scholarly journals Evaluation of an Automated Dental Unit Water System's Contamination Control Protocol

2012 ◽  
Vol 13 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Raghunath Puttaiah ◽  
Kathy KH Svoboda ◽  
Shih Ming Lin ◽  
Lucio Montebugnoli ◽  
Giovanni Dolci ◽  
...  
Keyword(s):  
Dental Treatment ◽  
System Simulation ◽  
Microbial Control ◽  
Water System ◽  
Water Systems ◽  
Sterile Water ◽  
Contamination Control ◽  
Plate Counts ◽  
Heterotrophic Plate Counts ◽  
Treatment Water

ABSTRACT Background This study addresses the efficacy of an automated decontamination protocol using the germicide ‘tetra acetyl ethylene diamine (TAED) perborate’ (Farmec SpA, Italy). The germicide TAED perborate protocol is used in the Castellini Dental Units fitted with an Autosteril unit (an automated device that can cycle 0.26% TAED perborate solution and sterile water for cleaning the water system between patients and overnight). Prior to testing the Autosteril and the 0.26% TAED perborate protocol on the Logos Jr Dental Unit (Castellini SpA, Italy), TAED perborate was used on a dental unit water system simulation device. Methods A dental unit water system simulation device equipped with four dental unit water systems and with naturally grown and mature biofilm contamination was used in this study (three treatment units and one control). One treatment group used a simulated 5 minutes contact with TAED perborate and sterile water for irrigation; the second used a simulated 5 minutes contact with TAED perborate and 2 ppm ClO2 for irrigation; the third used a simulated 5 minutes contact with TAED perborate and municipal water for irrigation. The control group used municipal water for irrigation with no cleaning/disinfection protocols. This protocol was repeated for 30 cycles. Laser scanning confocal microscopy (LSCM) was used to study the effects on natural and mature biofilms, and R2A agar used to quantify heterotrophic plate counts in the effluent irrigant. Antimicrobial efficacy was evaluated by challenging TAED perborate with microbes and spores (M. smegmatis and B. subtilis). Deleterious effects of the germicide were evaluated on metal and nonmetal parts of dental unit water systems. Heterotrophic plate counts using R2A agar and LSCM of the lines were conducted to assess biofilm and microbial control. Results Baseline water samples showed mean contamination >5.6 log10 cfu/ml. After initial cleaning, all three groups maintained mean contamination levels of less than 1.1 (SD <0.3) log10 cfu/ml. LSCM of baseline samples was positive for live biofilm in all groups. At the end of the study, viable biofilm was only present in the control. In the microbial challenge test, all vegetative organisms were killed within 30 seconds of contact, while spores were killed within 5 minutes. Corrosion was seen in metals used in US-manufactured dental unit materials, while not observed in those used in the Castellini Logos Jr dental unit. Conclusion In this study, the TAED perborate protocol was effective in biofilm control and control of dental treatment water contamination. Use of sterile water or 2 ppm ClO2 along with TAED treatment also controlled planktonic contamination effectively. Clinical significance Environmental biofilms contaminate dental unit water systems over time and affect the quality of dental treatment water. Contaminants include environmental biofilms, microbes, including gram-negative rods and endotoxins in high doses that are not of acceptable quality for treating patients. There are many germicidal protocols for treating this contamination and one such is the prescribed use of TAED perborate used in conjunction with sterile water for irrigation in the autosteril device, an integral component of the Castellini dental units for between patient decontamination of dental unit water systems. This study was conducted on an automated simulation dental unit water system to test the TAED perborate protocol's efficacy on naturally grown, mature environmental biofilms, it's efficacy on microbes and spores and it's effects on materials used in dental unit water systems. This translational research addresses both microbial control and material effects of TAED perborate in studying efficacy and possible deleterious effects and simulated use in dentistry. Currently, this antimicrobial use protocol is followed worldwide in the Castellini dental units that are used in day-to-day dental patient care. How to cite this article Puttaiah R, Svoboda KKH, Lin SM, Montebugnoli L, Dolci G, Spratt D, Siebert J. Evaluation of an Automated Dental Unit Water System's Contamination Control Protocol. J Contemp Dent Pract 2012;13(1):1-10.

