WorldWideScience

Sample records for irrigation canal network

  1. Root canal irrigants.

    Science.gov (United States)

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-10-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were 'root canal irrigants' and 'endodontic irrigants.' The reference lists of each article were manually checked for additional articles of relevance.

  2. Root canal irrigation

    NARCIS (Netherlands)

    L. van der Sluis; C. Boutsioukis; L.M. Jiang; R. Macedo; B. Verhaagen; M. Versluis

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  3. Roles of the combined irrigation, drainage, and storage of the canal network in improving water reuse in the irrigation districts along the lower Yellow River, China

    Science.gov (United States)

    Liu, Lei; Luo, Yi; He, Chansheng; Lai, Jianbin; Li, Xiubin

    2010-09-01

    SummaryThe commonly used irrigation system in the irrigation districts (with a combined irrigation area of 3.334 × 10 6 ha) along the lower Yellow River of China is canal network. It delivers water from the Yellow River to the fields, collects surface runoff and drainage from cropland, and stores both of them for subsequent irrigation uses. This paper developed a new combined irrigation, drainage, and storage (CIDS) module for the SWAT2000 model, simulated the multiple roles of the CIDS canal system, and estimated its performance in improving water reuse in the irrigation districts under different irrigation and water diversion scenarios. The simulation results show that the annual evapotranspiration (ET) of the double-cropping winter wheat and summer maize was the highest under the full irrigation scenario (automatic irrigation), and the lowest under the no irrigation scenario. It varied between these two values when different irrigation schedules were adopted. Precipitation could only meet the water requirement of the double-cropping system by 62-96% on an annual basis; that of the winter wheat by 32-36%, summer maize by 92-123%, and cotton by 87-98% on a seasonal basis. Hence, effective irrigation management for winter wheat is critical to ensure high wheat yield in the study area. Runoff generation was closely related to precipitation and influenced by irrigation. The highest and lowest annual runoff accounted for 19% and 11% of the annual precipitation under the full irrigation and no irrigation scenarios, respectively. Nearly 70% of the annual runoff occurred during months of July and August due to the concentrated precipitation in these 2 months. The CIDS canals play an important role in delivering the diversion water from the Yellow River, intercepting the surface runoff and drainage from cropland (inflow of the CIDS canal) and recharging the shallow aquifer for later use. Roughly 14-26% of the simulated total flow in the CIDS canal system recharged

  4. Statistical Analysis of Manning's roughness Coefficients in Non-vegetated Canals for Irrigation and Drainage Network of Moghan

    Directory of Open Access Journals (Sweden)

    Abolfazl Nasseri

    2017-03-01

    Full Text Available Introduction: Due to sensitiveness of flow to roughness coefficient (RC, selection of this coefficient is important in earth canals designing purposes. Precision selection of this coefficient is necessary for design and operation of earthen canals purposes. Overestimation of the actual amount of this coefficient will cause an underestimation for flow velocity. Accordingly, sedimentation in the earth canals will reduce canals’ capacitances. Adversely, underestimation of this coefficient will cause an overestimation for flow velocity and water flux in the earth canals. It will also increase the risk of soil erosion in the channels. This coefficient is expressed by Manning, Chezy and Darcy Weisbach equations. While, hydraulic engineers have selected Manning equation to estimate the flow rate in open channels due to ease of use and acceptable precision in the application of this equation. Water for crop production in Moghan, as one of the most important agricultural centers in Iran, is supplied from Moghan-Meel diversion dam via main canal of irrigation and drainage network with a capacity of 80 m3 s-1 with a length of 116 km. All of the branched 63-channel from the main channel are earthen. Continual sedimentation in the earth canals reduced the capacity of them and re-estimation the capacity of this canals needs to the precise quantities of variables such as roughness coefficient. Because the overestimation of the actual value of the coefficient would reduce the canals’ capacity and underestimation of the coefficient increase the risk of erosion in earth canals. The analysis of the correlation among variables, regression, analysis of statistical distribution of variables, analysis of variance of variables and the analysis of the events probabilities for stochastic variables can be made by statistical methods. Therefore, these methods were applied to analysis of roughness coefficient in the earth canals. Also, due to the importance of roughness

  5. Design of alluvial Egyptian irrigation canals using artificial neural networks method

    Directory of Open Access Journals (Sweden)

    Hassan Ibrahim Mohamed

    2013-06-01

    Full Text Available In the present study, artificial neural networks method (ANNs is used to estimate the main parameters which used in design of stable alluvial channels. The capability of ANN models to predict the stable alluvial channels dimensions is investigated, where the flow rate and sediment mean grain size were considered as input variables and wetted perimeter, hydraulic radius, and water surface slope were considered as output variables. The used ANN models are based on a back propagation algorithm to train a multi-layer feed-forward network (Levenberg Marquardt algorithm. The proposed models were verified using 311 data sets of field data collected from 61 manmade canals and drains. Several statistical measures and graphical representation are used to check the accuracy of the models in comparison with previous empirical equations. The results of the developed ANN model proved that this technique is reliable in such field compared with previously developed methods.

  6. Sediment transport in irrigation canals

    OpenAIRE

    Méndez V., N.J.

    1998-01-01

    The world population is rapidly increasing and is expected to double to about 10 billion by the year 2050. To support an increasing population in terms of food sufficiency, more and more water will be required. Irrigation is the most critical component of the modern package of inputs to effect high crop production. Irrigation has been the largest recipient of public agricultural investment in the developing world. Hence, continued investment in irrigation along with reforms in institutional a...

  7. The fluid mechanics of root canal irrigation.

    Science.gov (United States)

    Gulabivala, K; Ng, Y-L; Gilbertson, M; Eames, I

    2010-12-01

    Root canal treatment is a common dental operation aimed at removing the contents of the geometrically complex canal chambers within teeth; its purpose is to remove diseased or infected tissue. The complex chamber is first enlarged and shaped by instruments to a size sufficient to deliver antibacterial fluids. These irrigants help to dissolve dying tissue, disinfect the canal walls and space and flush out debris. The effectiveness of the procedure is limited by access to the canal terminus. Endodontic research is focused on finding the instruments and clinical procedures that might improve success rates by more effectively reaching the apical anatomy. The individual factors affecting treatment outcome have not been unequivocally deciphered, partly because of the difficulty in isolating them and in making the link between simplified, general experimental models and the complex biological objects that are teeth. Explicitly considering the physical processes within the root canal can contribute to the resolution of these problems. The central problem is one of fluid motion in a confined geometry, which makes the dispersion and mixing of irrigant more difficult because of the absence of turbulence over much of the canal volume. The effects of treatments can be understood through the use of scale models, mathematical modelling and numerical computations. A particular concern in treatment is that caustic irrigant may penetrate beyond the root canal, causing chemical damage to the jawbone. In fact, a stagnation plane exists beyond the needle tip, which the irrigant cannot penetrate. The goal is therefore to shift the stagnation plane apically to be coincident with the canal terminus without extending beyond it. Needle design may solve some of the problems but the best design for irrigant penetration conflicts with that for optimal removal of the bacterial biofilm from the canal wall. Both irrigant penetration and biofilm removal may be improved through canal fluid

  8. Reform in Indian canal irrigation: does technology matter?

    NARCIS (Netherlands)

    Narain, V.

    2008-01-01

    This paper examines the implications of technology - the design of canal irrigation for irrigation management reform. With reference to two different design systems in Indian irrigation - shejpali and warabandi - it shows that the potential for reform varies with the design of canal irrigation. Thre

  9. Reform in Indian canal irrigation: does technology matter?

    NARCIS (Netherlands)

    Narain, V.

    2008-01-01

    This paper examines the implications of technology - the design of canal irrigation for irrigation management reform. With reference to two different design systems in Indian irrigation - shejpali and warabandi - it shows that the potential for reform varies with the design of canal irrigation.

  10. Sediment transport in irrigation canals.

    NARCIS (Netherlands)

    Mendez V., N.J.

    1998-01-01

    The world population is rapidly increasing and is expected to double to about 10 billion by the year 2050. To support an increasing population in terms of food sufficiency, more and more water will be required. Irrigation is the most critical component of the modern package of inputs to effect high

  11. Sediment transport in irrigation canals

    NARCIS (Netherlands)

    Mendez V., N.J.

    1998-01-01

    The world population is rapidly increasing and is expected to double to about 10 billion by the year 2050. To support an increasing population in terms of food sufficiency, more and more water will be required. Irrigation is the most critical component of the modern package of inputs to

  12. Water losses from irrigation canals evaluation: comparison among different methodologies

    Science.gov (United States)

    Clemente, Paolo; De Luca, Domenico Antonio; Antonella Dino, Giovanna; Lasagna, Manuela

    2013-04-01

    The research investigates the field methodologies to evaluate water losses from canals, in order to find a reliable method to identify and quantify them. This study was conducted in five canal lines in Piedmont, north-western Italy, different for hydraulic, morphological, geological and hydrogeological contexts (De Luca et alii, 2012). At a regional scale, Piedmont network consists of several tens of thousands km of irrigation canals. The loss of water due to seepage from irrigation canals constitutes a substantial part of the usable water. Irrigation canals placed in natural soil or fine and coarse sediments are characterized by water losses ranging from 20 % to more than 50 %. These losses cause economic, hydrogeological and environmental consequences: water losses evaluation from irrigation canals in the basis for the sustainable water resource use and management. First, hydrogeological and hydrological characterisation of the study area and of the bottom of the irrigation canals was carried out for every investigated canal, in order to evaluate the relationships between groundwater and stream water (eg. piezometric and hydrogeochemical survey campaigns, infiltrometry tests, penetrometric tests and electrical tomographies, soil characterizations from the bottom of investigated canals). The canals seepage rates were subsequently estimated using different methodologies: empirical formulas, inflow-outflow tests and double tracer tests. The empirical formulas applied for the study underestimated the real amount of the losses probably due to the scarce number of the considered variables. Then the canals seepage rates were evaluated employing inflow-outflow tests, considered the best tool by several authors. This method allows the determination of seepage quantities measuring inflow and outflow of a canal test reach either by instruments. The canal discharge was evaluated using a current meter. This method, even if easy to apply and practical, is not efficient

  13. Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

    NARCIS (Netherlands)

    Paudel, K.

    2010-01-01

    Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since Ken

  14. Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

    NARCIS (Netherlands)

    Paudel, K.

    2010-01-01

    Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since

  15. Canals, DMADCanals-Irrigation canals in Millard Co., Published in 2007, Millard County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2007. It is described as 'DMADCanals-Irrigation canals in Millard Co.'. Data by this...

  16. Review of root canal irrigant delivery techniques and devices

    Directory of Open Access Journals (Sweden)

    Yeon-Jee Yoo

    2011-05-01

    Full Text Available Introduction Eliminating the residual debris and bacteria in the root canal system is one of the main purposes of the endodontic treatment. However, the complexity on the anatomy of the root canal system makes it difficult to eliminate the bacterial biofilm existing along the root canal surface and necrotic pulp tissue by mechanical instrumentation and chemical irrigation. Recently, more effective irrigant delivery systems for root canal irrigation have been developed. The purpose of this review was to present an overview of root canal irrigant delivery techniques and devices available in endodontics. Review The contents of this paper include as follows; - syringe-needle irrigation, manual dynamic irrigation, brushes - sonic and ultrasonic irrigation, passive ultrasonic irrigation, rotary brush, RinsEndo, EndoVac, Laser Conclusion Though technological advances during the last decade have brought to fruition new agitation devices that rely on various mechanisms, there are few evidence based study to correlate the clinical efficacy of these devices with improved outcomes except syringe irrigation with needle and ultrasonic irrigation. The clinicians should try their best efforts to deliver antimicrobial and tissue solvent solutions in predictable volumes safely to working length.

  17. Root canal irrigants: a review of their interactions, benefits, and limitations.

    Science.gov (United States)

    Jena, Amit; Sahoo, Sanjit Kumar; Govind, Shashirekha

    2015-04-01

    Endodontic treatment success depends on a combination of appropriate instrumentation, effective irrigation and decontamination of root canal spaces to apices, and obturation of the root canals. Irrigation of the root canal is paramount in determining periapical tissue healing. This article reviews presently available root canal irrigants, their interactions, advantages, and limitations. For this review, the authors performed a Medline search for all English language articles published through January 2014 with "root canal irrigants" and "endodontic irrigants" as keywords.

  18. Direct solutions for normal depths in curved irrigation canals

    CERN Document Server

    Zhang, X Y

    2013-01-01

    The normal depth is an important hydraulic element for canal design, operation and management. Curved irrigation canals including parabola, U-shaped and catenary canals have excellent hydraulic performance and strong ability of anti-frost heave, while the normal depths in the governing equations of the current common methods have no explicit analytical solution. They are only indirect methods by using trial procedures, numerical methods, and graphical tools. This study presents new direct formulas for normal depth in curved irrigation canals by applying for Marquardt method. The maximum relative error of the proposed formulas is less than 1% within the practice range by comparative analysis, and they are simple and convenient for manual calculations. The results may provide the reliable theoretical basis and useful reference for the design and operation management of irrigation canals.

  19. Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

    OpenAIRE

    Paudel, K.

    2010-01-01

    Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since Kennedy published his channel-forming discharge theory in 1895. Subsequently different theories have been developed and are used around the world. All of them assume uniform and steady flow conditions ...

  20. Factors affecting irrigant extrusion during root canal irrigation: a systematic review

    NARCIS (Netherlands)

    Boutsioukis, C.; Psimma, Z.; Sluis, van der L.W.M.

    2013-01-01

    The aim of the present study was to conduct a systematic review and critical analysis of published data on irrigant extrusion to identify factors causing, affecting or predisposing to irrigant extrusion during root canal irrigation of human mature permanent teeth. An electronic search was conducted

  1. Factors affecting irrigant extrusion during root canal irrigation: a systematic review

    NARCIS (Netherlands)

    Boutsioukis, C.; Psimma, Z.; van der Sluis, L.W.M.

    2013-01-01

    The aim of the present study was to conduct a systematic review and critical analysis of published data on irrigant extrusion to identify factors causing, affecting or predisposing to irrigant extrusion during root canal irrigation of human mature permanent teeth. An electronic search was conducted

  2. Antimicrobial irrigants in endodontic therapy: 1. Root canal disinfection.

    Science.gov (United States)

    Eliyas, Shiyana; Briggs, Peter F; Porter, Richard W J

    2010-01-01

    This paper highlights the importance of root canal disinfection. It discusses the different endodontic irrigants available and comments on how these can be used most effectively. Eliminating bacteria from the root canal system is an essential stage in endodontic therapy. Practitioners should be adequately informed and skilled in this vital aspect of endodontics.

  3. Comparison of 2 flushing methods used during passive ultrasonic irrigation of the root canal

    NARCIS (Netherlands)

    van der Sluis, Lucas; Wu, Min-Kai; Wesselink, Paul

    2009-01-01

    Objective: To determine the effect of irrigation time on the removal of dentin debris from root canals irrigated with passive ultrasonic irrigation comparing 2 flushing methods. Method and Materials: Root canals with a standardized groove in 1 canal wall, which was filled with dentin debris, were ir

  4. Interactions between root canal irrigants, sealers and dentin

    NARCIS (Netherlands)

    Neelakantan, P.

    2016-01-01

    The objective of this thesis was to determine the interactions between root filling materials and root dentin and to investigate if root canal irrigating solutions had an impact on these interactions. The following outcomes were assessed in the studies encompassed in this thesis: (i) dislocation res

  5. In vitro comparison of passive and continuous ultrasonic irrigation in curved root canals

    Science.gov (United States)

    Castelo-Baz, Pablo; Varela-Patiño, Purificación; Cantatore, Giuseppe; Domínguez-Perez, Ana; Ruíz-Piñón, Manuel; Martín-Biedma, Benjamín

    2016-01-01

    Background The efficacy of endodontic irrigation procedures can be compromised by the complexity of the root canal system. Delivering irrigants to the apical third of curved canals presents a particular challenge to endodontists. This study compared the effects of two ultrasonic irrigation techniques on the penetration of sodium hypochlorite into the main canal and simulated lateral canals of curved roots in extracted teeth. Material and Methods Two sets of simulated lateral canals were created at 2, 4, and 6 mm from the working length in 60 single-rooted teeth (6 canals/tooth, n = 360 canals). The teeth were randomly divided into three experimental irrigation groups: group 1 (n = 20), positive pressure irrigation (PPI); group 2 (n = 20), passive ultrasonic irrigation (PUI); and group 3 (n = 20), continuous ultrasonic irrigation (CUI). To assess the irrigation solution penetration, 20% Chinese ink (Sanford Rotring GmbH, Hamburg, Germany) was added to a 5% sodium hypochlorite solution and delivered into the curved root canals. The penetration of contrast solution into the simulated lateral canals was scored by counting the number of lateral canals (0-2) penetrated to at least 50% of the total length. Results The CUI group showed significantly higher (P irrigant penetration into the lateral canals and into the apical third of the main canals. The PPI group showed significantly lower sodium hypochlorite penetration (P irrigant penetration was observed in the PUI group than the PPI group. Conclusions Using CUI as the final rinse significantly increased the penetration of irrigant solution into the simulated lateral canals and apical third of curved roots. Key words:Continuous ultrasonic irrigation, curved root canals, passive ultrasonic irrigation, positive pressure irrigation, root canal irrigation.

  6. Role of the confinement of a root canal on jet impingement during endodontic irrigation

    NARCIS (Netherlands)

    Verhaagen, B.; Boutsioukis, C.; Heijnen, G. L.; van der Sluis, L. W. M.; Versluis, M.

    2012-01-01

    During a root canal treatment the root canal is irrigated with an antimicrobial fluid, commonly performed with a needle and a syringe. Irrigation of a root canal with two different types of needles can be modeled as an impinging axisymmetric or non-axisymmetric jet. These jets are investigated exper

  7. Choice of root canal irrigants by Serbian dental practitioners.

    Science.gov (United States)

    Tosić, Goran; Miladinović, Milan; Kovaević, Milorad; Stojanović, Miodrag

    2016-01-01

    Root canal treatment is considered to be the one of the most important procedures in endodontic treatment. To irrigate the root canal it is most common to use sodium hypochlorite (NaOCl), chlorhexodine, ethylenediaminetetraacetic acid (EDTA), local anesthetic solution, while the most used in Serbia is hydrogen peroxide (H2O2). The aim of this survey was to reveal the preferred root canal irrigants used by general dental practitioners in Serbia and to determine the influence of the continuing education program, delivered over the 3-year observation period, on work habits of dental practitioners. This was the first comprehensive survey of this nature carried out in Serbia. The survey was conducted in two instances, a 4-month observation period each, from November 1, 2009 to March 1, 2010 and from November 1, 2012 to March 1, 2013. Internet Web Page Survey was posted on the official web site of the Serbian Association of Private Dentists. In the first survey, 569 completed questionnaires were subjected to analysis. In the next attempt (3 years later), the survey was launched again and 615 completed questionnaires were analyzed using the same criteria. The statistical analysis was carried out with simple descriptive statistics applying the x2 test, at a significance level of p irrigant solution was H2O2 in 2009, while in 2012 it was yet H2O2, but also NaOCl, chlorhexodine, and a little less EDTA. This study shows significant changes in the irrigation protocol applied in Serbian dental community. After 3 years of observation, NaOCl became widely accepted as the irrigant of choice, whereas H2O2 lost its popularity.

  8. Disinfection of the root canal by sonic, ultrasonic and laser-activated irrigation

    NARCIS (Netherlands)

    van der Sluis, L.W.M.; Verhaagen, B.; Macedo, R.; Versluis, Andreas Michel; Cohenca, N.

    2014-01-01

    Irrigants are chemically inactivated after their reaction with the biofilm and therefore need to be mixed with fresh irrigants. Insight in the flow of the irrigant during a root canal treatment is crucial to understand the importance of the disinfection of the root canal system. This chapter

  9. Effect of the Irrigation Canal Network on Surface and Groundwater Interactions in the Lower Valley of the Cachapoal River, Chile Efecto de la Red de Canales de Riego en las Interacciones de Agua Superficial y Subterránea en la Parte Baja del Valle Del Río Cachapoal, Chile

    Directory of Open Access Journals (Sweden)

    José Luis Arumí

    2009-03-01

    Full Text Available Agricultural production of high value crops in Chile's Central Valley is highly dependent on surface and groundwater resources. They are connected and together form an integrated hydrological system, the individual components of which have to be studied. This research is addressed to answering two questions: 1 to what extent do irrigation and canal seepage contribute to groundwater recharge and 2 what is the influence of the interactions between the Cachapoal River and ground water. The study was carried out from 2003 to 2007 in Peumo Valley (34.3° S, 71.3° W. In winter, the irrigation canal network intercepts and diverts surface runoff, which flows to flat areas and recharges groundwater. In summer, infiltration from the canals recharges the aquifer directly and partially compensates for water uptake from plants and evaporation. The effects of both interactions keep groundwater at a relatively constant level over the whole year. The water balance of the valley is strongly affected by agricultural practices, groundwater recharge mainly originating from irrigation loss (22% and canal seepage (52%. It is important to know how management decisions, such as change in irrigation practices or canal lining, can affect the hydrological system and agricultural production within the valley.La producción agrícola de exportación en la Zona Central de Chile es altamente dependiente de los recursos hídricos superficiales y subterráneos, los que a su vez están conectados formando un solo sistema hidrológico a través de procesos que no están bien estudiados. Esta investigación apunta a responder dos preguntas de trabajo: 1 Entender el efecto de las filtraciones de los canales de riego en la recarga de los sistemas de aguas subterráneas; y 2 Identificar los patrones de interacción entre las aguas subterráneas y superficiales en el valle de Peumo. Este estudio se ejecutó entre los años 2003 y 2007 en el valle de Peumo, localizado en a Tercera

  10. Evaluation of hydraulic performance of downstream-controlled Maira-PHLC irrigation canals under crop-based irrigation operations

    NARCIS (Netherlands)

    Munir, S.; Schultz, B.; Suryadi, F.X.; Bharati, L.

    2012-01-01

    Demand-based irrigation systems are operated according to crop water requirements. As crop water requirements remain variable throughout the growing season, the discharges in the canal also vary to meet demands. The irrigation system under study is a demand-based semi-automatic irrigation system,

  11. Evaluation of hydraulic performance of downstream-controlled Maira-PHLC irrigation canals under crop-based irrigation operations

    NARCIS (Netherlands)

    Munir, S.; Schultz, B.; Suryadi, F.X.; Bharati, L.

    2012-01-01

    Demand-based irrigation systems are operated according to crop water requirements. As crop water requirements remain variable throughout the growing season, the discharges in the canal also vary to meet demands. The irrigation system under study is a demand-based semi-automatic irrigation system, wh

  12. The effect of four different irrigation systems in the removal of a root canal sealer.

    Science.gov (United States)

    Grischke, J; Müller-Heine, A; Hülsmann, M

    2014-09-01

    The aim of this study was to compare the efficiency of sonic, ultrasonic, and hydrodynamic devices in the removal of a root canal sealer from the surface and from simulated irregularities of root canals. Fifty-three root canals with two standardized grooves in the apical and coronal parts of longitudinally split roots were covered with AH Plus root canal sealer. Compared were the effects of (control) syringe irrigation, (1) CanalBrush, (2) passive ultrasonic irrigation, (3) EndoActivator, and (4) RinsEndo on the removal of the sealer. The specimens were divided into four groups (N = 12) and one control group (N = 5) via randomization. The amount of remaining sealer in the root canal irregularities was evaluated under a microscope using a 4-grade scoring system, whereas the remaining sealer on the root canal surface was evaluated with a 7-grade scoring system. Passive ultrasonic irrigation is more effective than the other tested irrigation systems or syringe irrigation in removing sealer from root canal walls (p ultrasonic irrigation shows a superior effect on sealer removal from the root canal surface during endodontic retreatment. Cleaning of lateral grooves seems not to be possible with one of the techniques investigated. Incomplete removal of root canal sealer during re-treatment may cause treatment failure. Passive Ultrasonic irrigation seems to be the most effective system to remove sealer from a root canal.

  13. Comparison of antimicrobial substantivity of root canal irrigants in instrumented root canals up to 72 h: an in vitro study.

    Science.gov (United States)

    Shahani, M N; Subba Reddy, V V

    2011-01-01

    Disinfection of the root canal system is one of the primary aims of root canal treatment. This can be achieved through the use of various antimicrobial agents in the form of irrigants and medicaments. The antimicrobial substantivity of 2% chlorhexidine gluconate, 1% povidone iodine, 2.5% hydrogen peroxide followed by 2% sodium hypochlorite, and 2% sodium hypochlorite alone as irrigants was assessed in instrumented root canals. 2% chlorhexidine showed antimicrobial substantivity lasting up to 72 h, followed by 1% povidone iodine, and 2% sodium hypochlorite. Thus 2% chlorhexidine should be used as a final rinse irrigant in endodontic treatment protocols.

  14. Comparison of antimicrobial substantivity of root canal irrigants in instrumented root canals up to 72 h: An in vitro study

    Directory of Open Access Journals (Sweden)

    M N Shahani

    2011-01-01

    Full Text Available Disinfection of the root canal system is one of the primary aims of root canal treatment. This can be achieved through the use of various antimicrobial agents in the form of irrigants and medicaments. The antimicrobial substantivity of 2% chlorhexidine gluconate, 1% povidone iodine, 2.5% hydrogen peroxide followed by 2% sodium hypochlorite, and 2% sodium hypochlorite alone as irrigants was assessed in instrumented root canals. 2% chlorhexidine showed antimicrobial substantivity lasting up to 72 h, followed by 1% povidone iodine, and 2% sodium hypochlorite. Thus 2% chlorhexidine should be used as a final rinse irrigant in endodontic treatment protocols.

  15. Comparison of irrigant penetration up to working length and into simulated lateral canals using various irrigating techniques.

    Science.gov (United States)

    Spoorthy, E; Velmurugan, N; Ballal, S; Nandini, S

    2013-09-01

    To evaluate the effect of an apical negative pressure system, a passive ultrasonic irrigation system and a combination of both apical negative pressure and passive ultrasonic irrigation on the penetration of the irrigating contrast solution (ICS) up to working length and into simulated lateral canals. The root canals of 64 single-rooted teeth were instrumented using the ProTaper rotary system. In each sample, three simulated lateral canals were created at 2, 4 and 6 mm levels from the root apex using a 06-size C+ file (Dentsply Maillefer, Ballaigues, Switzerland). Samples were randomly assigned into 4 experimental groups (n = 16): group I - conventional needle irrigation, group II - passive ultrasonic irrigation, group III - apical negative irrigation system and group IV - combination of passive ultrasonic irrigation and apical negative pressure irrigation system. To examine irrigating solution penetration, Indian ink was mixed with 5.25% NaOCl and delivered into the root canals. Samples were then assessed by direct observation of the images taken using Canon EOS rebel T3. The depth of penetration of ICS up to the working length and into the simulated lateral canals was analysed using chi-squared tests. The combination (ANP and PUI) and ANP group had significantly deeper ICS penetration up to the working length (P Endodontic Journal. Published by John Wiley & Sons Ltd.

  16. Laser-activated irrigation within root canals: cleaning efficacy and flow visualization

    NARCIS (Netherlands)

    de Groot, S.D.; Verhaagen, B.; Versluis, M.; Wu, M.K.; Wesselink, P.R.; van der Sluis, L.W.M.

    2009-01-01

    Aim  To test ex vivo the efficiency of laser-activated irrigation in removing dentine debris from the apical part of the root canal and to visualize in vitro the fluid dynamics during the activation of the irrigant by laser, using high-speed imaging at a relevant timescale. Methodology  Root canals

  17. Laser-activated irrigation within root canals : cleaning efficacy and flow visualization

    NARCIS (Netherlands)

    de Groot, S. D.; Verhaagen, B.; Versluis, M.; Wu, M. -K.; Wesselink, P. R.; van der Sluis, L. W. M.

    2009-01-01

    P>Aim To test ex vivo the efficiency of laser-activated irrigation in removing dentine debris from the apical part of the root canal and to visualize in vitro the fluid dynamics during the activation of the irrigant by laser, using high-speed imaging at a relevant timescale. Methodology Root canals

  18. A non-iterative cascaded predictive control approach for control of irrigation canals

    NARCIS (Netherlands)

    Negenborn, R.R.; Sahin, A.; Lukszo, Z.; De Schutter, B.; Morari, M.

    2009-01-01

    Irrigation canals transport water from water sources (such as large rivers and lakes) to water users (such as farmers). Irrigation canals are typically very large in nature, covering vast geographical areas, and involving a significant number of control actuators, such as pumps, gates, and locks. Th

  19. Passive ultrasonic irrigation of the root canal : a review of the literature

    NARCIS (Netherlands)

    van der Sluis, L. W. M.; Versluis, M.; Wu, M. K.; Wesselink, P. R.

    2007-01-01

    Ultrasonic irrigation of the root canal can be performed with or without simultaneous ultrasonic instrumentation. When canal shaping is not undertaken the term passive ultrasonic irrigation (PUI) can be used to describe the technique. In this paper the relevant literature on PUI is reviewed from a M

  20. Microstructure and wettability of root canal dentine and root canal filling materials after different chemical irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Antonijevic, Djordje; Milovanovic, Petar [Laboratory for Anthropology, Institute for Anatomy, Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Brajkovic, Denis [Department of Dentistry, Faculty of Medical Sciences, University of Kragujevac, Kragujevac (Serbia); Ilic, Dragan [Department of Restorative Medicine, School of Dental Medicine, University of Belgrade, Belgrade (Serbia); Hahn, Michael; Amling, Michael [Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Lottestr. 55A, 22529 Hamburg (Germany); Rakocevic, Zlatko [Laboratory for Atomic Physics, Institute for Nuclear Science “Vinca”, University of Belgrade, Belgrade (Serbia); Djuric, Marija [Laboratory for Anthropology, Institute for Anatomy, Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Busse, Björn, E-mail: b.busse@uke.uni-hamburg.de [Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Lottestr. 55A, 22529 Hamburg (Germany)

    2015-11-15

    Graphical abstract: - Highlights: • Different irrigation solutions and disinfectants were used for treatment of root canal dentine and gutta-percha points. • Materials surface characteristics were assessed using quantitative backscattered electron imaging, reference point indentation, and contact angle analyzer. • The most significant differences in mineralization, indentation, and adhesive outcomes were observed after ethylenediaminetetraacetic acid treatment. • Irrigation solutions confer to superior sealing ability of endodontic filling materials. • Micromechanical characteristics of dentine after irrigation are considerable reduced. - Abstract: The objective of this study was to determine the effects of various irrigation solutions on root canal dentine and gutta-percha surface properties. In addition, the effects of disinfectant chemicals on the wettability and surface morphological properties of the filling materials were evaluated. Ethylenediaminetetraacetic acid (EDTA), citric acid, and ozone were employed as irrigation solutions for dentine and gutta-percha treatment. Thereafter, the samples’ microstructure, degree of mineralization, and mechanical properties were assessed by means of quantitative backscattered electron imaging (qBEI) and reference point indentation (RPI). A contact angle analyzer was used to measure adhesion on the tested materials. Here, EDTA had the most significant affect on both the mechanical properties and the adhesive behavior of dentine. Citric acid did not affect dentine wettability, whereas the indentation properties and the mineralization were reduced. Similar effects were observed when ozone was used. The dentinal tubules were significantly widened in citric acid compared to the ozone group. EDTA causes considerable micromechanical surface alteration of dentine and gutta-percha, but represents the best option in clinical cases where a high adhesiveness of the filling materials is desired.

  1. Nested Canalizing Functions and Their Networks

    CERN Document Server

    Kadelka, Claus; Adeyeye, John O; Laubenbacher, Reinhard

    2014-01-01

    The concept of a nested canalizing Boolean function has been studied over the last decade in the context of understanding the regulatory logic of molecular interaction networks, such as gene regulatory networks. Such networks are predominantly governed by nested canalizing functions. Derrida values are frequently used to analyze the robustness of a Boolean network to perturbations. This paper introduces closed formulas for the calculation of Derrida values of networks governed by Boolean nested canalizing functions, which previously required extensive simulations. Recently, the concept of nested canalizing functions has been generalized to include multistate functions, and a recursive formula has been derived for their number, as a function of the number of variables. This paper contains a detailed analysis of the class of nested canalizing functions over an arbitrary finite field. In addition, the concept of nested canalization is further generalized and closed formulas for the number of such generalized fun...

  2. Utilizing geophysical methods for asessment and characterization of canal seepage in El Paso's lower valley irrigation delivery systems

    Science.gov (United States)

    Cegon, Amanda Brooke

    El Paso County Water Improvement District No. 1 (EPCWID No.1) delivers the Rio Grande water for agricultural production and urban uses through numerous networked irrigation canals. Of the nearly 86 billion gallons of water released annually for irrigation uses in Texas, billions are lost due to evaporation and seepage in unlined canals with 56 million gallons of the billions are lost in Franklin Canal annually due to improper lining and sediment variation of the canals. To characterize seepage patterns and identify areas of high seepage, Electrical Resistivity, Ground Truthing via soil sample analysis were used along three, half-mile long sectioned canals during irrigation and non-irrigation seasons. The data lines acquired were processed in EARTHIMAGER 2D to create 2D vertical resistivity inversion profiles to locate potential areas of high seepage/high resistivity. The research results will help El Paso County Water Improvement District No. 1 to develop management strategies to conserve water and improve the delivery efficiency systems which leads to economic growth in the Rio Grande Basin.

  3. Comparison of a continuous ultrasonic irrigation device and conventional needle irrigation in the removal of root canal debris.

    Science.gov (United States)

    Curtis, Tyson O; Sedgley, Christine M

    2012-09-01

    The purpose of this in vitro study was to compare a continuous ultrasonic irrigation device (VPro StreamClean System [VSS], Vista Dental Products, Racine, WI) with conventional needle irrigation when used as a final irrigation procedure to debride the apical region of the root canal. The null hypothesis that there is no difference was tested. Root canals of matched pairs (N = 20) of extracted human teeth were prepared to an apical size of 36/.04 using Profile series 29/.04 rotary files (Dentsply Tulsa Dental, Tulsa, OK) with 6% sodium hypochlorite (NaOCl) irrigation. One tooth of each pair was randomly assigned to receive final irrigation with either VSS or conventional needle irrigation. The gauge of the needle (#30), the irrigation cycles (ie, 5 mL NaOCl, 5 mL 15% EDTA, and 5 mL NaOCl), the irrigant flow rate (5 mL/min), and needle depth placement (1 mm from the working length [WL]) were experimental constants. Serial sections were obtained at 1 and 3 mm from the WL, stained with hematoxylin-eosin, and viewed at 100× magnification for the presence of debris. The percentage of debris in the canal lumen after VSS or conventional needle irrigation was compared by using the Wilcoxon matched pairs test. There was significantly less debris in the VSS group compared with the conventional needle irrigation group at the 1-mm level (1.50% [VSS] vs 9.90% [conventional needle irrigation], P = .0001) and the 3-mm level (0.45% [VSS] vs 5.16% [conventional needle irrigation], P = .0014). The null hypothesis was rejected. Final irrigation with the VSS compared with conventional needle irrigation delivery resulted in significantly less debris present in root canals at 1 and 3 mm from the WL. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Debris and smear removal in flattened root canals after use of different irrigant agitation protocols.

    Science.gov (United States)

    Ribeiro, Eduardo Milani; Silva-Sousa, Yara T C; Souza-Gabriel, Aline Evangelista; Sousa-Neto, Manoel Damião; Lorencetti, Karina Torales; Silva, Silvio Rocha Correa

    2012-06-01

    Scanning electron microscopy (SEM) can be used to analyze the presence of debris and smear layer on the internal walls of root canal. This study evaluated the debris and smear removal in flattened root canals using SEM after use of different irrigant agitation protocols. Fifty mandibular incisors were distributed into five groups (n = 10) according to the irrigant agitation protocol used during chemomechanical preparation: conventional syringe irrigation with NaviTip needle (no activation), active scrubbing of irrigant with brush-covered NaviTip FX needle, manual dynamic irrigation, continuous passive ultrasonic irrigation, and apical negative pressure irrigation (EndoVac system). Canals were irrigated with 5 mL of 2.5% NaOCl at each change of instrument and received a final flush with 17% EDTA for 1 min. After instrumentation, the roots were split longitudinally and SEM micrographs at ×100 and ×1,000 were taken to evaluate the amount of debris and smear layer, respectively, in each third. Data were analyzed by Kruskal-Wallis and Dunn's post-hoc tests (α = 5%). Manual dynamic activation left significantly (p protocols, while ultrasonic irrigation and EndoVac were the most effective (p 0.05) either among the irrigant agitation protocols or between the protocol-canal third interactions. Although none of the irrigant agitation protocols completely removed debris and smear layer from flattened root canals, the machine-assisted agitation systems (ultrasound and EndoVac) removed more debris than the manual techniques.

  5. On Modeling and Constrained Model Predictive Control of Open Irrigation Canals

    Directory of Open Access Journals (Sweden)

    Lihui Cen

    2017-01-01

    Full Text Available This paper proposes a model predictive control of open irrigation canals with constraints. The Saint-Venant equations are widely used in hydraulics to model an open canal. As a set of hyperbolic partial differential equations, they are not solved explicitly and difficult to design optimal control algorithms. In this work, a prediction model of an open canal is developed by discretizing the Saint-Venant equations in both space and time. Based on the prediction model, a constrained model predictive control was firstly investigated for the case of one single-pool canal and then generalized to the case of a cascaded canal with multipools. The hydraulic software SICC was used to simulate the canal and test the algorithms with application to a real-world irrigation canal of Yehe irrigation area located in Hebei province.

  6. A new method for real-time quantification of irrigant extrusion during root canal irrigation ex vivo

    NARCIS (Netherlands)

    Psimma, Z.; Boutsioukis, C.; Vasiliadis, L.; Kastrinakis, E.

    2013-01-01

    Aim (i) To introduce a new method of quantifying extruded irrigant during root canal irrigation ex vivo. (ii) to evaluate the effect of periapical tissue simulation and pressure equalization and (iii) to determine the effect of needle type, apical preparation size and apical constriction diameter

  7. Laser assisted irrigation and hand irrigation for root canal decontamination: a comparison

    Science.gov (United States)

    Olivi, M.; Stefanucci, M.; Todea, C.

    2014-01-01

    Aim: to compare the bactericidal efficiency of conventional method and LAI for root canal decontamination. Material and method: 22 human single root teeth, extracted for periodontal problems, mechanically prepared up to ISO 25 at the working lenght were divided in 2 groups: after sterilization, the teeth were infected with enterococcus faecalis and incubated for 4 weeks. Group A: 10 teeth were irrigated with conventional hand technique (CI): 3ml of 5% NaClO were used for two times of 30s each and after washing with sterile bi-distilled water for 20s, a final irrigation was performed with 3ml of 17% EDTA. Group B: 10 teeth were irrigated with 3ml of NaClO and activated by erbium laser, two cycles of 30s; also the final irrigation with 3ml of 17% EDTA was activated by erbium laser. In both the groups a resting time of 30s was used between the two sessions to allow the reaction rate of NaClO. The Erbium laser 2940 nm (LightWalker AT, Fotona; Lublijana, Slovenia) was used with 50microsecond pulse duration, at 15Hz, 20mJ, with a 600micron PIPS tip. Two samples were used as positive and negative control.

  8. Radiographic evaluation of root canal cleaning, main and laterals, using different methods of final irrigation

    Directory of Open Access Journals (Sweden)

    Gisselle Moraima CHÁVEZ-ANDRADE

    Full Text Available OBJECTIVE: To evaluate the efficacy of passive ultrasonic irrigation (PUI using intermittent or continuous flushing and conventional manual irrigation (CMI on the cleaning of main and simulated lateral root canals.MATERIAL AND METHOD: The root canals of 24 artificial teeth were prepared and simulated lateral canals were made in the medium and apical thirds of the root. The specimens were divided into three groups: G1- CMI, G2- PUI 1 (intermittent flushing and G3- PUI 2 (continuous flushing. Root canals were filled with contrast solution and the roots were radiographed pre- and post-irrigation. The digital images were transferred to Image Tool 3.0 software and the areas of root canal completely filled with contrast, and after irrigation with contrast remnant, were measured to obtain percentage data. Statistical analysis between groups was performed by ANOVA and Tukey tests.RESULT: In the apical third, G2 and G3 (PUI groups showed higher percentage of cleaning than G1 (CMI (p<0.05.CONCLUSION: Passive ultrasonic irrigation using intermittent flushing promoted a higher cleaning of simulated lateral canals than conventional manual irrigation in the apical third. There were no differences between groups in the main root canal and the middle third.

  9. Yard flooding by irrigation canals increased the risk of West Nile disease in El Paso, Texas

    Science.gov (United States)

    Cardenas, Victor M.; Jaime, Javier; Ford, Paula B.; Gonzalez, Fernando J.; Carrillo, Irma; Gallegos, Jorge E.; Watts, Douglas M.

    2011-01-01

    Purpose To investigate the effects of use of water from irrigation canals to flood residential yards on the risk of West Nile disease in El Paso, Texas. Methods West Nile disease confirmed cases in 2009–2010 were compared with a random sample of 50 residents of the county according to access to and use of water from irrigation canals by subjects or their neighbors, as well as geo-referenced closest distance between their home address and the nearest irrigation canal. A windshield survey of 600 meters around the study subjects’ home address recorded the presence of irrigation canals. The distance from the residence of 182 confirmed cases of West Nile disease reported in 2003–2010 to canals was compared to that of the centroids of 182 blocks selected at random. Results Cases were more likely than controls to report their neighbors flooded their yards with water from canals. Irrigation canals were more often observed in neighborhoods of cases than of controls. Using the set of addresses of 182 confirmed cases and 182 hypothetic controls the authors found a statistically significant inverse relation with risk of West Nile disease. Conclusions Flooding of yards with water from canals increased the risk of West Nile disease. PMID:21943648

  10. Irrigation of human prepared root canal – ex vivo based computational fluid dynamics analysis

    Science.gov (United States)

    Šnjarić, Damir; Čarija, Zoran; Braut, Alen; Halaji, Adelaida; Kovačević, Maja; Kuiš, Davor

    2012-01-01

    Aim To analyze the influence of the needle type, insertion depth, and irrigant flow rate on irrigant flow pattern, flow velocity, and apical pressure by ex-vivo based endodontic irrigation computational fluid dynamics (CFD) analysis. Methods Human upper canine root canal was prepared using rotary files. Contrast fluid was introduced in the root canal and scanned by computed tomography (CT) providing a three-dimensional object that was exported to the computer-assisted design (CAD) software. Two probe points were established in the apical portion of the root canal model for flow velocity and pressure measurement. Three different CAD models of 27G irrigation needles (closed-end side-vented, notched open-end, and bevel open-end) were created and placed at 25, 50, 75, and 95% of the working length (WL). Flow rates of 0.05, 0.1, 0.2, 0.3, and 0.4 mL/s were simulated. A total of 60 irrigation simulations were performed by CFD fluid flow solver. Results Closed-end side-vented needle required insertion depth closer to WL, regarding efficient irrigant replacement, compared to open-end irrigation needle types, which besides increased velocity produced increased irrigant apical pressure. For all irrigation needle types and needle insertion depths, the increase of flow rate was followed by an increased irrigant apical pressure. Conclusions The human root canal shape obtained by CT is applicable in the CFD analysis of endodontic irrigation. All the analyzed values –irrigant flow pattern, velocity, and pressure – were influenced by irrigation needle type, as well as needle insertion depth and irrigant flow rate. PMID:23100209

  11. Comparative antimicrobial efficacy of selected root canal irrigants on commonly isolated microorganisms in endodontic infection.

    Science.gov (United States)

    Dubey, Sandeep; Saha, Suparna Ganguly; Rajkumar, Balakrishnan; Dhole, Tapan Kumar

    2017-01-01

    This study aims to evaluate and compare the antimicrobial efficacy of three selected root canal irrigants (BioPure MTAD, metronidazole, aztreonam) against microbes commonly isolated from polymicrobial microbiota of root canal infection. This study was designed with four experimental groups (Group I - Bacteroides fragilis, Group II - Propionibacterium acnes, Group III - Enterococcus faecalis, Group IV - Candida albicans) based on the microbes selected for the study. Group I and Group II bacteria were used to compare and evaluate antimicrobial effect of BioPure MTAD, metronidazole, aztreonam, and normal saline. Group III and Group IV bacteria were used to compare and evaluate antimicrobial efficacy of BioPure MTAD, aztreonam, and normal saline. Normal saline was used as a control irrigant in this study. Agar disc diffusion method was applied to assess and compare the antimicrobial action of selected irrigants. Metronidazole was found to be the most effective root canal irrigant against B. fragilis and P. acnes among the tested irrigants. Mean zone of inhibition against E. faecalis has been shown to be maximum by BioPure MTAD, followed by aztreonam. Antifungal effect against C. albicans was only shown by BioPure MTAD. Overall, BioPure MTAD is the most effective root canal irrigant as it has shown an antibacterial effect against all the tested microorganisms. However, metronidazole showed maximum antibacterial effect against obligate anaerobes. Aztreonam also showed an antibacterial effect in the present study, raising its possibility to be used as a root canal irrigant in the future.

  12. Laser Induced Explosive Vapor and Cavitation Resulting in Effective Irrigation of the Root Canal. Part 2 : Evaluation of the Efficacy

    NARCIS (Netherlands)

    De Moor, Roeland Jozef Gentil; Blanken, Jan; Meire, Maarten; Verdaasdonk, Rudolf

    2009-01-01

    Background and Objectives: Limited information exists regarding the efficacy of laser activated irrigation (LAI) on removal of root canal debris. This study compares the efficacy of LAI for removal of debris in root canals as compared to conventional irrigation (CI) and passive ultrasonic irrigation

  13. Laser Induced Explosive Vapor and Cavitation Resulting in Effective Irrigation of the Root Canal. Part 2 : Evaluation of the Efficacy

    NARCIS (Netherlands)

    De Moor, Roeland Jozef Gentil; Blanken, Jan; Meire, Maarten; Verdaasdonk, Rudolf

    Background and Objectives: Limited information exists regarding the efficacy of laser activated irrigation (LAI) on removal of root canal debris. This study compares the efficacy of LAI for removal of debris in root canals as compared to conventional irrigation (CI) and passive ultrasonic irrigation

  14. The effect of root canal taper on the irrigant flow: evaluation using an unsteady Computational Fluid Dynamics model

    NARCIS (Netherlands)

    Boutsioukis, C.; Gogos, C.; Verhaagen, B.; Versluis, M.; Kastrinakis, E.; van der Sluis, L.W.M.

    2010-01-01

    Aim  To evaluate the effect of root canal taper on irrigant flow inside a prepared root canal during final irrigation with a syringe and two types of needles, using a Computational Fluid Dynamics (CFD) model. Methodology  A validated CFD model was used to simulate irrigant flow from either a side-ve

  15. The effect of root canal taper on the irrigant flow: evaluation using an unsteady Computational Fluid Dynamics model

    NARCIS (Netherlands)

    Boutsioukis, C.; Gogos, C.; Verhaagen, B.; Versluis, M.; Kastrinakis, E.; Sluis, van der L.W.M.

    2010-01-01

    Aim  To evaluate the effect of root canal taper on irrigant flow inside a prepared root canal during final irrigation with a syringe and two types of needles, using a Computational Fluid Dynamics (CFD) model. Methodology  A validated CFD model was used to simulate irrigant flow from either a side-v

  16. Uncontrolled removal of dentin during in vitro ultrasonic irrigant activation in curved root canals

    NARCIS (Netherlands)

    Retsas, A.; Koursoumis, A.; Tzimpoulas, N.; Boutsioukis, C.

