential component of standard procedures whenever universal precautions are practiced in dentistry.
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Affiliation(s)
- D L Lewis
- Faculty of Ecology, University of Georgia, Athens 30602
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23
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Abstract
This technique uses an individual applicator per application of an elastomeric adhesive to an acrylic resin tray. To help prevent contamination of the adhesive in the bottle, the Toothette toothbrush should not be dipped into the bottle a second time. A sufficient quantity of adhesive is absorbed with a single immersion into the adhesive to coat an entire tray. The uniformity of the surface application is more easily controlled compared with that of a brush applicator. Because only one immersion is required to coat a tray and the Toothette toothbrush is discarded after one application, cross-contamination of patients is prevented.
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Affiliation(s)
- J T White
- Dental Division, Veterans Administration Medical Center, Durham, N.C
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24
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Otis LL, Terezhalmy GT. The granulocytopenic patient: another consideration for antimicrobial prophylaxis. ORAL SURGERY, ORAL MEDICINE, AND ORAL PATHOLOGY 1985; 60:125-9. [PMID: 3162130 DOI: 10.1016/0030-4220(85)90228-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Infection in the granulocytopenic patient is often life-threatening, and the frequency and severity of infection are increased regardless of the cause of leukocyte suppression. Trimethoprim-sulfamethoxazole plus nystatin is known to be effective in preventing colonization and infection by the primary pathogens responsible for the morbidity and mortality associated with granulocytopenia. When treating granulocytopenic patients, clinicians should use proper barrier techniques to minimize nosocomial colonization. When foci of oral infection are present or bacteremia is predictable, appropriate antibiotics should be prescribed.
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