scholarly journals Effects of Iodine in Microbial Control of Dental Treatment Water

2011 ◽  
Vol 12 (3) ◽  
pp. 143-151 ◽  
Author(s):  
Raghunath Puttaiah ◽  
Jeff Seibert ◽  
Robert Spears
Keyword(s):  
Dental Treatment ◽  
Microbial Control ◽  
Water System ◽  
Water Source ◽  
Water Systems ◽  
Source Water ◽  
Municipal Water ◽  
Point Of Use ◽  
Low Levels ◽  
Treatment Water

ABSTRACT Objective To determine the effects of low levels of iodine constantly present in the dental unit water system on microbial control of dental treatment water and biofilm control. Materials and methods This study used a dental unit water system simulator with eight dental unit waterline systems built to scale and function, each controlled via computer. Each of the eight units was operated independently, four units supplied with self-contained water reservoirs and four units supplied with municipal water. Four units were precleaned to remove biofilm buildup. The study had a well-balanced design with equal representation (variables) of presence/absence of biofilms, selfcontained reservoirs for introduction of treatment water, source water directly connected to municipal water source and iodinated cartridges within the self-contained reservoirs and between municipal water and dental unit. Point-of-use iodinated resin cartridges (IRC) were retrofitted proximal to handpiece and air/ water syringe tip lines in four units, and iodinated resin water cartridges (IRSWC) were fitted to the other four units at the source water output. Heterotrophic plate counts were performed at baseline and twice weekly for a period of 6 weeks. One representative waterline sample was taken from each group at baseline and end-of-study to analyze changes in biofilm status using scanning electron microscopy. Results Waterlines not previously contaminated with biofilms did not show organization of biofilm matrix in units equipped with IRSWC. Constantly present low levels of iodine, demonstrated some disruption of biofilms in waterlines already contaminated with mature biofilms. All groups showed contamination levels < 500 cfu/ml (colony forming units per milliliter) consistent with the CDC and ADA guidelines. Conclusion In this 6 weeks study, IRSWC equipped waterlines showed disruption of established biofilms, controlled formation of new biofilms in clean lines and rendered the dental treatment water < 500 cfu/ml. Point-of-use iodinated resin cartridges were also effective in controlling contamination in the dental treatment water. Clinical significance Dental unit water systems that are in use get contaminated with microbes and biofilms in weeks of being put into use. These biofilms contaminate the treatment water thereby putting patients and staff at risk of infection by predominantly gram-negative microbes. Biofilms in the water systems must be cleaned periodically with a strong decontaminant and the dental treatment source water needs to be modified with a low-grade antimicrobial that can preserve the water quality yet safe to humans. In this translational research study, we evaluate the effects of elemental iodine dissolved in water flowing through an iodine containing cartridge in controlling biofilm and dental treatment water contamination using a dental unit water system simulator, prior to clinical utilization. How to cite this article Puttaiah R, Seibert J, Spears R. Effects of Iodine in Microbial Control of Dental Treatment Water. J Contemp Dent Pract 2011;12(3):143-151.

scholarly journals Evaluation of Two Methods in Controlling Dental Treatment Water Contamination

2011 ◽  
Vol 12 (2) ◽  
pp. 73-83 ◽  
Author(s):  
Raghunath Puttaiah ◽  
Ritu Bansal ◽  
Robert Harris ◽  
Anil Reddy
Keyword(s):  
Patient Care ◽  
Water Contamination ◽  
Laser Scanning ◽  
Dental Treatment ◽  
Tap Water ◽  
Water System ◽  
Water Systems ◽  
Low Grade ◽  
High Concentration ◽  
Treatment Water