    2016-01-01

    Introduction: The aim of this study was to examine the effect of file type and activation time on the uncontrolled removal of dentin during in vitro ultrasonic irrigant activation in prepared curved root canals. Methods: Seventy-two curved mesial root canals of human mandibular molars were prepared

  17. An evaluation of the influence of passive ultrasonic irrigation on the seal of root canal fillings

    NARCIS (Netherlands)

    van der Sluis, L. W. M.; Shemesh, H.; Wu, M. K.; Wesselink, P. R.

    2007-01-01

    Aim To evaluate the influence of passive ultrasonic irrigation (PUI) on the seal of root canal fillings. Methodology A total of 40 mandibular premolars were distributed equally into two groups and the root canals were cleaned and shaped; they were then filled with gutta-percha and AH26 (sealer) usin

  18. Uncontrolled removal of dentin during in vitro ultrasonic irrigant activation in curved root canals

    NARCIS (Netherlands)

    Retsas, A.; Koursoumis, A.; Tzimpoulas, N.; Boutsioukis, C.

    2016-01-01

    Introduction: The aim of this study was to examine the effect of file type and activation time on the uncontrolled removal of dentin during in vitro ultrasonic irrigant activation in prepared curved root canals. Methods: Seventy-two curved mesial root canals of human mandibular molars were prepared

  19. Effect of needle insertion depth and root canal curvature on irrigant extrusion ex vivo

    NARCIS (Netherlands)

    Psimma, Z.; Boutsioukis, C.; Kastrinakis, E.; Vasiliadis, L.

    2013-01-01

    Introduction The aim of this study was to evaluate the effect of needle type and insertion depth, apical preparation size, and root canal curvature on irrigant extrusion by using a recently introduced method. Methods Sixteen human teeth with a straight root canal (group A) and 16 with a moderatel

  20. Laser-activated irrigation within root canals: cleaning efficacy and flow visualization

    NARCIS (Netherlands)

    Groot, de S.D.; Verhaagen, B.; Versluis, M.; Wu, M.-K.; Wesselink, P.R.; Sluis, van der L.W.M.

    2009-01-01

    Aim: To test ex vivo the efficiency of laser-activated irrigation in removing dentine debris from the apical part of the root canal and to visualize in vitro the fluid dynamics during the activation of the irrigant by laser, using high-speed imaging at a relevant timescale. - Methodology: Root cana

  1. Effects of various irrigation/aspiration protocols on cleaning of flattened root canals.

    Science.gov (United States)

    Mendonça, Diego Henrique da Silva; Colucci, Vivian; Rached-Junior, Fuad Jacob Abi; Miranda, Carlos Eduardo Saraiva; Silva-Sousa, Yara Teresinha Corrêa; Silva, Silvio Rocha Corrêa da

    2015-01-01

    This study aimed to evaluate, by means of scanning electron microscopy (SEM), the cleaning of flattened root canals, varying irrigation/aspiration protocols during biomechanical preparation. Thirdy human mandibular incisors were distributed into three groups (n = 10) according to the aspiration/irrigation protocols: conventional, conventional + brush, and apical negative pressure irrigation. Irrigation procedure was performed with 5 mL of 1% NaOCl at each change of instrument; final irrigation was conducted with 17% EDTA for 5 min. After biomechanical preparation, the roots were sectioned and prepared for SEM analysis. The images obtained were evaluated under 35× and 1,000× magnification by three calibrated examiners, following a double-blind design. All data were analyzed using Kruskal-Wallis and Dunn's post hoc tests (α = 0.05). Canals wherein the conventional method and apical negative pressure irrigation were employed revealed less debris, statistically different from the conventional + brush group (p protocols. Comparing each root canal third revealed that the apical portion was difficult to clean as all the tested protocols showed similar high scores (p > 0.05), both for the presence of debris and smear layer. In conclusion, although none of the studied irrigation/aspiration protocols have completely cleaned flattened root canals, apical negative pressure irrigation was more effective in smear layer removal, whereas the conventional + brush protocol was the least effective in removing the debris and smear layer.

  2. [Endodontics in motion: new concepts, materials and techniques 3. The role of irrigants during root canal treatment].

    Science.gov (United States)

    van der Sluis, L W M

    2015-10-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm) and their products from the root canal wall, their removal out of the root canal system and their chemical dissolution or disruption. Each of the endodontic irrigation systems has its own irrigant flow characteristics, which should fulfill these aims. Without flow (convection), the irrigant would have to be distributed through diffusion. This process is slow and depends on temperature and concentration gradients. On the other hand, convection is a faster and more efficient transport mechanism. During irrigant flow, frictional forces will occur, for example between the irrigant and the root canal wall (wall shear stress). These frictional forces have a mechanical cleaning effect on the root canal wall. These frictional forces are the result of the flow characteristics related to the different irrigation systems.

  3. The influence of volume, type of irrigant and flushing method on removing artificially placed dentine debris from the apical root canal during passive ultrasonic irrigation

    NARCIS (Netherlands)

    van Der Sluis, LWM; Gambarini, G; Wu, MK; Wesselink, PR

    2006-01-01

    Aim To determine the influence of volume, irrigant and method of flushing on the removal of artificially-placed dentine debris from the apical part of root canals during passive ultrasonic irrigation. Methodolgy Access cavities were prepared in 15 canine teeth and their root canals instrumented to s

  4. Root Canal Irrigation: Chemical Agents and Plant Extracts Against Enterococcus faecalis

    Science.gov (United States)

    Borzini, Letizia; Condò, Roberta; De Dominicis, Paolo; Casaglia, Adriano; Cerroni, Loredana

    2016-01-01

    Background: There are various microorganisms related to intra and extra-radicular infections and many of these are involved in persistent infections. Bacterial elimination from the root canal is achieved by means of the mechanical action of instruments and irrigation as well as the antibacterial effects of the irrigating solutions. Enterococcus faecalis can frequently be isolated from root canals in cases of failed root canal treatments. Antimicrobial agents have often been developed and optimized for their activity against endodontic bacteria. An ideal root canal irrigant should be biocompatible, because of its close contact with the periodontal tissues during endodontic treatment. Sodium hypoclorite (NaOCl) is one of the most widely recommended and used endodontic irrigants but it is highly toxic to periapical tissues. Objectives: To analyze the literature on the chemotherapeutic agent and plant extracts studied as root canal irrigants. In particularly, the study is focused on their effect on Enterococcus faecalis. Method: Literature search was performed electronically in PubMed (PubMed Central, MEDLINE) for articles published in English from 1982 to April 2015. The searched keywords were “endodontic irrigants” and “Enterococcus faecalis” and “essential oil” and “plant extracts”. Results: Many of the studied chemotherapeutic agents and plant extracts have shown promising results in vitro. Conclusion: Some of the considered phytotherapic substances, could be a potential alternative to NaOCl for the biomechanical treatment of the endodontic space. PMID:28217184

  5. Influence of the endodontic irrigation needle and root canal enlargement on endodontic cleaning efficacy

    Directory of Open Access Journals (Sweden)

    Livia Etchebehere de Loiola

    2011-04-01

    Full Text Available ntroduction: The irrigation of root canals aims to their cleaning and disinfection, improving endodontic treatment success. Objective: To investigate the influence of the diameter and type of irrigation needle and the root canal enlargement on the mechanical efficacy of endodontic irrigation. Material and methods: Twelve human single-rooted mandibular incisors were used. During some instrumentation stages (enlargement by #20, #30, and #40 K file, root canals were filled with radiographic contrast solution mixed to propyleneglycol and zinc oxide. Needles with different diameters and designs were employed: G1 – 23G and lateral opening; G2 – 22G and apical opening; G3 – 30G and lateral opening; G4 – 30G and apical opening. The needles were inserted up to resistance, with 1 mm step-back to avoid root canal obliteration. The irrigation was performed with 2 mL of distilled water. Before and after irrigation/aspiration, teeth were radiographed at bucco-lingual and mesiodistal direction, using a digital radiographic system. Then, root canal areas, before (filled by contrast solution and after irrigation (remnant of contrast solution, were submitted to image subtraction with Adobe Photoshop CS4 software. Subsequently, the areas were measured by Image Tool 3.0 software, allowing the obtaining of the cleaning percentage for each modality. Data were analysed byusing Anova and Tukey’s test. The level of significance was set at P < 0.05. Results: For all root canal enlargements, 30G needles (G3 e G4 presented a better cleaning efficacy. In all groups, higher cleaning efficacy percentage was observed at #30 and #40 K file enlargement. Conclusion: Regardless their design, thinner needles were more effective; a better cleaning efficacy occurred in more enlarged root canals.

  6. Delineating ground water recharge from leaking irrigation canals using water chemistry and isotopes.

    Science.gov (United States)

    Harvey, F E; Sibray, S S

    2001-01-01

    Across the Great Plains irrigation canals are used to transport water to cropland. Many of these canals are unlined, and leakage from them has been the focus of an ongoing legal, economic, and philosophical debate as to whether this lost water should be considered waste or be viewed as a beneficial and reasonable use since it contributes to regional ground water recharge. While historically there has been much speculation about the impact of canal leakage on local ground water, actual data are scarce. This study was launched to investigate the impact of leakage from the Interstate Canal, in the western panhandle of Nebraska, on the hydrology and water quality of the local aquifer using water chemistry and environmental isotopes. Numerous monitoring wells were installed in and around a small wetland area adjacent to the canal, and ground water levels were monitored from June 1992 until January 1995. Using the water level data, the seepage loss from the canal was estimated. In addition, the canal, the monitoring wells, and several nearby stock and irrigation wells were sampled for inorganic and environmental isotope analysis to assess water quality changes, and to determine the extent of recharge resulting from canal leakage. The results of water level monitoring within study wells indicates a rise in local ground water levels occurs seasonally as a result of leakage during periods when the canal is filled. This rise redirects local ground water flow and provides water to nearby wetland ecosystems during the summer months. Chemical and isotopic results were used to delineate canal, surface, and ground water and indicate that leaking canal water recharges both the surface alluvial aquifer and upper portions of the underlying Brule Aquifer. The results of this study indicate that lining the Interstate Canal could lower ground water levels adjacent to the canal, and could adversely impact the local aquifer.

  7. Neglected Canals: Deterioration of Indigenous Irrigation System by Urbanization in the West Peri-Urban Area of Bangkok Metropolitan Region

    Directory of Open Access Journals (Sweden)

    Yuji Hara

    2012-01-01

    Full Text Available This paper discusses the deterioration of indigenous irrigation system traditionally developed in the past to serve the peri-urban agricultural lands that have been affected by rapid urbanization in the Bangkok Metropolitan Region. The study is based on data collection from mapping, field survey and interview analyses and identifies current canal deteriorating conditions in four categories: filled, covered, narrowed and shallow, and normal. The findings reveal that different types of canal deteriorations are associated with their private ownership. A typology of land configurations of urban and non-urban land uses along private canals is pointed out in order to understand their relation with canal deterioration types. Caused by urbanization, the degradation of the existing canal networks has provoked conflicts between local farmers and new proprietors, especially real estate developers. Such canal deterioration essentially reduces their ability to convey a water supply to feed agricultural lands, consequently leading to the discontinuation of land use for agriculture and its eventual transformation into urban developments.

  8. Optimizing the chemical aspect of root canal irrigation

    NARCIS (Netherlands)

    R.G. de Macedo

    2013-01-01

    Root canal treatment is aimed at the removal of inflamed and infected tissue present in the root canal system. It will prevent the entrance of new microorganisms or nutrients in order to maintain or create a healthy environment around the root. There is sufficient evidence that shows that traditiona

  9. Fractional-order mathematical model of an irrigation main canal pool

    Directory of Open Access Journals (Sweden)

    Shlomi N. Calderon-Valdez

    2015-09-01

    Full Text Available In this paper a fractional order model for an irrigation main canal is proposed. It is based on the experiments developed in a laboratory prototype of a hydraulic canal and the application of a direct system identification methodology. The hydraulic processes that take place in this canal are equivalent to those that occur in real main irrigation canals and the results obtained here can therefore be easily extended to real canals. The accuracy of the proposed fractional order model is compared by deriving two other integer-order models of the canal of a complexity similar to that proposed here. The parameters of these three mathematical models have been identified by minimizing the Integral Square Error (ISE performance index existing between the models and the real-time experimental data obtained from the canal prototype. A comparison of the performances of these three models shows that the fractional-order model has the lowest error and therefore the higher accuracy. Experiments showed that our model outperformed the accuracy of the integer-order models by about 25%, which is a significant improvement as regards to capturing the canal dynamics.

  10. Mortality of vertebrates in irrigation canals in an area of west-central Spain

    Directory of Open Access Journals (Sweden)

    P. Garcia

    2009-01-01

    Full Text Available Mortality patterns of vertebrates in irrigation canals have been poorly studied despite their potential impact on wildlife. Concrete irrigation canals in a cropland area in west-central Spain were monitored over 13 months to assess their impact on small fauna. A total of 134 vertebrates were found dead. Most were amphibians (86.46% or mammals (20.90%, though fishes, reptiles and a bird were also recorded. Mortality peaked in autumn months. Corrective measurements are needed to reduce this cause of non-natural mortality.

  11. BACTERICIDAL EFFECTS OF VARIOUS IRRIGATION SOLUTIONS AGAINST STAPHYLOCOCCUS AUREUS IN HUMAN ROOT CANAL

    Directory of Open Access Journals (Sweden)

    Recai Zan

    2015-01-01

    Full Text Available Purpose: The aim of the present study was to evaluate and to compare the antibacterial effects of various irrigation solutions against Staphylococcus aureus (S. aureus in human root canals. Materials and Methods: 120 single-root mandibular premolar teeth were selected. The teeth were prepared and sterilized. S. aureus was incubated in the root canals and kept at 37°C for 24h. The infected root canals were divided into one positive (saline and one negative (sodium hypochlorite control, and four experimental groups [Ethylene-diaminetetra-aceticacid, Chlorhexidine Gluconate, Super-oxidized water(SPO, Aqueous ozone] (n=20. Flow rate of irrigation was applied with 5 mL/min flow rate for 3 min to ensure standardization among all study groups. Following the irrigation, paper points were placed in the root canals and then transferred in sterile eppendorf. Remaining bacteria were counted on blood agar plates and the data were analyzed using one-way ANOVA and Tukey’s test. Results: Although there were statistically significant differences among SPO and other experimental groups (p0.05. Conclusion: Super-oxidized water may be recommended as an alternative irrigation solution instead of NaOCl against S. aureus in root canals.

  12. Root canal debris removal using different irrigating needles: An SEM study

    Directory of Open Access Journals (Sweden)

    Sheetal Ghivari

    2011-01-01

    Full Text Available Aim: This study was carried out to compare the efficacy of three irrigating needle designs in removal of debris from different parts of the root canal. Materials and Methods: Thirty human maxillary canines were prepared using HERO Shaper rotary system and irrigated with 1 ml of 5.25% sodium hypochlorite (NaOCl after each instrument change. Three 25-gauge irrigation needle designs - brush-covered Navi Tip FX (Group I, side-vented needle RC Twents (Group II and single-beveled (Group III irrigating needles - were tested for their efficiency in debris removal in three different parts of the root canal (n=10 canals per group. Following instrumentation, the roots were vertically sectioned and divided into coronal, middle and apical thirds for observation under scanning electron microscope (×200 magnification. Debris on the canal wall was evaluated by using a four-scale scoring system described by Paque and his co-workers. Results: The canals irrigated with brush-covered needle Navi Tip FX (Group I showed lower average debris score, indicating greater removal of debris in coronal third as compared to middle and apical thirds, whereas the canals irrigated with side-vented needle (Group II and single-beveled needle (Group III exhibited lower average score in the middle third than coronal and apical thirds. All the three needle designs exhibited higher debris score in apical third of the root canal. Tukey multiple comparisons test was applied at a significance level of P>0.05. A statistically significant difference (P<0.05 was observed in the debris removal in the coronal and middle thirds of root canals irrigated with brush-covered Navi Tip FX (Group I and side-vented (Group II needles, respectively, when compared with other needle design groups. Conclusion: Within the limitations of this study, it can be concluded that all the needle designs tested were effective in certain regions of the root canal with apical third uncleaned. Side-vented needle by

  13. Physicochemical Properties, Contamination and Suitability of Canal Water for Irrigation, Lahore Branch Pakistan

    Directory of Open Access Journals (Sweden)

    Tayyaba Aftab

    2011-12-01

    Full Text Available The pollution status of Lahore branch canal was determined by physical, chemical and metal constituents because the water is used for irrigation of lands in and around the city. The average result of each physical, chemical and metal parameter at 12 different sites (Location-1 to Location-12 of Lahore branch canal was compared with Food and Agricultural organization (FAO. All physical and chemical parameters were within standards limit while metals concentrations were found in variable quantities in canal water samples. cadmium, copper and chromium concentration was found much higher than the permissible FAO standards.

  14. Efficacy of different irrigants in the removal of calcium hydroxide from root canals.

    Science.gov (United States)

    Rödig, T; Vogel, S; Zapf, A; Hülsmann, M

    2010-06-01

    To compare the efficacy of different solutions (1% sodium hypochlorite, 10% citric acid and 20% EDTA) in the removal of calcium hydroxide from root canals. One hundred single-rooted maxillary incisors were prepared to size 50 and split longitudinally. Two standardized grooves were cut into the apical and coronal part of the root canal dentine and filled with calcium hydroxide. The reassembled teeth were irrigated with a syringe and a size 30 needle using the following irrigants: (i) 20% EDTA, (ii) 10% citric acid, (iii) 1% NaOCl, (iv) 10% citric acid + 1% NaOCl, (v) 20% EDTA + 1% NaOCl and (vi) water (control). Volume of irrigant was 20 mL in each group, and irrigation time was 5 min. Evaluation of cleanliness of the blinded specimens was performed by two calibrated observers under a microscope with 30x magnification using a four-grade scoring system as described by van der Sluis et al. (2007). Statistical evaluation was performed using a SAS-macro for non-parametric multifactorial analysis (P irrigation with EDTA and citric acid, whereas NaOCl and water showed the least effect. The combinations of irrigants did not result in improvement in terms of cleanliness. None of the irrigants nor their respective combinations were able to completely remove the calcium hydroxide. Chelating agents such as citric acid and EDTA showed the best results. The combination of chelators and NaOCl did not result in significant improvement of calcium hydroxide removal.

  15. The effect of apical preparation size on irrigant flow in root canals evaluated using an unsteady Computational Fluid Dynamics model

    NARCIS (Netherlands)

    Boutsioukis, C.; Gogos, C.; Verhaagen, B.; Versluis, M.; Kastrinakis, E.; van der Sluis, L.W.M.

    2010-01-01

    Aim  To evaluate the effect of apical preparation size on irrigant flow inside a root canal during final irrigation with a syringe and two different needles types, using a Computational Fluid Dynamics (CFD) model. Methodology  A validated CFD model was used to simulate the irrigant flow from either

  16. Evaluation of irrigant flow in the root canal using different needle types by an unsteady computational fluid dynamics model

    NARCIS (Netherlands)

    Boutsioukis, C.; Verhaagen, B.; Versluis, M.; Kastrinakis, E.; Wesselink, P.R.; van der Sluis, L.W.M.

    2010-01-01

    Introduction The aim of this study was to evaluate the effect of needle tip design on the irrigant flow inside a prepared root canal during final irrigation with a syringe using a validated Computational Fluid Dynamics (CFD) model. Methods A CFD model was created to simulate the irrigant flow inside

  17. Evaluation of Irrigant Flow in the Root Canal Using Different Needle Types by an Unsteady Computational Fluid Dynamics Model

    NARCIS (Netherlands)

    Boutsioukis, Christos; Verhaagen, Bram; Versluis, Michel; Kastrinakis, Eleftherios; Wesselink, Paul R.; Sluis, van der Lucas W.M.

    2010-01-01

    Introduction: The aim of this study was to evaluate the effect of needle tip design on the irrigant flow inside a prepared root canal during final irrigation with a syringe using a validated Computational Fluid Dynamics (CFD) model. Methods: A CFD model was created to simulate the irrigant flow insi

  18. On the waterfront: water distribution, technology and agrarian change in a south India canal irrigation system.

    NARCIS (Netherlands)

    Mollinga, P.P.

    1998-01-01

    This book discusses water distribution in the Tungabhadra Left Bank Canal irrigation system in Raichur district, Karnataka, India. The system is located in interior South India, where rainfall is limited (approximately 600 mm annually) and extremely variable. The region suffered from failed harvests

  19. Evaluation of a Sonic Device Designed to Activate Irrigant in the Root Canal

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Verhaagen, B.; Versluis, Andreas Michel; van der Sluis, Lucas W.M.

    2010-01-01

    Introduction The aims of this study were to evaluate the removal of dentin debris from the root canal by sonic or ultrasonic activation of the irrigant and the physical mechanisms of sonic activation by visualizing the oscillations of the sonic tip, both inside and outside the confinement of the

  20. Evaluation of a sonic device designed to activate irrigant in the root canal

    NARCIS (Netherlands)

    Jiang, L.M.; Verhaagen, B.; Versluis, M.; van der Sluis, L.W.M.

    2010-01-01

    Introduction The aims of this study were to evaluate the removal of dentin debris from the root canal by sonic or ultrasonic activation of the irrigant and the physical mechanisms of sonic activation by visualizing the oscillations of the sonic tip, both inside and outside the confinement of the

  1. Evaluation of a Sonic Device Designed to Activate Irrigant in the Root Canal

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Verhaagen, Bram; Versluis, Michel; van der Sluis, Lucas W. M.

    Introduction: The aims of this study were to evaluate the removal of dentin debris from the root canal by sonic or ultrasonic activation of the irrigant and the physical mechanisms of sonic activation by visualizing the oscillations of the sonic tip, both inside and outside the confinement of the

  2. On the waterfront : water distribution, technology and agrarian change in a South Indian canal irrigation system

    NARCIS (Netherlands)

    Mollinga, P.P.

    1998-01-01

    This book discusses water distribution in the Tungabhadra Left Bank Canal irrigation system in Raichur district, Karnataka, India. The system is located in interior South India, where rainfall is limited (approximately 600 mm annually) and extremely variable. The region suffered from failed

  3. Comparison of the effect of various irrigants on apically extruded debris after root canal preparation.

    Science.gov (United States)

    Parirokh, Masoud; Jalali, Shahrzad; Haghdoost, Ali Akbar; Abbott, Paul Vincent

    2012-02-01

    Several factors can influence the amount of apically extruded debris. The aim was to quantitatively compare the amount of debris extruded apically from root canals when 3 different irrigants were used during canal preparation with rotary instruments. Ninety-one extracted single-rooted human mandibular premolar teeth with straight root canals were used. The teeth were randomly divided into 1 control group (group 1, n = 4) and 3 experimental groups of 29 teeth each. Hero 642 instruments were used for root canal preparation in all teeth, and 3 different irrigants were used (group 2, 2% chlorhexidine; group 3, 5.25% sodium hypochlorite; group 4, 2.5% sodium hypochlorite). Seven Eppendorf tubes served as a second control group. Debris extruded from the apical foramen during root canal preparation was collected into preweighed Eppendorf tubes. The weight of the dry extruded debris was established by subtracting the preinstrumentation and postinstrumentation weight of the Eppendorf tubes for each group. The data obtained were analyzed by using one-way analysis of variance and Tukey honestly significant difference. Group 3 (sodium hypochlorite 5.25%) had the highest amount of extruded debris, which was significantly different from the other groups (P irrigant used can affect the amount of apically extruded debris. The 5.25% solution of sodium hypochlorite had the greatest amount of debris. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Antibacterial properties of root canal lubricants: a comparison with commonly used irrigants.

    Science.gov (United States)

    Wong, Samantha; Mundy, Lance; Chandler, Nicholas; Upritchard, Jenine; Purton, David; Tompkins, Geoffrey

    2014-12-01

    The aim was to assess in vitro the antibacterial activity of 10 root canal lubricants. K-Y Jelly personal lubricant, RC-Prep, File-Eze, File-Rite, EndoPrep Gel, Endosure Prep Crème 15%, Prep-Rite, Glyde, SlickGel ES and Alpha Glide were selected and compared in their antimicrobial properties to seven irrigants. Serial dilutions of each agent in tryptic soy broth were inoculated with either Enterococcus faecalis or Pseudomonas aeruginosa and incubated at 37C for 24 h. During incubation bacterial growth was measured by optical density (A(600)), and samples removed for cultivation on tryptic soy broth agar. Against both test bacteria after 1 h incubation, six lubricants recorded minimum bactericidal concentrations ranging from 1/10 to 1/80, whereas the inhibitory activity of the irrigants ranged from 1/20 to 1/640. Under these conditions, several lubricants exhibited antimicrobial activity comparable with some irrigants. Three irrigants, Consepsis (containing chlorhexidine), Endosure EDTA/C (containing cetrimide) and EndoPrep Solution (containing cetrimide), showed superior antibacterial action to lubricants against both species. The irrigants containing ethylenediamine tetraacetic acid and cetrimide were the most effective against both bacterial species at all time intervals. Antimicrobial activity of the lubricants did not correlate to pH values, which ranged from 2.9 to 10.3. Root canal lubricants have antibacterial properties that may help to disinfect canals. © 2014 Australian Society of Endodontology.

  5. Heavy metals in vegetables and respective soils irrigated by canal, municipal waste and tube well waters.

    Science.gov (United States)

    Ismail, Amir; Riaz, Muhammad; Akhtar, Saeed; Ismail, Tariq; Amir, Mamoona; Zafar-ul-Hye, Muhammad

    2014-01-01

    Heavy metal contamination in the food chain is of serious concern due to the potential risks involved. The results of this study revealed the presence of maximum concentration of heavy metals in the canal followed by sewerage and tube well water. Similarly, the vegetables and respective soils irrigated with canal water were found to have higher heavy metal contamination followed by sewerage- and tube-well-watered samples. However, the heavy metal content of vegetables under study was below the limits as set by FAO/WHO, except for lead in canal-water-irrigated spinach (0.59 mg kg(-1)), radish pods (0.44 mg kg(-1)) and bitter gourd (0.33 mg kg(-1)). Estimated daily intakes of heavy metals by the consumption of selected vegetables were found to be well below the maximum limits. However, a complete estimation of daily intake requires the inclusion of other dietary and non-dietary exposure sources of heavy metals.

  6. Chlorhexidine as a root canal irrigant: Antimicrobial and scanning electron microscopic evaluation

    Directory of Open Access Journals (Sweden)

    Živković Slavoljub

    2010-01-01

    Full Text Available Introduction. Selection of irrigant is very important for longterm success of root canal therapy. Objective. This study was undertaken to evaluate the antimicrobial effects of 2% chlorhexidine digluconate solution (CHX against five selected microorganisms and to evaluate its efficacy in root canal cleaning. Methods. In this study, by agar diffusion test, were evaluated antimicrobial effects of three root canal irrigants: 5.25% NaOCl, 2.5% NaOCl and 2% CHX. The microorganisms tested in this study were Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, Escherichia coli and Candida albicans. A scanning electron microscope was used to evaluate root canal cleaning ability of 5.25% NaOCl, 2.5% NaOCl, 2% CHX and 15% EDTA. Twelve extracted single-root human teeth were divided into four groups depending on the irrigant used during instrumentation. Mechanical preparation was performed with Step back technique and K files. Data were analyzed statistically by Student’s t-test. Results 5.25% NaOCl was the most effective against all tested microorganisms. 2.5% NaOCl and 2% CHX showed antimicrobial effects against all tested microorganisms but zones of inhibition were smaller. The best results in root canal walls cleaning were obtained in the group where the irrigant was 15% EDTA (score 2.33. In 5.25% NaOCl, 2.5% NaOCl and 2% CHX groups, there was more smear layer (score 4 and 5. Conclusion. 2% chlorhexidine digluconate showed strong antimicrobial effect on the tested microorganisms, but was not effective in cleaning root canal walls.

  7. Combined effects of photodynamic therapy and irrigants in disinfection of root canals.

    Science.gov (United States)

    Susila, Anand V; Sugumar, R; Chandana, C S; Subbarao, C V

    2016-06-01

    In this study, the combined effects of photodynamic therapy and irrigants in eradicating common endodontic pathogens are evaluated. Roots of 80 extracted single rooted teeth are divided into 2 groups (1) mechanical flushing; (2) antibacterial irrigation. After cleaning and shaping, they are inoculated with either (A) Streptococcus mutans or (B) Enterococcus faecalis and incubated. They are again subdivided and either only irrigated or irrigated and lased. Dentin shavings are taken from root canal walls and cultured. Statistical analysis using One-Way ANOVA and Post-hoc tests are done. The combination eradicated both bacteria. Antibacterial irrigants controlled S. mutans better than PDT (p = 0.041). The combination of PDT and antibacterial irrigation proposed in this study can be used in all primary cases for thorough and reliable disinfection of root canals but may be highly effective in resistant cases like endodontic failures, as E. faecalis is prevalent in such cases. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Antibacterial Efficacy of a New Sonic Irrigation Device for Root Canal Disinfection.

    Science.gov (United States)

    Neuhaus, Klaus W; Liebi, Melanie; Stauffacher, Simone; Eick, Sigrun; Lussi, Adrian

    2016-12-01

    Passive ultrasonic irrigation (PUI) is the most widespread method used to activate irrigation solutions. Concerns have been raised that PUI is less effective in curved root canals and is not passive at all. Our aim was to compare a novel passive sonic irrigation (PSI) device (6000 Hz) with PUI and manual irrigation (MI) with respect to their efficiency in removing different endodontic microorganisms from curved and straight root canals. We performed 2 experiments as follows. In a 3-day infection model, we included 8 groups of single or dual microbial species that were rinsed with 0.9% sodium chloride using PSI, PUI, or MI. Colony-forming units (CFUs) were counted after incubation, and log10 transformations were performed for statistical comparisons. In a 21-d infection model, we tested the same irrigation protocols on 4 groups of microorganisms and used 1.5% sodium hypochlorite as an irrigant. Infection control samples were taken at day 0, 3, 5, and 7 after treatment and were subsequently reincubated. Using sodium chloride as an irrigant, the amount of reduction in CFUs compared with the negative control was approximately 3 log10 units for PSI at 6000 Hz, 2 log10 units for PUI, and 1 log10 unit for MI. PSI reduced the microorganism CFUs significantly better than PUI. Using sodium hypochlorite led to a significant reduction in microorganism CFUs even with MI. After 3 days, compared with MI, microorganism regrowth significantly reduced after PSI and PUI treatment, but in these groups, in at least half of the samples, microorganisms were detectable after 7 days. PSI at 6000 Hz might be at least equal to PUI with respect to reduction of the microbial load in curved and straight root canals. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. Multivariate analysis of the cleaning efficacy of different final irrigation techniques in the canal and isthmus of mandibular posterior teeth

    Directory of Open Access Journals (Sweden)

    Yeon-Jee Yoo

    2013-08-01

    Full Text Available Objectives The aim of this study was to compare the cleaning efficacy of different final irrigation regimens in canal and isthmus of mandibular molars, and to evaluate the influence of related variables on cleaning efficacy of the irrigation systems. Materials and Methods Mesial root canals from 60 mandibular molars were prepared and divided into 4 experimental groups according to the final irrigation technique: Group C, syringe irrigation; Group U, ultrasonics activation; Group SC, VPro StreamClean irrigation; Group EV, EndoVac irrigation. Cross-sections at 1, 3 and 5 mm levels from the apex were examined to calculate remaining debris area in the canal and isthmus spaces. Statistical analysis was completed by using Kruskal-Wallis test and Mann-Whitney U test for comparison among groups, and multivariate linear analysis to identify the significant variables (regular replenishment of irrigant, vapor lock management, and ultrasonic activation of irrigant affecting the cleaning efficacy of the experimental groups. Results Group SC and EV showed significantly higher canal cleanliness values than group C and U at 1 mm level (p < 0.05, and higher isthmus cleanliness values than group U at 3 mm and all levels of group C (p < 0.05. Multivariate linear regression analysis demonstrated that all variables had independent positive correlation at 1 mm level of canal and at all levels of isthmus with statistical significances. Conclusions Both VPro StreamClean and EndoVac system showed favorable result as final irrigation regimens for cleaning debris in the complicated root canal system having curved canal and/or isthmus. The debridement of the isthmi significantly depends on the variables rather than the canals.

  10. Cytotoxicity of 5% Tamarindus indica extract and 3% hydrogen peroxide as root canal irrigation

    Directory of Open Access Journals (Sweden)

    Erawati Wulandari

    2008-09-01

    Full Text Available Background: Preparation of root canal is an important stage in endodontic treatment. During conducting preparation, it is always be followed with root canal irrigation that has aim to clean root canal from necrotic tissue remains, grind down dentin powder, micro organism, wet the root canal to make preparation process of root canal easier, and solute root canal content at area that can not be reached by equipment. Flesh of Tamarindus indica (pulpa tamarindorum is used as traditional medicine and it contains vitamin C (antioxidant, protein, fat, glucose, etc. Previous research shows that 5% tamarindus indica extract can clean smear layer but it is more cytotoxicity to cell line BHK–21 than sterilized aquabides. Purpose: This research is to compare cytotoxicity between 5% Tamarindus indica extract with 3% H2O2 as root canal irrigation material. Method: Four teen culture cell line BHK 21 divides into 2 groups. Group 1 is treated with 3% H2O2 and Group 2 is treated with 5% Tamarindus indica extract, for about 2.5 minutes in every group. Then, living and death cell percentage is measured. Data is analyzed with independent t test with significant level of 0.05%. Result: The research showed that death cell in group 1 was 29.3% and in group 2 was 21.1%. There was a significant different (p < 0.05 between group 1 and group 2. Conclusion: Cytotoxicity of 5% Tamarindus indica extract to the cell line BHK–21 is lower than 3% H2O2.

  11. Effect of root canal irrigating solutions on the compressive strength of tricalcium silicate cements.

    Science.gov (United States)

    Govindaraju, Lokhasudhan; Neelakantan, Prasanna; Gutmann, James L

    2017-03-01

    The aim of this study was to evaluate the effect of root canal irrigants on the compressive strength of hydraulic tricalcium silicate cements. Specimens (n = 60) of tricalcium silicate materials-Group 1: White ProRoot mineral trioxide aggregate (MTA), Group 2: NeoMTA Plus, Group 3: White MTA Angelus, and Group 4: Biodentine were exposed to one of the solutions (n = 20): Phosphate buffered saline (PBS; control), 3 % NaOCl, or 17 % EDTA for 5 min while being suspended in PBS. Compressive strength values were evaluated after 7 days of storage. The data were statistically analyzed by two-way ANOVA and Tukey's multiple comparison test (P = 0.05). Biodentine (BD) showed significantly higher compressive strength than the other materials (P Biodentine and NeoMTA Plus did not show a significant reduction in compressive strength when exposed to NaOCl. EDTA reduced the compressive strength of the cements tested. Tricalcium silicates were differentially influenced by root canal irrigants. It is essential to understand the composition of these materials prior to clinical use. Traces of irrigants from the root canal wall must be thoroughly removed.

  12. The effectiveness of syringe irrigation and ultrasonics to remove debris from simulated irregularities within prepared root canal walls.

    Science.gov (United States)

    Lee, S-J; Wu, M-K; Wesselink, P R

    2004-10-01

    To compare the ability of syringe irrigation and ultrasonic irrigation to remove artificially placed dentine debris from simulated canal irregularities within prepared root canals. After canal enlargement, twelve canines were split longitudinally into two halves. On the wall of one half of each root canal a standard groove of 4 mm in length, 0.2 mm in width and 0.5 mm in depth was cut, 2-6 mm from the apex, to simulate uninstrumented canal extensions. On the wall of the other half, three standard saucer-shaped depressions of 0.3 mm in diameter and 0.5 mm in depth were cut at 2, 4 and 6 mm from the apex to simulate uninstrumented canal irregularities. Each groove and depression were filled with dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in uninstrumented canal extensions and irregularities during canal preparation. Each tooth was re-assembled by reconnecting the two halves, using wire and an impression putty material. Two per cent NaOCl was then delivered into each canal either using syringe irrigation (n = 8) or using ultrasonic irrigation (n = 8). Before and after irrigation, images of the two halves of the canal wall were taken, using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The amount of remaining dentine debris in the grooves and depressions was evaluated by using a scoring system between 0-3: the higher the score, the more the debris. The data were analysed by means of the Mann-Whitney U-test. Both forms of irrigation reduced the debris score significantly. The debris score was statistically significantly lower after ultrasonic irrigation than after syringe irrigation (P = 0.002 for grooves, P = 0.047 for depressions). Ultrasonic irrigation ex vivo is more effective than syringe irrigation in removing artificially created dentine debris placed in simulated uninstrumented extensions and irregularities in straight, wide root canals.

  13. Optimization Of Irrigation Area of Ukai Right Bank Main Canal-A Linear Programming Approach

    Science.gov (United States)

    Bhuvandas, Nishi; Mirajkar, A. B.; Timbadiya, P. V.; Patel, P. L.

    2010-11-01

    This paper presents a Linear Programming (LP) model for obtaining optimized cropping area in the command of Ukai reservoir. The objective is to maximize the sum of the relative yields from all crops in the irrigated area for specific range of water availability like 100%, 90%, 80% and 70%. The present study is aimed to get the optimal allocation of irrigation water depending upon the availability of water from the source. The net revenue from agricultural production will be maximized for available irrigation water taking into account the sets of constraints like crop area, cropping pattern and water requirement. The model is applied to a part of Ukai reservoir system namely Ukai Right Bank Main Canal (URBMC), in Gujarat state, India.

  14. The impact of pH on cytotoxic effects of three root canal irrigants

    Science.gov (United States)

    Saghiri, Mohammad Ali; Delvarani, Abbas; Mehrvarzfar, Payman; Nikoo, Mohsen; Lotfi, Mehrdad; Karamifar, Kasra; Asgar, Kamal; Dadvand, Sahar

    2011-01-01

    Aim Cytotoxicity of root canal irrigants is important due to their close contact with host tissues. This study was to assess the possible impact of pH on cytotoxic effects of MTAD, 17% EDTA, and 2.6% NaOCl on the human gingival fibroblasts using MTT assay. Materials and methods Human gingival fibroblasts were exposed to the irrigants and their viability was assessed after 1, 6, and 12 h. The pH of the medium was measured in each interval. Light absorption values were measured for each culture medium using Elisa Reader device. Results NaOCl had significantly less cytotoxicity than EDTA and MTAD. Also irrigants cytotoxicity decreased in 12, 1, and 6 h, respectively. Conclusion It seems that variation of the pH resulted in variation in the cytotoxicity of solutions; i.e., it follows the pattern of the pH variation. PMID:23960509

  15. Irrigant flow in the root canal: experimental validation of an unsteady Computational Fluid Dynamics model using high-speed imaging

    NARCIS (Netherlands)

    Boutsioukis, C.; Verhaagen, B.; Versluis, M.; Kastrinakis, E.; Sluis, van der L.W.M.

    2010-01-01

    Aim  To compare the results of a Computational Fluid Dynamics (CFD) simulation of the irrigant flow within a prepared root canal, during final irrigation with a syringe and a needle, with experimental high-speed visualizations and theoretical calculations of an identical geometry and to evaluate the

  16. Irrigant flow in the root canal: experimental validation of an unsteady computational fluid dynamics model using high-speed imaging

    NARCIS (Netherlands)

    C. Boutsioukis; B. Verhaagen; M. Versluis; E. Kastrinakis; L.W.M. van der Sluis

    2010-01-01

    Aim  To compare the results of a Computational Fluid Dynamics (CFD) simulation of the irrigant flow within a prepared root canal, during final irrigation with a syringe and a needle, with experimental high-speed visualizations and theoretical calculations of an identical geometry and to evaluate the

  17. Release of Growth Factors into Root Canal by Irrigations in Regenerative Endodontics.

    Science.gov (United States)

    Zeng, Qian; Nguyen, Sean; Zhang, Hongming; Chebrolu, Hari Priya; Alzebdeh, Dalia; Badi, Mustafa A; Kim, Jong Ryul; Ling, Junqi; Yang, Maobin

    2016-12-01

    The aim of this study was to investigate the release of growth factors into root canal space after the irrigation procedure of regenerative endodontic procedure. Sixty standardized root segments were prepared from extracted single-root teeth. Nail varnish was applied to all surfaces except the root canal surface. Root segments were irrigated with 1.5% NaOCl + 17% EDTA, 2.5% NaOCl + 17% EDTA, 17% EDTA, or deionized water. The profile of growth factors that were released after irrigation was studied by growth factor array. Enzyme-linked immunosorbent assay was used to validate the release of transforming growth factor (TGF)-β1 and basic fibroblast growth factor (bFGF) at 4 hours, 1 day, and 3 days after irrigation. The final concentrations were calculated on the basis of the root canal volume measured by cone-beam computed tomography. Dental pulp stem cell migration on growth factors released from root segments was measured by using Transwell assay. Total of 11 of 41 growth factors were detected by growth factors array. Enzyme-linked immunosorbent assay showed that TGF-β1 was released in all irrigation groups. Compared with the group with 17% EDTA (6.92 ± 4.49 ng/mL), the groups with 1.5% NaOCl + 17% EDTA and 2.5% NaOCl + 17% EDTA had significantly higher release of TGF-β1 (69.04 ± 30.41 ng/mL and 59.26 ± 3.37 ng/mL, respectively), with a peak release at day 1. The release of bFGF was detected at a low level in all groups (0 ng/mL to 0.43 ± 0.22 ng/mL). Migration assay showed the growth factors released from root segments induced dental pulp stem cell migration. The root segment model in present study simulated clinical scenario and indicated that the current irrigation protocol released a significant amount of TGF-β1 but not bFGF. The growth factors released into root canal space induced dental pulp stem cell migration. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Effectiveness of conventional syringe irrigation, vibringe, and passive ultrasonic irrigation performed with different irrigation regimes in removing triple antibiotic paste from simulated root canal irregularities

    Science.gov (United States)

    Topçuoğlu, Hüseyin Sinan; Aktı, Ahmet; Topçuoğlu, Gamze; Düzgün, Salih; Ulusan, Özge; Akpek, Firdevs

    2016-01-01

    Background: This study evaluated the efficacy of a sonic device (Vibringe), passive ultrasonic irrigation (PUI), and conventional syringe irrigation (CSI) in the removal of triple antibiotic paste (TAP) from artificial standardized grooves in the apical and coronal thirds of a root canal. Materials and Methods: One-hundred eighteen root canals were prepared using the ProTaper system. The roots were split longitudinally, and a standardized groove was prepared in the apical and coronal parts of one segment. The grooves were filled with TAP, and the roots were reassembled. The roots were randomly divided into nine experimental groups and two control groups, according to the following irrigation methods: (1) CSI with sodium hypochlorite (NaOCl) + ethylenediaminetetraacetic acid (EDTA), (2) CSI/EDTA, (3) CSI/NaOCl, (4) PUI/NaOCl + EDTA, (5) PUI/EDTA, (6) PUI/NaOCl, (7) Vibringe/NaOCl + EDTA, (8) Vibringe/EDTA, and (9) Vibringe/NaOCl. The amount of remaining medicament was evaluated under a stereomicroscope. Results: In the apical third, Vibringe/NaOCl + EDTA and PUI/NaOCl + EDTA were superior to the other groups (P 0.05). In the coronal third, there was no significant difference between the experimental groups (P > 0.05). Conclusions: The use of the NaOCl/EDTA combination together with sonic or ultrasonic agitation improved the removal of TAP from the apical third. PMID:27563179

  19. Efficiency of final irrigation of root canal in removal of smear layer

    Directory of Open Access Journals (Sweden)

    Mitić Aleksandar

    2009-01-01

    Full Text Available Introduction A smear layer forms on the root canal walls as the consequence of root instrumentation. The smear layer formed in such a way considerably influences the quality of root obturation and endodontic treatment outcome. Objective The aim of this study was to ultrastructurally analyze the surface of intracanal dentine after removal of the smear layer by the solution of doxycycline, citric acid and detergent Tween-80 (MTAD. Methods The study involved 60 single-rooted, extracted, human teeth divided into four groups. All samples were instrumented by a step-back technique and manual K-files, and rinsed during instrumentation by 2% CHX and H2O2. The first group of samples was exclusively rinsed by CHX and H2O2; in the second group, besides using CHX and H2O2, MTAD solution was used for the final irrigation. The samples which were rinsed by distilled water (+ control and the samples rinsed by 5.25% NaOCl and 17% Na EDTA (-control served as control groups. All samples were observed under the scanning electronic microscope JEOL-JSM-5300. The coronary, middle and apex thirds of the radix region were analyzed. Results The obtained results of the SEM analysis showed that the application of 2% chlorhexidine and hydrogen peroxide did not give clear dentine walls, and the smear layer could not be removed completely. The application of the same combination (CHX and H2O2, added by the final MTAD irrigation solution, led to the efficient removal of the smear layer, while the morphological structure of dentine surface remained unchanged. Statistical analysis showed that canal walls in the experimental group with MTAD as the final irrigation were significantly clearer compared to the control group (p<0.001. Conclusion Based on the obtained results, it can be concluded that MTAD is an efficient solution for the final irrigation of the canal system.

  20. Antibacterial effect of urushiol on E. faecalis as a root canal irrigant

    Directory of Open Access Journals (Sweden)

    Sang-Wan Kim

    2017-02-01

    Full Text Available Objectives The purpose of this study was to compare the antibacterial activity of urushiol against Enterococcus faecalis (E. faecalis to that of NaOCl. Materials and Methods The canals of thirty two single rooted human teeth were instrumented with Ni-Ti files (ProTaper Next X1, X2, X3, Dentsply. A pure culture of E. faecalis ATCC 19433 was prepared in sterile brain heart infusion (BHI broth. The teeth were submerged in the suspension of E. faecalis and were incubated at 37℃ for 7 days to allow biofilm formation. The teeth were randomly divided into three experimental groups according to the irrigant used, and a negative control group where no irrigant was used (n = 8. Group 1 used physiologic normal saline, group 2 used 6% NaOCl, and group 3 used 10 wt% urushiol solution. After canal irrigation, each sample was collected by the sequential placement of 2 sterile paper points (ProTaper NEXT paper points, size X3, Dentsply. Ten-fold serial dilutions on each vials, and 100 µL were cultured on a BHI agar plate for 8 hours, and colony forming unit (CFU analysis was done. The data were statistically analyzed using Kruskal-Wallis and Mann-whitney U tests. Results Saline group exhibited no difference in the CFU counts with control group, while NaOCl and urushiol groups showed significantly less CFU counts than saline and control groups (p < 0.05. Conclusions The result of this study suggests 10% urushiol and 6% NaOCl solution had powerful antibacterial activity against E. faecalis when they were used as root canal irrigants.