ABSTRACT Dental unit water systems are contaminated with biofilms that amplify bacterial counts in dental treatment water in excess of a million colony forming units per milliliter (cfu/ml). The Centers for Disease Control and Prevention and the American Dental Association have agreed that the maximum allowable contamination of dental treatment water not exceed 500 cfu/ml. This study was conducted to evaluate two protocols in controlling contamination of dental unit water systems and dental treatment water. Both methods used an antimicrobial self-dissolving chlorine dioxide (ClO2) tablet at a high concentration (50 ppm) to shock the dental unit water system biofilms initially followed by periodic exposure. To treat dental treatment source water for patient care, 3 parts per million (ppm) ClO2 in municipal/tap water was compared to use of a citrus botanical extract dissolved in municipal water. Heterotrophic microbial counts of effluent water and laser scanning confocal microscopy were performed to evaluate effects of the two treatments. Results from this study indicated that both treatments were effective in controlling biofilm contamination and reducing heterotrophic plate counts <500 cfu/ml. A comprehensive study addressing compatibility of 50 ppm ClO2 on the metals and nonmetal components of the dental water system and effects of low-grade chemicals used on composite bonding to dentin and enamel is warranted before translation from efficacy studies to common clinical use. Clinical significance This study provides evidence-based information of using two methods of controlling dental treatment water contamination. The study was conducted in a clinical practice setting in an active dental clinic and the results are meaningful to a clinician who is interested in providing safe dental treatment water for patient care. How to cite this article Bansal R, Puttaiah R, Harris R, Reddy A. Evaluation of Two Methods in Controlling Dental Treatment Water Contamination. J Contemp Dent Pract 2011;12(2):73-83.

Parameters predictive of Legionella contamination in hot water systems: Association with trace elements and heterotrophic plate counts

2011 ◽  
Vol 45 (6) ◽  
pp. 2315-2321 ◽  
Author(s):  
Annalisa Bargellini ◽  
Isabella Marchesi ◽  
Elena Righi ◽  
Angela Ferrari ◽  
Stefano Cencetti ◽  
...  
Keyword(s):  
Trace Elements ◽  
Water Systems ◽  
Hot Water ◽  
Plate Counts ◽  
Heterotrophic Plate Counts

Evaluation of Legionella presence in the water system of a public building by semi-nested polymerase chain reaction as a rapid screening method complementary to plate count

2013 ◽  
Vol 13 (6) ◽  
pp. 1560-1568 ◽  
Author(s):  
Alejandra Serrano-Suárez ◽  
Rosa Araujo
Keyword(s):  
Polymerase Chain Reaction ◽  
Water Samples ◽  
Water System ◽  
Culture Method ◽  
Water Systems ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Public Building ◽  
Plate Counts ◽  
Polymerase Chain

The aim of this study was to apply a fast and efficient protocol for monitoring levels of Legionella contamination in high-risk water systems using molecular techniques and culture methods. Forty-nine water samples from a public building were analyzed by a culture method (BCYE agar) and a specific semi-nested polymerase chain reaction (PCR). The first 30 analyses using plate counts were positive in 28% of hot water and 8% of cold water samples. The analysis by PCR, obtained within 24 h of collection, revealed the presence of DNA in 100 and 54% respectively. Only four PCR results coincided with the cultures. A second survey (19 samples) was performed 1 year later. Semi-nested PCR revealed that 53% of the samples were positive; however, plate counts yielded no positive results. The 16S rRNA sequence comparison between the first and second samplings showed 100% homology. In conclusion, the study of the design of the building's water system, the use of a fast screening semi-nested PCR and a culture method for the detection of Legionella allowed accurate assessment of the contamination, thus contributing to the early implementation of measures to eliminate the presence of the bacteria in water systems and consequently reduce a latent public health risk.

Sewers and the Quality of Canals and Ditches in Amsterdam

1993 ◽  
Vol 27 (5-6) ◽  
pp. 61-67 ◽  
Author(s):  
E. Jacobs ◽  
J. W. van Sluis
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Sediment Quality ◽  
Water System ◽  
Water Systems ◽  
Sewer System ◽  
Water And Sediment ◽  
Combined Sewer ◽  
Water And Sediment Quality

The surface water system of Amsterdam is very complicated. Of two characteristic types of water systems the influences on water and sediment quality are investigated. The importance of the sewer output to the total loads is different for both water systems. In a polder the load from the sewers is much more important than in the canal basin. Measures to reduce the emission from the sewers are much more effective in a polder. The effect of these measures on sediment quality is more than the effect on water quality. Some differences between a combined sewer system and a separate sewer system can be found in sediment quality.

Design of rural water systems using dynamic models

1999 ◽  
Vol 39 (4) ◽  
pp. 221-231
Author(s):  
A. H. Lobbrecht
Keyword(s):  
Dynamic Models ◽  
Water System ◽  
Design Procedure ◽  
Real Data ◽  
Water Systems ◽  
Design Methods ◽  
Water Quality Criteria ◽  
Rural Water ◽  
Rural Water Systems ◽  
The Way

The properties of main water ways and infrastructure of rural water systems are often determined by very general design methods. These methods are based on standards that use only little information of the actual water system. Most design methods applied in the Netherlands are based on land use and soil texture. Standards have been developed on the basis of generalized properties of water systems. Details of the actual layout of the water system and the way in which that system is controlled, are usually not incorporated. Present-day dynamic simulation programs and the computer power currently available enable more detailed modeling and incorporation of location-specific data into models. Such models can be used to design the water system and can include real data. A model-based design method is introduced, in which the actual situation of the water system is taken into consideration as well as the way in which the water system is controlled. Stochastics concerning the operation and availability of controlling infrastructure are included in the method. Models can be evaluated by including real data. In this way the actual safety of the water system, for example during floods, can be determined. Water-quantity design criteria can be incorporated as well as water-quality criteria. Application of the method makes it possible to design safe water systems in which excess capacities are avoided and in which all requirements of interest are met. The method, called the ‘dynamic design procedure’, can result in considerable savings for water authorities when new systems have to be designed or existing designs have to be reconsidered.

scholarly journals Endotoxin contamination in the dental surgery

2007 ◽  
Vol 56 (9) ◽  
pp. 1230-1234 ◽  
Author(s):  
M. K. Huntington ◽  
J. F. Williams ◽  
C. D. Mackenzie
Keyword(s):  
Bacterial Load ◽  
Dental Surgery ◽  
Paired Samples ◽  
Dental Procedures ◽  
Large Numbers ◽  
Endotoxin Exposure ◽  
Endotoxin Contamination ◽  
Plate Counts ◽  
High Concentrations ◽  
Heterotrophic Plate Counts

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 2.0×106 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 ρ=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.

Why England and not China and India? Water systems and the history of the Industrial Revolution

2010 ◽  
Vol 5 (1) ◽  
pp. 29-50 ◽  
Author(s):  
Terje Tvedt
Keyword(s):  
Industrial Revolution ◽  
Water System ◽  
Water Systems ◽  
Trade Relations ◽  
The World ◽  
Long Time ◽  
History Of ◽  
Investment Capital ◽  
System Factor ◽  
Historical Accounts

AbstractGlobal history has centred for a long time on the comparative economic successes and failures of different parts of the world, most often European versus Asian regions. There is general agreement that the balance changed definitively in the latter part of the eighteenth century, when in continental Europe and England a transformation began that revolutionized the power relations of the world and brought an end to the dominance of agrarian civilization. However, there is still widespread debate over why Europe and England industrialized first, rather than Asia. This article will propose an explanation that will shed new light on Europe’s and England’s triumph, by showing that the ‘water system’ factor is a crucial piece missing in existing historical accounts of the Industrial Revolution. It is argued that this great transformation was not only about modernizing elites, investment capital, technological innovation, and unequal trade relations, but that a balanced, inclusive explanation also needs to consider similarities and differences in how countries and regions related to their particular water systems, and in how they could exploit them for transport and the production of power for machines.

scholarly journals An approach for developing a national estimate of waterborne disease due to drinking water and a national estimate model application

2006 ◽  
Vol 4 (S2) ◽  
pp. 201-240 ◽  
Author(s):  
Michael Messner ◽  
Susan Shaw ◽  
Stig Regli ◽  
Ken Rotert ◽  
Valerie Blank ◽  
...  
Keyword(s):  
Drinking Water ◽  
Environmental Protection Agency ◽  
Water System ◽  
Credible Interval ◽  
The United States ◽  
Water Systems ◽  
Epidemiologic Studies ◽  
Incidence Rates ◽  
Waterborne Disease ◽  
Public Water Systems