  1. Antibacterial effect of urushiol on E. faecalis as a root canal irrigant

    Science.gov (United States)

    Kim, Sang-Wan

    2017-01-01

    Objectives The purpose of this study was to compare the antibacterial activity of urushiol against Enterococcus faecalis (E. faecalis) to that of NaOCl. Materials and Methods The canals of thirty two single rooted human teeth were instrumented with Ni-Ti files (ProTaper Next X1, X2, X3, Dentsply). A pure culture of E. faecalis ATCC 19433 was prepared in sterile brain heart infusion (BHI) broth. The teeth were submerged in the suspension of E. faecalis and were incubated at 37℃ for 7 days to allow biofilm formation. The teeth were randomly divided into three experimental groups according to the irrigant used, and a negative control group where no irrigant was used (n = 8). Group 1 used physiologic normal saline, group 2 used 6% NaOCl, and group 3 used 10 wt% urushiol solution. After canal irrigation, each sample was collected by the sequential placement of 2 sterile paper points (ProTaper NEXT paper points, size X3, Dentsply). Ten-fold serial dilutions on each vials, and 100 µL were cultured on a BHI agar plate for 8 hours, and colony forming unit (CFU) analysis was done. The data were statistically analyzed using Kruskal-Wallis and Mann-whitney U tests. Results Saline group exhibited no difference in the CFU counts with control group, while NaOCl and urushiol groups showed significantly less CFU counts than saline and control groups (p < 0.05). Conclusions The result of this study suggests 10% urushiol and 6% NaOCl solution had powerful antibacterial activity against E. faecalis when they were used as root canal irrigants. PMID:28194365

  2. Minimal Apical Enlargement for Penetration of Irrigants to the Apical Third of Root Canal System: A Scanning Electron Microscope Study

    Science.gov (United States)

    Srikanth, P; Krishna, Amaravadi Gopi; Srinivas, Siva; Reddy, E Sujayeendranatha; Battu, Someshwar; Aravelli, Swathi

    2015-01-01

    Background: The aim of this study was to determine minimal apical enlargement for irrigant penetration into apical third of root canal system using scanning electron microscope (SEM). Materials and Methods: Distobuccal canals of 40 freshly extracted human maxillary first molar teeth were instrumented using crown-down technique. The teeth were divided into four test groups according to size of their master apical file (MAF) (#20, #25, #30, #35 0.06% taper), and two control groups. After final irrigation, removal of debris and smear layer from the apical third of root canals was determined under a SEM. Data was analyzed using Kruskal–Wallis and Mann–Whitney tests. Results: Smear layer removal in apical third for MAF size #30 was comparable with that of the control group (size #40). Conclusion: Minimal apical enlargement for penetration of irrigants to the apical third of root canal system is #30 size. PMID:26124608

  3. The simulation of cropping pattern to improve the performance of irrigation network in Cau irrigation area

    Science.gov (United States)

    Wahyuningsih, Retno; Rintis Hadiani, RR; Sobriyah

    2017-01-01

    Cau irrigation area located in Madiun district, East Java Province, irrigates 1.232 Ha of land which covers Cau primary channel irrigation network, Wungu Secondary channel irrigation network, and Grape secondary channel irrigation network. The problems in Cau irrigation area are limited availability of water especially during the dry season (planting season II and III) and non-compliance to cropping patterns. The evaluation of irrigation system performance of Cau irrigation area needs to be done in order to know how far the irrigation system performance is, especially based on planting productivity aspect. The improvement of irrigation network performance through cropping pattern optimization is based on the increase of water necessity fulfillment (k factor), the realization of planting area and rice productivity. The research method of irrigation system performance is by analyzing the secondary data based on the Regulation of Ministry of Public Work and State Minister for Public Housing Number: 12/PRT/M/2015. The analysis of water necessity fulfillment (k factor) uses Public Work Plan Criteria Method. The performance level of planting productivity aspect in existing condition is 87.10%, alternative 1 is 93.90% dan alternative 2 is 96.90%. It means that the performance of the irrigation network from productivity aspect increases 6.80% for alternative 1 and 9.80% for alternative 2.

  4. Canalization and symmetry in Boolean models for genetic regulatory networks

    Energy Technology Data Exchange (ETDEWEB)

    Reichhardt, C J Olson [Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bassler, Kevin E [Department of Physics, University of Houston, Houston, TX 77204-5005 (United States)

    2007-04-20

    Canalization of genetic regulatory networks has been argued to be favoured by evolutionary processes due to the stability that it can confer to phenotype expression. We explore whether a significant amount of canalization and partial canalization can arise in purely random networks in the absence of evolutionary pressures. We use a mapping of the Boolean functions in the Kauffman N-K model for genetic regulatory networks onto a k-dimensional Ising hypercube (where k = K) to show that the functions can be divided into different classes strictly due to geometrical constraints. The classes can be counted and their properties determined using results from group theory and isomer chemistry. We demonstrate that partially canalizing functions completely dominate all possible Boolean functions, particularly for higher k. This indicates that partial canalization is extremely common, even in randomly chosen networks, and has implications for how much information can be obtained in experiments on native state genetic regulatory networks.

  5. The Influence of Canalization on the Robustness of Boolean Networks

    CERN Document Server

    Kadelka, Claus; Laubenbacher, Reinhard

    2016-01-01

    Time- and state-discrete dynamical systems are frequently used to model molecular networks. This paper provides a collection of mathematical and computational tools for the study of robustness in Boolean network models. The focus is on networks governed by $k$-canalizing functions, a recently introduced class of Boolean functions that contains the well-studied class of nested canalizing functions. The activities and sensitivity of a function quantify the impact of input changes on the function output. This paper generalizes the latter concept to $c$-sensitivity and provides formulas for the activities and $c$-sensitivity of general $k$-canalizing functions as well as canalizing functions with more precisely defined structure. A popular measure for the robustness of a network, the Derrida value, can be expressed as a weighted sum of the $c$-sensitivities of the governing canalizing functions, and can also be calculated for a stochastic extension of Boolean networks. These findings provide a computationally eff...

  6. Evaluation of Chlorine Dioxide Irrigation Solution on the Microhardness and Surface Roughness of Root Canal Dentin.

    Science.gov (United States)

    Ballal, Nidambur Vasudev; Khandewal, Deepika; Karthikeyan, Saravana; Somayaji, Krishnaraj; Foschi, Federico

    2015-12-01

    The aim of this study was to evaluate the effect of chlorine dioxide and various other more common irrigation solutions on the microhardness and surface roughness of root canal dentin. Fifty human maxillary central incisors were sectioned longitudinally and treated for 1 minute with 5 ml of the following aqueous solutions (v/v%): Group 1: 13.8% chlorine dioxide, Group 2: 17% ethylene diamine tetraacetic acid (EDTA). Group 3: 7% maleic acid, Group 4: 2.5% sodium hypochlorite (5 ml/min), Group 5: Saline (control). Specimens were subjected to microhardness and surface roughness testing. Chlorine dioxide and sodium hypochlorite reduced the microhardness more than other test agents. The highest surface roughness was produced with maleic acid. Chlorine dioxide should be used cautiously during chemomechanical preparation of the root canal system in order to prevent untoward damage to the teeth.

  7. An update on the antibiotic-based root canal irrigation solutions

    Science.gov (United States)

    Mohammadi, Zahed

    2008-01-01

    Antibiotics are a valuable addition to health practitioners for the management of bacterial infections. During endodontic treatment and when managing trauma to the teeth, antibiotics may be applied systemically or locally. Due to the potential risk of adverse effects of systemic applications, and the ineffectiveness of systemic prescribed antibiotics in necrotic or pulpless teeth and the periradicular tissues, the local application of antibiotics may be a more effective mode for delivering antibiotics to infected root canals. The purpose of this article is to review the history, rationale, and applications of antibiotics and antibiotic-containing irrigants in endodontics. PMID:24171012

  8. Robust Proportional Integral Control of Water Level in an Irrigation Main Canal

    Directory of Open Access Journals (Sweden)

    Ybrain Hernández López

    2015-07-01

    Full Text Available Nowadays In this paper, the design of a robust PI controller for effective level control in the second poolof the irrigation main canal Güira de Melena is developed. A mathematical model that adequately describesthe dynamic behavior of the plant under study is obtained from system identification procedure.This model is characterized by its simplicity (first order with time delay. The robustness analysis of thedesigned PI controller vs parametric variations of the obtained mathematical model showed satisfactoryresults, and therefore the implementation of this controller is validated.

  9. The Effect of Smear Layer on Antimicrobial Efficacy of Three Root Canal Irrigants.

    Science.gov (United States)

    Zargar, Nazanin; Dianat, Omid; Asnaashari, Mohammad; Ganjali, Mojtaba; Zadsirjan, Saeede

    2015-01-01

    One of the main goals of endodontic treatment is to decrease the harboring bacteria within the root canal system and dentinal tubules. This experimental study attempted to investigate the antibacterial efficacy of three root canal irrigants in the presence and absence of smear layer (SL). A total of 210 sound extracted human single-rooted teeth were prepared. After creating the SL and its removal in half of the samples, they were infected with Candida albicans (C. albicans) and Actinomyces israelii (A. israelii). A total of 180 specimen were used to assess the antimicrobial efficacy of the three irrigants in presence and absence of SL, 24 specimen were placed in the positive and negative controls, 2 samples were utilized for scanning electron microscopy (SEM) analysis and 2 were used for Gram staining. Then, they were exposed to irrigants including 2.61% sodium hypochlorite (NaOCl), 0.2% chlorhexidine gluconate (CHX) and 1% povidone-iodine (PI) for 5, 30 and 60 min. Presence/absence of test microorganisms was determined by incubation of specimens in test tubes containing brain-heart infusion (BHI) broth and then measuring the colony forming units (CFU) on BHI agar. A cumulative logistic model was used to analyze the ordinal response. The 2.61% solution of NaOCl was significantly more effective than 0.2% CHX and the latter was more efficient than 1% PI for decreasing fungal and microbial infection of dentinal tubules in the presence and absence of SL. The presence of smear layer decreased the efficacy of antimicrobial irrigants. The minimum time required for elimination of fungal/microbial infection was 30 min.

  10. Irrigation Management, Evolving Canal Systems and Social Simulation in Hohokam Society, Central Arizona

    Science.gov (United States)

    Ertsen, Maurits; Murphy, John; Purdue, Louise

    2015-04-01

    As may societies that rely on irrigation, the Hohokam civilization in South West Arizona faced challenges arising from the variability and unpredictability of water supply and the physics underlying the flow of water through open channels. Such challenges can be overcome through cooperation and other forms of structured social interactions and institutions ranging from simple to complex. These interactions are influenced by and are influenced themselves by environmental conditions, including hydrology, soils and vegetation. At the same time, the environmental record provides clues to these interactions. To better understand these past interactions we combine geoarchaeological studies with flow simulations and Agent Based Modeling. Fieldwork conducted on Hohokam irrigation revealed new details about canal morphology, including shape, size, elevation, slope, and cleaning events. Micromorphological study of the sediments in these structures allow finer resolution in discerning the performance (velocity, discharge, etc.) of the canal channels and their evolution through time. We couple this with basic agent-based modeling to explore how these constraints might have required alternative strategies for cooperation. The combination of both approaches is key to discerning both broad differences between periods and fine variation within major chronological periods. We show that the coupling of social and physical models on very fine time scales can offer insight into the social arrangements and day-to-day life of people in the prehistoric past and inform our understanding of those societies' long-term changes.

  11. Neglected Canals: Deterioration of Indigenous Irrigation System by Urbanization in the West Peri-Urban Area of Bangkok Metropolitan Region

    OpenAIRE

    Yuji Hara; Makoto Yokohari; Vudipong Davivongs

    2012-01-01

    This paper discusses the deterioration of indigenous irrigation system traditionally developed in the past to serve the peri-urban agricultural lands that have been affected by rapid urbanization in the Bangkok Metropolitan Region. The study is based on data collection from mapping, field survey and interview analyses and identifies current canal deteriorating conditions in four categories: filled, covered, narrowed and shallow, and normal. The findings reveal that different types of canal de...

  12. Effect of calcium hydroxide and endodontic irrigants on fibre post bond strength to root canal dentine.

    Science.gov (United States)

    Renovato, S R; Santana, F R; Ferreira, J M; Souza, J B; Soares, C J; Estrela, C

    2013-08-01

    To analyse the effect of calcium hydroxide paste, endodontic irrigants and time of application on the bond strength of fibre posts to root canal dentine. Seventy bovine incisors were divided into 7 groups according to removal of calcium hydroxide and distilled water (CHW) (immediate - I; 21 days - 21 days; 6 months - 6 months) and endodontic irrigant (1% sodium hypochlorite - SH; 1% sodium hypochlorite + 17% EDTA - SHE). Fibre posts were cemented (RelyX U100), after which the roots were serially sectioned and submitted to a micro-push-out test. Data were analysed using two-way anova followed by the Tukey's and the Dunnett's tests (α = 0.05). The CHW groups were not significantly different from the control group in 13 of the 18 associated factors (P > 0.05). There were significant reductions in bond strength in the cervical (P = 0.0216) and middle (P = 0.0017) thirds of the root at 6 months in groups irrigated with SH. Irrigation with SHE reduced the bond strength significantly in the middle (P = 0.0488) and apical (P = 0.0252) thirds of the roots in the immediate groups and in the middle third (P = 0.0287) in the 21-day group. Bond strength was greater in the cervical than in the apical thirds of all immediate and 21-day groups (P irrigated with SH and tested at 6 months (cervical and middle thirds). There was a predominance of adhesive failures between resin cement and dentine in all groups. © 2012 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  13. The effective concentration of red betel leaf (Piper crocatum infusion as root canal irrigant solution

    Directory of Open Access Journals (Sweden)

    Fani Pangabdian

    2012-03-01

    Full Text Available Background: Smear layer is a debris consisting of organic and inorganic particles of calcified tissue, necrotic tissue, pulp tissue, and dentinoblast and microorganism processes that can close the entrance to the dentin tubuli. Smear layer, will not only inhibit the penetration of disinfection materials and sealers to the dentin tubuli, but will also reduce the attachment of root canal filling material so that root canal irrigation solution is needed to dissolve the smear layer. Red betel leaf (Piper crocatum infusion, on the other hand, contains saponin characterized as “surfactants” which can dissolve smear layer. Nevertheless, the effective concentration of the red betel leaf infusion has still not been known clearly. Purpose: This study is aimed to determine the effective concentration of the red betel leaf infusion for cleaning root canal walls from smear layer. Methods: Fiveteen extracted human teeth with straight single roots were randomized into 5 groups (n=3. The specimens were then shaped by using rotary instruments up to a size of 25/.07. During instrumentation, each canal was irrigated with 10, 20, 30 and, 40% red betel leaf infusion for treatment groups, while another was irrigated with aquadest for the control group. Root canal cleanliness was observed by using scanning electron microscope (SEM. Results: There were significant differences among treatment groups (p<0.05, except in the treatment groups irrigated with red betel leaf infusion with concentrations of 30% and 40% (p>0.05. Conclusion: It can be concluded that red betel leaf infusion with a concentration of 30% is effective for cleaning the root canal walls from the smear layer.Latar belakang: Smear layer adalah suatu debris yang mengandung partikel organik dan anorganik dari jaringan terkalsifikasi, jaringan nekrotik, proses dentinoblas, jaringan pulpa dan mikroorganisme yang dapat menutup jalan masuk ke tubuli dentin. Smear layer akan menghalangi penetrasi dari bahan

  14. Discharge measurement with salt dilution method in irrigation canals: direct sampling and geophysical controls

    Directory of Open Access Journals (Sweden)

    C. Comina

    2013-08-01

    Full Text Available An important starting point for designing management improvements, particularly in irrigation areas, is to record the baseline state of the water resources, including the amount of discharge from canals. In this respect discharge measurements by means of the salt dilution method is a traditional and well-documented technique. However, this methodology can be strongly influenced by the natural streaming characteristics of the canal (e.g. laminar vs. turbulent flow and accurate precautions must be considered in the choice of both the measuring section and the length of the measuring reach of the canal which can affect the plume shape. The knowledge of plume distribution in the measuring cross-section is of primary importance for a correct location of sampling points aimed in obtaining a reliable measurement. To obtain this, geophysical imaging of an NaCl plume from a slug-injection salt dilution test has been performed within this paper by means of cross-flow fast electric resistivity tomography (FERT in a real case history. Direct sampling of the same plume has been also performed with a multisampling optimization technique to obtain an average value over the measuring section by means of contemporarily sampling water in nine points. Results show that a correct visualization of the passage of the salt plume is possible by means of geophysical controls and that this can potentially help in the correct location of sampling points.

  15. Comparison of different irrigation activation regimens and conventional irrigation techniques for the removal of modified triple antibiotic paste from root canals.

    Science.gov (United States)

    Akman, Melek; Akbulut, Makbule Bilge; Aydınbelge, Hale Arı; Belli, Sema

    2015-05-01

    The aim of this study was to compare the efficacy of irrigation activation regimens and conventional syringe irrigation technique in the removal of modified triple antibiotic paste (mTAP) from root canal walls. Fifty-six extracted human mandibular premolars were prepared using ProTaper rotary files (Dentsply Maillefer, Ballaigues, Switzerland) up to size F4. The root canals were filled with mTAP medicament, and after 21 days, the roots were randomly assigned to 5 groups (n = 10) according to the irrigation regimens used: conventional syringe irrigation (CI), Self-Adjusting File (SAF; ReDent-Nova, Ra'anana, Israel), EndoVac (Discus Dental, Culver City, CA), EndoActivator (Dentsply, Tulsa, OK), and passive ultrasonic irrigation (PUI). In 3 teeth, mTAP was not removed (positive controls), and another 3 teeth were not filled with mTAP (negative controls). The roots were sectioned, and the amount of remaining medicament at each root half (n = 20) was evaluated at 30× magnification using a 4-grade scoring system. Data were evaluated using the Kruskal-Wallis and Mann-Whitney U tests. There were statistically significant differences among all experimental groups; of which, the CI group was the significantly least efficient in removing mTAP from the root canal (P .05). The SAF and PUI showed significantly better performances in removing mTAP from the coronal third (P irrigation activation regimens significantly improves the removal of mTAP from root canals when compared with CI. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  16. An in vitro evaluation of various irrigation techniques for the removal of double antibiotic paste from root canal surfaces

    Directory of Open Access Journals (Sweden)

    Hakan GOKTURK

    Full Text Available ABSTRACT Objective The aim of this study was to investigate the effectiveness of conventional syringe irrigations, passive ultrasonic irrigation (PUI, Vibringe, CanalBrush, XP-endo Finisher, and laser-activated irrigation (LAI systems in removing double antibiotic paste (DAP from root canals. Material and Methods One hundred five extracted single-rooted teeth were instrumented. The roots were split longitudinally. Three standard grooves were created and covered with DAP. The roots were distributed into seven groups: Group 1, beveled needle irrigation; Group 2, double side-vented needle irrigation; Group 3, CanalBrush; Group 4, XP-endo Finisher; Group 5, Vibringe; Group 6, PUI; Group 7, LAI. The amount of remaining DAP was scored under a stereomicroscope. Results Group 4, Group 6, and Group 7 removed significantly more DAP than the other protocols in the coronal region. Group 7 was more efficient in the middle region; however, no significant difference was found between Group 7 and Group 6. No differences were found between groups in the apical region either, except for the comparisons between groups 7 and 2, and groups 2 and 3. Conclusions None of the investigated protocols were able to completely remove the DAP from the grooves. The Vibringe and XP-endo Finisher systems showed results similar to those of conventional needle irrigation.

  17. Wireless sensor networks for irrigation management

    Science.gov (United States)

    Sustaining an adequate food supply for the world's population will require advancements in irrigation technology and improved irrigation management. Site-specific irrigation and automatic irrigation scheduling are examples of strategies to deal with declining arable land and limited fresh water reso...

  18. Assessment of the efficiency and water productivity in the Spanish irrigation associations "Canal Toro-Zamora" and "Canal Villagonzalo" from the Duero basin

    Science.gov (United States)

    Rodriguez-Sinobas, Leonor; Amado Mendoza Hidalgo, Edwin

    2017-04-01

    Within a water scarcity scenario, the irrigated agriculture economic sector would be affected by the reduction on water supply and this might have a negative impact on the National gross income. Water for irrigation in Spain comprises the 75% of total consumption. Therefore, the search for irrigation strategies dealing with sustainable irrigation by saving water and improving the environment quality is encouraged. Within this framework the assessment of water use in the irrigation districts to assist water stakeholder decisions is reinforced. Water resources can be assessed at field scheme or regional scale by analyzing the water use efficiency and the water productivity indicators. Which determine the water availability and the water supply quality in irrigation areas. Among then, the following are broadly used: water productivity WP, and irrigation water productivity IWP, annual relative water supply (ARWS) and the annual relative irrigation water supply (ARIS). Keeping in mind the water scarcity scenario for irrigation in the short and long term and the probably scenario of water allocation for different uses following criteria of efficiency and productivity, this work is aimed at assessing the water use efficiency and water productivity of two modernized Spanish irrigation districts CCRRs: "Canal Toro-Zamora" and "Canal Villagonzalo" from the Duero basin. For that purpose, the above indicators were estimated for years 2014 and 2015. Crop water requirements are needed to calculate the indicators. For this study, maize was chosen since it is the major crop in the area and its water needs were estimated with the FAO program Cropwat. Local crop coefficients (Kc) were determined with the open access application SpiderWebGis (http://maps.spiderwebgis.org/webgis/) which uses satelital images to monitor Kc coefficients in all crops across Spain. In both CCRRs the maize Kc coefficients were similar for all the phenology stages although a slightly spatial variability was

  19. Field application of self-healing concrete with natural fibres as linings for irrigation canals in Ecuador

    NARCIS (Netherlands)

    Sierra Beltran, M.G.; Jonkers, H.M.; Mors, R.M.; Mera-Ortiz, W.

    2015-01-01

    This paper describes the first field application of self-healing concrete with alkaliphilic spore-forming bacteria and reinforced with natural fibres. The application took place in the highlands in Ecuador in July 2014. The concrete was cast as linings for an irrigation canal that transports water f

  20. Field application of self-healing concrete with natural fibres as linings for irrigation canals in Ecuador

    NARCIS (Netherlands)

    Sierra Beltran, M.G.; Jonkers, H.M.; Mors, R.M.; Mera-Ortiz, W.

    2015-01-01

    This paper describes the first field application of self-healing concrete with alkaliphilic spore-forming bacteria and reinforced with natural fibres. The application took place in the highlands in Ecuador in July 2014. The concrete was cast as linings for an irrigation canal that transports water

  1. Field application of self-healing concrete with natural fibres as linings for irrigation canals in Ecuador

    NARCIS (Netherlands)

    Sierra Beltran, M.G.; Jonkers, H.M.; Mors, R.M.; Mera-Ortiz, W.

    2015-01-01

    This paper describes the first field application of self-healing concrete with alkaliphilic spore-forming bacteria and reinforced with natural fibres. The application took place in the highlands in Ecuador in July 2014. The concrete was cast as linings for an irrigation canal that transports water f

  2. Efficacy of Different Root Canal Irrigants on Smear Layer Removal after Post Space Preparation: A Scanning Electron Microscopy Evaluation.

    Science.gov (United States)

    Mirseifinejad, Rahele; Tabrizizade, Mehdi; Davari, Abdolrahim; Mehravar, Fateme

    2017-01-01

    Effective durable adhesion between post material and dentine using resin cements is essential for longevity of restoration. The aim of this in vitro study was to compare the effect of different irrigants on smear layer removal after post space preparation. A total of 75 extracted anterior human teeth were selected. The canals were instrumented by rotary system and then were filled. After preparing the post space, teeth were divided into 5 groups according to irrigants: 17% EDTA; 17% EDTA+2% CHX; 5.25% NaOCl; 17% EDTA+5.25% NaOCl; and saline. The canals were irrigated with 5 cc of each irrigants for 1 min. Specimens were examined with scanning electron microscopy (SEM). Hulsmann's score was used for marking of smear layer removal at coronal, middle and apical thirds of post space. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests. The results revealed that subsequent use of 17% EDTA+5.25% NaOCl was more effective than the other groups in smear layer removal. No statistical difference was found among different levels of root canal within each group. It can be concluded that 17% EDTA+5.25% NaOCl could be an effective irrigant for smear layer removal after post space preparation.

  3. The cleanliness differences of root canal walls after irrigated with East Java propolis extract and sodium hypoclorite solutions

    Directory of Open Access Journals (Sweden)

    Tamara Yuanita

    2017-03-01

    (n=10. The specimens were prepared with ProTaper. During instrumentation, the root canals were irrigated with different solutions: Control Group irrigated with aquadest; Group 1 irrigated with 8% East Java propolis extract; Group 2 irrigated with 2.5% NaOCl and Group 3 irrigated with 5% NaOCl. The root canals were cut at apical third and SEM scores were tested by using Mann-Whitney test at the significance level of p=0.05 and Median Control test. Result: The results of Mann-Whitney Test, there were significant differences between control group with Group 1, 2 and 3 (p<0.05. Based on the Median Control test, the value of 8% East Java propolis extracts was 1,000, which was the best value compared to 2.5% NaOCl, 5% NaOCl and aquadest. Conclusion: It can be concluded that 8% East Java propolis extract is the most effective solution for cleaning root canal walls compared with 2.5% NaOCl and 5% NaOCl.

  4. Micro-CT evaluation of the efficacy of hard-tissue removal from the root canal and isthmus area by positive and negative pressure irrigation systems.

    Science.gov (United States)

    Versiani, M A; Alves, F R F; Andrade-Junior, C V; Marceliano-Alves, M F; Provenzano, J C; Rôças, I N; Sousa-Neto, M D; Siqueira, J F

    2016-11-01

    To evaluate the removal of accumulated hard-tissue debris (AHTD) from the root canal system of mandibular molars by positive and negative pressure irrigation systems, using micro-CT imaging analysis. Mandibular molars with a single canal in the distal root and 2 canals connected by an isthmus in the mesial root were matched based on similar morphological dimensions using micro-CT evaluation and assigned to 2 experimental groups (n = 20 mesial and 10 distal canals), according to the irrigation protocol: apical positive (conventional irrigation) or negative (EndoVac system) pressure. Changes in root canal volume and surface area as well as percentage of uninstrumented canal wall surface and accumulated hard-tissue debris (AHTD) after canal preparation were compared statistically using the independent sample t-test and Mann-Whitney U-test, with the significance level set at 5%. Volume, surface area and percentage of static voxels in either mesial or distal root canal systems were not significantly different between groups before or after root canal preparation (P > 0.05). After preparation, AHTD was not observed in the distal canal of both groups. However, in the mesial root canal system, the conventional irrigation group was associated with a significantly higher median percentage of AHTD (11.48%; IQR: 5.9-22.6; range: 1.86-41.98) than the EndoVac group (3.40%; IQR: 1.5-7.3; range: 0.82-12.84) (P < 0.05). Neither irrigation protocol succeeded in rendering the mesial canal system free of AHTD; however, apical negative pressure irrigation resulted in lower levels of AHTD than conventional irrigation. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  5. An update on the management of endodontic biofilms using root canal irrigants and medicaments.

    Science.gov (United States)

    Mohammadi, Zahed; Soltani, Mohammad Karim; Shalavi, Sousan

    2014-01-01

    Microbial biofilm is defined as a sessile multicellular microbial community characterized by cells that are firmly attached to a surface and enmeshed in a self-produced matrix of extracellular polymeric substances. Biofilms play a very important role in pulp and periradicular pathosis. The aim of this article was to review the role of endodontic biofilms and the effects of root canal irrigants, medicaments as well as lasers on biofilms A Medline search was performed on the English articles published from 1982 to 2013 and was limited to papers published in English. The searched keywords were "Biofilms AND endodontics", "Biofilms AND sodium hypochlorite", "Biofilms AND chlorhexidine", "Biofilms AND MTAD", "Biofilms AND calcium hydroxide", "Biofilms AND ozone", "Biofilms AND lasers" and "Biofilms AND nanoparticles". The reference list of each article was manually searched to find other suitable sources of information.

  6. Washout resistance of fast-setting pozzolan cement under various root canal irrigants

    Directory of Open Access Journals (Sweden)

    Ga-Yeon Jang

    2013-11-01

    Full Text Available Objectives Fast-setting pozzolan cement (Endocem, Maruchi was recently developed. The aim of this study was to investigate the effects of various root canal irrigants on the washout of Endocem in comparison to the previously marketed mineral trioxide aggregate (ProRoot; Dentsply in a furcal perforation model. Materials and Methods ProRoot and Endocem were placed into acrylic molds on moist Oasis. Each mold was then immediately exposed to either physiologic saline, 2.5% sodium hypochlorite (NaOCl, or 2% chlorhexidine (CHX under gentle shaking for five minutes. Washout testing was performed by scoring scanning electron microscope (SEM images. Results Endocem exhibited higher washout resistance compared to ProRoot, especially in the NaOCl group. Conclusions These results suggest that Endocem can be considered a useful repair material for furcal perforation, especially in a single-visit scenario.

  7. Effectiveness of Various Endodontic Irrigants on the Micro-Hardness of the Root Canal Dentin: An in vitro Study.

    Science.gov (United States)

    Saha, Suparna Ganguly; Sharma, Vini; Bharadwaj, Anuj; Shrivastava, Poorvi; Saha, Mainak Kanti; Dubey, Sandeep; Kala, Shubham; Gupta, Shubhra

    2017-04-01

    Irrigating solutions used for the elimination of micro-organisms during root canal preparation may affect the chemical and the physical properties of dentin thereby rendering the tooth more susceptible to fracture. Therefore careful and judicious selection of irrigant is required which have maximum benefits with minimum undesirable properties. The aim of the present study was to evaluate the effect of various endodontic irrigants on the micro-hardness of the root canal dentin. This in vitro study was carried out on eighty freshly extracted mandibular premolars with single canals. They were decoronated at the cemento-enamel junction. Roots were sectioned longitudinally into two halves. They were then polished and placed in autopolymerised resin moulds with the polished surface facing outside. The samples were divided into four groups based on the irrigants in which they were immersed i.e., 3% Sodium Hypochlorite (3% NaOCl), 17% Ethylene Dioxide Tetra Acetic Acid (17% EDTA), 0.2% Chitosan and 6% Morindacitrifolia Juice (MCJ) for 15 minutes each. All the specimens were then subjected to micro-hardness testing using a Vickers micro-hardness tester. Statistical analysis was done using one way Analysis of Variance (ANOVA), Post-Hoc Tukey test and Paired t-test to compare the pre and post immersion micro-hardness values of the selected samples. The results of the present study indicated that 17% EDTA and 0.2% Chitosan, significantly decreased the micro-hardness of root dentin whereas 6% MCJ and 3% NaOCl had no significant effect on the microhardness before and after immersing in the irrigants. A 6% MCJ and 3% NaOCl which have significant antibacterial, antifungal, anti-inflammatory and smear layer removing properties showed negligible effect on the micro-hardness of root canal dentin making them suitable endodontic irrigating solution.

  8. Effect of Imidazolium-Based Silver Nanoparticles on Root Dentin Roughness in Comparison with Three Common Root Canal Irrigants.

    Science.gov (United States)

    Farshad, Melika; Abbaszadegan, Abbas; Ghahramani, Yasamin; Jamshidzadeh, Akram

    2017-01-01

    The aim of this study was to evaluate the effect of a nanosilver-based irrigant on dentin roughness in comparison with three commonly used root canal irrigation solutions. Three common irrigants including 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) and 2% chlorhexidine (CHX) and also an imidazolium-based silver nanoparticle solution (ImSNP) (5.7×10 (-8) mol/L), were used. Distilled water was used as control. Roots of 25 human anterior teeth were sectioned longitudinally to obtain 50 dentin samples. Roughness values were evaluated by atomic force microscopy analysis on 5 groups (n=10) after each group was treated in one of the tested irrigant solutions for 10 min. Values were statistically analyzed by One-way analysis of variance, followed by a post hoc Tukey's test for pair-wise comparison. Dentin roughness significantly increased from 95.82 nm (control) to 136.02 nm, 187.07 nm, 142.29 nm and 150.92 nm with NaOCl, CHX, ImSNP and EDTA, respectively. CHX demonstrated a significantly higher roughness value compared to the other tested irrigants while no significant differences were seen in NaOCl, ImSNP and EDTA groups (P>0.242). ImSNP affected the physicochemical properties of dentin and raised its surface roughness; thus, this irrigant could impact bacterial and restorative material adhesion to root canal dentin walls.

  9. Effect of Imidazolium-Based Silver Nanoparticles on Root Dentin Roughness in Comparison with Three Common Root Canal Irrigants

    Science.gov (United States)

    Farshad, Melika; Abbaszadegan, Abbas; Ghahramani, Yasamin; Jamshidzadeh, Akram

    2017-01-01

    Introduction: The aim of this study was to evaluate the effect of a nanosilver-based irrigant on dentin roughness in comparison with three commonly used root canal irrigation solutions. Methods and Materials: Three common irrigants including 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) and 2% chlorhexidine (CHX) and also an imidazolium-based silver nanoparticle solution (ImSNP) (5.7×10 -8 mol/L), were used. Distilled water was used as control. Roots of 25 human anterior teeth were sectioned longitudinally to obtain 50 dentin samples. Roughness values were evaluated by atomic force microscopy analysis on 5 groups (n=10) after each group was treated in one of the tested irrigant solutions for 10 min. Values were statistically analyzed by One-way analysis of variance, followed by a post hoc Tukey’s test for pair-wise comparison. Results: Dentin roughness significantly increased from 95.82 nm (control) to 136.02 nm, 187.07 nm, 142.29 nm and 150.92 nm with NaOCl, CHX, ImSNP and EDTA, respectively. CHX demonstrated a significantly higher roughness value compared to the other tested irrigants while no significant differences were seen in NaOCl, ImSNP and EDTA groups (P>0.242). Conclusion: ImSNP affected the physicochemical properties of dentin and raised its surface roughness; thus, this irrigant could impact bacterial and restorative material adhesion to root canal dentin walls. PMID:28179931

  10. Quantitative assessment of root canal roughness with calcium-based hypochlorite irrigants by 3D CLSM.

    Science.gov (United States)

    Oliveira, Juliana Santos; Raucci Neto, Walter; Faria, Natália Spadine de; Fernandes, Fernanda Silva; Miranda, Carlos Eduardo Saraiva; Abi Rached-Junior, Fuad Jacob

    2014-01-01

    Chemical solutions play important roles in endodontic treatment and promote ultrastructural changes in dentin surface. The aim of this study was to quantify root canal roughness at different concentrations of calcium hypochlorite (Ca(OCl)2) and sodium hypochlorite (NaOCl) by confocal laser scanning microscopy (CLSM). Fifty-two human mandibular premolars were sectioned and randomly organized into thirteen groups (n=8): saline (control); 1%, 2.5% and 5% NaOCl; 1%, 2.5% and 5% Ca(OCl)2; the hypochlorite groups were further divided into with or without EDTA. The chlorine concentrations of the different solutions were measured by iodine titration (%). The superficial roughness (Sa) was quantified by CLSM. Ca(OCl)2 presented substantial decrease in chlorine concentration that differed from the package indication, but without compromising the dentin ultrastructure changes. There were no significant differences in dentin roughness between Ca(OCl)2 or NaOCl at all studied concentrations. The combination with EDTA provided similar roughness values among the solutions (p>0.05). The 5% Ca(OCl)2 and NaOCl solutions significantly increased dentin roughness and did not differ from the EDTA association (p>0.05). Ca(OCl)2 promoted similar dentin roughness as the NaOCl at the same concentrations and combined with EDTA. It may be concluded that Ca(OCl)2 modified the root canal dentin roughness similarly to NaOCl, at the same concentrations and EDTA combinations used in this study. Ca(OCl)2 and NaOCl, both at 5%, significantly altered dentin roughness, overcoming EDTA association, thus Ca(OCl)2 concentrations ranging from 1% to 2.5% may be suitable solutions for root canal irrigation protocols.

  11. [Analysis of different endodontic sealers and strategies of root canal irrigation on the bond strength of fiber posts].

    Science.gov (United States)

    Zhu, Shujin; Liu, Cuiling; Zheng, Zheng; Yang, Liyuan; Gao, Xu

    2015-06-01

    To evaluate the influence of eugenol-containing and resin-containing endodontic sealers on the bond strength of fiber posts using different strategies of root canal irrigation. Forty-eight mandibular premolars were endodontically treated. The specimens were randomly assigned into two groups according to different endodontic sealers. Group A used Endofil (eugenol-containing endodontic sealer), and group B used AH-plus (resin-containing endodontic sealer). After post space preparation, each group was randomly assigned into three subgroups according to the strategies of root canal irrigation (eight premolars in each subgroup). Group Al and B1: 0.9%NaCl irrigation; Group A2 and B2: 17% ethylene diamine tetraacetic acid (EDTA)+5.25%NaClO+0.9%NaCl irrigation; Group A3 and B3: ultrasonic agitation associated with 1 7%EDTA+5.25%NaClO+0.9%NaCl. One week after the cementation of fiber posts using RelyX™ Unicem, a push-out test was performed to measure the bond strength of the posts. The microstructure of the root canal surface was examined under scanning electron microscope (SEM). The bond strengths of the six groups were as follows: Al (7.96±2.23) MPa, A2 (9.95±2.89) MPa, A3 (18.88±3.69) MPa, B1 (11.41±3.71) MPa, B2 (14.00±4.04) MPa, and B3 (19.14±3.27) MPa. Statistical analysis revealed a significant interaction between the different endodontic sealers and the strategies of root canal irrigation (P0.05). SEM showed that the root canal in group A3 and B3 achieved the cleanest surface with nearly all dentine tubules opened. The eugenol-containing endodontic sealer can impair the bond strength of fiber posts compared with the resin-containing sealer when the root canal is irrigated by 0.9% NaCl or 17%EDTA+5.25%NaClO+0.9%NaC. No difference was observed between the two sealers when using 17%EDTA+5.25% NaCIO+0.9%NaCl combined with ultrasonic irrigation.

  12. Evaluation of 4% Sodium Hypochlorite in eliminating Enterococcus faecalis from the Root Canal when Used with Three Irrigation Methods: An in vitro Study.

    Science.gov (United States)

    Priyank, Harsh; Pandey, Vinisha; Bagul, Abhishek; Majety, Kishore Kumar; Verma, Parul; Choudhury, Basanta Kumar

    2017-03-01

    Endodontic treatment removes all pathogens, such as Enterococcus faecalis from pulp and root canals. The aim of this study is to assess the usefulness of sodium hypo-chlorite (NaOCl) in removing E. faecalis from the root canal used with three different irrigation methods. This study was conducted on freshly extracted maxillary incisors. After biomechanical preparation, root canals were injected with E. faecalis. Three groups were made which contained 30 teeth in each group; 2 mL of NaOCl solution was used for irrigation followed by agitation with K-files in group I; 2 mL of NaOCl solution was used for irrigation and ultrasonic agitation was done in group II. In group III, an alternate irrigation with NaOCl and 3% hydrogen peroxide was done. The fourth group (control) was irrigated with sterile saline solution. E. fae-calis bacteria were sampled to the root canals with paper points and were transferred to tubes that contained 5 mL of brain heart infusion broth. Tubes were incubated and the presence of broth turbidity was suggestive of bacteria remaining in the root canal. All three groups showed no statistically significant difference. However, difference existed between experimental groups and control groups. The author concluded that all three methods of application of NaOCl were effective in disinfecting the root canal than the saline solution. No single irrigant has 100% efficiency. Thus by this study, a best irrigating solution with maximum properties can be established.

  13. Antimicrobial Efficacy and Cytocompatibility of Calcium Hypochlorite Solution as a Root Canal Irrigant: An in Vitro Investigation

    Science.gov (United States)

    Sedigh-Shams, Mahdi; Gholami, Ahmad; Abbaszadegan, Abbas; Yazdanparast, Roohollah; Saberi Nejad, Milad; Safari, Azam; Nabavizadeh, Mohammadreza; Ghasemi, Younes

    2016-01-01

    Introduction: The purpose of this study was to compare the antimicrobial efficacy of sodium hypochlorite (SH) and calcium hypochlorite (CH) against Enterococcus faecalis (E. faecalis) using quantitative real-time polymerase chain reaction (qPCR) analysis and also to compare their cytocompatibility on L929 murine fibroblasts using Mossman’s tetrazolium toxicity (MTT) assay. Methods and Materials: A broth micro-dilution susceptibility test was used to determine the minimum inhibitory concentration (MIC) of each irrigant against E. faecalis. Then, the root canals of 50 mature extracted human mandibular premolars were contaminated with E. faecalis and were randomly divided into three groups according to the irrigant used (n=20). Canals were irrigated with SH in group I (n=20) and CH in group II (n=20) at their obtained MIC. In group III (n=10), sterile saline was used. Microbial sampling was performed before and after biomechanical preparation. Quantitative PCR was used to quantify E. faecalis in the root canal samples. For cytocompatibility assessment, L929 murine fibroblasts were exposed to various concentrations of the irrigants. Results: Irrigation with test materials resulted in significant reduction in colony forming units (CFU) in post-instrumentation samples (with the MIC values of SH and CH against E. faecalis being 0.5% and 5%, respectively). However, the reduction in the normal saline group was not significant (P=0.203). In addition, 5% CH was more effective than 0.5% SH (P=0.006) in eliminating E. faecalis. Among the different concentrations of tested irrigants, 0.5% CH and 5% SH showed the least and the most cytotoxicity, respectively (Pfaecalis in planktonic state and also its biofilm and exhibited comparable cytocompatibility to that of 0.5% SH. PMID:27471525

  14. Ground-water hydrology of the Punjab region of West Pakistan, with emphasis on problems caused by canal irrigation

    Science.gov (United States)

    Greenman, D.W.; Swarzenski, W.V.; Bennett, G.D.

    1967-01-01

    that the scientific management of this ground-water reservoir is the key to permanent irrigation agriculture in the Punjab. The West Pakistan Water .and Power Development Authority has prepared a long-range program for reclaiming the irrigated lands of the Punjab. The essential feature of this program is a proposed network of tubewells (drilled wells) located with an .average density of about one per square mile. Groundwater withdrawals will serve the dual purpose of helping to supply irrigation requirements and of providing subsurface drainage. Despite the feasibility and inherent advantages of tubewell reclamation methods, it is inevitable that just as the superposition of the canal system on the native environment caused undesirable side effects, large-scale ground-water withdrawals again will disturb the hydrologic regimen. The distribtution of withdrawals and maintenance of a favorable salt balance are two distinct, but related aspects of the ground-water budget that present potential hazards that must be considered in the design and management of the tubewell projects. The availability of ground water for irrigation diminishes from northeast to southwest, or downgradient along the doab (an area lying between two rivers) and is negligible in the centers of the lower parts of the doabs, where the ground water is too highly mineralized for use. Ground-water supplies must be developed in areas where they are available and it might become necessary, under a program of maximum exploitation of ground-water resources, to transfer supplies from outside sources to points of use in the lower parts of the doabs. Several factors inherent in the tubewell system will tend to depreciate the quality of ground water with time. Among these are the addition of salts leached from the soils, increased concentration of salts due .to repeated cycles of recirculation, and the possible lateral and upward encroachment of saline water in response to pumping. It is reasonably ce

  15. An In-vivo Study Comparing Antimicrobial Activity of Chlorhexidine 0.2% to Sodium Hypochlorite 0.5% as Canal Irrigant

    Directory of Open Access Journals (Sweden)

    A.Vahid

    2004-03-01

    Full Text Available Statement of Problem: Bacterial agents are the primary cause of pulpoperiapical diseases.Therefore, an irrigating solution with proper antibacterial ability should be used to eliminate the bacterial agents during canal instrumentation.Purpose: The aim of present study was to compare the antibacterial effect of 0.2% chlorhexidine to 0.5% sodium hypochlorite as canal irrigating solutions.Materials and Methods: In this study 20 single canal teeth with necrotic pulps were selected by vitality tests and divided in two groups each one consists of ten. Each canal irrigated with 12 ml of 0.2% chlorhexidine in the first group and 0.5% sodium hypochloritein the second one. Each canal was instrumented by 6 k- type files by step back procedure (two minutes for each file. After canal instrumentation, sterile cotton pellet was placed onthe pulp chamber and the canals were filled temporarily by cavit. Samples were selected by two strile paper points both before the canal instrumentation (after accessing the canal and 48 hours later. Samples were cultured on Mitis salivarius agar and anaerobic blood agar and then, the colony counts were reported in terms of CFU/ml.Results: Elimination percent mean of streptococcus mutans and anaerobics with 0.2%chlorhexidine were 99.9 and 99.02 respectively and for 0.5% hypochlorite were 99.7, and 92.7 respectively.Conclusion: There was no significant difference between these two irrigating solutions by non parameteric Mann-Whitney test.

  16. Linking hydrology of traditional irrigation canals and socio-economic aspects of agricultural water use around Mt. Kilimanjaro

    Science.gov (United States)

    Kimaro, Jerome; Scharsich, Valeska; Huwe, Bernd; Bogner, Christina

    2017-04-01

    Traditional irrigation network around Mt. Kilimanjaro has been an important resource for both ecosystem functioning and agricultural production. However, a number of irrigation furrows can no longer maintain their discharge throughout the year and their future sustainability is uncertain. The actual efforts to improve the water supply were unsuccessful. We attribute this failure to a lack of information about the actual causes and extent of the problem. We suppose that there is a strong link between the socio-economic aspects like institutional and community management of the furrows and conflicts about water use. Therefore, we conducted a study to determine the relationship between current hydrological patterns and socio-economic aspects of agricultural water use. We measured discharge at 11 locations along an altitudinal gradient on the southern slopes of Mt. Kilimanjaro. Additionally, we conducted focus group discussions with participants from 15 villages and key informants interviews (n = 15). We found that the mean discharge did not differ significantly between dry and rainy seasons (ANOVA, p = 0.17). The overall discharge pattern indicated that furrows located in lower altitude had higher mean monthly discharge rate of 65 l s-1 compared to 11.5 l s-1 at the source area of the canals. This is due to the convergence of canals downstream. 41% of furrows were seasonal, 22% dry and only 37% perennial. Despite of a seemingly better water resource availability downstream, water conflicts are a major challenge across the whole mountain communities. Key informants and group discussions reported poor management of water on the district level. The Rural Moshi and Hai District Councils operate on a top down approach that give less power to the local water management committees. However, the latter have been an important part of the traditional management system for decades. Since 1990, the district authorities are using 65% of springs from the catchment to abstract water

  17. Pico Hydropower Application on Tidal Irrigation CanalSupporting The Indonesian Agricultural Activities Case Study: Telang II – Banyuasin

    Directory of Open Access Journals (Sweden)

    Darmawi Darmawi

    2013-01-01

    Full Text Available A review of waterwheel history has conducted to evaluate the possibility and thetechnology development in its relation to harvest the energy from the flowing water inand out of irrigation canal regarding the tidal movement. The study has conducted atthe east shore of South Sumatra. Hydro energy became a promising renewable energyin order to achieve at least 5% of total Indonesian national energy mix consumption in 2025. Tidal turbine energy is technologically potential for Indonesian futureregarding the beach of 81,000 kilometers long and 20 millions hectares of tidalswamp area out of 33 millions hectares available. Mechanical torque of 30 Nm isproduced by a waterwheel of 0.38 meter radius. An estimation of 60 watt at the peakof rain season could harvested from each tidal irrigation canal in Telang II. Thismechanical energy is applicable to generate small quantity water pump, water aerationinjector and small electric energy energy appliances.

  18. Quantifying seepage using heat as a tracer in selected irrigation canals, Walker River Basin, Nevada, 2012 and 2013

    Science.gov (United States)

    Naranjo, Ramon C.; Smith, David W.