In this paper, the US Environmental Protection Agency (EPA) presents an approach and a national estimate of drinking water related endemic acute gastrointestinal illness (AGI) that uses information from epidemiologic studies. There have been a limited number of epidemiologic studies that have measured waterborne disease occurrence in the United States. For this analysis, we assume that certain unknown incidence of AGI in each public drinking water system is due to drinking water and that a statistical distribution of the different incidence rates for the population served by each system can be estimated to inform a mean national estimate of AGI illness due to drinking water. Data from public water systems suggest that the incidence rate of AGI due to drinking water may vary by several orders of magnitude. In addition, data from epidemiologic studies show AGI incidence due to drinking water ranging from essentially none (or less than the study detection level) to a rate of 0.26 cases per person-year. Considering these two perspectives collectively, and associated uncertainties, EPA has developed an analytical approach and model for generating a national estimate of annual AGI illness due to drinking water. EPA developed a national estimate of waterborne disease to address, in part, the 1996 Safe Drinking Water Act Amendments. The national estimate uses best available science, but also recognizes gaps in the data to support some of the model assumptions and uncertainties in the estimate. Based on the model presented, EPA estimates a mean incidence of AGI attributable to drinking water of 0.06 cases per year (with a 95% credible interval of 0.02–0.12). The mean estimate represents approximately 8.5% of cases of AGI illness due to all causes among the population served by community water systems. The estimated incidence translates to 16.4 million cases/year among the same population. The estimate illustrates the potential usefulness and challenges of the approach, and provides a focus for discussions of data needs and future study designs. Areas of major uncertainty that currently limit the usefulness of the approach are discussed in the context of the estimate analysis.

Agricultural human-water systems: challenges, advances, and knowledge gaps

2021 ◽  
Author(s):  
Pedro Medeiros ◽  
Xi Chen ◽  
Thushara Gunda ◽  
Pieter van Oel ◽  
Giulia Vico ◽  
...  
Keyword(s):  
Cultural Values ◽  
Risk Perceptions ◽  
Crop Production ◽  
Management Practices ◽  
Causal Effect ◽  
Water System ◽  
Water Systems ◽  
Agricultural Water ◽  
Dynamic Interactions ◽  
Spatial And Temporal Scales

&lt;p&gt;Dynamic interactions between humans and water have produced unanticipated feedbacks, leading to unsustainability. Current water management practices are unable to capture the relevant spatial and temporal detail of the processes that drive the coupled human-water system. Whereas natural and socioeconomic processes occur slowly, local communities and individuals rapidly respond to ensure supply-demand balance. In this context, agricultural human-water systems stand out, as roughly 70% of global water demand is for agricultural uses. Additionally, interactions between humans and agricultural water systems involve many actors and occur at multiple spatial and temporal scales. For example, farmers are influenced by risk perceptions, and decisions made at the farm level influence regional hydrologic and socioeconomic systems, such as degradation and depletion of water sources as well as prices of crops. Regional behaviors, in turn, affect national and international dynamics associated with crop production and trade of associated investments. On the other hand, global and national priorities can also percolate down to the regional and local levels, influencing farmer decision-making through policies and programs supporting production of certain crops and local investments. Over the last decade, relevant phenomena in the coupled agricultural human-water systems have been described, as the irrigation efficiency paradox, reservoir effect, and river basin closure. Along with the globalization in the food market, attempts have been taken to developing and applying benchmarks for water-efficient food production, focusing on water productivities, water footprints and yield gaps for agricultural products. Furthermore, significant advancements have been achieved by incorporating social dimensions of agricultural human-water systems behavior. Fusion of quantitative datasets via observations, remote sensing retrieval, and physically-based models has been explored. Advancements have also been made to capture qualitative or relatively intangible concepts of community values, norms, and behaviors, by interacting with stakeholders, identifying the most important elements of their environments, and incorporating these insights into socio-hydrological models. Based on what has been done during the IAHS Panta Rhei decade and what we have learned, and despite recent efforts towards a more comprehensive understanding of the effects of human interventions in agricultural systems, several challenges persist, of which we highlight: 1) Identification of the cross-scale causal effect on agricultural water uses; 2) Quantification of human behavior uncertainties shaped by social norms and cultural values; 3) Development of a high spatial and temporal resolution global dataset.&lt;/p&gt;

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