    2016-11-16

    The Walker River is an important source of water for western Nevada. The river provides water for agriculture and recharge to local aquifers used by several communities. Farmers began diverting water from the Walker River in the 1860s to support growing agricultural development. Over time, the reduced inflows into Walker Lake from upstream reservoirs and diversions have resulted in 170 feet of lake level decline and increased dissolved-solids concentrations to levels that threaten aquatic ecosystems, including survival of Lahonton cutthroat trout, a native species listed in the Endangered Species Act. Investigations of the water-budget components in the Walker River Basin have revealed uncertainty in the recharge to aquifers from irrigation canals. To address this need, the U.S. Geological Survey conducted an extensive field study from March 2012 through October 2013 to quantify seepage losses in selected canals in the Smith Valley, Mason Valley, and Walker Lake Valley irrigation areas.The seepage rates estimated for the 2012 and 2013 irrigation seasons in the Smith Valley transect sites (Saroni and Plymouth canals) ranged between 0.01 to 2.5 feet per day (ft/d) (0.01 to 0.68 cubic feet per second per mile [ft3/s-mi]). From 2012 to 2013, the average number of days the canals had flowing water decreased from 190 to 125 due to drier climate and lack of water available for diversion from the Walker River. The nearly 50-percent reductions in volumetric loss rates between 2012 and 2013 were associated with less than average diversions into canals from the Walker River and reductions in infiltration rates following routine canal maintenance.Models developed for the Saroni canal in 2012 were recalibrated in 2013 to evaluate changes in seepage as a result of siltation. Just prior to the 2012 irrigation season, nearly the entire length of the canal was cleared of vegetation and debris to improve flow conveyance. In 2013, following the first year of maintenance, a 90-percent

  19. The effect of irrigating solutions on the apical sealing ability of MTA Fillapex and Adseal root canal sealers

    Directory of Open Access Journals (Sweden)

    Richa Singh

    2016-12-01

    Full Text Available Background. Maximum sealing ability or adhesion of endodontic sealers can be achieved after effective removal of the smear layer. Endodontic irrigants assist in adequate removal of the smear layer, improving the retention mechanism. The aim of this study was to evaluate the effect of two different root canal irrigation solutions (5.25% NaOCl followed by 17% EDTA and QMix on the apical sealing ability of two different root canal sealers (MTA Fillapex and Adseal. Methods. Forty-six single-canal teeth were divided into 4 experimental groups of 10 teeth each and a positive and negative group of 3 teeth each. The root canals were prepared using step-back technique. The teeth in groups 1 and 2 were irrigated with 5.25% NaOCl followed by 17% EDTA and the teeth in groups 3 and 4 were irrigated with QMix. Finally all the teeth were flushed with sterile saline and dried using paper points. Obturation was accomplished by gutta-percha using lateral condensation technique. MTA Fillapex sealer was used in groups 1 and 3 whereas Adseal was used in groups 2 and 4. Dye penetration method was used to evaluate apical leakage. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests using SPSS 14. Statistical significance was set at P < 0.05. Results. Group 3 showed maximum amount of apical leakage (3.7±0.3 mm whereas group 2 exhibited the least amount of apical leakage (2.1 ± 0.4 mm among all the experimental groups. Significant differences were found in the amount of apical leakage between all the groups (P = 0.00001. Conclusion. Within the limitations of this study, 5.25% sodium hypochlorite followed by 17% EDTA and Adseal resulted in the best apical seal.

  20. The effect of irrigating solutions on the apical sealing ability of MTA Fillapex and Adseal root canal sealers

    Science.gov (United States)

    Singh, Richa; Pushpa, Shankarappa; Arunagiri, Doraiswamy; Sawhny, Asheesh; Misra, Abhinav; Sujatha, Ramamurthy

    2016-01-01

    Background. Maximum sealing ability or adhesion of endodontic sealers can be achieved after effective removal of the smear layer. Endodontic irrigants assist in adequate removal of the smear layer, improving the retention mechanism. The aim of this study was to evaluate the effect of two different root canal irrigation solutions (5.25% NaOCl followed by 17% EDTA and QMix) on the apical sealing ability of two different root canal sealers (MTA Fillapex and Adseal). Methods. Forty-six single-canal teeth were divided into 4 experimental groups of 10 teeth each and a positive and negative group of 3 teeth each. The root canals were prepared using step-back technique. The teeth in groups 1 and 2 were irrigated with 5.25% NaOCl followed by 17% EDTA and the teeth in groups 3 and 4 were irrigated with QMix. Finally all the teeth were flushed with sterile saline and dried using paper points. Obturation was accomplished by gutta-percha using lateral condensation technique. MTA Fillapex sealer was used in groups 1 and 3 whereas Adseal was used in groups 2 and 4. Dye penetration method was used to evaluate apical leakage. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests using SPSS 14. Statistical significance was set at P < 0.05. Results. Group 3 showed maximum amount of apical leakage (3.7±0.3 mm) whereas group 2 exhibited the least amount of apical leakage (2.1 ± 0.4 mm) among all the experimental groups. Significant differences were found in the amount of apical leakage between all the groups (P = 0.00001). Conclusion. Within the limitations of this study, 5.25% sodium hypochlorite followed by 17% EDTA and Adseal resulted in the best apical seal. PMID:28096952

  1. Comparative evaluation of antimicrobial effect of herbal root canal irrigants (Morinda citrifolia, Azadirachta indica, Aloe vera) with sodium hypochlorite: An in vitro study

    Science.gov (United States)

    Babaji, Prashant; Jagtap, Kiran; Lau, Himani; Bansal, Nandita; Thajuraj, S.; Sondhi, Priti

    2016-01-01

    Aim and Objectives: Successful root canal treatment involves the complete elimination of microorganism from the root canal and the three-dimensional obturation of the canal space. Enterococcus faecalis is the most commonly found bacteria in failed root canal. Chemical irrigation of canals along with biomechanical preparation helps in the elimination of microorganisms. The present study was aimed to evaluate the antimicrobial effect of herbal root canal irrigants (Morinda citrifolia, Azadirachta indica extract, Aloe vera) with sodium hypochlorite (NaOCl). Materials and Methods: The bacterial E. faecalis (ATCC) culture was grown overnight in brain heart infusion (BHI) broth and inoculated in Mueller–Hinton agar plates. Antibacterial inhibition was assessed using agar well diffusion method. All five study irrigants were added to respective wells in agar plates and incubated at 37°C for 24 h. Bacterial inhibition zone around each well was recorded. Results were tabulated and statistically analyzed using Statistical Package for the Social Sciences software for Windows, version 19.0. (IBM Corp., Armonk, NY. Results: Highest inhibitory zone against E. faecalis was seen in NaOCl fallowed by M. citrifolia and A. indica extract, and the least by A. vera extract. Conclusion: Tested herbal medicine (A. indica extract, M. citrifolia, A. vera) showed inhibitory zone against E. faecalis. Hence, these irrigants can be used as root canal irrigating solutions. PMID:27382533

  2. In vitro study of the apical microleakage with resilon root canal filling using different final endodontic irrigants

    Science.gov (United States)

    Lahor-Soler, Eduard; Brunet-Llobet, Lluís; Farré, Magí; Pumarola, Josep

    2015-01-01

    Background Endodontic microleakage or microfiltration refers to the percolation of fluids and micro-organisms at the interface of the obturation material and the walls of the root canal system. The aim of this in vitro study was to compare apical microfiltration of Resilon root canal filling by employing three different final irrigant solutions. Material and Methods 128 single-rooted teeth were employed. The crowns were sectioned horizontally at the cemento-enamel junction and instrumented with 5.25% sodium hypochlorite (NaOCl) and 17% EDTA gel to obtain an instrumented 040 apical caliber. An intermediate irrigation was performed with distilled water. The roots were then randomly assigned to three experimental groups with three different final irrigants: (A) 20% citric acid (CA); (B) 2% chlorhexidine digluconate (CHX); and (C) 5.25% NaOCl, plus two control groups (positive and negative). They were then dried, obturated with RealSeal™, and cleared by Robertson’s technique. Apical microleakage was measured by the dye penetration method and assessed with a 4.5x stereomicroscope. Data were statistically analyzed by one way ANOVA and post hoc analysis for multiple comparisons. Results Mean and standard deviations for apical microleakage were: 2% CHX (0.24 mm ± 0.22), 20% CA (0.25 mm ± 0.20), and 5.25% NaOCl (0.87 mm ± 0.32). Significant differences were reported among the group irrigated with NaOCl, CHX and CA (Pirrigation was performed with NaOCl whilst lower rates were reported for CHX and CA. Key words:Apical filtration, endodontic irrigation, resin-based sealers, adhesion, root canal filling. PMID:26155335

  3. Comparison of positive-pressure, passive ultrasonic, and laser-activated irrigations on smear-layer removal from the root canal surface.

    Science.gov (United States)

    Sahar-Helft, Sharonit; Sarp, Ayşe Sena Kabaş; Stabholtz, Adam; Gutkin, Vitaly; Redenski, Idan; Steinberg, Doron

    2015-03-01

    The purpose of this study was to compare the efficacy of three irrigation techniques for smear-layer removal with 17% EDTA. Cleaning and shaping the root canal system during endodontic treatment produces a smear layer and hard tissue debris. Three irrigation techniques were tested for solution infiltration of this layer: positive-pressure irrigation, passive ultrasonic irrigation, and laser-activated irrigation. Sixty extracted teeth were divided into six equal groups; 17% EDTA was used for 60 sec irrigation of five of the groups. The groups were as follows: Group 1, treated only with ProTaper™ F3 Ni-Ti files; Group 2, positive-pressure irrigation, with a syringe; Group 3, passive ultrasonic irrigation, inserted 1 mm short of the working length; Group 4, passive ultrasonic irrigation, inserted in the upper coronal third of the root; Group 5, Er:YAG laser-activated irrigation, inserted 1 mm short of the working length; and Group 6, Er:YAG laser-activated irrigation, inserted in the upper coronal third of the root. Scanning electron microscopy showed that the smear layer is removed most efficiently using laser-activated irrigation at low energy with 17% EDTA, inserted either at the working length or only in the coronal upper third of the root. Amounts of Ca, P, and O were not significantly different on all treated dentin surfaces. Smear-layer removal was most effective when the root canals were irrigated using Er:YAG laser at low energy with 17% EDTA solution. Interestingly, removal of the smear layer along the entire canal was similar when the laser was inserted in the upper coronal third and at 1 mm short of the working length of the root canal. This effect was not observed with the ultrasonic and positive-pressure techniques.

  4. Comparison of sealer penetration using the EndoVac irrigation system and conventional needle root canal irrigation.

    Science.gov (United States)

    Kara Tuncer, Aysun; Unal, Bayram

    2014-05-01

    The aim of this study was to compare the effect of the EndoVac irrigation system (SybronEndo, Orange, CA) and conventional endodontic needle irrigation on sealer penetration into dentinal tubules. Forty single-rooted, recently extracted human maxillary central incisors were randomly divided into 2 groups according to the irrigation technique used: conventional endodontic needle irrigation and EndoVac irrigation. All teeth were instrumented using the ProFile rotary system (Dentsply Maillefer, Ballaigues, Switzerland) and obturated with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany) labeled with fluorescent dye. Transverse sections at 1, 3, and 5 mm from the root apex were examined using confocal laser scanning microscopy. The total percentage and maximum depth of sealer penetration were then measured. Mann-Whitney test results showed that EndoVac irrigation resulted in a significantly higher percentage of sealer penetration than conventional irrigation at both the 1- and 3-mm levels (P irrigation system significantly improved the sealer penetration at the 1- to 3-mm level over that of conventional endodontic needle irrigation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Effect of Maintaining Apical Patency on Irrigant Penetration into the Apical Two Millimeters of Large Root Canals : An In Vivo Study

    NARCIS (Netherlands)

    Vera, Jorge; Hernandez, Erick M.; Romero, Monica; Arias, Ana; van der Sluis, Lucas W. M.

    2012-01-01

    Introduction: Factors such as complex root canal anatomy and the vapor lock phenomenon have been shown to limit the penetration of irrigating solutions into the apical third in both in vivo and in vitro studies involving small and wide canals. Hence, the aim of this study was to determine whether

  6. Irrigant Flow beyond the Insertion Depth of an Ultrasonically Oscillating File in Straight and Curved Root Canals : Visualization and Cleaning Efficacy

    NARCIS (Netherlands)

    Malki, Maher; Verhaagen, Bram; Jiang, Lei-Meng; Nehme, Walid; Naaman, Alfred; Versluis, Michel; Wesselink, Paul; van der Sluis, Lucas

    2012-01-01

    Introduction: The purpose of this study was to evaluate the influence of the insertion depth of an ultrasonically oscillating file on the ability to remove dentin debris from simulated canal irregularities in an extracted tooth model of a straight root canal and its influence on the flow of irrigant

  7. Effect of passive ultrasonic irrigation and manual dynamic irrigation on smear layer removal from root canals in a closed apex in vitro model.

    Science.gov (United States)

    Andrabi, Syed Mukhtar-Un-Nisar; Kumar, Ashok; Zia, Afaf; Iftekhar, Huma; Alam, Sharique; Siddiqui, Shiraz

    2014-08-01

    To compare the effect of passive ultrasonic irrigation with manual dynamic irrigation on smear layer removal from root canals using a closed apex in vitro model. The root canals of 45 freshly-extracted human single-rooted mandibular premolar teeth were prepared by the Pro-Taper rotary system to an apical preparation of F4 size. Prepared teeth were randomly divided into three groups; two experimental groups and one control group (n = 15) on the basis of the type of activation of final irrigation as follows: (a) Group A, 3% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA), no activation received; (b) Group B, 3% NaOCl and 17% EDTA, ultrasonic activation with a small file; and (c) Group C, 3% NaOCl and 17% EDTA, manual activation with a master gutta-percha point. The prepared teeth were decoronated and split into two halves longitudinally, and observed under a scanning electron microscope to assess the removal of the smear layer. In the apical-third region, the mean smear scores for groups B and C were significantly less than those of Group A (control group) (P < 0.05). Both activation techniques are important adjuncts in removing the smear layer, with manual dynamic activation being a simpler, safer, and more cost-effective technique. © 2013 Wiley Publishing Asia Pty Ltd.

  8. The Effect of Needle-insertion Depth on the Irrigant Flow in the Root Canal : Evaluation Using an Unsteady Computational Fluid Dynamics Model

    NARCIS (Netherlands)

    Boutsioukis, Christos; Lambrianidis, Theodor; Verhaagen, Bram; Versluis, Michel; Kastrinakis, Eleftherios; Wesselink, Paul R.; van der Sluis, Lucas W. M.

    2010-01-01

    Introduction: The aim of this study was to evaluate the effect of needle-insertion depth on the irrigant flow inside a prepared root canal during final irrigation with a syringe and two different needle types using a Computational Fluid Dynamics (CFD) model. Methods: A validated CFD model was used t

  9. The evaluation of removal of calcium hydroxide paste from an artificial standardized groove in the apical root canal using different irrigation methodologies

    NARCIS (Netherlands)

    van der Sluis, L. W. M.; Wu, M. K.; Wesselink, P. R.

    2007-01-01

    Aim: To evaluate the capacity to remove a calcium hydroxide (Ca(OH)(2)) paste from the root canal and to evaluate the efficacy of Ca(OH)(2) removal during passive ultrasonic irrigation using either sodium hypochlorite (NaOCl) or water as an irrigant. Methodology: Sixteen mandibular premolars were us

  10. The effect of needle-insertion depth on the irrigant flow in the root canal: evaluation using an unsteady computational fluid dynamics model

    NARCIS (Netherlands)

    Boutsioukis, C.; Lambrianidis, T.; Verhaagen, B.; Versluis, M.; Kastrinakis, E.; Wesselink, P.R.; van der Sluis, L.W.M.

    2010-01-01

    Introduction The aim of this study was to evaluate the effect of needle-insertion depth on the irrigant flow inside a prepared root canal during final irrigation with a syringe and two different needle types using a Computational Fluid Dynamics (CFD) model. Methods A validated CFD model was used to

  11. Hard tissue debris removal from the mesial root canal system of mandibular molars with ultrasonically and laser-activated irrigation: a micro-computed tomography study.

    Science.gov (United States)

    Verstraeten, J; Jacquet, W; De Moor, R J G; Meire, M A

    2017-08-07

    This study is to investigate the efficacy of different irrigant activation techniques on removal of accumulated hard tissue debris (AHTD) in mesial roots of human mandibular molars. Extracted human mandibular molars with an isthmus between the mesial root canals were selected based on micro-CT (μCT) scans. The mesial canals were instrumented to an apical diameter ISO30 using ProTaper rotary files. Teeth were randomly assigned to three irrigant activation groups (n = 10): ultrasonically activated irrigation (UAI) using a size 20 Irrisafe for 3 × 20 s, laser-activated irrigation (LAI) with an Er:YAG laser (2940 nm) and plain 300 μm fiber tip inside the canal (20 mJ, 20 Hz, 3 × 20 s), and laser-activated irrigation with identical parameters with a 400 μm photon-induced photoacoustic streaming (PIPS) tip held at the canal entrance. All teeth were scanned with μCT before and after instrumentation and after irrigant activation. After reconstruction and image processing, the canal system volume filled with hard tissue debris before and after irrigant activation was calculated. Changes in hard tissue debris volumes were compared between groups using one-way ANOVA. The percentage volume of hard tissue debris (vol%) was significantly lower after irrigant activation in all groups. Although the lowest debris values were observed in the laser groups, no significant differences in the vol% of accumulated hard tissue debris after activation were observed between groups. Accumulated hard tissue debris was reduced significantly in all activation groups. Ultrasonically and laser-activated irrigation regimens performed similarly in this respect. None of the tested methods was able to render the root canal systems free of debris.

  12. Quantifying canal leakage rates using a mass-balance approach and heat-based hydraulic conductivity estimates in selected irrigation canals, western Nebraska, 2007 through 2009

    Science.gov (United States)

    Hobza, Christopher M.; Andersen, Michael J.

    2010-01-01

    The water supply in areas of the North Platte River Basin in the Nebraska Panhandle has been designated as fully appropriated or overappropriated by the Nebraska Department of Natural Resources (NDNR). Enacted legislation (Legislative Bill 962) requires the North Platte Natural Resources District (NPNRD) and the NDNR to develop an Integrated Management Plan (IMP) to balance groundwater and surface-water supply and demand in the NPNRD. A clear understanding of the groundwater and surface-water systems is critical for the development of a successful IMP. The primary source of groundwater recharge in parts of the NPNRD is from irrigation canal leakage. Because canal leakage constitutes a large part of the hydrologic budget, spatially distributing canal leakage to the groundwater system is important to any management strategy. Surface geophysical data collected along selected reaches of irrigation canals has allowed for the spatial distribution of leakage on a relative basis; however, the actual magnitude of leakage remains poorly defined. To address this need, the U.S. Geological Survey, in cooperation with the NPNRD, established streamflow-gaging stations at upstream and downstream ends from two selected canal reaches to allow a mass-balance approach to be used to calculate daily leakage rates. Water-level and sediment temperature data were collected and simulated at three temperature monitoring sites to allow the use of heat as a tracer to estimate the hydraulic conductivity of canal bed sediment. Canal-leakage rates were estimated by applying Darcy's Law to modeled vertical hydraulic conductivity and either the estimated or measured hydraulic gradient. This approach will improve the understanding of the spatial and temporal variability of canal leakage in varying geologic settings identified in capacitively coupled resistivity surveys. The high-leakage potential study reach of the Tri-State Canal had two streamflow-gaging stations and two temperature monitoring

  13. Ex vivo evaluation of various instrumentation techniques and irrigants in reducing E. faecalis within root canals.

    Science.gov (United States)

    Basmaci, F; Oztan, M D; Kiyan, M

    2013-09-01

    To evaluate ex vivo the effectiveness of single-file instrumentation techniques compared with serial Ni-Ti rotary instrumentation with several irrigation regimens in reducing E. faecalis within root canals. A total of 81 extracted human mandibular premolar teeth with a single root canal were infected with E. faecalis before and after canal preparation. Samples were divided randomly into 9 groups, as follows: group 1-A: sterile phosphate-buffered saline + Self-adjusting file, group 1-B: 5% sodium hypochlorite + 15% EDTA + Self-adjusting file, group 1-C: 5% sodium hypochlorite + 7% maleic acid + Self-adjusting file, group 2-A: sterile phosphate-buffered saline + Reciproc (R25), group 2-B: 5% sodium hypochlorite + 15% EDTA + Reciproc (R25), group 2-C: 5% sodium hypochlorite + 7% maleic acid + Reciproc (R25), group 3-A: sterile phosphate-buffered saline + ProTaper, group 3-B: 5% sodium hypochlorite + 15% EDTA + ProTaper, group 3-C: 5% sodium hypochlorite + 7% maleic acid + ProTaper. anova was used to analyse statistically the differences in terms of reduction in colony counts between the groups, and Dunn's post hoc test was used for multiple comparisons. All techniques and irrigation regimens significantly reduced the number of bacterial cells in the root canal (P irrigants. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  14. 辅助根管冲洗器械的研究新进展%Advances in auxiliary root canal irrigation instrument

    Institute of Scientific and Technical Information of China (English)

    吴丽更; 穆颖

    2012-01-01

    Root canal irrigation is a must in root canal therapy, however,not a irrigating solution or a com-bination of some irrigating solutions can completely remove the smear layer. Consequently, auxiliary root canal irrigation instrument arises to improve the cleaning efficiency of root canal system . This article reviews four kinds of auxiliary root canal irrigation instruments, namely, the manual irrigation system, pressure switch system, acoustic system and ul-trasonic system.%目前尚未发现一种冲洗液或多种冲洗液的联合应用能够彻底清除根管玷污层.因此,各种辅助根管冲洗器械应运而生,以提高根管系统的清洁率.本文就各种辅助根管冲洗器械如:手动冲洗系统、压力转换系统、声波系统、超声波系统作一综述.

  15. Remote sensing and hydrogeological methodologies for irrigation canal leakage detection: the Osasco and Fossano test sites (NorthWestern Italy)

    Science.gov (United States)

    Perotti, Luigi; Clemente, Paolo; De Luca, Domenico Antonio; Dino, Giovanna; Lasagna, Manuela

    2013-04-01

    Seventy percent of global fresh water is usually used for irrigation. This rate is three times the amount of water used by industry and ten times the amount used in domestic and urban environment (Hotchkiss et al., 2001). However, the average efficiency of the water transport for agricultural purposes in different contexts (at world scale) is variable between 30% and 80%. Studies conducted in Italy confirms that rates are similar from the case studies abroad. In this research, satellite image analysis and hydrological-hydrogeological methods were used in two pilot sites (Osasco channel and Fossano channel, in the Noth-Western Italy) to identify the areas most prone to this problem and to quantify the losses. The aim of the study is to define a multidisciplinary approach in order to identify the critical situations of irrigation channels for a sustainable water resource use and management. The use of remote sensing techniques can identify, on a regional scale and at relative low cost, the channels section potentially critical upon which focus the attention and perform in-situ investigation. The presence of leakage from the irrigation canals, indeed, tends to induce variations of moisture on the surface ground. These variations affect the vegetation (e.g. vegetation state), and certain physical characteristics of the soil (e.g. the capacity and thermal conductivity). The analysis of these anomalies, conducted with digital image processing techniques (with infrared spectrum bands particularly sensitive to the above indicators) help to identify those areas with anomalies related to increased losses (Huang and Fipps, 2002). The use of satellite imagery in the proposed approach is an innovative application of Earth Observation for land and water monitoring (Huang et al., 2005). After the identification of anomalies, hydrological-hydrogeological methods were applied to evaluate the losses. At fist an hydrogeological characterisation of the study area and the bottom of the

  16. Microbiological evaluation of different irrigation protocols on root canal disinfection in teeth with apical periodontitis: an in vivo study.

    Science.gov (United States)

    Cohenca, Nestor; Silva, Lea Assed Bezerra; Silva, Raquel Assed Bezerra; Nelson-Filho, Paulo; Heilborn, Carlos; Watanabe, Evandro; Saraiva, Maria Conceição Pereira

    2013-01-01

    The present in vivo study was designed to evaluate the efficacy of apical negative pressure irrigation (ANP), passive ultrasonic irrigation (PUI) and positive pressure irrigation (PP) in the reduction of intracanal bacteria of dogs' teeth with pulp necrosis and apical periodontitis. Eighty root canals were randomly distributed into 3 experimental and 2 control groups according to the irrigation delivery system: group ANP (n=20), group PUI (n=20), group PP (n=20), group PC (positive control - sterile saline irrigation; n=10) and group NC (negative control - vital pulps not subjected to bacterial inoculation; n=10). The first sample (S1) was collected at baseline, and the second sample (S2) was collected after the disinfection protocols. All samples were seeded in culture media for anaerobic bacteria. CFU counts were analyzed statistically by the Kruskal-Wallis, Dwass-Steel-Critchlow-Fligner post-hoc and Chi-square followed by Tukey like multiple comparisons for proportions (α=0.05). All experimental groups were effective in reducing Gram-positive bacteria compared with PC (p0.05). In dog's teeth with apical periodontitis, the use of ANP and PUI can be considered promising disinfection protocols as both delivery systems promoted a significant bacterial reduction.

  17. Analysis and Calculation of Conveyance Efficiency of an Irrigation Canal System%灌溉渠系水利用系数的分析与计算

    Institute of Scientific and Technical Information of China (English)

    高传昌; 张世宝; 刘增进

    2001-01-01

    灌溉渠系的布置形式一般可分为串联渠系、等效并联渠系和非等效并联渠系,对这3种灌溉渠系水利用系数进行了理论研究。用实例验证了上述的理论分析。研究成果可应用于实际灌溉工程。%Layout forms of irrigation canal system can be generally classified as three categories: series-wound canal system, equivalent shunt-wound canal system and nonequivalent shunt-wound canal system. The conveyance efficiencies of these three kinds of irrigation canal system were theoretically analyzed. Practical verification showed that theoretical values were dependable.

  18. Irrigation network extraction methodology from LiDAR DTM using Whitebox and ArcGIS

    Science.gov (United States)

    Mahor, M. A. P.; De La Cruz, R. M.; Olfindo, N. T.; Perez, A. M. C.

    2016-10-01

    Irrigation networks are important in distributing water resources to areas where rainfall is not enough to sustain agriculture. They are also crucial when it comes to being able to redirect vast amounts of water to decrease the risks of flooding in flat areas, especially near sources of water. With the lack of studies about irrigation feature extraction, which range from wide canals to small ditches, this study aims to present a method of extracting these features from LiDAR-derived digital terrain models (DTMs) using Geographic Information Systems (GIS) tools such as ArcGIS and Whitebox Geospatial Analysis Tools (Whitebox GAT). High-resolution LiDAR DTMs with 1-meter horizontal and 0.25-meter vertical accuracies were processed to generate the gully depth map. This map was then reclassified, converted to vector, and filtered according to segment length, and sinuosity to be able to isolate these irrigation features. Initial results in the test area show that the extraction completeness is greater than 80% when compared with data obtained from the National Irrigation Administration (NIA).

  19. An application of a dynamical set point policy to main irrigation canals using in-line storage

    Science.gov (United States)

    Hashemy Shahdany, S. M.; Maestre, J. M.; Van Overloop, P. J.; Monem, M. J.

    2012-04-01

    In this study a set of different set points are taken into account for several pools of the Dez irrigation canal. The set points are calculated according to the water demands that are expected during the next hours. The rationale behind considering a group of set points is that it can be interesting to store water into different pools, as in-line reservoirs, in order to reduce the delay time and to compensate possible mismatches between upstream supply and downstream demand. A severe and sudden increasing - decreasing flow schedule has been applied by using Sobek hydrodynamic model for normal operation and operation with using in-line storage. A controller is used to choose between these set points in order to obtain the highest possible control performance. To this end, we consider a model predictive controller that follows each of the set points. As a consequence, different control vectors are calculated and only the one that minimizes the expected cost is implemented. This policy is repeated in a receding horizon fashion each time step. Finally, in order to test the proposed technique, we have carried out different simulations that compare it with other popular techniques such as local feedback PI and standard MPC. The proposed method enables main irrigation canals continue to flow at night in large and medium size main canals.

  20. Effect of master apical file size and taper on irrigation and cleaning of the apical third of curved canals.

    Directory of Open Access Journals (Sweden)

    Nahid Mohammadzadeh Akhlaghi

    2014-04-01

    Full Text Available Canal preparation generates a substantial amount of debris and smear layer (SL. The size and taper of the Master Apical File (MAF affects on penetration of irrigants and subsequently canal cleaning efficacy. The aim of this study was to evaluate the effect of MAF size and taper on penetration of irrigants to the apical third of curved mesiobuccal (MB canals of mandibular first molars.Eighty-nine human mandibular first molars were divided into one control group (n=5 without rotary instrumentation and 6 experimental groups (n=14 each that were prepared with the following RaCe rotary files as MAF: 25.04 (group1, 25.06 (group 2, 30.04 (group 3, 30.06 (group 4, 35.04 (group 5 and 35.06 (group 6. All the experimental groups were rinsed with 2 ml of 17 % EDTA followed by 2 ml of 5.25% NaOCl. Debridement of the MB canals was evaluated using scanning electron microscope (SEM. The data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests (P<0.05.Group 6 (MAF=35.06 showed 100% acceptable debridement. This rate was 92.9% for MAF=35.04. In group 4 (MAF=30.06 smear layer (SL was removed in the three-forth of the samples and debris was removed in 92.9% of them. Acceptable debridement was not achieved in most samples of groups 1 and 2 (25.04 and 25.06, respectively and the mentioned two groups had statistically significant difference in this respect with the other groups (P<0.05.Based on this study, 30.06 may be considered as the minimum MAF size for acceptable debridement.

  1. Confocal laser scanning, scanning electron, and transmission electron microscopy investigation of Enterococcus faecalis biofilm degradation using passive and active sodium hypochlorite irrigation within a simulated root canal model.

    Science.gov (United States)

    Mohmmed, Saifalarab A; Vianna, Morgana E; Penny, Matthew R; Hilton, Stephen T; Mordan, Nicola; Knowles, Jonathan C

    2017-08-01

    Root canal irrigation is an important adjunct to control microbial infection. The aim of this study was to investigate the effect of 2.5% (wt/vol) sodium hypochlorite (NaOCl) agitation on the removal, killing, and degradation of Enterococcus faecalis biofilm. A total of 45 root canal models were manufactured using 3D printing with each model comprising an 18 mm length simulated root canal of apical size 30 and taper 0.06. E. faecalis biofilms were grown on the apical 3 mm of the models for 10 days. A total of 60 s of 9 ml of 2.5% NaOCl irrigation using syringe and needle was performed, the irrigant was either left stagnant in the canal or agitated using manual (Gutta-percha), sonic, and ultrasonic methods for 30 s. Following irrigation, the residual biofilms were observed using confocal laser scanning, scanning electron, and transmission electron microscopy. The data were analyzed using one-way ANOVA with Dunnett post hoc tests at a level of significance p ≤ .05. Consequence of root canal irrigation indicate that the reduction in the amount of biofilm achieved with the active irrigation groups (manual, sonic, and ultrasonic) was significantly greater when compared with the passive and untreated groups (p < .05). Collectively, finding indicate that passive irrigation exhibited more residual biofilm on the model surface than irrigant agitated by manual or automated (sonic, ultrasonic) methods. Total biofilm degradation and nonviable cells were associated with the ultrasonic group. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  2. [Effects of canal-lining project on groundwater and ecological environment in Hetao Irrigation District of Inner Mongolia].

    Science.gov (United States)

    Du, Jun; Yang, Pei-Ling; Ren, Shu-Mei; Li, Yun-Kai; Wang, Yong-Zhong; Yuan, Xiao-Qi; Li, Xian-Yue; Du, Jing

    2011-01-01

    The canal-lining project in Hetao Irrigation District (HID) for water-saving irrigation has been implemented for many years. By using statistical method, ordinary Kriging, and software ArcGIS 9.0, this paper analyzed the spatiotemporal variation of groundwater table depth and salinity in HID in September, 2001 and 2009. In the meantime, the vegetation distribution on the both shores of the lining part and non-lining part of Yangjiahe channel was also investigated. After the many years implementation of the project, the water diversion amount in HID in 2009 was reduced to 44.5 x 10(8) m3. The region area of groundwater table with a depth of 2.5-3.0 m was increased from 1.2 x 10(4) hm2 in 2001 to 9.11 x 10(4) hm2 in 2009. The region area of groundwater table with a depth of 2.0-2.5 m in 2009 took 80% of the total area of HID. In the northwestern region of HID, the groundwater salinity had reduced from 5000-10000 mg x L(-1) to 3000-5000 mg x L(-1). In Wulate irrigation region, the areas of salt water belt and half-salt water belt were increasing. After the canal-lining of Yangjiahe channel, the plant species and diversity index on both shores reduced, and some herbaceous plants with shallow roots showed degradation signs. The implementation of the project and the reduction of water diversion for irrigation did not exert negative effects on the maintenance of water surface area of Wuliangsuhai Lake.

  3. Irrigation system management assisted by thermal imagery and spatial statistics

    Science.gov (United States)

    Thermal imaging has the potential to assist with many aspects of irrigation management including scheduling water application, detecting leaky irrigation canals, and gauging the overall effectiveness of water distribution networks used in furrow irrigation. Many challenges exist for the use of therm...

  4. Comparative evaluation of debris removal from root canal wall by using EndoVac and conventional needle irrigation: An in vitro study

    Directory of Open Access Journals (Sweden)

    Vandana J Gade

    2013-01-01

    Full Text Available Context: Microbial control is of paramount importance in Clinical Endodontics. Therefore, cleaning and disinfection of root canals are essential to achieve endodontic success. Aims: The purpose of this study is to compare the efficacy of EndoVac irrigation system and conventional needle (30 gauges side venting needle irrigation for removal of debris from the root canal walls at coronal, middle and apical third by using the scanning electron microscopy (SEM. Settings and Design: An in vitro randomized control trial study. Materials and Methods: A total of 20 mandibular premolars with completely formed roots were selected and randomly divided into two groups - Group 1: Irrigation with the Conventional system and Group 2: EndoVac irrigation. After access opening and working length determination biomechanical preparation completed up to a rotary protaper F4 file. Groupwise irrigation with sodium hypochlorite and ethylenediaminetetraacetic acid was done with each canal in between instrumentation. Then, the teeth were sectioned in buccolingual direction and the halves were sputter-coated with gold palladium and coronal, middle and apical third were examined by SEM at x2000 magnification. Statistical Analysis: Mann-Whitney test for comparison between methods, Kruskal-Wallis test for comparison among thirds and Miller test for individual comparisons. Results: The apical, middle and cervical root canal thirds were evaluated and the results were analyzed statistically by the Mann-Whitney test for comparison between methods, Kruskal-Wallis test for comparison among thirds and Miller test for individual comparisons. Conclusions: EndoVac group resulted in significantly less debris at apical third compared with the conventional needle irrigation group. There was no statistical significant difference found in debris removal at coronal and middle third of root canal wall between the EndoVac group and conventional needle irrigation group.

  5. Evaluation of smear layer removal and marginal adaptation of root canal sealer after final irrigation using ethylenediaminetetraacetic, peracetic, and etidronic acids with different concentrations.

    Science.gov (United States)

    Ulusoy, Özgür İlke; Zeyrek, Salev; Çelik, Bülent

    2017-02-12

    The purpose of this study was to investigate the effects of different irrigation solutions on the smear layer removal and marginal adaptation of a resin-based sealer to root canal dentine. A total of 152 instrumented roots were irrigated with the following irrigants: 9,18% etidronic acid (HEBP), 0.5, 1,2% peracetic acid (PAA), 17% ethylenediaminetetraacetic acid (EDTA), saline. The amount of smear layer was evaluated using scanning electron microscope (SEM) in seventy root samples. Eighty-two roots were filled with AH Plus and gutta-percha. Slices obtained from apical third of each specimen were viewed with SEM to assess marginal adaptation. Use of 9% and 18% HEBP resulted in more efficient smear layer removal in the apical third than the other chelators (p acid is a promising candidate for final irrigation of root canals.

  6. Apical microleakage of different root canal sealers after use of maleic acid and EDTA as final irrigants.

    Science.gov (United States)

    Ulusoy, Ozgür Ilke; Nayir, Yelda; Celik, Kezban; Yaman, Sis Darendeliler

    2014-01-01

    This study aimed to compare the effects of ethylenediaminetetraacetic acid (EDTA) and maleic acid (MA) on the sealing ability of various root canal sealers. Eighty root canals were instrumented and irrigated with either EDTA or MA. They were divided into eight experimental groups and obturated as follows: Group 1: MA + Hybrid Root SEAL/gutta-percha. Group 2: EDTA + Hybrid Root SEAL/gutta-percha. Group 3: MA + iRoot SP/gutta-percha. Group 4: EDTA + iRoot SP/gutta-percha. Group 5: MA + EndoREZ/EndoREZ points. Group 6: EDTA + EndoREZ/EndoREZ points. Group 7: MA + AH Plus/gutta-percha. Group 8: EDTA + AH Plus/gutta-percha. Another ten roots were used as negative and positive controls. The microleakage of each sample was measured at 2-min intervals for 8 min using the fluid filtration method. Data were statistically analyzed with one-way ANOVA, post-hoc Tukey, and paired-samples t tests. The minimum microleakage values were obtained from the teeth obturated with AH Plus and EndoREZ selaers (p EDTA in terms of microleakage (p EDTA. The type of final irrigation solution seems to influence the postobturation apical seal. Use of AH Plus and EndoREZ sealers showed better sealing ability compared with IRoot SP and Hybrid Root SEAL.

  7. Dams on historic canal navigation networks; Les barrages sur le reseau des canaux historiques de navigation

    Energy Technology Data Exchange (ETDEWEB)

    Houde, L. [Parks Canada, Gatineau, PQ (Canada)

    2006-07-01

    This paper presented an overview of historic dams and other water retention structures within the Parks Canada network. It described the engineering achievement that went into the construction of these structures and how they have evolved over time. For the past century, the construction of canals has played a major role in Canada's economic development. The networks of canals have been used for transportation, commerce and military purposes and have acquired heritage and recreational value. Several canals, along with their locks and dams, have been recognized as having historical importance, such as the Chambly Canal in Quebec, and the Rideau Canal in Ottawa, Ontario. 14 refs.

  8. Chicanery at the canal. Changing practice in irrigation management in Western Mexico.

    NARCIS (Netherlands)

    Zaag, van der P.

    1992-01-01

    Existing studies of irrigation systems show that technical elements influence social processes, and also, that certain social relationships may have technical implications. However, little has been said about the precise content of this interplay. A better insight seems important, as irrigation syst

  9. Ultrasonic versus sonic activation of the final irrigant in root canals instrumented with rotary/reciprocating files: An in-vitro scanning electron microscopy analysis

    OpenAIRE

    Neha Deepak Khalap; Sharad Kokate; Vibha Hegde

    2016-01-01

    Aim: To compare the smear layer and debris removal in root canals instrumented with two different kinematic motions after ultrasonic and sonic irrigation activation. Materials and Methods: Eighty freshly extracted teeth were selected for the study and randomly divided the samples into two groups (n = 40) for instrumentation with either rotary ProTaper NEXT (PTN) or reciprocating WaveOne (WO) file systems. These (n = 40) were further divided into two groups (n = 20) where the final irrigant wa...

  10. Comparison the Effects of Different Root Canal Irrigants on the Retention of Quarts Fiber Posts Cemented by Resin Cement

    Directory of Open Access Journals (Sweden)

    Mehdi Shirinzad

    2012-01-01

    Full Text Available Introduction: Root canal irrigants could change the structure of root dentin and affect the posts retention the purpose of this study was to compare the effects of three different endodontic irrigants on the retention of quarts fiber posts cemented by different resin cements. Materials & Methods: In this in-vitro study, 10 mm long post spaces were prepared in root canals of 120 premolars after endodontic therapy and cutting the crowns at the cementoenamel junction. The teeth were randomly divided into four equal groups based on the irrigants as follows: distilled water, 2% chlorhexidine, 0.25% iodine and 1% NaOCl. Quarts fiber posts were cemented by Panavia F2. Samples were stored at 370c and humidity of 100% for one week. After thermocycling, the retention of fiber posts were measured by tensile test and modes of failure were reported. Data were analyzed by One-Way ANOVA, Tukey and Fisher's exact tests.Results: The mean and standard deviation of the posts retention were 367.08±63.07, 377.59±72.02, 363.11±68.53 and 342.89±74.94 for distilled water, chlorhexidine 2%, iodine 0.25% and sodium hypochlorite, respectively. One-way ANOVA showed that there was a significant difference among the groups (P<0.001. The results of Tukey test showed that posts retention was significantly higher after rinsing by chlorhexidine (P<0.01Conclusion: According to the results of this study, chlorhexidine rinse had a favorable effect on retention of posts cemented by resin cement.

  11. Apical microleakage of different root canal sealers after use of maleic acid and EDTA as final irrigants

    Directory of Open Access Journals (Sweden)

    Özgür İlke ULUSOY

    2014-01-01

    Full Text Available This study aimed to compare the effects of ethylenediaminetetraacetic acid (EDTA and maleic acid (MA on the sealing ability of various root canal sealers. Eighty root canals were instrumented and irrigated with either EDTA or MA. They were divided into eight experimental groups and obturated as follows: Group 1: MA + Hybrid Root SEAL/gutta-percha. Group 2: EDTA + Hybrid Root SEAL/gutta-percha. Group 3: MA + iRoot SP/gutta-percha. Group 4: EDTA + iRoot SP/gutta-percha. Group 5: MA + EndoREZ/EndoREZ points. Group 6: EDTA + EndoREZ/EndoREZ points. Group 7: MA + AH Plus/gutta-percha. Group 8: EDTA + AH Plus/gutta-percha. Another ten roots were used as negative and positive controls. The microleakage of each sample was measured at 2-min intervals for 8 min using the fluid filtration method. Data were statistically analyzed with one-way ANOVA, post-hoc Tukey, and paired-samples t tests. The minimum microleakage values were obtained from the teeth obturated with AH Plus and EndoREZ selaers (p < 0.001. The samples with Hybrid Root SEAL showed the maximum leakage (p < 0.001. There were significant differences between the groups irrigated with MA or EDTA in terms of microleakage (p < 0.05. Use of MA resulted in higher microleakage values compared with those using EDTA. The type of final irrigation solution seems to influence the postobturation apical seal. Use of AH Plus and EndoREZ sealers showed better sealing ability compared with IRoot SP and Hybrid Root SEAL.

  12. Water implications in Mediterranean irrigation networks: Problems and solutions

    Directory of Open Access Journals (Sweden)

    Laura Romero Marrero, Modesto Pérez-Sánchez, P. Amparo López-Jiménez

    2017-01-01

    Full Text Available Agriculture is a significant user of water and energy in Mediterranean coasts of Europe, such as Spanish Mediterranean regions. Water implications of such irrigations are well known but there are many problems that must be taken into account when designing each phase of the irrigation system, not only in the construction phase but in the exploitation, control and maintenance of all the elements in the network. All the possible problems in each part of the irrigation system will be analyzed in the following paper, proposing several solutions to avoid these problems or mitigate its consequences. These solutions go from the simple maintenance of pipes and valeus to the implementation of more sophisticated systems, such as SCADA, or management strategies, such as benchmarking.

  13. Micro-Computed Tomographic Evaluation of Hard Tissue Debris Removal after Different Irrigation Methods and Its Influence on the Filling of Curved Canals.

    Science.gov (United States)

    Freire, Laila Gonzales; Iglecias, Elaine Faga; Cunha, Rodrigo Sanches; Dos Santos, Marcelo; Gavini, Giulio

    2015-10-01

    The aim of this study was to compare the efficacy of passive ultrasonic irrigation (PUI) and the EndoVac (EV) System (Discus Dental, Culver City, CA) in hard tissue debris removal and its influence on the quality of the root canal filling with the aid of micro-computed tomographic scanner. Twenty-four mandibular molars were subjected to 4 microtomographic scannings (ie, before and after instrumentation, after final irrigation, and after obturation) using the SkyScan 1176 X-ray microtomograph (Bruker microCT, Kontich, Belgium) at a resolution of 17.42 μm. Mesial canals were prepared using R25 Reciproc instruments (VDW GmbH, Munich, Germany) and divided into 2 groups according to the final irrigation method: the PUI group (n = 12) and the EV group (n = 12). All specimens were filled with the continuous wave of condensation technique. CTAn and CTvol software (Bruker microCT) were used for volumetric analysis and 3-dimensional model reconstruction of the root canals, hard tissue debris, and the filling material. Data were statistically analyzed using the Student t test. Analysis of the micro-computed tomographic scans revealed debris accumulated inside the root canals, occupying an average of 3.4% of the canal's volume. Irrigation with PUI and the EV system reduced the volume of hard tissue debris in 55.55% and 53.65%, respectively, with no statistical difference between them (P > .05). Also, there was no difference among the groups with regard to the volume of filling material and voids (P > .05). PUI and the EV system were equally efficient in the removal of hard tissue debris and the quality of root canal filling was similar in both groups, with no influence from the irrigation method. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Effect of different final irrigation methods on the removal of calcium hydroxide from an artificial standardized groove in the apical third of root canals.

    Science.gov (United States)

    Capar, Ismail Davut; Ozcan, Erhan; Arslan, Hakan; Ertas, Huseyin; Aydinbelge, Hale Ari

    2014-03-01

    The aim of this study was to compare the efficacy of conventional syringe, ultrasonic, EndoVac (Discus Dental, Culver City, CA), and Self-Adjusting File (SAF) (Re-Dent-Nova, Ra'nana, Israel) irrigation systems in removing calcium hydroxide (Ca[OH]2) from simulated root canal irregularities. The root canals of 88 extracted single-rooted teeth were prepared using ProTaper rotary instruments (Dentsply Maillefer, Ballagiues, Switzerland) up to size F4. The roots were split longitudinally, and a standardized groove was prepared in the apical part of 1 segment. The root halves were reassembled, and Ca(OH)2 medicament was placed into the root canals using a Lentulo spiral. The roots were randomly divided into 4 experimental groups and 2 control groups according to the different irrigation systems used: conventional syringe irrigation, continuous passive ultrasonic irrigation (PUI), EndoVac irrigation, and SAF irrigation. Each group was then divided into 2 subgroups (n = 10) according to the irrigation protocol: subgroup 1: 10 mL 2.5% NaOCl and subgroup 2: 10 mL 17% EDTA + 10 mL 2.5% NaOCl. The amount of remaining medicament was evaluated under a stereomicroscope at 30× magnification using a 4-grade scoring system. The influences of the different Ca(OH)2 medicament removal methods and irrigation protocols were statistically evaluated using 2-way analysis of variance and Tukey post hoc tests. In the NaOCl-irrigated groups, PUI removed significantly more Ca(OH)2 medicament than the other techniques (P .05). In the EDTA/NaOCl-irrigated groups, the SAF and PUI removed significantly more Ca(OH)2 than the other techniques (P < .05). The use of the SAF system with the combination of EDTA and NaOCl enhanced Ca(OH)2 removal when compared with the use of only NaOCl irrigation with the SAF. Continuous PUI and SAF were more effective than EndoVac, and conventional syringe irrigation in the removal of the Ca(OH)2 medicament from an artificial standardized groove in the apical part of

  15. Soil Fertility Assessment of The Lugu Main Canal Of Wurno Irrigation ...

    African Journals Online (AJOL)

    acer

    the quality of the environment and conserving natural resources (FAO ... Irrigation agriculture could have adverse effects on soil ... oxide and ammonia volatilization which lead to permanent ... The project comprises of a storage reservoir with ...

  16. Effectiveness of four different final irrigation activation techniques on smear layer removal in curved root canals : a scanning electron microscopy study.

    Directory of Open Access Journals (Sweden)

    Puneet Ahuja

    2014-02-01

    Full Text Available The aim of this study was to assess the efficacy of apical negative pressure (ANP, manual dynamic agitation (MDA, passive ultrasonic irrigation (PUI and needle irrigation (NI as final irrigation activation techniques for smear layer removal in curved root canals.Mesiobuccal root canals of 80 freshly extracted maxillary first molars with curvatures ranging between 25° and 35° were used. A glide path with #08-15 K files was established before cleaning and shaping with Mtwo rotary instruments (VDW, Munich, Germany up to size 35/0.04 taper. During instrumentation, 1 ml of 2.5% NaOCl was used at each change of file. Samples were divided into 4 equal groups (n=20 according to the final irrigation activation technique: group 1, apical negative pressure (ANP (EndoVac; group 2, manual dynamic agitation (MDA; group 3, passive ultrasonic irrigation (PUI; and group 4, needle irrigation (NI. Root canals were split longitudinally and subjected to scanning electron microscopy. The presence of smear layer at coronal, middle and apical levels was evaluated by superimposing 300-μm square grid over the obtained photomicrographs using a four-score scale with X1,000 magnification.Amongst all the groups tested, ANP showed the overall best smear layer removal efficacy (p < 0.05. Removal of smear layer was least effective with the NI technique.ANP (EndoVac system can be used as the final irrigation activation technique for effective smear layer removal in curved root canals.

  17. Evaluation of Root Canal Dentin Erosion after Different Irrigation Methods Using Energy-dispersive X-ray Spectroscopy.

    Science.gov (United States)

    Wang, Zhejun; Maezono, Hazuki; Shen, Ya; Haapasalo, Markus

    2016-12-01

    The purpose of this study was to examine the level of erosion in root dentin caused by different irrigation methods and protocols. Thirty-five extracted upper molar teeth were instrumented and divided into 7 groups to undergo treatment by different methods: negative control, GentleWave System (Sonendo Inc, Laguna Hills, CA), and syringe needle irrigation following different protocols. The teeth were instrumented to size #25/.08 or #30/.09 for needle irrigation groups and to ProTaper size S1 for the GentleWave group under 5% sodium hypochlorite (NaOCl). The needle irrigation groups were subjected to final rinses of 2 minutes of 3% NaOCl + 2 minutes of 8% EDTA (3% N2 + 8% E2), 2 minutes of 3% NaOCl + 2 minutes of 8% EDTA + 1 minute of 3% NaOCl (3% N2 + 8% E2 + 3% N1), 2 minutes of 5% NaOCl + 2 minutes of 17% EDTA (5% N2 + 17% E2), 2 minutes of 5% NaOCl + 2 minutes of 17% EDTA + 1 minute of 5% NaOCl (5% N2 + 17% E2 + 5% N1), and 5 minutes of 5% NaOCl + 5 minutes of 17% EDTA + 5 minutes of 5% NaOCl (5% N5 + 17% E5 + 5% N5), respectively. The root canal surface was observed by scanning electron microscopy, and the dentin composition was analyzed by continuous line scanning for 300 μm into dentin using energy-dispersive X-ray spectroscopy. A slight but statistically significant decrease of calcium and an increase of carbon was measured in the 5% N2 + 17% E2 group in comparison with the control; no significant difference was found among GentleWave, 3% N2 + 8% E2, and 5% N2 + 17% E2 (P > .05). A final 1-minute rinse with 3% or 5% NaOCl reduced calcium and phosphorus to a significantly lower level than in groups without a 1-minute final rinse (P irrigation with 5% NaOCl for 5 minutes removed almost all calcium and phosphorus. Scanning electron microscopy showed canal wall erosion when an additional final irrigation with NaOCl was done. NaOCl followed by final EDTA irrigation performed either by syringe needle or the GentleWave System caused

  18. Chicanery at the canal : changing practice in irrigation management in Western Mexico

    OpenAIRE

    Zaag, van der, P.

    1992-01-01

    Existing studies of irrigation systems show that technical elements influence social processes, and also, that certain social relationships may have technical implications. However, little has been said about the precise content of this interplay. A better insight seems important, as irrigation systems, when put into operation, often have unforeseen organisational and social consequences, and a disappointing performance. The present thesis aims to answer the question: How do the soci...

  19. Radiographic Healing after a Root Canal Treatment Performed in Single-rooted Teeth with and without Ultrasonic Activation of the Irrigant : A Randomized Controlled Trial

    NARCIS (Netherlands)

    Liang, Yu-Hong; Jiang, Lei-Meng; Jiang, Lan; Chen, Xiao-Bo; Liu, Ying-Yi; Tian, Fu-Cong; Bao, Xu-Dong; Gao, Xue-Jun; Versluis, Michel; Wu, Min-Kai; van der Sluis, Luc

    2013-01-01

    Introduction: The aim of this study was to compare the outcome of a root canal treatment with and without additional ultrasonic activation of the irrigant. Methods: Single-rooted teeth with radiographic evidence of periapical bone loss were randomly assigned to 2 treatment groups. In both groups syr

  20. A novel methodology providing insights into removal of biofilm-mimicking hydrogel from lateral morphological features of the root canal during irrigation procedures

    NARCIS (Netherlands)

    Macedo, R. G.; Robinson, J. P.; Verhaagen, B.; Walmsley, A. D.; Versluis, M.; Cooper, P. R.; van der Sluis, L. W. M.

    2014-01-01

    AimTo introduce and characterize a reproducible hydrogel as a suitable biofilm mimic in endodontic research. To monitor and visualize the removal of hydrogel from a simulated lateral canal and isthmus for the following: I) Ultrasonic-Activated Irrigation (UAI) with water, ii) UAI with NaOCl and iii)

  1. Influence of irrigation sequence on the adhesion of root canal sealers to dentin: a fourier transform infrared spectroscopy and push-out bond strength analysis

    NARCIS (Netherlands)

    P. Neelakantan; S. Sharma; H. Shemesh; P.R. Wesselink

    2015-01-01

    Introduction There is a lack of evidence on the chemical interaction between sealers and dentin. The influence of irrigation on the chemical interaction between root canal sealers and dentin was analyzed by using Fourier transform infrared spectroscopy (FTIRS) and measurement of dislocation resistan

  2. A comparative evaluation of different irrigation activation systems on smear layer removal from root canal: An in-vitro scanning electron microscope study

    Directory of Open Access Journals (Sweden)

    Nishi Singh

    2014-01-01

    Full Text Available Aim: The aim of the following study is to compare the evaluation of different irrigation activation system-F-File, CanalBrush (CB and EndoActivator (EA in removing smear layer from root canal. Materials and Methods: Root canals of eighty single rooted decoronated premolar teeth were instrumented using crown-down technique and then equally divided into four groups on basis of irrigation activation methods used: Without irrigation - control group, irrigation with F-File, CB, EA into Group I, II, III respectively. Samples were then longitudinally sectioned and examined under scanning electron microscope by three qualified observers using score from 1 to 4. Data was analyzed using Statistical Package for Social Sciences (SPSS, version 15.0 (SPSS Inc., Chicago IL at significance level of P ≤ 0.05. Results: Minimum mean score was observed in Group II at coronal, apical locations. Group III had minimum score at middle third. Groups difference in score were found to be significant statistically for all three locations as well as for overall assessment (P < 0.001. Conclusion: CB remove smear layer more efficiently from the root canal than F-File and EA in coronal and apical region.

  3. Comparison of the Antimicrobial Efficacy of Two Antibiotics Sparfloxacin and Augmentin as Experimental Root Canal Irrigating Solutions against Enterococcus faecalis - An Invitro Study

    Science.gov (United States)

    Venigalla, Bhuvan Shome; Surakanti, Jayaprada Reddy; Thumu, Jayaprakash; Chennamaneni, Krishna Chaitanya; Kalluru, Rama S.

    2016-01-01

    Introduction One of the main goals of endodontic treatment is root canal disinfection and to prevent subsequent chances of reinfection. Adjuvant to instrumentation, root canal irrigants are required to eliminate the bacteria found on the root canal walls and lateral canals within the dentinal tubules. Aim To measure and compare the antibacterial efficacy of two antibiotics as experimental root canal irrigating solutions against Enterococcus faecalis (E. faecalis). Materials and Methods Fifteen Brain Heart Infusion agar plates were inoculated with Enterococcus faecalis-American Type Culture Collection (ATCC) 29212. 5 micrograms (mcg) Sparfloxacin discs, 30mcg Augmentin discs, and sterile paper test discs saturated with 2% Chlorhexidine (CHX), 3% Sodium Hypochlorite (NaOCl) and 5% NaOCl solutions were placed on agar plates. Sodium Chloride 0.9% (NaCl) paper discs were used as controls. Fifteen plates were incubated aerobically at 37°C. Results were expressed as per the terms of the diameter of the inhibition zone. Results Results suggested a statistically significant difference in the zones of inhibition between five irrigating solutions (p < 0.001). Conclusion Although, zones of inhibition were found in all the groups, 5mcg Sparfloxacin and 30mcg Augmentin showed maximum antimicrobial activity against E.faecalis. PMID:27135003

  4. Antimicrobial and cytotoxic effects of phosphoric acid solution compared to other root canal irrigants

    Directory of Open Access Journals (Sweden)

    Maíra PRADO

    2015-04-01

    Full Text Available Phosphoric acid has been suggested as an irrigant due to its effectiveness in removing the smear layer. Objectives : The purpose of this study was to compare the antimicrobial and cytotoxic effects of a 37% phosphoric acid solution to other irrigants commonly used in endodontics. Material and Methods : The substances 37% phosphoric acid, 17% EDTA, 10% citric acid, 2% chlorhexidine (solution and gel, and 5.25% NaOCl were evaluated. The antimicrobial activity was tested against Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Actinomyces meyeri, Parvimonas micra, Porphyromonas gingivalis, and Prevotella nigrescens according to the agar diffusion method. The cytotoxicity of the irrigants was determined by using the MTT assay. Results : Phosphoric acid presented higher antimicrobial activity compared to the other tested irrigants. With regard to the cell viability, this solution showed results similar to those with 5.25% NaOCl and 2% chlorhexidine (gel and solution, whereas 17% EDTA and 10% citric acid showed higher cell viability compared to other irrigants. Conclusion : Phosphoric acid demonstrated higher antimicrobial activity and cytotoxicity similar to that of 5.25% NaOCl and 2% chlorhexidine (gel and solution.

  5. Antimicrobial and cytotoxic effects of phosphoric acid solution compared to other root canal irrigants.

    Science.gov (United States)

    Prado, Maíra; Silva, Emmanuel João Nogueira Leal da; Duque, Thais Mageste; Zaia, Alexandre Augusto; Ferraz, Caio Cezar Randi; Almeida, José Flávio Affonso de; Gomes, Brenda Paula Figueiredo de Almeida

    2015-01-01

    Phosphoric acid has been suggested as an irrigant due to its effectiveness in removing the smear layer. The purpose of this study was to compare the antimicrobial and cytotoxic effects of a 37% phosphoric acid solution to other irrigants commonly used in endodontics. The substances 37% phosphoric acid, 17% EDTA, 10% citric acid, 2% chlorhexidine (solution and gel), and 5.25% NaOCl were evaluated. The antimicrobial activity was tested against Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Actinomyces meyeri, Parvimonas micra, Porphyromonas gingivalis, and Prevotella nigrescens according to the agar diffusion method. The cytotoxicity of the irrigants was determined by using the MTT assay. Phosphoric acid presented higher antimicrobial activity compared to the other tested irrigants. With regard to the cell viability, this solution showed results similar to those with 5.25% NaOCl and 2% chlorhexidine (gel and solution), whereas 17% EDTA and 10% citric acid showed higher cell viability compared to other irrigants. Phosphoric acid demonstrated higher antimicrobial activity and cytotoxicity similar to that of 5.25% NaOCl and 2% chlorhexidine (gel and solution).

  6. Types of trematodes infecting freshwater snails found in irrigation canals in the East Nile locality, Khartoum, Sudan

    DEFF Research Database (Denmark)

    Mohammed, Nidal A. I.; Madsen, Henry; Ahmed, Abdel Aziz A. R. M.

    2016-01-01

    Background: The planorbid freshwater snails of the two genera, Biomphalaria and Bulinus -have been vigorously studied due to the role they play as intermediate hosts of schistosomiasis. In Sudan specifically, most studies have focused on the chemical and ecological control of the two genera......, but few studies have looked at their biological control. This study explored the coexistence of other species of freshwater snails and the two genera along with their trematode infections in relation to a number of environmental factors in the East Nile locality, Khartoum state, Sudan. Methods: Freshwater...... snails from irrigation canals (abueshreens) were sampled monthly from January 2004 to December 2005. The snails were examined for trematode infections by cercarial emergence immediately after collection and then weekly for an additional four weeks to allow for the maturation of prepatent infections...

  7. [Alpha-hemolytic streptococci and root canal irrigants. An evaluation of the bactericidal efficacy of sodium hypochlorite and chlorhexidine gluconate plus cetrimide].

    Science.gov (United States)

    D'Arcangelo, C; Di Nardo Di Maio, F; Varvara, G

    1998-09-01

    The main bacterial species present in pulpal and periapical microbic flora is alpha-hemolytic streptococci. They are regarded as facultative anaerobes which prefer to grow in anaerobiosis. Canal irrigation plays an important role in the success of endodontic treatment given that, on the one hand, it encourages the gradual elimination of the smear layer, and on the other it neutralises microbic flora in the root canal. The aim of this study was to test the microbiological efficacy of sodium hypochlorite 1% and s new generation irrigant based on chlorhexidine 0.2% and cetrimide 0.2%. The test was performed on the following alpha-hemolytic streptococci bacteria (Dasit, Cornaredo, Italy): Streptococcus mitis ATCC 9811; Streptococcus mutans ATCC 35668; Streptococcus salivarius ATCC 13419; Streptococcus sanguis ATCC 10556. The working concentration (CFU/ml) was defined as 0.5 Mc Farland which corresponds to a concentration of microorganisms of approximately 1.5 x 10(8) bacteria. The following canal irrigants were used: 1) cetrimide 0.2% + chlorhexidine 0.2% (Cetrexidin Vebas, S. Giuliano Milanese, Italy); 2) NaOCl 1% (Ogna, Milan, Italy). Each individual substance remained in contact with the bacterial species used in the test for 10'-20'-30'. The results obtained show the bactericidal efficacy of both the irrigants used, even after a short period of contact. This does not mean that all irrigants are equal and/or promise the same results. This was a microbiological study, but it is nonetheless important to take other variables into account, such as contact time. Moreover, in order to increase the probabilities for the success of endodontic treatment, canal irrigants must also present other characteristics, namely: biocompatibility, scarce toxicity, high proteolytic power.

  8. Anopheline ecology and malaria transmission during the construction of an irrigation canal in an endemic district of Odisha, India

    Directory of Open Access Journals (Sweden)

    B. K. Panigrahi

    2013-12-01

    Full Text Available Background & objectives: A new irrigation canal system is under construction in Dhenkanal district of Odisha, to increase the production of rice crop and thereby improve the living standard of farmers in the project area. Construction of canal may increase the transmission of malaria by creating vector breeding habitats. Knowledge about bionomics of vectors will support authorities for appropriate management of the disease in a changing ecological set up. The aim of this study was to assess the malaria transmission in the bank of the canal area under construction. Methods: The entomological survey was carried out in three seasons, winter, summer and rainy during the period November 2008-October 2010 in the study area. Adult mosquitoes were collected by using suction tubes and flash lights. Mosquito species identification was done by using standard keys, separated according to abdominal conditions and were kept in an isopropanol for further molecular analysis of sibling species, presence of sporozoites and human blood meal. Larvae were collected by dippers and reared in the laboratory, and the emerged adults were identified to species. The epidemiology of malaria was evaluated from the data collected by the State Health Department. Insecticide succeptibility test was done by WHO method. Results: The adult mosquito collection from the study area showed the prevalence of 14 species belonging to three genera, i.e. Anopheles, Culex and Aedes. The per man hour densities (PMHD of An. culicifacies were 3.8, 1.4, 4.8; that of An. annularis were 2.1, 1, 2.1; and that of An. fluviatilis were 1.4, 0.3, 0.6 during winter, summer and rainy seasons respectively. Sibling species identified were: An. culicifacies A, B, C and D, An. annularis A and An. fluviatilis S. Sporozoite rates of An. culicifacies A and C were 1.1 and 0.5% respectively and that of An. annularis A was 2% (reported for the first time in the state. Both the vectors (An. culicifacies and An

  9. Impact of lining material on chemical and microbial irrigation water quality of Nubaria canal, Egypt

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed Azzam

    2016-02-01

    Full Text Available Objective: To assess the effect of lining material (cement of Nubaria canal (Beheira Governorate, Egypt on its water quality. Methods: Trace metal ions (Fe, Zn, Cu, Pb, and Cd and bacterial indictors for water samples collected from two types of stations (lined and unlined during successive four seasons were analyzed. The effect of lining on bacterial indicators; total viable bacterial count at 22 and 37 °C, total coliform, fecal coliform and fecal streptococci and presence of some bacterial species were studied. Results: Bacterial indicators and trace metals showed seasonal variations, where the highest values were recorded during summer. A significant reduction for Cu (P < 0.05, Zn (P < 0.01 and Cd (P < 0.001 was recorded in lined stations compared to those of unlined ones. Bacterial indicators recorded the lowest counts in lined stations during all seasons, while there was a significant reduction (P < 0.05 between total coliform values (1.70 ± 0.50 in lined stations and unlined ones (3.57 ± 1.01 during summer. Escherichia coli bacteria were predominant in water samples of Nubaria canal, where it recorded 34.4% of bacterial isolates. Conclusions: Lined material plays a role for reducing the bacterial growth and metals concentration, therefore the lining of canal helps in preventing the discharge of sewage pollution into canal.

  10. The cleanliness differences of root canal irrigated with 0.002% saponin of mangosteen peel extract and 2.5% NaOCl

    Directory of Open Access Journals (Sweden)

    Anis Sakinah

    2015-06-01

    Full Text Available Background: Root canal treatment consists of preparation, sterilization, and obturation. During root canal preparation, debris is smeared over the dentinal surface forming a smear layer. Smear layer will reduce the attachment of root canal filling materials. Organic material in smear layer can be substrated for microorganism. Preparation of root canal should be followed by irrigation. NaOCl is common irrigation solution in endodontics. It has been very effective for their disinfecting and tissue-dissolving properties, but it is incapable of removing the smear layer. On the other hand, saponin of mangosteen peel extract has an ability as a surfactant to lower the surface tension, and it can dissolve debris containing of anorganic and organic materials. Purpose: This study aims to know the differences between 2.5% NaOCl and 0.002% saponin of mangosteen peel extract in removing the debris in the root canal after the preparation procedure. Method: Three groups of teeth (7 teeth in each were instrumented with K-file and irrigated as follow: group 1 (control with aquadest; group 2 with 2.5% NaOCl; and group 3 with 0.002% saponin of mangosteen peel extract. Furthermore, those teeth were split horizontally and longitudinally 4mm above the apical. The apical third of root canal walls was observed by a scanning electron microscope (SEM. Result: There were significant differences between each group (p<0.05. Median value of the group 3 was score 1 considered as the smallest value. It indicates that Group 3 with 0.002% saponin of mangosteen peel extract was the cleanest group. Conclusion:It can be concluded that 0.002% saponin of mangosteen peel extract can clean the smear layer of the root canal better than 2.5% NaOCl.

  11. Irrigant flow beyond the insertion depth of an ultrasonically oscillating file in straight and curved root canals: visualization and cleaning efficacy.

    Science.gov (United States)

    Malki, Maher; Verhaagen, Bram; Jiang, Lei-Meng; Nehme, Walid; Naaman, Alfred; Versluis, Michel; Wesselink, Paul; van der Sluis, Lucas

    2012-05-01

    The purpose of this study was to evaluate the influence of the insertion depth of an ultrasonically oscillating file on the ability to remove dentin debris from simulated canal irregularities in an extracted tooth model of a straight root canal and its influence on the flow of irrigant in both straight and curved canals. A tooth model with artificial depressions in 1 canal wall at 0.5, 2, 4, and 6 mm from the working length was used. Ultrasonic-activated irrigation was performed with the file inserted 1, 2, 3, 4, or 5 mm short of the working length. Dye penetration and high-speed recordings of the flow in straight and curved canals showed the static and dynamic behavior of the flow during ultrasonic activation. The overall cleaning efficacy decreased with increasing distance between the file and the apex, with the depressions next to the file and within 3 mm in front of the file being the cleanest. The flow observed from the visualization experiments matched this distance, suggesting a direct relation between flow and cleaning. The observed flow depth increased with increasing power setting; the curvature of the root canal had no influence on the flow depth. High-speed imaging showed a start-up phase with deeper fluid activation than in the steady phase afterward. The ultrasonically oscillating file could remove dentin debris up to 3 mm in front of the file tip, coinciding with the extent of the observed flow. The root canal curvature had no influence on the irrigant flow. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. Effect of different final irrigating solutions on smear layer removal in apical third of root canal: A scanning electron microscope study

    Directory of Open Access Journals (Sweden)

    Sayesh Vemuri

    2016-01-01

    Full Text Available Aim: The aim of this in vitro study is to compare the smear layer removal efficacy of different irrigating solutions at the apical third of the root canal. Materials and Methods: Forty human single-rooted mandibular premolar teeth were taken and decoronated to standardize the canal length to 14 mm. They were prepared by ProTaper rotary system to an apical preparation of file size F3. Prepared teeth were randomly divided into four groups (n = 10; saline (Group 1; negative control, ethylenediaminetetraacetic acid (Group 2, BioPure MTAD (Group 3, and QMix 2 in 1 (Group 4. After final irrigation with tested irrigants, the teeth were split into two halves longitudinally and observed under a scanning electron microscope (SEM for the removal of smear layer. The SEM images were then analyzed for the amount of smear layer present using a three score system. Statistical Analysis: Data are analyzed using the Kruskal-Wallis test and Mann-Whitney U-test. Results: Intergroup comparison of groups showed statistically significant difference in the smear layer removal efficacy of irrigants tested. QMix 2 in 1 is most effective in removal of smear layer when compared to other tested irrigants. Conclusion: QMix 2 in 1 is the most effective final irrigating solution for smear layer removal.

  13. Antifungal effects of root canal irrigants and medicaments. An update review.

    Science.gov (United States)

    Mohammadi, Zahed; Shalavi, Sousan

    2014-01-01

    Fungi, especially Candida albicans, play an important role in persistent/secondary endodontic infections. There are several irrigants and medicaments in the field of endodontics. The purpose of this paper is to review the antifungal activity of sodium hypochlorite, chlorhexidine, MTAD, Tetraclean, EDTA, calcium hydroxide and MTA.

  14. Chicanery at the canal : changing practice in irrigation management in Western Mexico

    NARCIS (Netherlands)

    Zaag, van der P.

    1992-01-01

    Existing studies of irrigation systems show that technical elements influence social processes, and also, that certain social relationships may have technical implications. However, little has been said about the precise content of this interplay. A better insight seems important, as irriga

  15. Application of Canal Automation at the Central Arizona Irrigation and Drainage District

    Science.gov (United States)

    The Central Arizona Irrigation and Drainage District (CAIDD) began delivering water to users in 1987. Although designed for automatic control, the system was run manually until a homemade SCADA (Supervisory Control and Data Acquisition) system was developed by a district employee. In 2002, problem...

  16. Low cost drip irrigation in Burkina Faso : unravelling actors, networks and practices

    NARCIS (Netherlands)

    Wanvoeke, M.J.V.

    2015-01-01

    Title: Low cost drip irrigation in Burkina Faso: Unravelling Actors, Networks and Practices In Burkina Faso, there is a lot of enthusiasm about Low Cost Drip Irrigation (LCDI) as a tool to irrigate vegetables, and thus improve food security, solve wat

  17. Effectiveness of different irrigation techniques on smear layer removal in apical thirds of mesial root canals of permanent mandibular first molar: A scanning electron microscopic study

    Directory of Open Access Journals (Sweden)

    Pranav Khaord

    2015-01-01

    Full Text Available Aim: The aim of this study was to compare smear layer removal after final irrigant activation with sonic irrigation (SI, manual dynamic agitation (MDA, passive ultrasonic irrigation (PUI, and conventional syringe irrigation (CI. Materials and Methods: Forty mesial canals of mandibular first molars (mesial roots were cleaned and shaped by using ProTaper system to size F1 and sodium hypochlorite 3% and 17% ethylenediaminetetraacetic acid. The specimens were divided into 4 equal groups (n = 10 according to the final irrigation activation technique: Group 1, PUI; group 2, manual dynamic activation (MDA; group 3, SI; and group 4, control group (simple irrigation. Samples were split longitudinally and examined under scanning electron microscope for smear layer presence. Results: Control groups had the highest smear scores, which showed the statistically significant highest mean score at P < 0.05. This was followed by ultrasonic, MDA, and finally sonic, with no significant differences between them. Conclusions: Final irrigant activation with sonic and MDA resulted in the better removal of the smear layer than with CI.

  18. Ultrasonic versus sonic activation of the final irrigant in root canals instrumented with rotary/reciprocating files: An in-vitro scanning electron microscopy analysis

    Science.gov (United States)

    Khalap, Neha Deepak; Kokate, Sharad; Hegde, Vibha

    2016-01-01

    Aim: To compare the smear layer and debris removal in root canals instrumented with two different kinematic motions after ultrasonic and sonic irrigation activation. Materials and Methods: Eighty freshly extracted teeth were selected for the study and randomly divided the samples into two groups (n = 40) for instrumentation with either rotary ProTaper NEXT (PTN) or reciprocating WaveOne (WO) file systems. These (n = 40) were further divided into two groups (n = 20) where the final irrigant was activated using either Ultrasonics (Passive Ultrasonic Irrigation; PUI) or Sonics (EndoActivator; EA). Group 1: PTN + EA; Group 2: PTN + PUI; Group 3: WO + EA; and Group 4: WO + PUI. During instrumentation, a total of 4 ml of 5.25% NaOCl was used for irrigation. The final irrigation protocol included NaOCl and Smear Clear Solution. The samples were processed by scanning electron microscopic examination for debris and smear layer scoring, and statistical analysis was done. Results: The mean debris and smear layer score was less in the group instrumented by PTN with sonic activation of the irrigant. Conclusion: A combination of PTN instrumentation with sonic irrigation activation by EA is more effective in debris and smear layer removal in the groups tested. PMID:27563189

  19. Ultrasonically Activated Irrigation to Remove Calcium Hydroxide from Apical Third of Human Root Canal System: A Systematic Review of In Vitro Studies.

    Science.gov (United States)

    Ethem Yaylali, Ibrahim; Kececi, Ayse Diljin; Ureyen Kaya, Buglem

    2015-10-01

    The aim of this systematic review was to summarize the outcomes of in vitro studies comparing ultrasonically activated irrigation versus other irrigation techniques for removing calcium hydroxide (Ca[OH]2) from the apical third of root canals. The research question was developed according to the PICO strategy. A comprehensive literature search was performed. The Medline, Embase, and TRIP electronic databases were searched. A hand search of the reference lists of identified articles was performed to isolate relevant articles. Two reviewers critically assessed the studies against our inclusion and exclusion criteria. Evaluation of the risk of bias of the studies was performed independently by the 2 reviewers. After study selection, 62 were assessed for eligibility. Of these, 9 met the inclusion criteria and were included in the systematic review. Because considerable heterogeneity was found in the methodologies, it was not possible to combine the results of studies in a meta-analysis. Ultrasonically activated irrigation was found to be superior to syringe irrigation and apical negative pressure irrigation, but insufficient evidence was found to indicate its superiority over the other irrigation techniques such as sonically activated irrigation, the Self-Adjusting File, (ReDent-Nova, Ra'anana, Israel) and the RinsEndo, (Dürr Dental, Bietigheim, Germany). On the basis of available evidence, we determined the effectiveness of ultrasonically activated irrigation compared with syringe and apical negative pressure irrigation. Because of the small sample sizes, low number of included studies, and limitations, further research is needed to confirm our results. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  20. 土地整治项目灌溉渠道衬砌方案经济比选研究%Research on Economic Scheme Comparison of Irrigation Canal about Land Consolidation Project

    Institute of Scientific and Technical Information of China (English)

    岳小松

    2016-01-01

    Irrigation channel is an important infrastructure of farmland , leakage of canal bed is the main way of water loss , lining can reduce leakage loss and improve irrigation efficiency.By studying irrigation canal unit cost ahout the same discharge with different section and lining fashion, the results showed:in three sections, the trapezoidal cross section irrigation canal unit cost was lowest, the rectangular cross section irri-gation canal took second place, the U-shaped cross section irrigation canal unit cost was highest.Among five lining fashion, the trapezoidal cross section with slope prefabricated irrigation canal unit cost was lowest , the U-shaped cross section with prefabricated irrigation canal unit cost was highest.%灌溉渠道是农田重要的基础设施,而渠床渗漏是渠系水量损失的主要途径,渠道衬砌可减少渠床渗漏损失,提高灌溉效益。不同的衬砌方案效益各不相同,通过对相同流量、不同断面和不同衬砌方式的渠道进行单价分析,考察较适宜的衬砌方案。结果表明,3种断面中梯形断面渠道单价最低;矩形断面渠道单价次之,U型断面渠道单价最高。5种衬砌方式中,梯形断面边坡预制渠道单价最低,预制U型槽单价最高。

  1. Wireless sensor networks for canopy temperature sensing and irrigation management

    Science.gov (United States)

    For researchers, canopy temperature measurements have proven useful in characterizing crop water stress and developing protocols for irrigation management. Today, there is heightened interest in using remote canopy temperature measurements for real-time irrigation scheduling. However, without the us...

  2. Smear layer removal and canal cleanliness using different irrigation systems (EndoActivator, EndoVac, and passive ultrasonic irrigation): field emission scanning electron microscopic evaluation in an in vitro study.

    Science.gov (United States)

    Mancini, Manuele; Cerroni, Loredana; Iorio, Lorenzo; Armellin, Emiliano; Conte, Gabriele; Cianconi, Luigi

    2013-11-01

    The purpose of this study was to evaluate the effectiveness of different irrigating methods in removing the smear layer at 1, 3, 5, and 8 mm from the apex of endodontic canals. Sixty-five extracted single-rooted human mandibular premolars were decoronated to a standardized length of 16 mm. Specimens were shaped to ProTaper F4 (Dentsply Maillefer, Ballaigues, Switzerland) and irrigated with 5.25% NaOCl at 37°C. Teeth were divided into 5 groups (2 control groups [n = 10] and 3 test groups [n = 15]) according to the final irrigant activation/delivering technique (ie, sonic irrigation, passive ultrasonic irrigation [PUI], or apical negative pressure). Root canals were then split longitudinally and observed by field emission scanning electron microscopy. The presence of debris and a smear layer at 1, 3, 5, and 8 mm from the apex was evaluated. Scores were analyzed by Kruskal-Wallis and Mann-Whitney U tests. The EndoActivator System (Dentsply Tulsa Dental Specialties, Tulsa, OK) was significantly more efficient than PUI and the control groups in removing the smear layer at 3, 5, and 8 mm from the apex. The EndoVac System (Discus Dental, Culver City, CA) removed statistically significantly more smear layer than all groups at 1, 3, 5, and 8 mm from the apex. At 5 and 8 mm from the apex, PUI and the EndoVac did not differ statistically significantly, but both performed statistically better than the control groups. In our study, none of the activation/delivery systems completely removed the smear layer from the endodontic dentine walls; nevertheless, the EndoActivator and EndoVac showed the best results at 3, 5, and 8 mm (EndoActivator) and 1, 3, 5, and 8 mm (EndoVac) from the apex. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  3. A Comparative Study of the Quality of Apical Seal in Resilon/Epiphany SE Following Intra canal Irrigation With 17% EDTA, 10% Citric Acid, And MTAD as Final Irrigants - A Dye Leakage Study Under Vacuum.

    Science.gov (United States)

    Balasubramanian, Saravana Karthikeyan; Saraswathi, Vidya; Ballal, Nidambur Vasudev; Acharya, Shashi Rashmi; Sampath, J Sivakumar; Singh, Sandeep

    2017-02-01

    Adequate apical sealing ability of the root canal filling material is an essential requisite for a successful endodontic therapy. Various endodontic irrigants are used for the removal of smear layer before obturating with a solid core material, thereby, reducing microleakage and improving apical seal. Resilon, a synthetic material was developed as an alternative to replace the conventional gutta-percha (standard root canal filling material) and traditional sealers for the obturation of endodontically treated teeth. To evaluate and compare in-vitro, the post obturation apical seal obtained with Resilon /Epiphany SE (Self Etch) sealer following irrigation with 17% Ethylenediamine Tetra-Acetic Acid (EDTA), 10% citric acid, and MTAD (a mixture of doxycycline, citric acid, and a detergent, Tween 80), as final irrigants in combination with Sodium hypochlorite (NaOCl) using dye leakage under vacuum method. Fifty five single rooted human maxillary central incisors were subjected to root canal instrumentation. Based on the final irrigation solution, samples were divided into three experimental groups (n=15); (I) 17% EDTA + 1.3% NaOCl, (II) 10% citric acid + 1.3% NaOCl, (III) MTAD + 1.3% NaOCl and two control groups (positive and negative) with 0.9% normal saline as a final irrigant. The samples were obturated with resilon/epiphany SE sealer according to manufacturer instructions and placed in 2% rhodamine B dye solution under vacuum pressure for 30 minutes and allowed to remain in the dye for seven days. All samples were then longitudinally split and examined for dye leakage under stereomicroscope and the data were statistically analysed using one-way ANOVA and post hoc tukey test. Statistically significant difference (p=0.001) was observed in the mean apical leakage between the experimental and the control groups. However, there was no significant difference (p>0.05) observed in the mean apical leakage amongst the three experimental groups. 17% EDTA, 10% citric acid, and

  4. A Comparative Study of the Quality of Apical Seal in Resilon/Epiphany SE Following Intra canal Irrigation With 17% EDTA, 10% Citric Acid, And MTAD as Final Irrigants – A Dye Leakage Study Under Vacuum

    Science.gov (United States)

    Saraswathi, Vidya; Ballal, Nidambur Vasudev; Acharya, Shashi Rashmi; Sampath, J. Sivakumar; Singh, Sandeep

    2017-01-01

    Introduction Adequate apical sealing ability of the root canal filling material is an essential requisite for a successful endodontic therapy. Various endodontic irrigants are used for the removal of smear layer before obturating with a solid core material, thereby, reducing microleakage and improving apical seal. Resilon, a synthetic material was developed as an alternative to replace the conventional gutta-percha (standard root canal filling material) and traditional sealers for the obturation of endodontically treated teeth. Aim To evaluate and compare in-vitro, the post obturation apical seal obtained with Resilon /Epiphany SE (Self Etch) sealer following irrigation with 17% Ethylenediamine Tetra-Acetic Acid (EDTA), 10% citric acid, and MTAD (a mixture of doxycycline, citric acid, and a detergent, Tween 80), as final irrigants in combination with Sodium hypochlorite (NaOCl) using dye leakage under vacuum method. Materials and Methods Fifty five single rooted human maxillary central incisors were subjected to root canal instrumentation. Based on the final irrigation solution, samples were divided into three experimental groups (n=15); (I) 17% EDTA + 1.3% NaOCl, (II) 10% citric acid + 1.3% NaOCl, (III) MTAD + 1.3% NaOCl and two control groups (positive and negative) with 0.9% normal saline as a final irrigant. The samples were obturated with resilon/epiphany SE sealer according to manufacturer instructions and placed in 2% rhodamine B dye solution under vacuum pressure for 30 minutes and allowed to remain in the dye for seven days. All samples were then longitudinally split and examined for dye leakage under stereomicroscope and the data were statistically analysed using one-way ANOVA and post hoc tukey test. Results Statistically significant difference (p=0.001) was observed in the mean apical leakage between the experimental and the control groups. However, there was no significant difference (p>0.05) observed in the mean apical leakage amongst the three

  5. Integration of wireless sensor networks into automatic irrigation scheduling of a center pivot

    Science.gov (United States)

    A six-span center pivot system was used as a platform for testing two wireless sensor networks (WSN) of infrared thermometers. The cropped field was a semi-circle, divided into six pie shaped sections of which three were irrigated manually and three were irrigated automatically based on the time tem...

  6. Comparison of the Antibacterial Effect of Sodium Hypochlorite and Aloe Vera Solutions as Root Canal Irrigants in Human Extracted Teeth Contaminated with Enterococcus Faecalis

    Directory of Open Access Journals (Sweden)

    Sahebi S.

    2013-10-01

    Full Text Available Statement of Problem: The main purpose of a root canal treatment is to eliminate the bacteria and their products from the pulp space. Sodium hypochlorite has excellent antibacterial properties, but also some negative features. Purpose: The aim of the present study is to compare the antimicrobial effect of Aloe Vera so-lution with sodium hypochlorite on E.faecalis in the root canals of human extracted teeth. Materials and Method: Sixty human extracted single rooted teeth were selected for this in vitro study. The teeth recruited in this study had no cracks, internal resorption, external resorption and calcification. Enterococcus faecalis was injected in the root canals of all teeth. The teeth were then divided into three groups randomly. Each group consisted of 20 teeth that were all rinsed with one of the following solutions: sodium hypochlorite 2.5%, Aloe vera and normal saline. Subsequent to rinsing, root canals of all teeth were sampled. The samples were cultured and growth of the bacteria was assessed after 48 hours. The number of colonies of the bacteria was then counted. Results: The difference between the inhibitory effect of Aloe vera and normal saline on E.faecalis was not significant according to independent t-test (p= 0.966. The inhibitory effect of sodium hypochlorite on E.faecalis was much greater than that of Aloe vera and normal saline (p< 0.001. Conclusion: Aloe vera solution is not recommended as a root canal irrigator, but future studies are suggested to investigate the antibacterial effect of Aloe vera with longer duration of exposure and as an intra canal medicament.

  7. Evaluation of Effects on the Adhesion of Various Root Canal Sealers after Er:YAG Laser and Irrigants Are Used on the Dentin Surface.

    Science.gov (United States)

    Ozkocak, Ismail; Sonat, Bade

    2015-08-01

    The aim of this study was to evaluate the bond strength of various root canal sealers after various irrigation solutions and Er:YAG laser irradiation were used on root canal dentin. One hundred fifty freshly extracted human maxillary single-rooted teeth were used in this study. Teeth were sectioned transversally 4 mm below the cementoenamel junction. The root canal of each specimen was prepared using a tapered bur. Teeth were divided into 3 main groups by sealer (AH Plus Jet [Dentsply DeTrey, Konstanz, Germany], EndoSequence BC Sealer [Brasseler, Savannah, GA], and Real Seal [SybronEndo, Orange, CA]) and then divided into 5 subgroups by dentin treatment (distilled water, calcium hydroxide, sodium hypochlorite, EDTA, and Er:YAG laser). The specimens were placed immediately at 37°C and 100% humidity for 1 week. Then, the push-out test was applied. The maximum failure load was recorded in newtons and was used to calculate the push-out bond strength in MPa. Then, 3 random specimens from each group were examined under scanning electron microscopy. The resin root canal sealers had higher push-out bond strength than the bioceramic sealer, and the differences were statistically significant (P < .05) except in the sodium hypochlorite groups. The EDTA and Er:YAG laser applications removed the smear layer and increased the bond strength. The highest adhesion was observed in EDTA groups when each sealer was evaluated in itself. The bonding strength of root canal sealers is influenced by their properties and various dentin surface treatments. The scanning electron microscopic study showed that although the dentinal tubules were open, at the profile examination the sealers did not penetrate into the dentin canals in all specimens. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Evaluation of bond strength of D.T.Light- post to root canal using dual-cure and self-cure resin cements after irrigation with various solutions

    Directory of Open Access Journals (Sweden)

    Atai M.

    2008-11-01

    Full Text Available "nBackground and Aim: Nonmetallic tooth- colored posts adhere to canal walls by dentin bonding agents and resin cements. Better retention and proper distribution of stress result from enough and proper bonding. The purpose of this study was to evaluate bond strength of D.T. Light - post with two different resin cements (self-cure & dual-cure and to investigate the effect of irrigating solutions applied in root canal on bond strength of the resin cements and D.T.Light- post to root canal wall. "nMaterials and Methods: In this experimental study 40 single root teeth (maxillary canine & central were selected and stored in 0.1% thymol solution for one week and transferred to distilled water. The teeth were decoronated 2mm above CEJ. The canal space was mechanically enlarged using k-files (up to # 70. The teeth were randomly divided into two groups. The first group was irrigated with 2.6% NaOCl, and the second was irrigated with normal saline. After drying, the teeth were filled with gutta percha cones using lateral condensing method. After two weeks the post space was prepared and D.T.Light- post was inserted in each subgroup using self or dual-cure cements according to manufacturer's instructions. After thermocycling, the apical part was cut 1cm below CEJ. The remained length was divided into 9 equal sequential sections. Each section was submitted to shear push-out test in universal testing machine. Statistical analysis of the bond strength data was performed using ANOVA and post hoc tests with p<0.05 as the level of significance. All failed specimens were examined under stereomicroscope. Degrees of conversion of the cements were determined by FTIR. "nResults: Significant difference in bond strength values were found among sites (P=0.001 and cements (P=0.03. With increasing in depth, bond strength decreased. The mean bond strength value in dual-cure resin cement was higher than self-cure cement. The irrigating solutions caused no significant

  9. The Effect of Root Canal Irrigation with Combination of Sodium Hypo-chlorite and Chlorhexidine Gluconate on the Sealing Ability of Obturation Materials.

    Science.gov (United States)

    Homayouni, Hamed; Majd, Nima Moradi; Zohrehei, Heidar; Mosavari, Behrad; Adel, Mamak; Dajmar, Reyhaneh; Homayouni, Ali

    2014-01-01

    The aim of this study was to evaluate the effect of the precipitate that was formed by combining Sodium Hypochlorite (NaOCl) and Chlorhexidine Gluconate (CHX) on the sealing ability of root canal obturation materials. The fluid filtration method was conducted on a total of 100 roots. Samples were randomly divided into two control (n=5) and three experimental groups (n=30). The samples in group 1 were irrigated with 1.5 mL of 2.5% NaOCl, and then the smear layers of the teeth were removed by 17% EDTA, while the specimens of group 2 were irrigated by 1.5 mL of 2.5% NaOCl and 1.5 mL of 2% CHX; after the smear layer removal, a final flush with 1.5 mL of 2.5% NaOCl was performed. The samples of group 3 were irrigated the same as group 1 but after the smear layer removal canals were irrigated again with 1.5 mL of 2.5% NaOCl and then a final flush with 1.5 mL of 2% CHX was performed. Teeth were obturated with gutta-percha and AH26 sealer and after seven days, microleakage was evaluated by the fluid filtration technique. The results were analyzed by the ANOVA and Tukey's test. The samples in group 3 had significantly greater microleakage compared to teeth in group 1, 2 (p<0.05), and the specimens in group 1 showed significantly less amount of microleakage than samples in group 2, 3 (p<0.05). The presence of the precipitate that is formed due to interaction between NaOCl and CHX has negative effect on the sealing ability of gutta-percha and AH26 sealer.

  10. Armenia - Irrigation Infrastructure

    Data.gov (United States)

    Millennium Challenge Corporation — This study evaluates irrigation infrastructure rehabilitation in Armenia. The study separately examines the impacts of tertiary canals and other large infrastructure...

  11. Analysis of efficiency of water utilization in canal-system in Hetao irrigation district based on Horton fractal%基于Horton分形的河套灌区渠系水利用效率分析

    Institute of Scientific and Technical Information of China (English)

    屈忠义; 杨晓; 黄永江; 杜斌; 杨俊林

    2015-01-01

    大型灌区灌溉水利用效率是关系国民经济发展和水资源高效利用的重要评价指标。该文采用分维定律对内蒙古河套灌区输配水渠系布置结构与渠系水分利用效率进行评价。根据河套灌区现状的渠系资料,应用Horton定律计算出河套灌区及灌域的分形维数(乌兰布和1.14,解放闸1.86,永济2.21,义长1.8,乌拉特1.99,河套灌区1.88)。在此基础上对不同灌域的渠系水利用效率与分维值进行了分析,拟合了灌溉引水量、灌溉面积与分维值多元曲线,得出了渠系结构优化下的不同灌域的渠系水利用效率提高潜力(乌兰布和19.01%,解放闸28.8%,永济32.7%,义长27.07%,乌拉特30.7%)与灌区平均效率提高潜力(27.19%)。由此提出不同灌域渠系改造方案,对于灌区的科学管理与节水工程规划具有重要的理论意义和应用价值,同时对相似灌区的规划和节水改造具有很好的参考价值。%Efficiency of water utilization in large irrigation districts and water-saving potential can reflect degree of water resources utilization and is an important evaluation index of national economic development. It is unknown about effects of canal-system framework on water utilization efficiency in canal-system. In this study, we assessed the relationship between canal-system framework and water utilization efficiency in Hetao Irrigation District, China. The Hetao Irrigation District was divided into Wulanbuhe, Jiefangzha, Yongji, Yichang, and Wulate sub-irrigation districts. The canal-system of Hetao Irrigation district had complex structure with one general canal, 16 trunk canals, 48 sub-main canals, and 57 000 of branch, lateral, field, and sublateral canals. The general, trunk, sub-main, branch, lateral, field and sublateral canals were graded into the first, second,…, and seventh levels. The information on irrigation area, amount, and water use efficiency of each sub-irrigation

  12. Modeling irrigation networks for the quantification of potential energy recovering: a case study

    OpenAIRE

    Modesto Pérez-Sánchez; Francisco Javier Sánchez-Romero; Helena M. Ramos; P. Amparo López-Jiménez

    2016-01-01

    Water irrigation systems are required to provide adequate pressure levels in any sort of network. Quite frequently, this requirement is achieved by using pressure reducing valves (PRVs). Nevertheless, the possibility of using hydraulic machines to recover energy instead of PRVs could reduce the energy footprint of the whole system. In this research, a new methodology is proposed to help water managers quantify the potential energy recovering of an irrigation water network with adequate condit...

  13. Comparison of the Antibacterial Effect of Sodium Hypochlorite and Aloe Vera Solutions as Root Canal Irrigants in Human Extracted Teeth Contaminated with Enterococcus Faecalis

    Directory of Open Access Journals (Sweden)

    Sahebi S.

    2014-03-01

    Full Text Available Statement of Problem: The main purpose of a root canal treatment is to eliminate the bacteria and their products from the pulp space. Sodium hypochlorite has excellent antibacterial properties but also some negative features. Purpose: The aim of the present study is to compare the antimicrobial effect of Aloe Vera solution with sodium hypochlorite on E.faecalis in the root canals of human extracted teeth. Materials and Method: Sixty human extracted single rooted teeth were selected for this in vitro study. Only teeth without conditions such as cracks, internal resorption, external resorption and calcification were included in the study. Enterococcus faecalis was injected in the root canals of all teeth. The teeth were then divided into three groups randomly. Each group consisted of 20 teeth that were all rinsed with one of the following solutions: sodium hypochlorite 2.5%, Aloe vera and normal saline. Subse-quent to rinsing, root canals of all teeth were sampled. The samples were cultured and growth of the bacteria was assessed after 48 hours. The number colonies of the bacte-ria were then counted. Results: The difference between the inhibitory effect of Aloe vera and normal saline on E.faecalis was not significant according to independent T-test (p= 0.966. The in-hibitory effect of sodium hypochlorite on E.faecalis was much greater than that of Aloe vera and normal saline (p< 0.001. Conclusion: Aloe vera solution is not recommended as a root canal irrigator but it is suggested for the future studies to investigate the antibacterial effect of Aloe vera for longer durations and as an intracanal medicament.

  14. 伊犁灌区末级渠系量水研究%Water-measuring research of last canal system in Yili irrigation district

    Institute of Scientific and Technical Information of China (English)

    戚玉彬; 张月云

    2015-01-01

    为了全面了解伊犁灌区末级渠系的量水现状,促进农业用水按方计量收费,对末级渠系的量水情况进行了调查研究,通过访谈调查、资料数据统计分析和典型灌区实地勘察,提出了加大政策扶持力度、配套量水设施、加强少数民族水管技术人才培养和发挥农民用水户协会作用的措施和建议。%In order to understand fully water-measuring present situation in Yili irrigation district last canal system,promote agricultural water metering and charging according to the party,investigated on water-measuring situation of last canal system. Based on the interview survey,sta-tistical data analysis and field investigation of typical irrigation district. Therefore proposed to increase policy supporting,support water-measuring facilities,intensify the training of minority technical personnel of water-measuring and play the role of water user association of farmers.

  15. In vitro comparison of antimicrobial effect of sodium hypochlorite solution and Zataria multiflora essential oil as irrigants in root canals contaminated with Candida albicans

    Directory of Open Access Journals (Sweden)

    Mahdi Sedigh-Shams

    2016-01-01

    Full Text Available Introduction: This study compared the antifungal effect of Zataria multiflora essential oil (EO with that of sodium hypochlorite (NaOCl as an irrigant for root canals infected with Candida albicans. Materials and Methods: Sixty mandibular premolars were infected with C. albicans suspension. After 72 h of incubation, the samples were divided into four groups. Teeth in Group 1 were irrigated with minimum fungicidal concentration (MFC of Z. multiflora EO, in Group 2 with twice the MFC of Z. multiflora, in Group 3 with MFC of NaOCl, and in Group 4 with distilled water (DW. Pre- and post-operative samples were cultured, and fungal colony count of each specimen was obtained. Data were analyzed using Kruskal-Wallis and Mann-Whitney tests (P 0.05. However, antifungal efficacies of these irrigants were significantly different from those of Z. multiflora EO at MFC and DW (P < 0.05. Conclusion: Our results showed that Z. multiflora EO at twice the MFC had the same antifungal efficacy as NaOCl at MFC.

  16. In vitro comparison of antimicrobial effect of sodium hypochlorite solution and Zataria multiflora essential oil as irrigants in root canals contaminated with Candida albicans

    Science.gov (United States)

    Sedigh-Shams, Mahdi; Badiee, Parisa; Adl, Alireza; Sarab, Milad Dadollahi; Abbaszadegan, Abbas; Nabavizadeh, Mohammadreza

    2016-01-01

    Introduction: This study compared the antifungal effect of Zataria multiflora essential oil (EO) with that of sodium hypochlorite (NaOCl) as an irrigant for root canals infected with Candida albicans. Materials and Methods: Sixty mandibular premolars were infected with C. albicans suspension. After 72 h of incubation, the samples were divided into four groups. Teeth in Group 1 were irrigated with minimum fungicidal concentration (MFC) of Z. multiflora EO, in Group 2 with twice the MFC of Z. multiflora, in Group 3 with MFC of NaOCl, and in Group 4 with distilled water (DW). Pre- and post-operative samples were cultured, and fungal colony count of each specimen was obtained. Data were analyzed using Kruskal-Wallis and Mann-Whitney tests (P 0.05). However, antifungal efficacies of these irrigants were significantly different from those of Z. multiflora EO at MFC and DW (P < 0.05). Conclusion: Our results showed that Z. multiflora EO at twice the MFC had the same antifungal efficacy as NaOCl at MFC. PMID:26957804

  17. A comparative evaluation of smear layer removal by using edta, etidronic acid, and maleic acid as root canal irrigants: An in vitro scanning electron microscopic study

    Science.gov (United States)

    Kuruvilla, Aby; Jaganath, Bharath Makonahalli; Krishnegowda, Sahadev Chickmagaravalli; Ramachandra, Praveen Kumar Makonahalli; Johns, Dexton Antony; Abraham, Aby

    2015-01-01

    Aim: The purpose of this study is to evaluate and compare the efficacy of 17% EDTA, 18% etidronic acid, and 7% maleic acid in smear layer removal using scanning electron microscopic image analysis. Materials and Methods: Thirty, freshly extracted mandibular premolars were used. The teeth were decoronated to obtain working length of 17mm and instrumentation up to 40 size (K file) with 2.5% NaOCl irrigation between each file. The samples were divided into Groups I (17% ethylenediaminetetraacetic acid (EDTA)), II (18% etidronic acid), and III (7% maleic acid) containing 10 samples each. Longitudinal sectioning of the samples was done. Then the samples were observed under scanning electron microscope (SEM) at apical, middle, and coronal levels. The images were scored according to the criteria: 1. No smear layer, 2. moderate smear layer, and 3 heavy smear layer. Statistical Analysis: Data was analyzed statistically using Kruskal–Wallis analysis of variance (ANOVA) followed by Mann-Whitney U test for individual comparisons. The level for significance was set at 0.05. Results: The present study showed that all the three experimental irrigants removed the smear layer from different tooth levels (coronal, middle, and apical). Final irrigation with 7% maleic acid is more efficient than 17% EDTA and 18% etidronic acid in the removal of smear layer from the apical third of root canal. PMID:26069414

  18. Techniques and Materials Used by General Dentists during Root Canal Treatment Procedures: Findings from the National Dental Practice-Based Research Network

    Science.gov (United States)

    Eleazer, Paul D.; Gilbert, Gregg H.; Funkhouser, Ellen; Reams, G.J.; Law, A.S.; Benjamin, Paul L.

    2015-01-01

    Background Little is known about which materials and techniques general dentists (GDs) use during root canal procedures. The objectives were to: (1) quantify GD’s use of specific endodontic armamentarium; (2) quantify inappropriate use; and (3) ascertain if inappropriate use is associated with dentists’ practice characteristics. Methods GDs in the National Dental Practice-Based Research Network reported in a questionnaire materials and techniques they use during root canal procedures. Results 1,490 (87%) of eligible GDs participated. Most (93%; n=1,383) used sodium hypochlorite to irrigate. The most commonly used sealers were zinc oxide-eugenol (43%) and resin (40%), followed by calcium hydroxide (26%). A majority (62%; n=920) used a compaction obturation technique; 36% (n=534) used a carrier-based method. Most (96%; n=1,423) used gutta percha as a filler; 5% used paste fillers. Few used irrigants (n=46), sealers (n=4), techniques (n=49) or fillers (n=10) that investigators classified as ‘inappropriate’. Conclusions GDs use a broad range of endodontic techniques and materials, often adapting to newer technologies as they become available. Few GDs use armamentarium that the investigators classified as inappropriate. Practical Implications GDs use many types of endodontic techniques and materials, but only a very small percentage is not appropriate. PMID:26562726

  19. Effectiveness of the ProTaper Next and Reciproc Systems in Removing Root Canal Filling Material with Sonic or Ultrasonic Irrigation: A Micro-computed Tomographic Study.

    Science.gov (United States)

    Martins, Milena Perraro; Duarte, Marco Antonio Hungaro; Cavenago, Bruno Cavalini; Kato, Augusto Shoji; da Silveira Bueno, Carlos Eduardo

    2017-03-01

    The aim of this study was to evaluate the effectiveness of ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland) and Reciproc (VDW, Munich, Germany) systems in removing filling material from oval root canals using sonic or ultrasonic irrigation as additional cleaning methods. Thirty-two human extracted mandibular premolars with oval canals were prepared using the ProTaper Universal system (Dentsply Maillefer) up to instrument F4 (40/.06) and then filled by the single-cone technique using Endofill sealer (Dentsply Maillefer). The teeth were randomly divided into 4 groups (n = 8) according to the instrumentation system and the additional cleaning method as follows: Reciproc 40 with ultrasonic activation, Reciproc 40 with sonic agitation, ProTaper Next (X2, X3, and X4) with ultrasonic activation, and ProTaper Next (X2, X3, and X4) with sonic agitation. All specimens were analyzed using micro-computed tomographic imaging before and after removal of the filling material and also after applying the additional cleaning methods. The data, in mm(3) of remaining filling material, were analyzed by the Kruskal-Wallis, Dunn, and Mann-Whitney tests. None of the retreatment protocols completely removed the filling material from the root canals, and there was no significant difference between the instrumentation systems or between root thirds assessed in terms of the average volume of remaining filling material (P > .05). Likewise, no significant difference was observed between the additional cleaning methods in any of the root canal thirds assessed (P > .05). The ProTaper Next and Reciproc systems were equivalent with respect to effectiveness in removing filling material regardless of the additional cleaning method used. The additional cleaning methods were also equivalent and did not improve the removal of filling material significantly. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  20. Irrigation Canals or Laterals on Agricultural Land in the Conterminous United States, 1992: National Resource Inventory Conservation Practice 320

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the estimated percentage of the 1-km grid cell that is covered by or subject to the agricultural conservation practice (CP320), Irrigation...

  1. Modelling energy production by small hydro power plants in collective irrigation networks of Calabria (Southern Italy)

    Science.gov (United States)

    Zema, Demetrio Antonio; Nicotra, Angelo; Tamburino, Vincenzo; Marcello Zimbone, Santo

    2017-04-01

    The availability of geodetic heads and considerable water flows in collective irrigation networks suggests the possibility of recovery potential energy using small hydro power plants (SHPP) at sustainable costs. This is the case of many Water Users Associations (WUA) in Calabria (Southern Italy), where it could theoretically be possible to recovery electrical energy out of the irrigation season. However, very few Calabrian WUAs have currently built SHPP in their irrigation networks and thus in this region the potential energy is practically fully lost. A previous study (Zema et al., 2016) proposed an original and simple model to site turbines and size their power output as well as to evaluate profits of SHPP in collective irrigation networks. Applying this model at regional scale, this paper estimates the theoretical energy production and the economic performances of SHPP installed in collective irrigation networks of Calabrian WUAs. In more detail, based on digital terrain models processed by GIS and few parameters of the water networks, for each SHPP the model provides: (i) the electrical power output; (iii) the optimal water discharge; (ii) costs, revenues and profits. Moreover, the map of the theoretical energy production by SHPP in collective irrigation networks of Calabria was drawn. The total network length of the 103 water networks surveyed is equal to 414 km and the total geodetic head is 3157 m, of which 63% is lost due to hydraulic losses. Thus, a total power output of 19.4 MW could theoretically be installed. This would provide an annual energy production of 103 GWh, considering SHPPs in operation only out of the irrigation season. The single irrigation networks have a power output in the range 0.7 kW - 6.4 MW. However, the lowest SHPPs (that is, turbines with power output under 5 kW) have been neglected, because the annual profit is very low (on average less than 6%, Zema et al., 2016). On average each irrigation network provides an annual revenue from

  2. Impacts of irrigation network sectoring as an energy saving measure on olive grove production.

    Science.gov (United States)

    Navarro Navajas, J M; Montesinos, P; Poyato, E Camacho; Rodríguez Díaz, J A

    2012-11-30

    In recent years, improving water use efficiency has been one of the most important challenges for the agricultural sector. However, such improvements have led to the installation of pressurized irrigation systems which generally require more energy to operate, especially in plantations on sloping and mountainous lands. Thus, the reduction of energy use in these systems has also become a major issue. Irrigation network sectoring has been proposed as one of the most effective energy saving measures. Typically, however, the potential benefits of this management strategy have been evaluated by means of theoretical approaches in networks that were originally designed to supply water on demand and not after water application in real irrigation districts designed following sectoring strategies. In this work, this measure is applied to an irrigation district devoted to olive grove production in a mountainous area that was designed according to this management strategy. With this aim, the WEBSO (Water and Energy Based Sectoring Operation) algorithm, which was developed in a previous work, has been modified in order to take into account the specific characteristics of the irrigation district and its actual management, as well as to analyze sensitivity to several irrigation water depths in terms of both energy demand and yields. An economic analysis of the potential benefits of this management strategy is also carried out. The results show that this measure has lead to a nearly 30% reduction in energy consumption, while increasing farmers' profits by 13% compared to traditional on-demand operations. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Canalization and control in automata networks: body segmentation in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Manuel Marques-Pita

    Full Text Available We present schema redescription as a methodology to characterize canalization in automata networks used to model biochemical regulation and signalling. In our formulation, canalization becomes synonymous with redundancy present in the logic of automata. This results in straightforward measures to quantify canalization in an automaton (micro-level, which is in turn integrated into a highly scalable framework to characterize the collective dynamics of large-scale automata networks (macro-level. This way, our approach provides a method to link micro- to macro-level dynamics--a crux of complexity. Several new results ensue from this methodology: uncovering of dynamical modularity (modules in the dynamics rather than in the structure of networks, identification of minimal conditions and critical nodes to control the convergence to attractors, simulation of dynamical behaviour from incomplete information about initial conditions, and measures of macro-level canalization and robustness to perturbations. We exemplify our methodology with a well-known model of the intra- and inter cellular genetic regulation of body segmentation in Drosophila melanogaster. We use this model to show that our analysis does not contradict any previous findings. But we also obtain new knowledge about its behaviour: a better understanding of the size of its wild-type attractor basin (larger than previously thought, the identification of novel minimal conditions and critical nodes that control wild-type behaviour, and the resilience of these to stochastic interventions. Our methodology is applicable to any complex network that can be modelled using automata, but we focus on biochemical regulation and signalling, towards a better understanding of the (decentralized control that orchestrates cellular activity--with the ultimate goal of explaining how do cells and tissues 'compute'.

  4. Comparative evaluation of antimicrobial activity of hydroalcoholic extract of Aloe vera, garlic, and 5% sodium hypochlorite as root canal irrigants against Enterococcus faecalis: An in vitro study

    Directory of Open Access Journals (Sweden)

    Swati Ramesh Karkare

    2015-01-01

    Full Text Available Introduction: Enterococcus faecalis are the most resistant and predominant microorganisms recovered from root canals of teeth where previous treatment has failed. Over the past decade, interest in drugs derived from medicinal plants has markedly increased. In dentistry, phytomedicines has been used as an anti-inflammatory, antibiotic, analgesic, sedative, and also as an endodontic irrigant. In endodontics, because of the cytotoxic reactions of most of the commercial intracanal medicaments and their inability to eliminate bacteria completely from dentinal tubules, the trend is shifting toward use of biologic medication extracted from natural plants. Aim: To compare the antimicrobial efficacy of newer irrigating agents which would probably be as effective or more and at the same time less irritating to the tissues than sodium hypochlorite (NaOCl. The objective of this study was to compare the antimicrobial activity of saturated and diluted (1:1 hydroalcoholic extract of Aloe vera, garlic, and 5% NaOCl against E. faecalis using the commonly used agar diffusion method. Results: Saturated hydroalcoholic extract of A. vera showed the highest zone of inhibition against E. faecalis. NaOCl, which is considered as gold standard, also showed higher zones of inhibition.

  5. Comparative evaluation of antimicrobial activity of hydroalcoholic extract of Aloe vera, garlic, and 5% sodium hypochlorite as root canal irrigants against Enterococcus faecalis: An in vitro study.

    Science.gov (United States)

    Karkare, Swati Ramesh; Ahire, Nivedita Pramod; Khedkar, Smita Uday

    2015-01-01

    Enterococcus faecalis are the most resistant and predominant microorganisms recovered from root canals of teeth where previous treatment has failed. Over the past decade, interest in drugs derived from medicinal plants has markedly increased. In dentistry, phytomedicines has been used as an anti-inflammatory, antibiotic, analgesic, sedative, and also as an endodontic irrigant. In endodontics, because of the cytotoxic reactions of most of the commercial intracanal medicaments and their inability to eliminate bacteria completely from dentinal tubules, the trend is shifting toward use of biologic medication extracted from natural plants. To compare the antimicrobial efficacy of newer irrigating agents which would probably be as effective or more and at the same time less irritating to the tissues than sodium hypochlorite (NaOCl). The objective of this study was to compare the antimicrobial activity of saturated and diluted (1:1) hydroalcoholic extract of Aloe vera, garlic, and 5% NaOCl against E. faecalis using the commonly used agar diffusion method. Saturated hydroalcoholic extract of A. vera showed the highest zone of inhibition against E. faecalis. NaOCl, which is considered as gold standard, also showed higher zones of inhibition.

  6. Effect of different root canal irrigants on the sealing ability of two all-in-one self-etch adhesives: An in vitro study

    Science.gov (United States)

    Agrawal, Rashi; Tyagi, Shashi Prabha; Nagpal, Rajni; Mishra, Chandrakar Chaman; Singh, Udai Pratap

    2012-01-01

    Aim: To evaluate the effect of different root canal irrigants on the sealing ability of two self-etch adhesives, using dye penetration method, within the pulp chamber. Materials and Methods: 72 extracted human molars were divided into six groups, according to the irrigant and self-etch adhesives used. After de-roofing the pulp chamber with a carborundum disc, the pulp was extirpated using excavator and broaches. In 36 samples, pulp chambers were bonded with Xeno V after irrigation with either 2% CHX (Group1: Xe-CHX) ; 17% EDTA + 5.25% NaOCl (Group2: Xe- EDTA + NaOCl) or normal saline (Group3: Xe-NS) and in other half samples, pulp chambers were bonded with Adper Easy One after irrigation with either 2% CHX (Group 4: Ad-CHX); 17%EDTA + 5.25% NaOCl (Group5: Ad-EDTA+NaOCl) or normal saline (Group 6: Ad-NS). All the samples were restored with Filtek Z350. Ten teeth from each group were assessed for dye penetration. Two samples in each group were viewed under scanning electron microscope to observe resin-dentin interfacial adaptation. Data was statistically analyzed using Mann–Whitney and Kruskal Wallis tests at a significance level of P < 0.05. Results: Mean microleakage scores and standard deviation observed were: Group 1 (Xe-CHX): 2.8 ± 0.42, Group 2 (Xe-EDTA + NaOCl): 2.3 ± 0.82, Group 3 (Xe-NS): 2.9 ± 0.31, Group 4 (Ad-CHX): 1.2 ± 0.91, Group 5 (Ad-EDTA + NaOCl): 0.8 ± 0.63, Group 6 (Ad-NS): 1.9 ± 0.99. Conclusions: Adper Easy One showed significantly less leakage than Xeno V when normal saline was used as an irrigant. EDTA treatment followed by NaOCl application significantly reduced microleakage and improved the interfacial adaptation with Adper Easy One. CHX did not significantly affect the sealing ability of both one-step self-etch adhesives tested. PMID:23112488

  7. Effect of different root canal irrigants on the sealing ability of two all-in-one self-etch adhesives: An in vitro study

    Directory of Open Access Journals (Sweden)

    Rashi Agrawal

    2012-01-01

    Full Text Available Aim: To evaluate the effect of different root canal irrigants on the sealing ability of two self-etch adhesives, using dye penetration method, within the pulp chamber. Materials and Methods: 72 extracted human molars were divided into six groups, according to the irrigant and self-etch adhesives used. After de-roofing the pulp chamber with a carborundum disc, the pulp was extirpated using excavator and broaches. In 36 samples, pulp chambers were bonded with Xeno V after irrigation with either 2% CHX (Group1: Xe-CHX ; 17% EDTA + 5.25% NaOCl (Group2: Xe- EDTA + NaOCl or normal saline (Group3: Xe-NS and in other half samples, pulp chambers were bonded with Adper Easy One after irrigation with either 2% CHX (Group 4: Ad-CHX; 17%EDTA + 5.25% NaOCl (Group5: Ad-EDTA+NaOCl or normal saline (Group 6: Ad-NS. All the samples were restored with Filtek Z350. Ten teeth from each group were assessed for dye penetration. Two samples in each group were viewed under scanning electron microscope to observe resin-dentin interfacial adaptation. Data was statistically analyzed using Mann-Whitney and Kruskal Wallis tests at a significance level of P < 0.05. Results: Mean microleakage scores and standard deviation observed were: Group 1 (Xe-CHX: 2.8 ± 0.42, Group 2 (Xe-EDTA + NaOCl: 2.3 ± 0.82, Group 3 (Xe-NS: 2.9 ± 0.31, Group 4 (Ad-CHX: 1.2 ± 0.91, Group 5 (Ad-EDTA + NaOCl: 0.8 ± 0.63, Group 6 (Ad-NS: 1.9 ± 0.99. Conclusions: Adper Easy One showed significantly less leakage than Xeno V when normal saline was used as an irrigant. EDTA treatment followed by NaOCl application significantly reduced microleakage and improved the interfacial adaptation with Adper Easy One. CHX did not significantly affect the sealing ability of both one-step self-etch adhesives tested.

  8. Laser induced explosive vapor and cavitation resulting in effective irrigation of the root canal. Part 1: a visualization study

    NARCIS (Netherlands)

    Blanken, J.; de Moor, R.J.G.; Meire, M.; Verdaasdonk, R.

    2009-01-01

    Background and Objectives: Limited information exists regarding the induction of explosive vapor and cavitation bubbles in an endodontic rinsing solution. It is also not clear whether a fiber has to be moved in the irrigation solution or can be kept stationary. No information is available on safe

  9. Laser Induced Explosive Vapor and Cavitation Resulting in Effective Irrigation of the Root Canal. Part 1 : A Visualization Study

    NARCIS (Netherlands)

    Blanken, Jan; De Moor, Roeland Jozef Gentil; Meire, Maarten; Verdaasdonk, Rudolf

    Background and Objectives: Limited information exists regarding the induction of explosive vapor and cavitation bubbles in an endodontic rinsing solution. It is also not clear whether a fiber has to be moved in the irrigation solution or can be kept stationary. No information is available on safe

  10. Laser Induced Explosive Vapor and Cavitation Resulting in Effective Irrigation of the Root Canal. Part 1 : A Visualization Study

    NARCIS (Netherlands)

    Blanken, Jan; De Moor, Roeland Jozef Gentil; Meire, Maarten; Verdaasdonk, Rudolf

    2009-01-01

    Background and Objectives: Limited information exists regarding the induction of explosive vapor and cavitation bubbles in an endodontic rinsing solution. It is also not clear whether a fiber has to be moved in the irrigation solution or can be kept stationary. No information is available on safe po

  11. 根管冲洗液对粪肠球菌作用的研究进展%Research progress on root canal irrigation solutions on the role of Enterococcus faecalis

    Institute of Scientific and Technical Information of China (English)

    张荣德; 董瑞红; 段彦盛

    2012-01-01

    粪肠球菌是一种最常见的导致根管治疗失败的细菌,如何控制根管内的粪肠球菌是研究的热点.根管冲洗剂是杀灭和抑制粪肠球菌的有效方法之一,本文就根管内粪肠球菌的感染特点、常用根管冲洗液以及冲洗剂联合使用对其的作用等方面作一综述.%Enterococcus faecalis is the main root canal treatment failure and refractory periapical root canal bacteria detected. The study on Enterococcus faecalis within the root canal infection characteristics and the sensitivity of the clinical root canal irrigation fluid has reviewed in this paper.

  12. 基于于随机-确定模型的渠井结合灌区用水优化配置%Study on Optimized Redistribution of Water Resources in Well-canal Irrigated Area Based on Stochastic-determination Model

    Institute of Scientific and Technical Information of China (English)

    贺屹; 祝田多娃

    2011-01-01

    research results in practice, the Visual Modflow software is used as a platform, and a groundwater stochastic-determination model ( GSDM) is developed based on time-series model and radial basis function neural network model (RBF-ANN) to make an intensive analysis of water pattern on a basis of prediction model of groundwater regime for Jinghui Canal Irrigated Area. The results provide a useful and powerful basis for the sustainable development and utilization of groundwater and optimized redistribution of water resources in irrigated areas.%陕西省泾惠渠灌区是一个比较典型的渠井结合灌区.由于该灌区地下水的掠夺式开发利用,使得地下水位总体上呈下降趋势,造成许多环境地质问题.如何合理开发利用地下水,优化配置灌溉水资源,是该渠井结合灌区和谐发展的关键.该研究以Visual Modflow软件为平台,并基于时间序列模型和径向基函数神经网络模型(RBFANN),建立了灌区地下水随机-确定动态预测模型,在对灌区水资源供需平衡分析的基础上,通过模型模拟计算,对灌区水资源进行优化配置,为该灌区合理开发利用地下水和灌溉水资源提供依据.

  13. The phase diagram of random Boolean networks with nested canalizing functions

    CERN Document Server

    Peixoto, Tiago P

    2010-01-01

    We obtain the phase diagram of random Boolean networks with nested canalizing functions. Using the annealed approximation, we obtain the evolution of the number $b_t$ of nodes with value one, and the network sensitivity $\\lambda$, and we compare with numerical simulations of quenched networks. We find that, contrary to what was reported by Kauffman et al. [Proc. Natl. Acad. Sci. 2004 101 49 17102-7], these networks have a rich phase diagram, were both the "chaotic" and frozen phases are present, as well as an oscillatory regime of the value of $b_t$. We argue that the presence of only the frozen phase in the work of Kauffman et al. was due simply to the specific parametrization used, and is not an inherent feature of this class of functions. However, these networks are significantly more stable than the variants where all possible Boolean functions are allowed.

  14. An Intelligent Irrigation System Based on Wireless Sensor Network and Fuzzy Control

    Directory of Open Access Journals (Sweden)

    Liai Gao

    2013-05-01

    Full Text Available In order to resolve the problems which include loss of soil fertility and waste of water resource in agriculture production, we design an intelligent irrigation system based on wireless sensor networks and fuzzy control. The system mainly consists of wireless sensor networks and the monitoring center. All of the nodes in Monitoring area use solar power, collect the information of soil moisture, together with the growth information of different crops in different periods. Soil moisture content deviation and the rate of change of deviation are taken as input variables of fuzzy controller, and the fuzzy control regular database is established for the fuzzy irrigation control system. The monitoring center receives the data transmission from wireless sensor network node, and output information of irrigation water demands to the relay via a wireless sensor network to control opening and closing time of the valve in crop areas. The experimental results show that the system has a stable and reliable data transmission, which achieve real-time monitoring of soil on crop growth, give a right amount of irrigation based on crops growth information, which has broad application prospects.

  15. Various irrigation protocols for final rinse to improve bond strengths of fiber posts inside the root canal.

    Science.gov (United States)

    Bitter, Kerstin; Hambarayan, Ani; Neumann, Konrad; Blunck, Uwe; Sterzenbach, Guido

    2013-08-01

    Irrigation after post space preparation and its effects on the bond strength of different adhesive strategies are still an issue of interest. The aim of the present study was to investigate the effects of various irrigation protocols (IPs) on the push-out bond strengths of fiber posts. One-hundred and fifty extracted human anterior teeth were divided into three groups (n = 50 each) and endodontically treated. The post space was irrigated before post placement using the following five IPs in each group: IP1 (control): 5 ml of distilled water; IP2: 5.25% sodium hypochlorite (NaOCl) applied with passive ultrasonic irrigation (PUI); IP3: 1% NaOCl applied with PUI; IP4: 18% ethylenediaminetetracetic acid (EDTA) followed by 5.25% NaOCl; and IP5: 2% chlorhexidine (CHX). Fiber posts placement in each group was performed using three different adhesive strategies. A self-etch adhesive system revealed higher bond strength (16.2 ± 6.9 MPa) compared with an etch-and-rinse adhesive (8.5 ± 4.2 MPa) and a self-adhesive resin cement (9.2 ± 4.7 MPa). The use of 18% EDTA/5.25% NaOCl increased the bond strength of the self-adhesive resin cement. Conversely, this IP decreased the bond strength for the etch-and-rinse adhesive system, whilst 1% NaOCl enhanced the bond strength for the same system. Consequently, each adhesive strategy may need to be adapted to a specific IP. © 2013 Eur J Oral Sci.

  16. A Bayesian network approach to knowledge integration and representation of farm irrigation: 1. Model development

    Science.gov (United States)

    Wang, Q. J.; Robertson, D. E.; Haines, C. L.

    2009-02-01

    Irrigation is important to many agricultural businesses but also has implications for catchment health. A considerable body of knowledge exists on how irrigation management affects farm business and catchment health. However, this knowledge is fragmentary; is available in many forms such as qualitative and quantitative; is dispersed in scientific literature, technical reports, and the minds of individuals; and is of varying degrees of certainty. Bayesian networks allow the integration of dispersed knowledge into quantitative systems models. This study describes the development, validation, and application of a Bayesian network model of farm irrigation in the Shepparton Irrigation Region of northern Victoria, Australia. In this first paper we describe the process used to integrate a range of sources of knowledge to develop a model of farm irrigation. We describe the principal model components and summarize the reaction to the model and its development process by local stakeholders. Subsequent papers in this series describe model validation and the application of the model to assess the regional impact of historical and future management intervention.

  17. An Intelligent Irrigation System Based on Wireless Sensor Network and Fuzzy Control

    OpenAIRE

    Liai Gao; Meng Zhang; Geng Chen

    2013-01-01

    In order to resolve the problems which include loss of soil fertility and waste of water resource in agriculture production, we design an intelligent irrigation system based on wireless sensor networks and fuzzy control. The system mainly consists of wireless sensor networks and the monitoring center. All of the nodes in Monitoring area use solar power, collect the information of soil moisture, together with the growth information of different crops in different periods. Soil moisture content...

  18. The Root Canal Biofilm

    NARCIS (Netherlands)

    Sluis, van der L.W.M.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, M.; Chávez de Paz, E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  19. Research of the path optimization in agricultural water-saving irrigation and canal system water distribution in Ant colony algorithm

    Directory of Open Access Journals (Sweden)

    Deng Lei Lei

    2016-01-01

    Full Text Available To realize the management and control of the water-saving irrigation of the path pipeline distribution in field plots, get the terrain information through remote sensing technology and analyze the path and the amount of the water in the field plots by the ant colony algorithm according to the matter of the low generality in most parts in China. The result shows that the rules were put forward with shorter path, smaller cost and the most utilization of water eventually. It can be widely used in most areas which is lack of water and scientific technology.

  20. Assessing and Testing Hydrokinetic Turbine Performance and Effects on Open Channel Hydrodynamics: An Irrigation Canal Case Study.

    Energy Technology Data Exchange (ETDEWEB)

    Gunawan, Budi [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Neary, Vincent Sinclair [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mortensen, Josh [United States Bureau of Reclamation, Denver, CO (United States); Roberts, Jesse D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    Hydrokinetic energy from flowing water in open channels has the potential to support local electricity needs with lower regulatory or capital investment than impounding water with more conventional means. MOU agencies involved in federal hydropower development have identified the need to better understand the opportunities for hydrokinetic (HK) energy development within existing canal systems that may already have integrated hydropower plants. This document provides an overview of the main considerations, tools, and assessment methods, for implementing field tests in an open-channel water system to characterize current energy converter (CEC) device performance and hydrodynamic effects. It describes open channel processes relevant to their HK site and perform pertinent analyses to guide siting and CEC layout design, with the goal of streamlining the evaluation process and reducing the risk of interfering with existing uses of the site. This document outlines key site parameters of interest and effective tools and methods for measurement and analysis with examples drawn from the Roza Main Canal, in Yakima, WA to illustrate a site application.

  1. 根管冲洗液对多物种细菌生物膜的影响%Effect of Root Canal Irrigation Solution on Multispecies Biofilms

    Institute of Scientific and Technical Information of China (English)

    逄爱慧; 李明; 杜田丰; 杨焰; 万盼; 甘艳; 马净植

    2014-01-01

    Objective To evaluate the effect of chlorhexidine digluconate(CHX),a solution for root canal irrigation,on multispecies biofilms in vitro.Methods CHX(2%)was used to irrigate multispecies biofilms,which were formed on sterile hydroxyapatite disk coated with type Ⅰ collagen.Three minutes later,the antibacterial effect was examined by confocal laser scanning microscopy(CLSM).Results The multispecies biofilms incubated in aerobic and anaerobic hydroxyapatite disks for three weeks grew well.CHX could kill some of the bacterial cells in the multispecies biofilms in both aerobic group(33.0 ± 3.0)% and anaerobic group(40.0±2.8)%,but neither did deionized water(P<0.05).Conclusion CHX has bactericidal effects against multispecies biofilms invitro.However,using CHX alone can not obtain an optimal outcome of root canal irriga-tion.%目的:探讨洗必泰葡萄糖酸盐(C H X)作为根管冲洗试剂,对多物种细菌生物膜的影响。方法在Ⅰ型胶原包被的羟磷灰石片上制备多物种细菌生物膜,应用2%CHX冲洗,处理3 min后,激光扫描共聚焦显微镜观察灭菌效果。结果经过有氧或厌氧培养3周的多物种细菌生物膜生长状态良好;应用2%CHX处理有氧培养或厌氧培养多物种细菌生物膜可以杀灭一部分细菌,死菌比例分别为(33.0±3.0)%、(40.0±2.8)%,无菌去离子水几乎没有杀灭细菌的能力(P<0.05)。结论 CHX具有明显的杀灭多物种细菌生物膜的作用,但是尚不能达到完美的根管冲洗消毒效果。

  2. Modeling Irrigation Networks for the Quantification of Potential Energy Recovering: A Case Study

    Directory of Open Access Journals (Sweden)

    Modesto Pérez-Sánchez

    2016-06-01

    Full Text Available Water irrigation systems are required to provide adequate pressure levels in any sort of network. Quite frequently, this requirement is achieved by using pressure reducing valves (PRVs. Nevertheless, the possibility of using hydraulic machines to recover energy instead of PRVs could reduce the energy footprint of the whole system. In this research, a new methodology is proposed to help water managers quantify the potential energy recovering of an irrigation water network with adequate conditions of topographies distribution. EPANET has been used to create a model based on probabilities of irrigation and flow distribution in real networks. Knowledge of the flows and pressures in the network is necessary to perform an analysis of economic viability. Using the proposed methodology, a case study has been analyzed in a typical Mediterranean region and the potential available energy has been estimated. The study quantifies the theoretical energy recoverable if hydraulic machines were installed in the network. Particularly, the maximum energy potentially recovered in the system has been estimated up to 188.23 MWh/year with a potential saving of non-renewable energy resources (coal and gas of CO2 137.4 t/year.

  3. Optimization of Water Allocation between Different Crops in Water Stress Conditions in Qazvin Irrigation Network

    Directory of Open Access Journals (Sweden)

    Mehdi Mohammad khani

    2017-06-01

    Full Text Available Introduction: Evaluations show the necessity of using optimization models in order to determine optimal allocation of water in different water conditions. Its use can be proposed according to developed model abilities in this study in order to optimize water productivity and provide sustainable management and development of water resources over irrigation and drainage networks. Basic needs of the earth growing population and limitation of water and soil resources remindnecessity of optimal use of resources. World’s more than 280 million hectare lands are covered by irrigation networks (Khalkhali et al., 2006. The efficiency of most projects is between 30-50 percent and studies show that performance of most irrigation and drainage networks is not desirable and they have not achieved their aims. Hirich et al. (2014 Used deficit irrigation to improve crop water productivity of sweet corn, chickpea, faba bean and quinoa. For all crops, the highest water productivity and yield were obtained when deficit irrigation was applied during the vegetative growth stage. During the second season 2011 two cultivars of quinoa, faba bean and sweet corn have been cultivated applying 6 deficit irrigation treatments (rainfed, 0, 25, 50, 75 and 100% of full irrigation only during the vegetative growth stage, while in the rest of a crop cycle full irrigation was provided except for rainfed treatment. For quinoa and faba bean, treatment receiving 50% of the full irrigation during the vegetative growth stage recorded the highest yield and water productivity, while for sweet corn applying 75% of full irrigation was the optimal treatment in terms of yield and water productivity. Moghaddasi et al. (2010 worked examines and compares this approach with that based on the optimization method to manage agricultural water demand during drought to minimize damage. The results show that the optimization method resulted in 42% more income for the agricultural sector using the

  4. Occurrence and potential crop uptake of emerging contaminants and related compounds in an agricultural irrigation network

    Energy Technology Data Exchange (ETDEWEB)

    Calderon-Preciado, Diana [IDAEA-CSIC, Jordi Girona, 18, E-08034 Barcelona (Spain); Matamoros, Victor, E-mail: victor.matamoros@udg.edu [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain); Bayona, Josep M. [IDAEA-CSIC, Jordi Girona, 18, E-08034 Barcelona (Spain)

    2011-12-15

    Emerging contaminants have received much attention in recent years due to their presence in surface waters, but little attention has been paid to their occurrence in agricultural irrigation waters. This study investigated the occurrence of these compounds in an agricultural irrigation network in northeastern Spain and, for the first time, using two plant uptake models, estimated the concentration of selected micropollutants in crops. The concentration of micropollutants in agricultural irrigation waters ranged from 10 to 5130 ng L{sup -1} and exhibited some attenuation over the course of the irrigation network. Bromoform, chloroform, diclofenac, caffeine, ibuprofen, naproxen, methyl dihydrojasmonate, galaxolide, butylated hydroxytoluene, and butylated hydroxyanisole were the most abundant contaminants (> 200 ng L{sup -1}, on average). The estimated concentration of micropollutants in crops ranged from < 1 to 7677 ng kg{sup -1}, with the neutral compounds being the most abundant. Moreover, the predicted data obtained by fate models generally agreed with experimental data. Finally, human exposure to micropollutants through fruit and vegetable consumption was estimated to be 9.8 {mu}g per person and week ({Sigma} 27 contaminants detected). Further studies are needed to determine the health implications that the presence of these compounds in fruit and vegetables may have for consumers.

  5. Occurrence and potential crop uptake of emerging contaminants and related compounds in an agricultural irrigation network.

    Science.gov (United States)

    Calderón-Preciado, Diana; Matamoros, Víctor; Bayona, Josep M

    2011-12-15

    Emerging contaminants have received much attention in recent years due to their presence in surface waters, but little attention has been paid to their occurrence in agricultural irrigation waters. This study investigated the occurrence of these compounds in an agricultural irrigation network in northeastern Spain and, for the first time, using two plant uptake models, estimated the concentration of selected micropollutants in crops. The concentration of micropollutants in agricultural irrigation waters ranged from 10 to 5130 ng L(-1) and exhibited some attenuation over the course of the irrigation network. Bromoform, chloroform, diclofenac, caffeine, ibuprofen, naproxen, methyl dihydrojasmonate, galaxolide, butylated hydroxytoluene, and butylated hydroxyanisole were the most abundant contaminants (>200 ng L(-1), on average). The estimated concentration of micropollutants in crops ranged from <1 to 7677 ng kg(-1), with the neutral compounds being the most abundant. Moreover, the predicted data obtained by fate models generally agreed with experimental data. Finally, human exposure to micropollutants through fruit and vegetable consumption was estimated to be 9.8 μg per person and week (Σ 27 contaminants detected). Further studies are needed to determine the health implications that the presence of these compounds in fruit and vegetables may have for consumers. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Study of capillary network directionality and irrigation of hypoxic tissue in an angiogenesis lattice model

    Science.gov (United States)

    Moglia, Belén; Guisoni, Nara; Albano, Ezequiel V.

    2013-12-01

    To shed light on the understanding of the angiogenesis process, we study a simplified lattice model for the capillary network formation between an existing blood vessel and an initially hypoxic tissue. We consider that the cells of the tissue surface can release growth factors that will diffuse, leading to the formation of new capillaries that ultimately arrive at the tissue. Additionally, we consider the local production of growth factors by the growing capillary network. We also propose the existence of an inhibition mechanism at the hypoxic surface, i.e., a fixed number of neighboring sites of an already irrigated site of the hypoxic tissue stop releasing growth factors due to the arrival of nutrients. Particularly, the goal of this work is to study the effect of the release of local growth factors and the inhibition mechanism on properties such as the directionality of the growing network and the irrigation of the hypoxic tissue. Therefore we propose the quantification of these two relevant features for angiogenesis modeling. We establish a relationship between the model behavior without the release of local growth factors in the presence of the inhibition mechanism and a normal angiogenesis process. In this situation, the model gives a directional capillary network and a good irrigation of the hypoxic tissue. On the other hand, for a large number of released local growth factors in the absence of the inhibition mechanism, the model could be appropriate for the description of tumor angiogenesis. In this case, the model provides a rather small directionality for the growing structure, with a worse degree of irrigation of the hypoxic tissue, as well as a more tortuous capillary network with many closed branches and loops.

  7. Ultrasonic versus sonic activation of the final irrigant in root canals instrumented with rotary/reciprocating files: An in-vitro scanning electron microscopy analysis

    National Research Council Canada - National Science Library

    Khalap, Neha Deepak; Kokate, Sharad; Hegde, Vibha

    2016-01-01

    ... (n = 20) where the final irrigant was activated using either Ultrasonics (Passive Ultrasonic Irrigation; PUI) or Sonics (EndoActivator; EA). Group 1: PTN + EA; Group 2: PTN + PUI; Group 3: WO + EA; and Group 4: WO + PUI...

  8. Irrigation network design and reconstruction and its analysis by simulation model

    Directory of Open Access Journals (Sweden)

    Čistý Milan

    2014-06-01

    Full Text Available There are many problems related to pipe network rehabilitation, the main one being how to provide an increase in the hydraulic capacity of a system. Because of its complexity the conventional optimizations techniques are poorly suited for solving this task. In recent years some successful attempts to apply modern heuristic methods to this problem have been published. The main part of the paper deals with applying such technique, namely the harmony search methodology, to network rehabilitation optimization considering both technical and economic aspects of the problem. A case study of the sprinkler irrigation system is presented in detail. Two alternatives of the rehabilitation design are compared. The modified linear programming method is used first with new diameters proposed in the existing network so it could satisfy the increased demand conditions with the unchanged topology. This solution is contrasted to the looped one obtained using a harmony search algorithm

  9. Irrigation in endodontics.

    Science.gov (United States)

    Haapasalo, M; Shen, Y; Wang, Z; Gao, Y

    2014-03-01

    Irrigation is a key part of successful root canal treatment. It has several important functions, which may vary according to the irrigant used: it reduces friction between the instrument and dentine, improves the cutting effectiveness of the files, dissolves tissue, cools the file and tooth, and furthermore, it has a washing effect and an antimicrobial/antibiofilm effect. Irrigation is also the only way to impact those areas of the root canal wall not touched by mechanical instrumentation. Sodium hypochlorite is the main irrigating solution used to dissolve organic matter and kill microbes effectively. High concentration sodium hypochlorite (NaOCl) has a better effect than 1 and 2% solutions. Ethylenediaminetetraacetic acid (EDTA) is needed as a final rinse to remove the smear layer. Sterile water or saline may be used between these two main irrigants, however, they must not be the only solutions used. The apical root canal imposes a special challenge to irrigation as the balance between safety and effectiveness is particularly important in this area. Different means of delivery are used for root canal irrigation, from traditional syringe-needle delivery to various machine-driven systems, including automatic pumps and sonic or ultrasonic energy.

  10. Antimicrobial effect of different root canal irrigant combinations on infected root canals under passive ultrasonic irrigation%超声下不同根管冲洗剂组合对感染根管内粪肠球菌杀灭效果的研究

    Institute of Scientific and Technical Information of China (English)

    张敏; 仇臖; 侯晖; 李琳; 周洁; 范晓敏

    2014-01-01

    AIM:To compare the antimicrobial effect of different root canal irrigant combinations under pas-sive ultrasonic irrigation in root canals.METHODS:90 human root canals contaminated with Enterococcus faecalis were randomly divided into 4 experimental groups (group A:25 g/L NaClO/20 g/L CHX,group B:25 g/L NaClO 30 mL/L H2 O2 ,group C:10 g/L NaClO 20 g/L CHX,group D:10 g/L NaClO/30 mL/L H2 O2 )and 2 two control groups (group E:52.5 g/L NaClO,group F:0.9%normal saline,n=10,5 were used as base line control).Before and after treatment bacterial content on the surface of root canal walls and at 100,200,300 μm in depth inside the dentinal tubules was measured and analyzed by means of one-way analysis of variance.RESULTS:On the surface and at different depths of dentine,the bactericidal efficiency of groups of A,B,C,D and E were significantly greater than that of group F (P0.05 )except at depth of 200 ~300um,the bactericidal efficiency of group A was lower than that of group E (P0.05).CONCLUSION:The combination of 25 g/L NaClO and 20 g/L CHX can be considered to be the ideal irrigant of root canal disinfection.%目的:比较超声作用下不同根管冲洗剂组合对根管内粪肠球菌的杀灭效果。方法:取粪肠球菌感染根管模型样本90个,随机分为6组(n=15),其中5个样本用于基线对照,10个样本分别按相应分组处理,A组:25 g/L次氯酸钠液液+20 g/L洗必泰液;B组:25 g/L次氯酸钠液+30 mL/L过氧化氢液;C组:10 g/L次氯酸钠液+20 g/L洗必泰液;D组:10 g/L次氯酸钠液+30 mL/L过氧化氢液;E组:52.5 g/L次氯酸钠液阳性对照;F组:生理盐水阴性对照。处理前后从样本的根管壁表面采样,并钻取不同深度牙本质进行细菌培养和计数。结果:A、B、C、D、E组根管壁表面及不同深度牙本质的细菌清除率均显著高于F组(P<0.05);对各层牙本质的细菌清除率,A组高于B、C、D组(P<0.05

  11. Estimation of furrow irrigation sediment loss using an artificial neural network

    Science.gov (United States)

    The area irrigated by furrow irrigation in the U.S. has been steadily decreasing but still represents about 20% of the total irrigated area in the U.S. Furrow irrigation sediment loss is a major water quality issue and a method for estimating sediment loss is needed to quantify the environmental imp...

  12. Groundwater Resources Evolution and Agricultural Ecological Security in Jinghui Canal Irrigation Area%泾惠渠灌区地下水资源演变与农田生态安全

    Institute of Scientific and Technical Information of China (English)

    刘燕; 张盼盼; 王建莹; 郭曼

    2014-01-01

    通过对泾惠渠灌区地下水形成机理及其演变态势的分析,认为气候条件变化、地质条件变化以及人类活动的负面影响是导致灌区地下水资源量衰减的主要原因,其中人类活动(地表水引水灌溉、地下水开采等)的影响作用最为突出。同时也指出了灌区水资源衰减所引发的农田生态安全问题,地下水资源的衰减已经影响到灌区的可持续发展。从灌溉水量的大小、时间分配以及地下水开采量几个方面讨论了灌区水资源调控方式,指出只有合理联合使用地表水和地下水、涵养地下水源,才能实现灌区水资源的可持续开发利用,确保灌区农业供水安全,维护灌区农田生态环境良性循环。%Based on the recharge mechanism and development trends of the groundwater in Jinghui Canal irrigation area,it was pointed out that cli-mate changes,geological condition changes and the negative impacts of human activities had caused the reduction of groundwater resources,espe-cially irrigation diversion and groundwater exploitation. In the meantime,it also pointed out the agricultural ecological security problems caused by groundwater resources reduction,which had threatened the sustainable development of irrigation area. Aimed at these issues,measures to adjust and control water resources were discussed which included irrigation water quantity,distribution of irrigation time and groundwater exploitation. Fi-nally,it pointed out that the combination use of surface water and groundwater were the effective way to realize the sustainability of groundwater re-sources,water supply safety and thus keeping the virtuous cycle of agricultural eco-environment in Jinghui Canal irrigation area.

  13. Canal Water Scarcity Hits Farmers

    Institute of Scientific and Technical Information of China (English)

    张忠潮

    2007-01-01

    Acute shortage of canal water for irrigation in this district has caused resentment among the farmers.The water is being released in the various channels for just one week in a month,which is not enough to meet the irrigation needs of the farmers who are preparing their fields for paddy

  14. Mandibular Second Premolar with Four Canals

    Directory of Open Access Journals (Sweden)

    Javad Ghiasi

    2015-09-01

    Full Text Available A mandibular second premolar with four canals is an interesting example of anatomic variations. This report describes a case of a mandibular second premolar with three roots and four canals (one mesiobuccal, two distobuccal and one lingual. The canals were prepared using K-files and irrigated with NaOCl (5.25% and normal saline as the final irrigant. The canals were filled laterally with gutta percha and AH26 sealer (De Trey, Dentsply, Switzerland. This case shows a rare anatomic configuration and points out the importance of looking for additional canals.

  15. 派瑞松联合外耳道冲洗治疗真菌性外耳道炎的临床研究%Clinical study on Pevisone combined with canal irrigation in the treatment of fungal otitis externa

    Institute of Scientific and Technical Information of China (English)

    孙俊; 杜友红; 罗婷婕

    2012-01-01

    Objective To evaluate the methods and results of Pevisone combined with canal irrigation in the treatment of fungal otitis externa. Methods 80 cases which were selected from September 2009 to September 2011 admitted to hospital with fungal otitis externa were randomly divided into two groups, experimental group of 42 patients was given canal irriga -tion combined with Pevisone; control group of 38 cases was given canal irrigation. Follow-up of 10 - 15 days, two groups were compared before and after treatment of the disease points, clinical efficacy and adverse reactions. Results During follow-up comparing in two groups after treatment, the patient's condition points were lower than before treatment (P <0.05); the disease points, clinical efficacy and adverse reaction rates of experimental group were better than the control group (P < 0.05). Conclusion Canal irrigation combined with Pevisone in the treatment of fungal otitis externa, can significantly re -duce the patient's condition deteriorated, avoid adverse reactions, improve clinical efficacy.%目的 探讨派瑞松联合外耳道冲洗治疗真菌性外耳道炎的方法及效果.方法随机选取本院2009年9月~2011年9月收治的80例真菌性外耳道炎患者分成两组,实验组42例,行派瑞松联合外耳道冲洗治疗;对照组38例,单纯行外耳道冲洗.随访10~15 d,比较两组患者治疗前后的病情积分、临床疗效和不良反应.结果 随访期间两组内相比,治疗后患者的病情积分均低于治疗前(P <0.05);两组间相比,实验组患者的病情积分、临床疗效和不良反应发生率均优于对照组(P <0.05).结论应用派瑞松联合外耳道冲洗治疗真菌性外耳道炎,可显著减轻患者的病情恶化,避免不良反应,提高临床疗效.

  16. Adaptation of irrigation networks to climate change: Linking robust design and stakeholder contribution

    Energy Technology Data Exchange (ETDEWEB)

    Granados, A.; Martín-Carrasco, F.J.; García de Jalón, S.; Iglesias, A.

    2015-07-01

    Agriculture is a particularly sensitive sector to the potential impacts of climate change. Thus, irrigation infrastructure is required to be robust to cope with these potential threats. The objective of this research is designing more robust irrigation networks, considering cost and stakeholder contribution. To that end, the investigation was addressed in three phases: a sensitivity analysis to understand the effectiveness of the distinct variables, a cost-effectiveness analysis assessing their efficiency, and a global study of the most efficient variables to provide an insight into their function. The sensitivity analysis indicates that the networks oversized by means of the coefficient of utilisation or the factor of safety, behave better than those oversized via the continuous specific discharge; moreover, the degree of freedom has been shown ineffective. The cost-effectiveness analysis shows that the coefficient of utilisation and the factor of safety are the most efficient variables, as they introduced safety margin oversizing fewer network elements and to a lesser extent than the continuous specific discharge. It also shows that stakeholder contribution, conveyed as a reduction of the degree of freedom, plays an important role in the network’s adaptive capacity to change. The global study of these variables reveals the subtlety of the coefficient of utilisation, which is the variable that better reproduces the farmer behaviour during demand increase scenarios. In conclusion, the results identify the coefficient of utilisation as the variable which provides the safest margins and reveal the importance of stakeholder contribution in absorb the demand increase in a better manner. (Author)

  17. Adaptation of irrigation networks to climate change: Linking robust design and stakeholder contribution

    Directory of Open Access Journals (Sweden)

    Alfredo Granados

    2015-12-01

    Full Text Available Agriculture is a particularly sensitive sector to the potential impacts of climate change. Thus, irrigation infrastructure is required to be robust to cope with these potential threats. The objective of this research is designing more robust irrigation networks, considering cost and stakeholder contribution. To that end, the investigation was addressed in three phases: a sensitivity analysis to understand the effectiveness of the distinct variables, a cost-effectiveness analysis assessing their efficiency, and a global study of the most efficient variables to provide an insight into their function. The sensitivity analysis indicates that the networks oversized by means of the coefficient of utilisation or the factor of safety, behave better than those oversized via the continuous specific discharge; moreover, the degree of freedom has been shown ineffective. The cost-effectiveness analysis shows that the coefficient of utilisation and the factor of safety are the most efficient variables, as they introduced safety margin oversizing fewer network elements and to a lesser extent than the continuous specific discharge. It also shows that stakeholder contribution, conveyed as a reduction of the degree of freedom, plays an important role in the network’s adaptive capacity to change. The global study of these variables reveals the subtlety of the coefficient of utilisation, which is the variable that better reproduces the farmer behaviour during demand increase scenarios. In conclusion, the results identify the coefficient of utilisation as the variable which provides the safest margins and reveal the importance of stakeholder contribution in absorb the demand increase in a better manner.

  18. Modernisation Strategy for National Irrigation Systems in the Philippines: Balanac and Sta. Maria River Irrigation Systems

    NARCIS (Netherlands)

    Delos Reyes, M.L.F.

    2017-01-01

    This book examines the nature and impact of irrigation system rehabilitation on increasing the actual area irrigated by the publicly funded canal irrigation systems of the Philippines. It proposes a system diagnosis approach for the development of a more appropriate and climate-smart irrigation

  19. 浅谈从化市塘料总灌渠灌区项目的建设管理%The construction and management of the Tang liao’s main canal Irrigated Area in Conghua city

    Institute of Scientific and Technical Information of China (English)

    袁梦; 黄锦宜

    2014-01-01

    Taking the Tang liao’s main canal Irrigated Area construction in Conghua city as an example, this paper mainly expounds on construction and management of irrigation area, implementing the reform in the system of legal person responsible for project, the system of public bidding for project, the system of construction and supervision and the system of contract management, the principle of"quality system"strictly,While making management after project completion,To ensure better play the role of irrigation project.%以从化市塘料总灌渠灌区工程建设为例,阐述了灌区项目的建设管理,要严格实行项目法人责任制、招标投标制、建设工程监理制、合同管理制和工程质量终身负责制,同时做好工程完工后的管理工作,确保灌区工程更好的发挥作用。

  20. The role of genome and gene regulatory network canalization in the evolution of multi-trait polymorphisms and sympatric speciation

    Directory of Open Access Journals (Sweden)

    Hogeweg Paulien

    2009-07-01

    Full Text Available Abstract Background Sexual reproduction has classically been considered as a barrier to the buildup of discrete phenotypic differentiation. This notion has been confirmed by models of sympatric speciation in which a fixed genetic architecture and a linear genotype phenotype mapping were assumed. In this paper we study the influence of a flexible genetic architecture and non-linear genotype phenotype map on differentiation under sexual reproduction. We use an individual based model in which organisms have a genome containing genes and transcription factor binding sites. Mutations involve single genes or binding sites or stretches of genome. The genome codes for a regulatory network that determines the gene expression pattern and hence the phenotype of the organism, resulting in a non-linear genotype phenotype map. The organisms compete in a multi-niche environment, imposing selection for phenotypic differentiation. Results We find as a generic outcome the evolution of discrete clusters of organisms adapted to different niches, despite random mating. Organisms from different clusters are distinct on the genotypic, the network and the phenotypic level. However, the genome and network differences are constrained to a subset of the genome locations, a process we call genotypic canalization. We demonstrate how this canalization leads to an increased robustness to recombination and increasing hybrid fitness. Finally, in case of assortative mating, we explain how this canalization increases the effectiveness of assortativeness. Conclusion We conclude that in case of a flexible genetic architecture and a non-linear genotype phenotype mapping, sexual reproduction does not constrain phenotypic differentiation, but instead constrains the genotypic differences underlying it. We hypothesize that, as genotypic canalization enables differentiation despite random mating and increases the effectiveness of assortative mating, sympatric speciation is more likely

  1. Syringe irrigation: blending endodontics and fluid dynamics

    NARCIS (Netherlands)

    C. Boutsioukis; L.W.M. van der Sluis

    2015-01-01

    Syringe irrigation remains a widely used irrigant delivery method during root canal treatment. An interdisciplinary approach involving well-established methods from the field of fluid dynamics can provide new insights into the mechanisms involved in cleaning and disinfection of the root canal system

  2. Syringe irrigation: blending endodontics and fluid dynamics

    NARCIS (Netherlands)

    Boutsioukis, C.; van der Sluis, L.W.M.; Basrani, B.

    2015-01-01

    Syringe irrigation remains a widely used irrigant delivery method during root canal treatment. An interdisciplinary approach involving well-established methods from the field of fluid dynamics can provide new insights into the mechanisms involved in cleaning and disinfection of the root canal system

  3. Multiple-use Management of Irrigation Systems: Technical Constraints and Challenges

    Science.gov (United States)

    Gowing, J.; Li, Q.; Mayilswami, C.; Gunawardhana, K.

    It is now widely recognised that many irrigation systems, originally planned only for irrigation supply, are de facto multiple-use systems. However, the importance of non- irrigation uses (such as bathing, laundry, livestock watering and fishing), to the liveli- hoods of the rural poor has generally been ignored. This has significant implications for irrigation engineers, water resources managers and other decision-makers. An im- proved understanding of competition and complementarity between these uses and irrigation demands is essential for effective multiple-use management of irrigation systems.This paper presents a study of multiple-use management, where the focus is on integrating aquaculture within irrigation systems with and without secondary storage. The Lower Bhavani scheme in South India and Mahaweli System H in Sri- Lanka were selected as representative smallholder irrigation schemes: - The Lower Bhavani scheme comprises a 200km contour canal serving a command area of 78,500ha. Apart from the main dam, there are no storage structures within the irriga- tion system. - Mahaweli System H comprises a command area of 43,000ha served by three main canals. The feature of particular interest in this scheme is the large number of secondary storage structures (known locally as tanks), which are in- tegrated within the canal network. It is apparent from these two sites and from studies elsewhere that non-irrigation uses are important to the livelihoods of the local peo- ple, but these uses are largely opportunistic. The failure to give explicit recognition to non-irrigation uses has important implications for assessments of economic per- formance and water productivity of irrigation systems. However, any attempt to give proper recognition to these alternative uses also has implication for irrigation project management. This paper describes a detailed study of water management in the two irrigation systems. The method of investigation involves in-depth studies in

  4. Irrigation Water Conveyance by Ditch and Canal on Agricultural Land in the Conterminous United States, 1992: National Resource Inventory Conservation Practice 428

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the estimated percentage of the 1-km grid cell that is covered by or subject to the agricultural conservation practice (CP428), Irrigation...

  5. Development of an artificial neural network-based software for prediction of power plant canal water discharge temperature

    Energy Technology Data Exchange (ETDEWEB)

    Romero, C.E.; Shan, J.F. [Lehigh University, Bethlehem, PA (United States). Energy Research Center

    2005-11-01

    Power plant cooling water systems that interact with nearby effluents are complex non-linear, large-time-delay systems. A neural network-based software tool was developed for prediction of the canal water discharge temperature at a coal-fired power plant as a function of plant operating parameters and local weather conditions, including tide information. The plant has four units totaling an installed capacity of 1550 MW and its water thermal discharge is environmentally regulated. In the summer months, when the price of electricity is very profitable and the risk of exceeding the canal temperature limit is greater, the tradeoff between maximum generation and environmental compliance violations is financially significant. The software is a predictive tool to assist in scheduling load generation among the plant's four units without exceeding a thermal discharge limit of 95{sup o}F. Back propagation neural network architectures were trained using plant operating data with an 'off-set' component. The artificial intelligence models produced reasonable trends for year-round prediction and different operational scenarios. Comparison of measured and predicted canal temperatures indicated an accuracy of less than 0.3{sup o}F over the range between 90 and 95{sup o}F. The software tool was developed as an Object Linking and Embedding (OLE) for Process Control (OPC) client, with real-time communication and interface with the plant Distributed Control System (DCS).

  6. Online decision support system for surface irrigation management

    Science.gov (United States)

    Wang, Wenchao; Cui, Yuanlai

    2017-04-01

    Irrigation has played an important role in agricultural production. Irrigation decision support system is developed for irrigation water management, which can raise irrigation efficiency with few added engineering services. An online irrigation decision support system (OIDSS), in consist of in-field sensors and central computer system, is designed for surface irrigation management in large irrigation district. Many functions have acquired in OIDSS, such as data acquisition and detection, real-time irrigation forecast, water allocation decision and irrigation information management. The OIDSS contains four parts: Data acquisition terminals, Web server, Client browser and Communication system. Data acquisition terminals are designed to measure paddy water level, soil water content in dry land, ponds water level, underground water level, and canals water level. A web server is responsible for collecting meteorological data, weather forecast data, the real-time field data, and manager's feedback data. Water allocation decisions are made in the web server. Client browser is responsible for friendly displaying, interacting with managers, and collecting managers' irrigation intention. Communication system includes internet and the GPRS network used by monitoring stations. The OIDSS's model is based on water balance approach for both lowland paddy and upland crops. Considering basic database of different crops water demands in the whole growth stages and irrigation system engineering information, the OIDSS can make efficient decision of water allocation with the help of real-time field water detection and weather forecast. This system uses technical methods to reduce requirements of user's specialized knowledge and can also take user's managerial experience into account. As the system is developed by the Browser/Server model, it is possible to make full use of the internet resources, to facilitate users at any place where internet exists. The OIDSS has been applied in

  7. Management Strategy of Canal-well Combined Irrigation Based on Critical Groundwater Depth%渠井结合灌区控制性关键地下水位及其管理策略研究

    Institute of Scientific and Technical Information of China (English)

    赵孟哲; 魏晓妹; 降亚楠; 李建承

    2015-01-01

    针对我国北方大型灌区出现的地下水“采补失衡”问题,以陕西省泾惠渠灌区为例,通过对其渠井结合灌溉发展历程的回顾,分析了地下水位变化对灌区高效安全用水的影响,探讨了灌区地下水位控制目标;基于地下水位控制目标,利用水均衡法分析了控制性开采总量与关键地下水位之间的定量关系;选取2002年(平水年)为代表年,计算了灌区各分区的控制性关键地下水位所对应的蓝、黄、红线埋深值;根据灌区2010年实测地下水位埋深与关键地下水位埋深的对比分析,划分了灌区地下水管理分区,并对各分区的地下水管理策略进行了探讨。%For large-scale irrigation areas in the North of China ,the imbalance of exploitation and replenishment of underground water is an important problem remained to be managed with .Taking Jinghuiqu irrigation district in Shanxi province as the research area , based on historical review ,the important influence of groundwater for irrigation efficiency and water safety is discussed ,and the con‐trol objective of groundwater for irrigation district is proposed in this paper .According to water balance method ,the quantitative re‐lationship of groundwater level and water yield is ascertained .Taking 2002 year for normal flow year ,the critical groundwater depths of divided areas are determined based on the groundwater exploitation amount in this paper .By comparing the measured groundwater depth with the critical groundwater depth ,the whole irrigation district is divided into different types of management zones .In the end ,the paper discusses the regionalized management strategy from the aspect of canal-well irrigation district .

  8. Limitations of navigation through Nubaria canal, Egypt.

    Science.gov (United States)

    Samuel, Magdy G

    2014-03-01

    Alexandria port is the main Egyptian port at the Mediterranean Sea. It is connected to the Nile River through Nubaria canal, which is a main irrigation canal. The canal was designed to irrigate eight hundred thousand acres of agricultural lands, along its course which extends 100 km. The canal has three barrages and four locks to control the flow and allow light navigation by some small barges. Recently, it was decided to improve the locks located on the canal. More than 40 million US$ was invested in these projects. This decision was taken to allow larger barges and increase the transported capacity through the canal. On the other hand, navigation through canals and restricted shallow waterways is affected by several parameters related to both the channel and the vessel. Navigation lane width as well as vessel speed and maneuverability are affected by both the channel and vessel dimensions. Moreover, vessel dimensions and speed will affect the canal stability. In Egypt, there are no guide rules for navigation through narrow and shallow canals such Nubaria. This situation threatens the canal stability and safety of navigation through it. This paper discussed the characteristics of Nubaria canal and the guide rules for navigation in shallow restricted water ways. Dimensions limitation for barges navigating through Nubaria canal is presented. New safe operation rules for navigation in Nubaria canal are also presented. Moreover, the implication of navigation through locks on canal discharge is estimated.

  9. Limitations of navigation through Nubaria canal, Egypt

    Directory of Open Access Journals (Sweden)

    Magdy G. Samuel

    2014-03-01

    Full Text Available Alexandria port is the main Egyptian port at the Mediterranean Sea. It is connected to the Nile River through Nubaria canal, which is a main irrigation canal. The canal was designed to irrigate eight hundred thousand acres of agricultural lands, along its course which extends 100 km. The canal has three barrages and four locks to control the flow and allow light navigation by some small barges. Recently, it was decided to improve the locks located on the canal. More than 40 million US$ was invested in these projects. This decision was taken to allow larger barges and increase the transported capacity through the canal. On the other hand, navigation through canals and restricted shallow waterways is affected by several parameters related to both the channel and the vessel. Navigation lane width as well as vessel speed and maneuverability are affected by both the channel and vessel dimensions. Moreover, vessel dimensions and speed will affect the canal stability. In Egypt, there are no guide rules for navigation through narrow and shallow canals such Nubaria. This situation threatens the canal stability and safety of navigation through it. This paper discussed the characteristics of Nubaria canal and the guide rules for navigation in shallow restricted water ways. Dimensions limitation for barges navigating through Nubaria canal is presented. New safe operation rules for navigation in Nubaria canal are also presented. Moreover, the implication of navigation through locks on canal discharge is estimated.

  10. Calibrating a flow model in an irrigation network: Case study in Alicante, Spain

    Directory of Open Access Journals (Sweden)

    Modesto Pérez-Sánchez

    2017-04-01

    Full Text Available The usefulness of models depends on their validation in a calibration process, ensuring that simulated flows and pressure values in any line are really occurring and, therefore, becoming a powerful decision tool for many aspects in the network management (i.e., selection of hydraulic machines in pumped systems, reduction of the installed power in operation, analysis of theoretical energy recovery. A new proposed method to assign consumptions patterns and to determine flows over time in irrigation networks is calibrated in the present research. As novelty, the present paper proposes a robust calibration strategy for flow assignment in lines, based on some key performance indicators (KPIF coming from traditional hydrological models: Nash-Sutcliffe coefficient (non-dimensional index, root relative square error (error index and percent bias (tendency index. The proposed strategy for calibration was applied to a real case in Alicante (Spain, with a goodness of fit considered as “very good” in many indicators. KPIF parameters observed present a satisfactory goodness of fit of the series, considering their repeatability. Average Nash-Sutcliffe coefficient value oscillated between 0.30 and 0.63, average percent bias values were below 10% in all the range, and average root relative square error values varied between 0.65 and 0.80.

  11. Effective management for acidic pollution in the canal network of the Mekong Delta of Vietnam: a modeling approach.

    Science.gov (United States)

    Phong, Ngo Dang; Hoanh, Chu Thai; Tuong, To Phuc; Malano, Hector

    2014-07-01

    Acidic pollution can cause severe environmental consequences annually in coastal areas overlain with acid sulfate soils (ASS). A water quality model was used as an analytical tool for exploring the effects of water management options and other interventions on acidic pollution and salinity in Bac Lieu, a coastal province of the Mekong Delta. Fifty eight percent of the provincial area is covered by ASS, and more than three-fourths (approximately 175,000 ha) are used for brackish-water shrimp culture. Simulations of acid water propagation in the canal network indicate that the combination of opening the two main sluices along the East Sea of the study area at high tide for one day every week in May and June and widening the canals that connect these sluices to the West Sea allows for adequate saline water intake and minimizes the acidic pollution in the study area. On the other hand, canal dredging in the freshwater ASS area should be done properly as it can create severe acidic pollution. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Volumetric water control in a large-scale open canal irrigation system with many smallholders: The case of Chancay-Lambayeque in Peru

    NARCIS (Netherlands)

    Vos, J.M.C.; Vincent, L.F.

    2011-01-01

    Volumetric water control (VWC) is widely seen as a means to increase productivity through flexible scheduling and user incentives to apply just enough water. However, the technical and social requirements for VWC are poorly understood. Also, many experts assert that VWC in large-scale open canals

  13. General Dentists’ Use of Isolation Techniques During Root Canal Treatment: from the National Dental Practice-Based Research Network

    Science.gov (United States)

    Lawson, Nathaniel C.; Gilbert, Gregg H.; Funkhouser, Ellen; Eleazer, Paul D.; Benjamin, Paul L.; Worley, Donald C.

    2015-01-01

    Introduction A preliminary study done by a National Dental Practice-Based Research Network precursor observed that 44% of general dentists (GDs) reported always using a rubber dam (RD) during root canal treatment (RCT). This full-scale study quantified use of all isolation techniques, including RD use. Methods Network practitioners completed a questionnaire about isolation techniques used during RCT. Network Enrollment Questionnaire data provided practitioner characteristics. Results 1,490 of 1,716 eligible GDs participated (87%); 697 (47%) reported always using a RD. This percentage varied by tooth type. These GDs were more likely to always use a RD: do not own a private practice; perform less than 10 RCT/month; have postgraduate training. Conclusions Most GDs do not use a RD all the time. Ironically, RDs are used more frequently by GDs who do not perform molar RCT. RD use varies with tooth type and certain dentist, practice, and patient characteristics. PMID:26015159

  14. 灌区渠系引水量及气象因素变化对地下水埋深的研究%Study on Impact of Irrigation Canal System Diverted and Meteorological Factors Changes on Groundwater Depth

    Institute of Scientific and Technical Information of China (English)

    李伟

    2016-01-01

    In order to study the canal system been obtained as well as the meteorological factors and the connection between the buried depth of groundwater,the article takes irrigation area as the research object,through descriptive statistical analysis method,establish the diverted-embedded depth of groundwater,the water surface evaporation-embedded depth of groundwater diagram.The results shows that during the reproductive period (April-November),diverted,evaporation and groundwater depth area is in a good trend,and has significant correlation.Therefore,fully develop the relationship between the buried depth of groundwater,the water surface evaporation quantity,and reasonable exploitation of groundwater for irrigation area,and is of great significance to the full implementation of water saving reconstruction project in the irrigation area.%为了研究渠系引水量以及气象因素与地下水埋深之间的联系,以河套灌区为研究对象,通过描述性统计分析方法,建立起引水量———地下水埋深、水面蒸发量———地下水埋深关系图。结果表明:在生育期内(4月-11月),引水量、蒸发量与地下水埋深的区域整体变化趋势较好,相关性显著。因此,充分研究出引水量、水面蒸发量对地下水埋深的关系,将对于灌区地下水的合理开采与配置以及灌区全面实施节水改造工程具有重要的意义。

  15. Development of a project on North Unit Irrigation District’s Main Canal at the Monroe Drop, using a novel low-head hydropower technology called the SLH100

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Abraham [Natel Energy, Inc., Alameda, CA (United States); Schneider, Gia [Natel Energy, Inc., Alameda, CA (United States); McKinstry, Katherine [Natel Energy, Inc., Alameda, CA (United States); Harwood, Meghan [Natel Energy, Inc., Alameda, CA (United States)

    2017-03-14

    Natel Energy is a low­-head, distributed hydropower company based out of Alameda, CA. Natel manufactures and sells proprietary hydroelectric turbines called hydroEngines® that are suitable for low-­head, high-­flow settings, and range from 30kW to 1 MW of capacity per unit. Natel’s hydroEngine is a state­-of­the-­art two stage impulse turbine, using blades mounted symmetrically on two belts perpendicular to the axis of travel, and using linearly­-moving foils, rather than a rotor, to enable efficient conversion of kinetic energy of large volumes of water at low head with no risk of cavitation. In addition, the hydroEngine can be installed at or above tailwater level, reducing the excavation necessary to build the powerhouse and thus reducing total installed cost and project footprint. Thus, the hydroEngine technology enables a new generation of small hydro installations with low cost of project development, fish-­friendly operations, and small project footprint. In September of 2015, Natel Energy formally commissioned its first project installation in Madras, Oregon, installing 1 SLH100 turbine at an existing drop structure on the North Unit Irrigation District (NUID) Main Canal. The water falls between 13.5 feet to 16.5 feet at this structure, depending on flow. The plant has an installed capacity of 250 kW and an expected annual generation of approximately 873 MWh. The plant operates at an annual capacity factor of 40%, and a capacity factor over the irrigation season, or period of available flow, of 80%. Annual capacity factor is calculated as a percentage of plant operating hours relative to a total of 8,760 hours in a year; because the irrigation canal in which the Project is located only runs water from April to October, the available flow capacity factor is higher. Net greenhouse gas reductions from the Monroe Project are estimated to be 602 tCO2/year. The purpose of this report is to provide an overview of the specifications for Natel’s first

  16. 4种冲洗方法对弯曲根管玷污层影响的体外研究%In Vitro Study of Four Endodontic Irrigation Protocols on Smear Layer Removal in Curved Canals

    Institute of Scientific and Technical Information of China (English)

    马艳华; 许崇游; 李荣华; 殷恺

    2014-01-01

    Objective To investigate the effective endodontic irrigation protocols on smear layer removal from curved canals. Methods Forty extracted mandibular first molars with curved mesial root canal were selected and decoronat-ed. Mesiobuccal root canal was instrumented to F3 using handed ProTaper system, and randomly divided into four groups ac-cording to final irrigation protocols: syringe irrigation (group A), #30K file agitation (group B), passive ultrasonic irrigation (PUI, group C) and combination of #30K file agitation and PUI (group D). The ultrasonic file was located within 0.5 mm coro-nal from start of the curvature. All root canals were mesio-distally split, snicked at the start of the curvature and 2 mm apical-ly from the start of the curvature, and divided into three sections. They wereⅠ,ⅡandⅢfrom coronal to apical. The smear layer of each section of root canal was examined under scanning electron microscope (SEM). Results Group D presented small amounts of scattered or thin smear layers and obtained the lowest score at each section of root canal wall. At sectionⅠandⅡ, there was no significant difference in smear layer score between group D and group C. The smear layer scores were both significantly lower in group D and group C than those of group A and group B (P<0.05). At sectionⅢ, the smear layer score was significantly lower in group D than that of group A, group B and group C, and which was significantly lower in group B and group C than that of group A (P<0.05). Conclusion When ultrasonic file was located coronal from the start of the curvature, K file, which was the same size as dimension of apical portion preparation to agitate and PUI can remove smear layer from curved canals efficiently.%目的:研究有效去除弯曲根管玷污层的冲洗方案。方法选取40颗近中根管弯曲的下颌第一磨牙,截冠。手用ProTaper根管锉预备近颊根管至F3后,依最终冲洗方法不同随机分为4组,A组为注

  17. Irrigation dynamics associated with positive pressure, apical negative pressure and passive ultrasonic irrigations: a computational fluid dynamics analysis.

    Science.gov (United States)

    Chen, José Enrique; Nurbakhsh, Babak; Layton, Gillian; Bussmann, Markus; Kishen, Anil

    2014-08-01

    Complexities in root canal anatomy and surface adherent biofilm structures remain as challenges in endodontic disinfection. The ability of an irrigant to penetrate into the apical region of a canal, along with its interaction with the root canal walls, will aid in endodontic disinfection. The aim of this study was to qualitatively examine the irrigation dynamics of syringe irrigation with different needle tip designs (open-ended and closed-ended), apical negative pressure irrigation with the EndoVac® system, and passive ultrasonic-assisted irrigation, using a computational fluid dynamics model. Syringe-based irrigation with a side-vented needle showed a higher wall shear stress than the open-ended but was localised to a small region of the canal wall. The apical negative pressure mode of irrigation generated the lowest wall shear stress, while the passive-ultrasonic irrigation group showed the highest wall shear stress along with the greatest magnitude of velocity.

  18. 3种根管消毒方法的效果对比%Comparison of the antimicrobial effects of Nd:YAG laser,Er:YAG laser and ultrasonic irrigation on infected root canals

    Institute of Scientific and Technical Information of China (English)

    黄仙波; 杨永进; 李广

    2015-01-01

    AIM:To compare the in vitro and in vivo root canal disinfection effects of Nd:YAG laser (NdL),Er:YAG laser(ErL),ultrasonic irrigation(US)and normal saline(NS)irrigation.METHODS:For the in vitro study,85 single -rooted teeth were selected and contaminated with Enterococcus faecalis.The specimens were randomly divided into 4 groups(n=20)and were then treated with NdL,ErL,US and NS irrigation respectively.Bac-teria were collected from the root canals and cultured.For the in vivo study,280 teeth with chronic apical periodontitis were selected and randomly divided into 4 groups(n=70).After root canal preparation,the root canals were treated with NdL,ErL,US and NS respectively,and were then filled.The patients were followed-up at 1 d,3 d,5 d and 1 year after treatment.RESULTS:In vitro study showed that the root canal disinfection effects of NdL and ErL were sig-nificantly stronger than that of US and NS (P0. 05 ).In vivo study showed that NdL,ErL and US decreased the incidence of EIAE after root canal filling at 1 d (P0.05).CONCLUSION:Nd:YAG laser and Er:YAG laser is effective in root canal disinfection.%目的:对比Nd:YAG激光、Er:YAG激光、超声冲洗等根管消毒方法对感染根管的消毒效果。方法:选择85个新鲜拔除的人单根管离体牙建立粪肠球菌感染模型后,随机分为4组(n=20),分别用Nd:YAG激光、Er:YAG激光、超声冲洗、生理盐水冲洗,通过细菌培养法对比各组的杀菌率。临床选取280例慢性根尖周炎病例,随机分为4组(n=70)。根管预备后分别用和体外实验相同的4种方法处理根管后进行根管充填,对术后1、3、5 d及1年后的疗效进行评价。结果:体外实验显示,Nd:YAG激光、Er:YAG激光的杀菌效果均显著优于超声冲洗组和阴性对照组(P<0.05),而超声冲洗组与阴性对照组无明显差异(P>0.05)。临床试验表明,Nd:YAG激光、Er:YAG激光、超声冲洗组均

  19. Modeling Root Length Density of Field Grown Potatoes under Different Irrigation Strategies and Soil Textures Using Artificial Neural Networks

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Sepaskhah, A R; Andersen, Mathias Neumann

    2014-01-01

    Root length density (RLD) is a highly wanted parameter for use in crop growth modeling but difficult to measure under field conditions. Therefore, artificial neural networks (ANNs) were implemented to predict the RLD of field grown potatoes that were subject to three irrigation strategies and three......) of the eight input variables: soil layer intervals (D), percentages of sand (Sa), silt (Si), and clay (Cl), bulk density of soil layers (Bd), weighted soil moisture deficit during the irrigation strategies period (SMD), geometric mean particle size diameter (dg), and geometric standard deviation (σg...... under a range of soil physical conditions with a high degree of accuracy and may be used in crop growth modeling....

  20. INSTRUMENTATION OF CURVED CANALS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Senthil Kumar

    2013-02-01

    Full Text Available INTRODUCTION: Nature seldom draws a straight line. Nowhere is thi s more apparent than in the anatomy of teeth roots and root canal systems o f human teeth. Even teeth with straight roots can harbor severely curved canals. Canal shapi ng is a critical aspect of endodontic treatment because it influences the outcome of the subsequent phases of canal irrigation and filling and the success of the treatment itself. In fact, curved canals are the most common endodontic complexity 1 . The need for some manner of root canal preparation pri or to root canal filling has long been recognized as an essential step in endodontic t reatment. Concepts concerning the role and purpose of this canal preparation, however, have differ ed remarkably at different times in the development of endodontics and in the hands of diffe rent practitioners 2

  1. IMPACT OF CANAL DESIGN LIMITATIONS ON WATER DELIVERY OPERATIONS AND AUTOMATION

    Science.gov (United States)

    Irrigation canals are often designed for water transmission. The design engineer simply ensures that the canal will pass the maximum design discharge. However, irrigation canals frequently operated far below design capacity. Because demands and the distribution of flow at bifurcations (branch points...

  2. Seismic Risk Management of Irrigation System in an Earthquake

    Science.gov (United States)

    Kobayashi, Akira; Hayashi, Takuma; Yamamoto, Kiyohito; Kiyama, Shoichi

    A risk analysis method of an irrigation system in an earthquake is proposed. The irrigation system consists of irrigation tanks and canals. The damage probability of the irrigation tanks and canals was obtained from both numerical simulation and actual disaster data from the Mid Niigata prefecture earthquake. The losses due to reduced crop yield, restoration and secondary disaster were considered in the risk assessment. The probability of annual peak ground acceleration was introduced from the earthquake records in Niigata prefecture. To reduce the damage probability, an enhanced foundation of canals on flat land and widening of the embankment were applied. It was found that the countermeasures for the irrigation tanks were more effective than those for the canals. In the case of a large secondary disaster of the irrigation system on flat land, the countermeasures for the irrigation system were very effective.

  3. [Endodontic microbiology: antimicrobial canal medications].

    Science.gov (United States)

    Seltzer, S; Farber, P A

    1989-06-01

    Medicaments used for reducing or eliminating microorganisms from infected root canals include: irrigating solutions, such as sodium hypochlorite, urea peroxide and hydrogen peroxide, chloramine, iodine-potassium-iodide solution, and chlorhexidine solution. In addition, various intracanal drugs, such as calcium hydroxide and antibiotics, are in use. The characteristics of these drugs are discussed.

  4. HBPU填缝密封胶在贵港达开灌区中干渠改造工程中的应用%Application of HBPU sealant in renovation of middle trunk canal of Dakai irrigation zone

    Institute of Scientific and Technical Information of China (English)

    梁钧威; 陈建国

    2015-01-01

    结合贵港达开灌区干渠伸缩缝改造工程,总结HBPU填缝胶在渠道伸缩缝的止水应用经验,介绍HBPU的物理化学性能,简述该干渠伸缩缝应用HBPU填缝胶止水的技术方案、施工工艺及效果等。质检结果:采用HBPU填缝密封胶渠段的稳渗强度为2.604 L/m2⋅h,防渗和止水效果好。%HBPU sealant had been used in renovation of trunk canal expansion joints for Dakai irrigation zone in Guigang City. The authors summarize the application experience,make an introduction on the physic-chemical properties of HBPU sealant,present the technical program,construction technology and application effects. The re⁃sults of quality examination demonstrate good anti-seepage and water stop effects,with a steady seepage strength of 2.604L/m2⋅h.

  5. S形根管经往复运动单支锉系统预备后的形态对冲洗效果的影响%Effect of the morphology of S-shaped root canals with reciprocating single file system on root canal irrigation

    Institute of Scientific and Technical Information of China (English)

    苏征; 侯本祥; 方厂云; 侯晓玫

    2014-01-01

    Objective: To evaluate effect of the morphology of simulated S-shaped root canals with Reciproc or Mtwo instruments on root canal irrigation. Methods: A total of 40 simulated S-shaped resin blocks were randomly divided into 2 groups (n=20), which was prepared by Reciproc or Mtwo. Blue ink was injected with constant speed and volume into the canals using 30G lateral opening syringe. hTe distance from needle tip to apex and vapor lock length were measured. A type of 25# 0.04 gutta-percha point was used to stir and remove the vapor lock. hTe time for removal of the vapor lock was recorded. Another syringe was used to inject saline into the canals and to measure the length of stagnant water. Results: hTe distance from needle tip to apex in the Reciproc group was signiifcantly longer than that in the Mtwo group [(4.276 ± 0.221) mm vs (3.459 ± 0.205) mm,P<0.05]. The vapor lock length in the Reciproc group was signiifcantly longer than that in the Mtwo group [(4.472 ± 0.230) mm vs (3.668±0.217) mm,P<0.05]. hTe time to remove vapor lock was signiifcantly shorter in the Reciproc group than that in the Mtwo group [(10.13 ± 1.79) s vs (15.29 ± 2.15) s,P<0.05]. The length of stagnant water was also shorter in the Reciproc group than that in the Mtwo group[(1.351 ± 0.142) mm vs (2.245 ± 0.206) mm,P<0.05]. Conclusion: hTe morphology of S-shaped root canal affects the root canal irrigation. hTe effect of root canal irrigated by Reciproc is better than that by Mtwo.%目的:比较S形根管经Reciproc和Mtwo两种机用镍钛器械预备后的形态对根管冲洗效果的影响。方法:40个S形树脂模拟根管,随机分为2组(n=20),分别使用Reciproc和Mtwo完成根管预备;使用30G侧方开口冲洗针头结合注射器,定速定量将蓝黑色墨汁注入预备后根管内,记录针头与根尖孔距离和气锁长度;使用25#/0.04锥度牙胶尖扰动方法排除气锁,记录气锁去除时间;抽取生理盐水对完全充盈后根管内

  6. [Irrigants and intracanal medicaments in endodontics].

    Science.gov (United States)

    Zehnder, Matthias; Lehnert, Birgit; Schönenberger, Kathrin; Waltimo, Tuomas

    2003-01-01

    Modern, biologic root canal therapy should be performed with suitable irrigating solutions and intracanal medicaments. The goal of endodontic treatment is to free the treated tooth from infection and prevent reinfection as thoroughly as possible by means which do not put the organism at risk. In this review of the literature, an evidence-based concept for irrigation and medication of root canal systems is presented. Irrigants and medicaments are discussed with respect to their antimicrobial, tissue-dissolving and endotoxin-decontaminating capacity in relation to their systemic toxicity. Recent findings pertaining to interactions of root canal medicaments and irrigating solutions and their impact on a sound irrigating and medicating concept are discussed.

  7. An experimental study on the grape orchard: Effects comparison of two irrigation systems

    Directory of Open Access Journals (Sweden)

    Kadbhane Sharad J.

    2017-03-01

    Full Text Available Table grape (Vitis vinifera cultivars is a major cash crop in the Nashik district of India, which requires irrigation water throughout the year as per demand instantly. Canal irrigation is the adopted irrigation systems in the study area, but canal irrigation has got several serious disadvantages, such as mismatching rotation schedules and crop water demands, water allotment system and restrictions on the use of efficient irrigation methods. The storing the canal water in the farm pond instead of directly applying to the field using the free flooding method is alternate solution to overcome the disadvantages of the canal irrigation system. Once the canal water storing in the pond, it increases the possibilities to use the advance irrigation system like drip, subsurface, sprinkler etc. to enhance water use efficiency. The comparative study between the canal water directly applying for the field and canal water storing in the farm pond then use for irrigation, executed through the field experiments carried out on the grape orchard during a period April 2013 to March 2016. Results have been evaluated based on grape yield, water-productivity, berry size, and biomass. Water productivity (kg·m-3 with respect to water delivery to crop through the pond irrigation method was found 37% higher than the canal irrigation method during the study period. Based on the results, this study recommended the use of the farm pond to store the canal water and use it as per crop demand using advance irrigation systems.

  8. Multistate nested canalizing functions

    CERN Document Server

    Adeyeye, J O; Laubenbacher, R; Li, Y

    2013-01-01

    The concept of a nested canalizing Boolean function has been studied over the course of the last decade in the context of understanding the regulatory logic of molecular interaction networks, such as gene regulatory networks. Such functions appear preferentially in published models of such networks. Recently, this concept has been generalized to include multi-state functions, and a recursive formula has been derived for their number, as a function of the number of variables. This paper carries out a detailed analysis of the class of nested canalizing functions over an arbitrary finite field. Furthermore, the paper generalizes the concept further, and derives a closed formula for the number of such generalized functions. The paper also derives a closed formula for the number of equivalence classes under permutation of variables. This is motivated by the fact that two nested canalizing functions that differ by a permutation of the variables share many important properties with each other. The paper contributes ...

  9. Src64 controls a novel actin network required for proper ring canal formation in the Drosophila male germline.

    Science.gov (United States)

    Eikenes, Åsmund Husabø; Malerød, Lene; Lie-Jensen, Anette; Sem Wegner, Catherine; Brech, Andreas; Liestøl, Knut; Stenmark, Harald; Haglund, Kaisa

    2015-12-01

    In many organisms, germ cells develop as cysts in which cells are interconnected via ring canals (RCs) as a result of incomplete cytokinesis. However, the molecular mechanisms of incomplete cytokinesis remain poorly understood. Here, we address the role of tyrosine phosphorylation of RCs in the Drosophila male germline. We uncover a hierarchy of tyrosine phosphorylation within germline cysts that positively correlates with RC age. The kinase Src64 is responsible for mediating RC tyrosine phosphorylation, and loss of Src64 causes a reduction in RC diameter within germline cysts. Mechanistically, we show that Src64 controls an actin network around the RCs that depends on Abl and the Rac/SCAR/Arp2/3 pathway. The actin network around RCs is required for correct RC diameter in cysts of developing germ cells. We also identify that Src64 is required for proper germ cell differentiation in the Drosophila male germline independent of its role in RC regulation. In summary, we report that Src64 controls actin dynamics to mediate proper RC formation during incomplete cytokinesis during germline cyst development in vivo.

  10. Evaluation of Control and Adjustment Structures of the Shibab Main Canal Using HEC-RAS

    Directory of Open Access Journals (Sweden)

    maryam mohammadi

    2017-02-01

    Full Text Available Introduction: Poor performance of irrigation and drainage networks causes to reduce the transfer and distribution throughputs and in result comes useless water and makes too much consumption in forming. A significant portion of water losses in irrigation and drainage networksis related to transmission and distribution. Therefor more consideration in thrirrigation network management, improve irrigation efficiency and also the exploitation of water resources, especially in the agricultural sector is necessary. Controlling and adjusting structures of water level in the direction of drainage and irrigation canals can influence on increasing of throughput and decrease the use of water. So, right choosing and recognition of the deficiencies of these structures helps carry up the throughput of the networks and prevents to waste water. It is hard to solve equations of water flow in canals and related institutions by using analytic methods. For this reason, this research was done with HEC-RAS hydraulical model in the main channelof irrigation and drainage network of Sistan plain. Materials and Methods: Sistan plain is located in southeastern of Iran with good potential for agricultural production because of the alluvial sediments from Hirmand River. 23820 ha of the Sistan plain is covered by 5 blocksof the Shibab irrigation and drainage network. While Sistan’sShibab irrigation network efficiency is low, HEC-RAS Hydraulics model in unsteady condition was performed to control and adjust this network’s main canal in approximately 19 Km length. In this research, the evaluation model in the canal was performed for more suitable intakingwater in the quadruple order 2 canals . So, the existing structure’s operation was analyzed on controlling structures in management and lack of management situations.This research was assessed during a 15-day impounding period using hydraulic model of HEC-RAS with the aim of performance and operation evaluation of

  11. 75 FR 53332 - San Carlos Irrigation Project, Arizona

    Science.gov (United States)

    2010-08-31

    ... of San Carlos Irrigation Project (SCIP) water delivery facilities near the communities of Casa Grande... major canals, such as the Florence-Casa Grande, Casa Grande, and North Side canals, and construction of new check structures and cross-drainage features. The existing Florence Canal and Florence-Casa...

  12. Review of ultrasonic irrigation in endodontics: increasing action of irrigating solutions

    Science.gov (United States)

    Mozo, Sandra; Llena, Carmen

    2012-01-01

    Introduction: Effective irrigant delivery and agitation are prerequisites for successful endodontic treatment. Ultrasonic irrigation can be performed with or without simultaneous ultrasonic instrumentation. Existing literature reveals that ultrasonic irrigation may have a very positive effect on chemical, biological and physical debridement of the root canal system as investigated in many in vitro studies. Objective: The purpose of this review article was to summarize and discuss the available information concerning ultrasonic irrigation in endodontics. Methods: This article presents an overview of ultrasonic irrigation methods and their debridement efficacy. In this paper the relevant literature on passive ultrasonic irrigation is reviewed. Information from original scientific papers or reviews listed in MEDLINE and Cochrane were included in the review. Results: The use of ultrasound in the irrigation procedure results in improved canal cleanliness, better irrigant transfer to the canal system, soft tissue debridement, and removal of smear layer and bacteria. There are many in vitro studies, but there is a need to standardize protocols, and correlate the clinical efficacy of ultrasonic devices with improved treatment outcomes. Understanding the basis of ultrasonic irrigation is fundamental for clinicians and researchers to improve the design and use of ultrasonic irrigation. Key words:Ultrasonic irrigation, ultrasound, smear layer, endodontics. PMID:22143738

  13. A comparative study of wireless and wired sensors networks for deficit irrigation management

    Science.gov (United States)

    Torres Sánchez, Roque; Domingo Miguel, Rafael; Valles, Fulgencio Soto; Perez-Pastor, Alejandro; Lopez Riquelme, Juan Antonio; Blanco Montoya, Victor

    2016-04-01

    In recent years, the including of sensors in the context of agricultural water management, has received an increasing interest for the establishment of irrigation strategies, such as regulated deficit irrigation (RDI). These strategies allow a significant improvement of crop water productivity (marketable yield / water applied), especially in woody orchards. The application of these deficit irrigation strategies, requires the monitoring of variables related to the orchard, with the purpose of achieving an efficiently irrigation management, since it is necessary to know the soil and plant water status to achieve the level of water deficit desired in each phenological stage. These parameters involve the measurements of soil and plant parameters, by using appropriate instrumentation devices. Traditional centralized instrumentation systems include soil matric potential, water content and LVDT sensors which information is stored by dataloggers with a wired connection to the sensors. Nowadays, these wired systems are being replaced by wireless ones due, mainly, to cost savings in wiring and labor. These technologies (WSNs) allow monitoring a wide variety of parameters in orchards with high density of sensors using discrete and autonomous nodes in the trees or soil places where it is necessary, without using wires. In this paper we present a trial in a cherry crop orchard, with different irrigation strategies where both a wireless and a wired system have been deployed with the aim of obtaining the best criteria on how to select the most suitable technology in future agronomic monitoring systems. The first stage of this study includes the deploying of nodes, wires, dataloggers and the installation of the sensors (same for both, wired and wireless systems). This stage was done during the first 15 weeks of the trial. Specifically, 40 MPS6 soil matric potential, 20 Enviroscan water content and 40 (LVDT and band) dendometers were installed in order to cover the experimental

  14. Spectrophotometric determination of irrigant extrusion using passive ultrasonic irrigation, EndoActivator, or syringe irrigation.

    Science.gov (United States)

    Rodríguez-Figueroa, Carolina; McClanahan, Scott B; Bowles, Walter R

    2014-10-01

    Sodium hypochlorite (NaOCl) irrigation is critical to endodontic success, and several new methods have been developed to improve irrigation efficacy (eg, passive ultrasonic irrigation [PUI] and EndoActivator [EA]). Using a novel spectrophotometric method, this study evaluated NaOCl irrigant extrusion during canal irrigation. One hundred fourteen single-rooted extracted teeth were decoronated to leave 15 mm of the root length for each tooth. Cleaning and shaping of the teeth were completed using standardized hand and rotary instrumentation to an apical file size #40/0.04 taper. Roots were sealed (not apex), and 54 straight roots (n = 18/group) and 60 curved roots (>20° curvature, n = 20/group) were included. Teeth were irrigated with 5.25% NaOCl by 1 of 3 methods: passive irrigation with needle, PUI, or EA irrigation. Extrusion of NaOCl was evaluated using a pH indicator and a spectrophotometer. Standard curves were prepared with known amounts of irrigant to quantify amounts in unknown samples. Irrigant extrusion was minimal with all methods, with most teeth showing no NaOCl extrusion in straight or curved roots. Minor NaOCl extrusion (1-3 μL) in straight roots or curved roots occurred in 10%-11% of teeth in all 3 irrigant methods. Two teeth in both the syringe irrigation and the EA group extruded 3-10 μL of NaOCl. The spectrophotometric method used in this study proved to be very sensitive while providing quantification of the irrigant levels extruded. Using the PUI or EA tip to within 1 mm of the working length appears to be fairly safe, but apical anatomy can vary in teeth to allow extrusion of irrigant. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Agro-Economic Design of Cropping Pattern in Hendijan Irrigation and Drainage Network with Emphasis on Water Resources

    Directory of Open Access Journals (Sweden)

    A Madeh Khaksar

    2012-02-01

    Full Text Available Recently, design of cropping pattern based on water resources is getting a high priority. This scheme is complicated, and affected by multiple factors. For investigation, designer must gather a huge data, and classify them. The method of processing and analyzing of the information is important. The method of linear programming based on Lingo software for Hendijan irrigation and drainage network was used. On the basis of water resources situation, physical limitations, ecology and economical parameters, hydromodule was determined. The model with initial data for crop pattern is performed by software to produce projected hydromodule. In this survey, sensitivity analysis on water cost was conducted. Result showed that by increasing water cost and rotation intensity, revenue for each consumption water unit was decreased. The maximum benefit for all available conditions of water on the case of non intensity would be 140 percent, for 3% of crops. The maximum benefit was 133346682 Rls per hectare based on water availability for 2006.

  16. Debris and irrigant extrusion potential of 2 rotary systems and irrigation needles.

    Science.gov (United States)

    Altundasar, Emre; Nagas, Emre; Uyanik, Ozgur; Serper, Ahmet

    2011-10-01

    The purpose of this study was to compare the amount of apically extruded irrigant using 2 Ni-Ti rotary systems. Forty mandibular premolars with single canals were randomly assigned into 4 groups. Flower arrangement foam cubes were weighed with a precision balance before being attached to the apical portions of all teeth. In group 1, preparation was completed with ProTaper files. In group 2 canals were prepared with RaCe files. In groups 1 and 2, the irrigant was delivered with a 30-gauge conventional dental needle. In groups 3 and 4, teeth were prepared as in groups 1 and 2 with the exception that the irrigant was delivered with a side-vented irrigation needle. The weight of the extruded material (irrigant and debris) for each group was calculated by comparing the pre- and postinstrumentation weights of the foams used for periapical modeling. Obtained data were analyzed by Kruskal-Wallis and Mann-Whitney U tests, with P equals .05 as the level for statistical significance. ProTaper files used with regular needle irrigation had the highest fluid extrusion. The lowest irrigant extrusion was observed with the RaCe system combined with a side-vented irrigation needle. Within the limitations of this study, it can be concluded that irrigation needle and rotary instruments have an effect on the amount of extruded root canal irrigant.

  17. Review of ultrasonic irrigation in endodontics: increasing action of irrigating solutions.

    Science.gov (United States)

    Mozo, Sandra; Llena, Carmen; Forner, Leopoldo

    2012-05-01

    Effective irrigant delivery and agitation are prerequisites for successful endodontic treatment. Ultrasonic irrigation can be performed with or without simultaneous ultrasonic instrumentation. Existing literature reveals that ultrasonic irrigation may have a very positive effect on chemical, biological and physical debridement of the root canal system as investigated in many in vitro studies. The purpose of this review article was to summarize and discuss the available information concerning ultrasonic irrigation in endodontics. This article presents an overview of ultrasonic irrigation methods and their debridement efficacy. In this paper the relevant literature on passive ultrasonic irrigation is reviewed. Information from original scientific papers or reviews listed in MEDLINE and Cochrane were included in the review. The use of ultrasound in the irrigation procedure results in improved canal cleanliness, better irrigant transfer to the canal system, soft tissue debridement, and removal of smear layers and bacteria. There are many in vitro studies, but there is a need to standardize protocols, and correlate the clinical efficacy of ultrasonic devices with improved treatment outcomes. Understanding the basis of ultrasonic irrigation is fundamental for clinicians and researchers to improve the design and use of ultrasonic irrigation.

  18. Irrigants in non-surgical endodontic treatment.

    Science.gov (United States)

    Regan, John D; Fleury, Alex A P

    2006-01-01

    This paper highlights that one of the main goals of root canal treatment is the elimination of microorganisms from the contaminated root canal system. Instrumentation alone will not allow for adequate debridement and disinfection of the complex and diverse root canal system. Chemomechanical debridement is required. The importance of the use of irrigants during non-surgical root canal treatment has frequently been neglected both during instruction of dental students and later in the clinical practice of endodontics. The article highlights 'shape, clean and fill' vs. 'clean, shape and fill' to enable chemomechanical debridement. Our protocol advises mechanical debridement and copious irrigation for a minimum of twenty minutes with 2.5% to 6% solutions of sodium hypochlorite, followed by a rinse with a 17% solution of ethylenediaminetetraacetic acid and a final rinse with 2% chlorhexidine. The canals are dried with high volume aspirators and sterile paper points.

  19. canal24

    Data.gov (United States)

    California Department of Resources — Canal system center lines in the Central Valley of California and adjacent areas captured from 1:24,000-scale USGS topographic maps. Updates and modifications made...

  20. Scanning electron microscopic evaluation of root canal surfaces ...

    African Journals Online (AJOL)

    2014-07-15

    Jul 15, 2014 ... junction. Canal length was determined by placing a size 10 K-file. The working .... at the root tip of each tooth to prevent the flow of irrigants through ..... Sotokawa T. An analysis of clinical breakage of root canal instruments.

  1. Prevalence of persistent pain 3 to 5 years post primary root canal therapy and its impact on oral health-related quality of life: PEARL Network findings.

    Science.gov (United States)

    Vena, Donald A; Collie, Damon; Wu, Hongyu; Gibbs, Jennifer L; Broder, Hillary L; Curro, Frederick A; Thompson, Van P; Craig, Ronald G

    2014-12-01

    The frequency of persistent pain 3-5 years after primary root canal therapy and its impact on the patient's perceived oral health-related quality of life was determined in a practice-based research network. All patients presenting to participating network practices who received primary root canal therapy and restoration for a permanent tooth 3-5 years previously were invited to enroll. Persistent pain was defined as pain occurring spontaneously or elicited by percussion, palpation, or biting. The patient also completed an oral health-related quality of life questionnaire (Oral Health Impact Profile-14). Sixty-four network practices enrolled 1323 patients; 13 were ineligible, 12 did not receive a final restoration, and 41 were extracted, leaving 1257 for analysis. The average time to follow-up was 3.9 ± 0.6 years. Five percent (63/1257) of the patients reported persistent pain, whereas 24 of 63 (38%) exhibited periapical pathosis and/or root fracture (odontogenic pain). No obvious odontogenic cause for persistent pain was found for 39 of 63 (62%). Teeth treated by specialists had a greater frequency of persistent pain than teeth treated by generalists (9.3% vs 3.0%, respectively; P tooth type, type of dentist, and arch were not found to be associated with nonodontogenic persistent pain; however, ethnicity and a preoperative diagnosis of pulpitis without periapical pathosis were. Patients reporting pain with percussion tended to experience pain with other stimuli that negatively impacted quality of life including oral function and psychological discomfort and disability. These results suggest that a small percentage (3.1%) of patients experience persistent pain not attributable to odontogenic causes 3-5 years after primary root canal therapy that may adversely impact their quality of life. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. Time Series Forecasting of Daily Reference Evapotranspiration by Neural Network Ensemble Learning for Irrigation System

    Science.gov (United States)

    Manikumari, N.; Murugappan, A.; Vinodhini, G.

    2017-07-01

    Time series forecasting has gained remarkable interest of researchers in the last few decades. Neural networks based time series forecasting have been employed in various application areas. Reference Evapotranspiration (ETO) is one of the most important components of the hydrologic cycle and its precise assessment is vital in water balance and crop yield estimation, water resources system design and management. This work aimed at achieving accurate time series forecast of ETO using a combination of neural network approaches. This work was carried out using data collected in the command area of VEERANAM Tank during the period 2004 - 2014 in India. In this work, the Neural Network (NN) models were combined by ensemble learning in order to improve the accuracy for forecasting Daily ETO (for the year 2015). Bagged Neural Network (Bagged-NN) and Boosted Neural Network (Boosted-NN) ensemble learning were employed. It has been proved that Bagged-NN and Boosted-NN ensemble models are better than individual NN models in terms of accuracy. Among the ensemble models, Boosted-NN reduces the forecasting errors compared to Bagged-NN and individual NNs. Regression co-efficient, Mean Absolute Deviation, Mean Absolute Percentage error and Root Mean Square Error also ascertain that Boosted-NN lead to improved ETO forecasting performance.

  3. New software to compute branched canal networks. KANET program system for the flow engineering and mechanical structure computation of canal networks; Neue Software zur Berechnung verzweigter Kanalnetze. KANET-Programmsystem zur stroemungstechnischen und strukturmechanischen Berechnung von Kanalnetzen

    Energy Technology Data Exchange (ETDEWEB)

    Kammel, C. [RWTH Aachen (Germany). Lehrstuhl fuer Stahlbau; Gruss, J. [Stadtwerke AG Duisburg (Germany); Gruss, W. [Deutsche Babcock AG, Kempen (Germany)

    1998-03-01

    The sector overlapping, modular designed KANET computation program is presented, a high-grade technical aid for the design and subsequent computation of canal systems with regard to the flow mechanism and mechanical structure. (orig.) [Deutsch] Vorgestellt wird das im Berechnungsumfang bereichsuebergreifende modular aufgebaute KANET-Programmsystem, ein technisch hochwertiges Arbeitsmittel fuer die Planung und Nachrechnung von Kanalsystemen hinsichtlich der Stroemungs- und Strukturmechanik. (orig.)

  4. Ultrastructural investigation of root canal dentine surface after application of active ultrasonic method

    Directory of Open Access Journals (Sweden)

    Mitić Aleksandar

    2008-01-01

    Full Text Available INTRODUCTION The basic work principle of all ultrasonic techniques is the piezoelectric effect of producing high frequency ultrasounds of small length, which are transmitted over the endodontic extensions or canal instruments into the root canal. When in contact with the tissue, ultrasonic vibrations are converted into mechanical oscillations. Ultrasonic waves and the obtained oscillations along with the synergic effect of irrigation bring about the elimination of smear layer from the root canal walls. OBJECTIVE The aim of the study was to ultrastucturally examine the effect of smear layer removal from the walls of canals by the application of the active ultrasonic method without irrigation, that is by the application of ultrasound and irrigation using distilled water and 2.5% NaOCl. METHOD The investigation comprised 35 single-canal, extracted human teeth. After removal of the root canal content, experimental samples were divided into three groups. According to the procedure required, the first group was treated by ultrasound without irrigation; the second one by ultrasound with irrigation using distilled water; and the third group was treated by ultrasound and irrigation using 2.5% NaOCl solution. The control samples were treated by machine rotating instruments (Pro-File and were rinsed by distilled water. RESULTS The obtained results showed that the ultrasonic treatment of the root canal without irrigation did not remove the smear layer. The dentine canals are masked, and big dentine particles are scattered on the intertubular dentine. The ultrasonic treatment by using irrigation with distilled water provides cleaner dentine walls and open dentine tubules but with smaller particles on the intertubular dentine. The ultrasound treatment by using irrigation with 2.5% NaOCl solution provides a clean intertubular dentine surface without a smear layer and clearly open dentine tubules. CONCLUSION Instrumentation of the root canal by application of

  5. DE CANALES

    Directory of Open Access Journals (Sweden)

    Roberto Carlos Guevara C.

    2013-01-01

    Full Text Available La amplia utilización de redes WiFi en los diversos escenarios sociales está generando una especie de saturación de canales, que a su vez ocasiona interferencia entre estas redes. Esta situación genera solapamiento de canales, lo que hace que las tasas de trasferencia se reduzcan. En este artículo se detalla esta situación, y se estructura y aplica un experimento para encontrarle solución al problema. También se presentan los resultados tabulados y graficados utilizando la herramienta de software libre inSSider.

  6. The Impact of a Local Development Project on Social Capital: Evidence from the Bohol Irrigation Scheme in the Philippines

    National Research Council Canada - National Science Library

    Hogeun Park; Takuji W Tsusaka; Valerien O Pede; Kyung-Min Kim

    2017-01-01

    ...’ social capital in Bohol, The Philippines. From this perspective, we hypothesized that social behaviors of local farmers are influenced by the availability of canal irrigation due to the collective water management required in irrigated societies...

  7. Understanding water delivery performance in a large-scale irrigation system in Peru

    NARCIS (Netherlands)

    Vos, J.M.C.

    2005-01-01

    During a two-year field study the performance of the water delivery was evaluated in a large-scale irrigation system on the north coast of Peru. Flow measurements were carried out along the main canals, along two secondary canals, and in two tertiary blocks in the Chancay-Lambayeque irrigation

  8. 耳内镜下外耳道冲洗联合曲安奈德益康唑乳膏治疗霉菌性外耳道炎的疗效分析%Analysis of Curative Effect of Combined Treatment of Mycotic Otitis Externa Triamcinolone Acetonide and Econazole Nitrate Cream's Ear Canal Irrigation Under Endoscope

    Institute of Scientific and Technical Information of China (English)

    郭瑞永; 熊明炤; 王璟; 高原

    2016-01-01

    目的:探讨耳内镜下外耳道冲洗联合曲安奈德益康唑乳膏治疗霉菌性外耳道炎的疗效。方法选择我院2013年1月~2015年12月收治的104例霉菌性外耳道炎患者作为研究对象,随机分为对照组和观察组,各52例。对照组患者常规采用耳内镜下外耳道冲洗治疗,观察组增加曲安奈德益康唑乳膏进行治疗,观察两组临床疗效及复发率情况。结果观察组总有效率、复发率均优于对照组(P<0.05)。结论霉菌性外耳道炎应用耳内镜下外耳道冲洗联合曲安奈德益康唑乳膏治疗疗效可靠,复发率较低。%Objective To investigate the curative effect of endoscopic ear canal irrigation combined with Triamcinolone acetonide and econazole nitrate cream cloth medicine in the treatment of mycotic otitis externa. MethodsSelect our hospital from January 2013 to December 2015, 104 cases of fungal otitis external patients as the research object, randomly divided into the control group and the observation group, each of 52 cases. Patients in the control group using conventional endoscopic ear canal irrigation treatment, the observation group added triamcinolone acetonide and econazole nitrate cream cloth treatment, observe two groups of clinical curative effect and recurrence rate.Results The total effective rate and recurrence rate of the observation group were better than those of the control group (P<0.05).Conclusion Effect of mycotic otitis externa by endoscopic ear canal irrigation combined with triamcinolone acetonide and econazole nitrate cream cloth treatment is reliable, low recurrence rate.

  9. Uncontrolled removal of dentin during in vitro ultrasonic irrigant activation

    NARCIS (Netherlands)

    Boutsioukis, C.; Tzimpoulas, N.

    2016-01-01

    Introduction: The aim of this study was to evaluate uncontrolled removal of dentin during in vitro ultrasonic irrigant activation in prepared root canals using 2 different files. Methods: Fifty-four human single-rooted teeth with straight root canals were prepared to size 35/.06 taper. The specimens

  10. Uncontrolled removal of dentin during in vitro ultrasonic irrigant activation

    NARCIS (Netherlands)

    Boutsioukis, C.; Tzimpoulas, N.

    2016-01-01

    Introduction: The aim of this study was to evaluate uncontrolled removal of dentin during in vitro ultrasonic irrigant activation in prepared root canals using 2 different files. Methods: Fifty-four human single-rooted teeth with straight root canals were prepared to size 35/.06 taper. The specimens

  11. Analysis of Irrigation Water Quality at Kadawa Irrigation Project for Improved Productivity

    Directory of Open Access Journals (Sweden)

    AR Sanda

    2014-09-01

    Full Text Available In the face of water scarcity and the several negative consequences, such as water wastage, flooding, water logging, soil losses and production losses, conserving the finite amount of fresh water is a must. The quality of irrigation water must therefore be ascertained. The chemical quality of three sources of irrigation water from canal and drainage water, namely drainage water, fresh irrigation water from canal, and drainage/irrigation water mixture, were analyzed from Kadawa irrigation Project for year 2013 and 2014 cropping seasons, with the view to evaluating the potential risks associated with their use in irrigation and hence their suitability or otherwise for irrigation purposes. The analysis revealed that the use of drainage water alone for irrigation may result in problems associated with salinity, while a blend of drainage/irrigation water in the ratio of 1:1 is a viable means of water conservation and a good means of crop production. DOI: http://dx.doi.org/10.3126/ije.v3i3.11082 International Journal of Environment Vol.3(3 2014: 235-240

  12. Comparison of the Cleaning Efficacy of Different Final Irrigation Techniques

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Lak, Bram; Eijsvogels, Leonardus M.; Wesselink, Paul; van der Sluis, Lucas W. M.

    Introduction: The aim of this study was to evaluate the removal of dentin debris from artificially made grooves in standardized root canals by 6 different final irrigation techniques. Methods: Conventional syringe irrigation, manual dynamic activation (MDA) with tapered or nontapered gutta-percha

  13. Comparison of the Cleaning Efficacy of Different Final Irrigation Techniques

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Lak, Bram; Eijsvogels, Leonardus M.; Wesselink, Paul; van der Sluis, Lucas W. M.

    2012-01-01

    Introduction: The aim of this study was to evaluate the removal of dentin debris from artificially made grooves in standardized root canals by 6 different final irrigation techniques. Methods: Conventional syringe irrigation, manual dynamic activation (MDA) with tapered or nontapered gutta-percha (G

  14. Depolarization canals and interstellar turbulence

    CERN Document Server

    Fletcher, A; Fletcher, Andrew; Shukurov, Anvar

    2006-01-01

    Recent radio polarization observations have revealed a plethora of unexpected features in the polarized Galactic radio background that arise from propagation effects in the random (turbulent) interstellar medium. The canals are especially striking among them, a random network of very dark, narrow regions clearly visible in many directions against a bright polarized Galactic synchrotron background. There are no obvious physical structures in the ISM that may have caused the canals, and so they have been called Faraday ghosts. They evidently carry information about interstellar turbulence but only now is it becoming clear how this information can be extracted. Two theories for the origin of the canals have been proposed; both attribute the canals to Faraday rotation, but one invokes strong gradients in Faraday rotation in the sky plane (specifically, in a foreground Faraday screen) and the other only relies on line-of-sight effects (differential Faraday rotation). In this review we discuss the physical nature o...

  15. Evaluation of Artificial Neural Networks for Electrical Conductivity and Flow Rate-based Prediction of the Nitrate Nitrogen Concentration in the U-Tapao Canal, Hatyai, Thailand

    Directory of Open Access Journals (Sweden)

    Suvalee Chuvanich

    2017-07-01

    Full Text Available The aim of this study was to identify suitable artificial neural network (ANN models for the EC-based and flow rate-based prediction of the nitrate nitrogen (NO3-N concentration in the U-Tapao canal, located in the southern part of Thailand. Two types of four layer ANNs of the feed-forward back propagation (FFBP and cascade-forward back propagation (CFBP types were evaluated for this prediction. The selected inputs of the ANNs were EC and flow rate, which were collected daily from December 2014 to March 2015. Overall, the study found that the four layer FFBP with 2 neurons in the input layer, 20 neurons in the first hidden layer, 30 neurons in the second hidden layer, and a single neuron in the output layer with a tan-sigmoid transfer function was the optimal model. The FFBP model produced slightly more accurate results than the CFBP model. Linear regression analysis was used to predict NO3-N, which was compared with the results of the ANNs and the performance of the ANNs was better than that of the linear regression analysis. Therefore, the ANN approach proved to be suitable as an alternative to laboratory-based analysis for the prediction of NO3-N values in the U-Tapao canal.

  16. Integrated Watershed Pollution Control at Wujingang Canal, China

    Science.gov (United States)

    Zheng, Z.; Yang, X.; Luo, X.

    2012-04-01

    With a drainage area of 400 square kilometers, Wujingang Canal is located at the economically developed Yangtz Delta of eastern China. As a major tributary, the canal contributes a significant amount of pollutant load to the Lake Tai. Over the past many years, water quality of the canal and its tributaries could not meet the lowest Category V of Chinese surface water quality standard, indicating that its water is not suitable for the purposes of irrigation or scenic views. Major pollution sources in the watershed include industries, residential households, agriculture, fishery, and animal feedlot operations. A comprehensive plan with a budget of 2 billion RMB for the Wujingang watershed pollution control was developed in 2008 and has been implemented progressively ever since. Major components of the plan include: (1) advanced treatment of wastewater from industries and municipal sewage plants for further removal of nitrogen and phosphorous; (2) industrial wastewater reuse; (3) contiguous treatment of sewage from rural residential households with cost-effective technologies such as tower ecofilter system; (4) recycling of rural wastes to generate high-value added products using technologies such as multi-phase anaerobic co-digestion; and (5) making full use of the local landscape and configuring physical, chemical, and biological pollutant treatment structures to build the "clean river network" for treatment of mildly polluted agricultural discharge and surface runoff. Through the implementation of the above measures, water quality of the Wujingang Canal and its tributaries is expected to improve to meet Category IV of Chinese surface water quality standard by 2012, and Category III standard by 2020. Keywords watershed pollution control, non-point source pollution, rural sewage, rural waste, Lake Tai

  17. Comparison of the flow characteristics of irrigants with standard and Max-i-Probe needles.

    Science.gov (United States)

    Devi, Arpana Arthi; Abbott, Paul V

    2012-08-01

    The objectives of this study were to determine the direction and pattern of flow of irrigating solutions inside simulated root canals with different irrigation needles; and to determine whether different needle designs increase the likelihood of irrigating solution passing through the apical foramen. Two types of needles were compared: a standard needle with a bevel and an open end, and a needle with a side opening and closed rounded tip. Observations of irrigant flow within the canals indicated that the side-venting needle can be dangerous if the needle gauge is small and it reaches the full length of the canal, since this allowed irrigants to flow into the periapical area. With the standard needle, the fluid did not go beyond the tip of the needle when minimal irrigating pressure was employed. As the size of canal increased, the fluid did not extrude beyond the tip of both needles. However, if the needles bound in the canals, then the fluid was forced away from the needle tip, and the pressure applied to the syringe was directly proportional to the distance the fluid flowed away from the needle tip. Both side-venting and standard needles can be used for irrigation safely and effectively if a dynamic irrigation technique (moving the needle up and down inside the canals while irrigating) is employed. © 2012 The Authors. Australian Endodontic Journal © 2012 Australian Society of Endodontology.

  18. Morphometrical analysis of cleaning capacity using nickel-titanium rotary instrumentation associated with irrigating solutions in mesio-distal flattened root canals Análise morfológica da capacidade de limpeza promovida pela instrumentação rotatória, associada à soluções irrigantes, com limas de níquel-titânio em canais radiculares com achatamento mesio-distal

    Directory of Open Access Journals (Sweden)

    Melissa Andréia Marchesan

    2003-03-01

    Full Text Available Variations in the internal anatomy of root canals may interfere with the success of root canal because tissue remnants may remain in the isthmus, re-entrances and ramifications of flattened root canals making instrumentation more difficult. Successful root canal treatment depends fundamentally on shaping, cleaning, disinfection and obturation. This study verified the quality of cleaning of ProFile .04 rotary technique associated with different irrigating solutions: 0.5% sodium hypochlorite, calcium hydroxide + Tergentol and 2% chlorhexidine in canals with mesio-distal flattening. Twelve human mandibular central incisors were randomly divided into 3 groups and instrumented up to ProFile 0.4 #35 file after cervical preparation, and processed histologically. After optical microscopic evaluation, statistical analysis showed that the percentage of cleaning of the three irrigating solutions was statistically different. Two-by-two comparisons classified the irrigating solutions in increasing order of cleaning: calcium hydroxide + Tergentol As variações da anatomia interna de cada canal radicular podem interferir no sucesso da terapêutica endodôntica devido ao fato de que em canais radiculares achatados, pode persistir remanescentes teciduais em istmos, reentrâncias e ramificações dificultando a execução das técnicas de instrumentação. O sucesso do tratamento dos canais radiculares depende fundamentalmente do preparo da forma, limpeza, desinfecção e obturação. Poucos trabalhos avaliaram a limpeza dos canais radiculares após a instrumentação rotatória. O presente trabalho verificou a qualidade de limpeza dos canais radiculares, por meio da microscopia óptica, promovida pela técnica de instrumentação rotatória associada ao hipoclorito de sódio 0,5%, HCT20 e clorexidina, em canais achatados no sentido mésio-distal. Doze incisivos centrais inferiores humanos foram divididos aleatoriamente em três grupos para que fossem

  19. Effect of different irrigation techniques on the removal of calcium hydroxide paste from an artificial root canal cavity of internal root resorption:an in vitro study%不同冲洗技术去除模拟牙内吸收窝洞中氢氧化钙糊剂效果的体外研究

    Institute of Scientific and Technical Information of China (English)

    刘贺; 钱君荣; 耿海霞

    2016-01-01

    目的:评估不同冲洗技术去除模拟牙内吸收窝洞内氢氧化钙糊剂的效果。方法:收集110颗单根离体牙, ProTaper预备至F3。将牙根纵向劈成两半,制备标准化的模拟牙内吸收窝洞后将两半牙根复位。5颗牙齿作为阴性对照组,不向根管内导入氢氧化钙糊剂。105颗牙齿导入氢氧化钙糊剂,其中5颗作为阳性对照组不去除根管中的氢氧化钙糊剂,其余100颗牙齿根据使用的不同冲洗技术随机分成5组(n=20):常规冲洗针头冲洗组、主尖锉清理组、根管刷刷洗组、超声荡洗组、音波震荡组。体式显微镜下观察使用5种不同冲洗技术去除模拟牙内吸收窝洞后氢氧化钙糊剂剩余的量,使用van der Sluis 4级评分系统进行评分,Kruskal-Wallis检验以及Mann-Whitney检验(P<0.05)对数据进行统计分析。结果:超声荡洗组、音波震荡组较其他组模拟牙内吸收窝洞内氢氧化钙糊剂剩余的量较少(P<0.05)。超声荡洗组与音波震荡组间无明显统计学差异(P>0.05)。常规冲洗针头冲洗组、主尖锉清理组和根管刷刷洗组间无明显统计学差异(P>0.05)。结论:超声荡洗和音波震荡去除模拟牙内吸收窝洞内氢氧化钙糊剂效果较好。%Objective:To evaluate the efficacy of different irrigation techniques to remove calcium hydroxide(CH) from a simulated internal root resorption cavity. Method:110 clinically extracted teeth with single root were collected and prepared using the ProTaper system to size F3.The roots were split longitudinally,standardized simulated internal root re-sorption cavities were prepared in the two root halves,and the root halves were reassembled. The root canals of 5 teeth that were not filled with CH served as the negative control group. The root canals of 105 teeth were filled with CH,5 of them were not subjected to the CH removal procedure,antoher 100 teeth were

  20. In vivo microbiological evaluation of the effect of biomechanical preparation of root canals using different irrigating solutions Avaliação microbiológica in vivo do efeito do preparo biomecânico dos canais radiculares utilizando diferentes soluções irrigadoras

    Directory of Open Access Journals (Sweden)

    Mário Tanomaru Filho

    2006-04-01

    Full Text Available The aim of this study was to evaluate the antimicrobial effect of biomechanical preparation using different irrigating solutions. Seventy-eight root canals from premolars of four dogs were used. After experimental induction of periapical lesions, the root canals were prepared using the following solutions for irrigation: Group 1 2.5% sodium hypochlorite (NaOCl; Group 2 2% chlorhexidine (CHX; Group 3 saline solution and Group 4 control group with no biomechanical preparation. The microbiological evaluation of the root canals was performed by counting the colony forming units (CFUs using different culture mediums. Two absorbent paper cones were used in each root canal in order to collect the microbiological samples before, and thirty days after the biomechanical preparation. The culture plates were incubated in aerobic, anaerobic and microaerophilic environment. Statistical evaluation was carried out using analysis of variance, Tukey and Student tests. The results demonstrated that there was reduction in the number of microorganisms in the NaOCl and CHX groups (pO objetivo deste estudo foi avaliar o efeito antimicrobiano do preparo biomecânico com diferentes soluções irrigadoras. Foram utilizados 78 canais radiculares de pré-molares de 4 cães. Após indução experimental das lesões periapicais, os canais radiculares foram preparados utilizando as seguintes soluções irrigadoras: grupo 1 hipoclorito de sódio a 2,5% (NaOCl; grupo 2 clorexidina a 2% (CHX; grupo 3 soro fisiológico. No grupo 4 (controle não foi realizado preparo biomecânico. A avaliação microbiológica do canal radicular foi realizada pela contagem de unidades formadoras de colônia, em ufc, nos diferentes meios de cultura. Foram utilizados 2 cones de papel absorvente em cada canal radicular para a realização da colheita microbiológica antes e 30 dias após o preparo biomecânico. As placas de cultura foram incubadas em ambiente de aerobiose, anaerobiose e

  1. How to bond to root canal dentin

    Science.gov (United States)

    Nica, Luminita; Todea, Carmen; Furtos, Gabriel; Baldea, Bogdan

    2014-01-01

    Bonding to root canal dentin may be difficult due to various factors: the structural characteristic of the root canal dentin, which is different from that of the coronal dentin; the presence of the organic tissue of the dental pulp inside the root canal, which has to be removed during the cleaning-shaping of the root canal system; the smear-layer resulted after mechanical instrumentation, which may interfere with the adhesion of the filling materials; the type of the irrigants used in the cleaning protocol; the type of the sealer and core material used in the obturation of the endodontic space; the type of the materials used for the restoration of the endodontically treated teeth. The influence of the cleaning protocol, of the root canal filling material, of the type of the adhesive system used in the restoration of the treated teeth and of the region of the root canal, on the adhesion of several filling and restorative materials to root canal dentin was evaluated in the push-out bond strength test on 1-mm thick slices of endodontically treated human teeth. The results showed that all these factors have a statistically significant influence on the push-out bond strength. Formation of resin tags between radicular dentin and the investigated materials was observed in some of the samples at SEM analysis.

  2. Formation and removal of apical vapor lock during syringe irrigation: a combined experimental and Computational Fluid Dynamics approach

    NARCIS (Netherlands)

    Boutsioukis, C.; Kastrinakis, E.; Lambrianidis, T.; Verhaagen, B.; Versluis, M.; Sluis, van der L.W.M.

    2014-01-01

    Aim (i) To evaluate the effect of needle type and insertion depth, root canal size and irrigant flow rate on the entrapment of air bubbles in the apical part of a root canal (apical vapor lock) during syringe irrigation using experiments and a Computational Fluid Dynamics (CFD) model, (ii) to invest

  3. Formation and removal of apical vapor lock during syringe irrigation : a combined experimental and Computational Fluid Dynamics approach

    NARCIS (Netherlands)

    Boutsioukis, C.; Kastrinakis, E.; Lambrianidis, T.; Verhaagen, B.; Versluis, M.; van der Sluis, L. W. M.

    2014-01-01

    Aim(i) To evaluate the effect of needle type and insertion depth, root canal size and irrigant flow rate on the entrapment of air bubbles in the apical part of a root canal (apical vapor lock) during syringe irrigation using experiments and a Computational Fluid Dynamics (CFD) model, (ii) to investi

  4. Comparison of final irrigation techniques in removal of calcium hydroxide.

    Science.gov (United States)

    Yücel, Ali Çağın; Gürel, Melek; Güler, Eda; Karabucak, Bekir

    2013-12-01

    The aim of this study was to compare new irrigation systems with a conventional irrigation technique for the removal of inter-appointment calcium hydroxide [Ca(OH)2 ]. Forty-seven extracted human single-rooted teeth were instrumented, and Ca(OH)2 paste was placed into root canals by using a lentulo spiral at the apical third. Teeth were randomly divided into three groups according to different irrigation protocols using a 30-gauge slot-tipped needle, EndoVac system and ProUltra® PiezoFlow™ ultrasonic irrigation system. Scanning electron microscopic images of the selected root canal surfaces (cervical, middle and apical third) were evaluated using a 5-grade scale. The influence of the irrigation system was evaluated using a two-way analysis of variance test and Tukey's test. The EndoVac and PiezoFlow groups demonstrated the lowest scale values (cleanest canals); however, there was no statistical difference between these two groups. The conventional irrigation group exhibited significantly higher scores (P ultrasonic irrigation systems improved the removal of the intracanal medicament resulting in cleaner root canal walls. © 2011 The Authors. Australian Endodontic Journal © 2011 Australian Society of Endodontology.

  5. Rational Allocation of Surface and Groundwater Resources in Well-canal Combined Irrigation Area Based on Support Vector Machines%基于支持向量机的井渠结合灌区地表水地下水合理配置

    Institute of Scientific and Technical Information of China (English)

    刘菁扬; 粟晓玲

    2015-01-01

    地表水和地下水的合理配置是井渠结合灌区实现水资源优化,合理调控地下水位的重要途径。以陕西省泾惠渠地下水位变化的主要影响因素为输入变量,以当年平均地下水位为输出变量,建立了基于支持向量机的地下水位动态模拟模型,模拟不同水文年不同渠首引水量和地下水开采量等17种组合情景的地下水位及其变幅,并以多年采补平衡为地表水地下水合理配置的目标。结果表明,丰、平、枯不同水文年的井渠用水比分别为0.3~0.4、0.2~0.3、0.44~0.55时,可实现灌区地下水多年采补平衡。%The rational allocation of surface water and groundwater is an important way for well-canal combined irrigation area to a‐chieve the optimized and reasonable regulation of groundwater level .A dynamic simulation model of groundwater level based on sup‐port vector machine was established with input variables ,the main factors of groundwater level changes ,and output variables ,aver‐age groundwater level changes in irrigation areas of that year .The groundwater level under 17 kinds combinations of hydrology sce‐narios and water use were forecast by using the model which was tested and aimed to reach the rational allocation between surface water and groundwater ,and keep the balance between extraction and supplement .The results showed that when the ratio of well and canal irrigation water utilization was 0 .3~0 .4 ,0 .2~0 .3 ,0 .44~0 .55 in the wet year ,mean year and dry year ,respectively ,the balance between groundwater recharge and discharge would be kept during many years .

  6. Stratification and enumeration of Boolean functions by canalizing depth

    Science.gov (United States)

    He, Qijun; Macauley, Matthew

    2016-01-01

    Boolean network models have gained popularity in computational systems biology over the last dozen years. Many of these networks use canalizing Boolean functions, which has led to increased interest in the study of these functions. The canalizing depth of a function describes how many canalizing variables can be recursively "picked off", until a non-canalizing function remains. In this paper, we show how every Boolean function has a unique algebraic form involving extended monomial layers and a well-defined core polynomial. This generalizes recent work on the algebraic structure of nested canalizing functions, and it yields a stratification of all Boolean functions by their canalizing depth. As a result, we obtain closed formulas for the number of n-variable Boolean functions with depth k, which simultaneously generalizes enumeration formulas for canalizing, and nested canalizing functions.

  7. Stratification and enumeration of Boolean functions by canalizing depth

    CERN Document Server

    He, Qijun

    2015-01-01

    Boolean network models have gained popularity in computational systems biology over the last dozen years. Many of these networks use canalizing Boolean functions, which has led to increased interest in the study of these functions. The canalizing depth of a function describes how many canalizing variables can be recursively picked off, until a non-canalizing function remains. In this paper, we show how every Boolean function has a unique algebraic form involving extended monomial layers and a well-defined core polynomial. This generalizes recent work on the algebraic structure of nested canalizing functions, and it yields a stratification of all Boolean functions by their canalizing depth. As a result, we obtain closed formulas for the number of n-variable Boolean functions with depth k, which simultaneously generalizes enumeration formulas for canalizing, and nested canalizing functions.

  8. Boolean nested canalizing functions: a comprehensive analysis

    CERN Document Server

    Li, Yuan; Murrugarra, David; Aguilar, Boris; Laubenbacher, Reinhard

    2012-01-01

    Boolean network models of molecular regulatory networks have been used successfully in computational systems biology. The Boolean functions that appear in published models tend to have special properties, in particular the property of being nested canalizing, a property inspired by the concept of canalization in evolutionary biology. It has been shown that networks comprised of nested canalizing functions have dynamic properties that make them suitable for modeling molecular regulatory networks, namely a small number of (large) attractors, as well as relatively short limit cycles. This paper contains a detailed analysis of this class of functions, based on a novel normal form as polynomial functions over the Boolean field. The concept of layer is introduced that stratifies variables into different classes depending on their level of dominance. Using this layer concept a closed form formula is derived for the number of nested canalizing functions with a given number of variables. Additional metrics analyzed in...

  9. Prospects for Improving Gravity-Fed Surface Irrigation Systems in Mediterranean European Contexts

    Directory of Open Access Journals (Sweden)

    Daniele Masseroni

    2017-01-01

    Full Text Available Traditionally, most irrigation practices in Southern Europe have been based on gravity-fed surface irrigation systems. Currently, these systems remain a relevant typology in the European Union (EU member states of the Mediterranean areas, where it is often the only sustainable method for farmers due to the small size of agricultural holdings, their reduced capacity and readiness to invest and the low ratio between yield profits and irrigation costs. In the last several years, in response to European and national directives, surface irrigation has garnered increasing attention at the political and bureaucratic levels due to frequent criticisms of its postulated low efficiency and high water wastage. However, these systems commonly provide a number of ecosystem services and nature-based solutions that increase the positive externalities in different rural socio-ecological contexts and often have the potential to extend these services and provide solutions that are compatible with economical sustainability. This study aims to discuss the prospects for new practices and for the rehabilitation and modernization of the gravity-fed surface irrigation systems in EU Mediterranean areas to enhance water efficiency, thus gaining both economic advantages and environmental benefits. The difficulties, stimuli for improvements and peculiarities of the irrigation water management of four rural environments located in Italy, Spain and Portugal were analyzed and compared to the current state of the gravity-fed surface irrigation systems with hypothetical future improvements achievable by innovative technologies and practices. In these different case studies, the current gravity-fed surface irrigation systems have an obsolete regulatory structure; water-use efficiency is not a driving criterion for the management of the conveyance and distribution canal network, and farmers are not yet adequately encouraged to adopt more efficient gravity-fed irrigation practices

  10. Factorial analysis of root canal irrigants and cements on coronal microleakage after cementing metal post-cores%根管冲洗液和黏结剂对金属桩核黏固后根管微渗漏影响的析因分析

    Institute of Scientific and Technical Information of China (English)

    郑政; 刘翠玲; 蓝菁; 高旭

    2014-01-01

    Objective To evaluate the effect of different root canal irrigants and cements on coronal microleakage and the interaction effects after cementing metal post-cores. Methods Ninety newly extracted single-rooted mandibular human premolars were endodontically treated. Post spaces were prepared in the root canals, and Co-Cr post-cores were cast routinely. The specimens were randomly divided into six groups (n=15) via a two-way factorial design method. The irrigant factors (A) included A1: no irrigant (75% alcohol wiping), A2: 3% H2O2+0.9% NaCl, and A3: 15% ethylenediamine tetraacetic acid (EDTA)+5.25% NaClO. The cement factors (B) included B1: zinc polycarboxylate cement, and B2: glass ionomer cement. The specimens received treatments based on the grouping of A1B1, A1B2, A2B1, A2B2, A3B1, and A3B2. All samples were sectioned longitudinally after being immersed in India ink for three weeks. The microleakages were observed using a stereomicroscope. The SPSS 13.0 software package was used for factorial analysis. Results The mean microleakage scores and standard deviations were as follows: Group A1B1: (1 192.59±417.84) μm, Group A1B2: (1 317.38±527.35) μm, Group A2B1: (1 429.33±482.68) μm, Group A2B2: (1 026.79±459.49) μm, Group A3B1: (1 448.29±561.02) μm, and Group A3B2:(1 922.47±678.86) μm. The A2B2 group showed minimum microleakage, whereas the A3B2 group showed maximum microleakage. The microleakage degrees among different irrigants presented significant statistical difference (P0.05). An interactive effect on the microleakage existed between the irrigants and the cements after cementing the metal post-cores (P0.05),但根管冲洗液和黏结剂对于微渗漏的发生有交互作用(P<0.05)。结论黏固金属桩核时,3%H2O2+0.9%NaCl溶液冲洗根管联合玻璃离子水门汀黏结剂在减少微渗漏的发生方面有一定优势;15%EDTA和5.25%NaClO联合玻璃离子水门汀会加重根管微渗漏的发生。

  11. Sensing technologies for precision irrigation

    CERN Document Server

    Ćulibrk, Dubravko; Minic, Vladan; Alonso Fernandez, Marta; Alvarez Osuna, Javier; Crnojevic, Vladimir

    2014-01-01

    This brief provides an overview of state-of-the-art sensing technologies relevant to the problem of precision irrigation, an emerging field within the domain of precision agriculture. Applications of wireless sensor networks, satellite data and geographic information systems in the domain are covered. This brief presents the basic concepts of the technologies and emphasizes the practical aspects that enable the implementation of intelligent irrigation systems. The authors target a broad audience interested in this theme and organize the content in five chapters, each concerned with a specific technology needed to address the problem of optimal crop irrigation. Professionals and researchers will find the text a thorough survey with practical applications.

  12. Sleeping with the enemy: Dichotomies and polarisation in Indian policy debates on the environmental and social effects of irrigation

    OpenAIRE

    Mollinga, Peter P.

    2005-01-01

    Large-scale, government-managed canal irrigation represents the technocratic approach to water development. Large-scale irrigation faces many problems but they have been relegated to the periphery in the water debate generally and about large dams in particular. It has given rise to dichotomous thinking and polarised politics. This paper explores these issues in case of large canal irrigation in India. The debates imply implication for institutions, science and technology and developmental pr...

  13. A rapid appraisal process on an irrigation system in Pakistan; Evaluacion rapida de una zona de riego tipica de Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Carmona, Victor Manuel; Ojeda-Bustamante, Waldo [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico); Contijoch, Manuel [Banco Mundial (Mexico)

    2006-07-15

    This paper presents the results obtained on the implementation of a rapid appraisal process on an irrigation system in the province of Punjab in Pakistan. The purpose of the evaluation was to know the present irrigation service quality and to propose some alternative to improve it. The evaluation results were: the canal inflow is smaller than peak crop water requirement; net aquifer loss; crops are always under stress which is reflected on low crop yields, the secondary canal network has not control structures and was not designed for rotation, insufficient human-human communication between canal operators; the operators have no complementary training course to enhance their capacity; discrepancy between the service the canal is supposed to provide and the real service it offers. The suggested actions to improve the irrigation service were: the irrigation service must be client oriented; the irrigation users should participate to determine the irrigation service characteristics; the difference between actual and stage irrigation service must be eliminated; clear definition on water allocation; implement a modernization program to provide the irrigation service required. The evaluation methodology used can be applied in other countries like Mexico for the analysis of large irrigation systems making an optimal use of time and resources. [Spanish] En el presente trabajo se muestran los resultados obtenidos al aplicar una metodologia de evaluacion rapida de sistemas de riego a una zona de la provincia del Punjab, Pakistan. El objetivo de la evaluacion fue conocer el estado actual del servicio de riego que ofrece la agencia responsable del manejo del riego en un distrito del Punjab y proponer alternativas para mejorarlo. Los principales resultados de esta evaluacion fueron los siguientes: la falta de capacidad de los canales, el abatimiento neto del acuifero; el estres hidrico continuo de los cultivos, que propicia un bajo rendimiento; la red secundaria de canales no

  14. Root canal debridement: an online study guide.

    Science.gov (United States)

    2008-05-01

    The Editorial Board of the Journal of Endodontics has developed a literature-based study guide of topical areas related to endodontics. This study guide is intended to give the reader a focused review of the essential endodontic literature and does not cite all possible articles related to each topic. Although citing all articles would be comprehensive, it would defeat the idea of a study guide. This section will present root canal debridement including subdivisions on canal access, canal debridement, orifice enlargement and preflaring, crown-down technique, balanced force, nickel titanium and other shape memory alloys, rotary engine-driven techniques, endodontic instruments, irrigation, electronic apex locators, sonics/ultrasonics, smear layer, and intracanal medicaments.

  15. Depolarization canals and interstellar turbulence

    Science.gov (United States)

    Fletcher, A.; Shukurov, A.

    Recent radio polarization observations have revealed a plethora of unexpected features in the polarized Galactic radio background that arise from propagation effects in the random (turbulent) interstellar medium. The canals are especially striking among them, a random network of very dark, narrow regions clearly visible in many directions against a bright polarized Galactic synchrotron background. There are no obvious physical structures in the ISM that may have caused the canals, and so they have been called Faraday ghosts. They evidently carry information about interstellar turbulence but only now is it becoming clear how this information can be extracted. Two theories for the origin of the canals have been proposed; both attribute the canals to Faraday rotation, but one invokes strong gradients in Faraday rotation in the sky plane (specifically, in a foreground Faraday screen) and the other only relies on line-of-sight effects (differential Faraday rotation). In this review we discuss the physical nature of the canals and how they can be used to explore statistical properties of interstellar turbulence. This opens studies of magnetized interstellar turbulence to new methods of analysis, such as contour statistics and related techniques of computational geometry and topology. In particular, we can hope to measure such elusive quantities as the Taylor microscale and the effective magnetic Reynolds number of interstellar MHD turbulence.

  16. De la gouvernance appliquée à la gestion de l’irrigation : le cas du canal de la Neste (Hautes-Pyrénées)

    OpenAIRE

    Ricart, Sandra; Clarimont, Sylvie

    2015-01-01

    Depuis quelques années, la ressource en eau n’est plus seulement appréhendée en termes de disponibilité et d’usage (vision utilitariste) mais aussi comme un bien commun à transmettre aux générations futures (vision patrimoniale). Ces deux conceptions de l’eau demeurent grandement antinomiques malgré les efforts déployés pour concilier viabilité économique, maintien des équilibres écologiques et participation sociale. Dans ce contexte, l’irrigation constitue un élément majeur pour comprendre l...

  17. Differential diagnoses for persistent pain after root canal treatment: a study in the National Dental Practice-based Research Network.

    Science.gov (United States)

    Nixdorf, Donald R; Law, Alan S; John, Mike T; Sobieh, Radwa M; Kohli, Richie; Nguyen, Ruby H N

    2015-04-01

    Pain present 6 months after root canal treatment (RCT) may be of odontogenic or nonodontogenic origin. This is important because treatments and prognoses are different; therefore, the aim of this study was to provide specific diagnoses of patients reporting pain 6 months after receiving initial orthograde RCT. We enrolled patients from the Midwest region of an existing prospective observational study of pain after RCT. Pain at 6 months was defined as ≥1 day of pain and average pain intensity of at least 1 of 10 over the preceding month. An endodontist and an orofacial pain practitioner independently performed clinical evaluations, which included periapical and cone-beam computed tomographic radiographs, to determine diagnoses. Thirty-eight of the 354 eligible patients in the geographic area (11%) met the pain criteria, with 19 (50%) consenting to be clinically evaluated. As the sole reason for pain, 7 patients (37%) were given odontogenic diagnoses (4 involving the RCT tooth and 3 involving an adjacent tooth). Eight patients (42%) were given nonodontogenic pain diagnoses (7 from referred temporomandibular disorder pain and 1 from persistent dentoalveolar pain disorder). Two patients (11%) had both odontogenic and nonodontogenic diagnoses, whereas 2 (11%) no longer fit the pain criteria at the time of the clinical evaluation. Patients reporting "tooth" pain 6 months after RCT had a nonodontogenic pain diagnosis accounting for some of this pain, with temporomandibular disorder being the most frequent nonodontogenic diagnosis. Dentists should have the necessary knowledge to differentiate between these diagnoses to adequately manage their patients. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Irrigation System

    Science.gov (United States)

    1984-01-01

    Under contract with Marshall Space Flight Center, Midwest Research Institute compiled a Lubrication Handbook intended as a reference source for designers and manufacturers of aerospace hardware and crews responsible for maintenance of such equipment. Engineers of Lindsay Manufacturing Company learned of this handbook through NASA Tech Briefs and used it for supplemental information in redesigning gear boxes for their center pivot agricultural irrigation system.

  19. Reabilitação de redes coletivas de sistemas pressurizados de irrigação Rehabilitation of collective networks of pressurized irrigation systems

    Directory of Open Access Journals (Sweden)

    Heber P. Gomes

    2005-12-01

    Full Text Available Apresenta-se, neste trabalho, um método de otimização econômica para a reabilitação de redes ramificadas pressurizadas de distribuição de água para projetos de irrigação que se encontram com deficiência de vazão e pressão nos pontos de consumo. O método poderá ser aplicado a redes malhadas de abastecimento urbano, desde que sejam transformadas em ramificadas, através do método do seccionamento fictício. A metodologia empregada se baseia no método Granados, de otimização econômica de redes pressurizadas; trata-se de um processo iterativo que seleciona, a cada passo, as possibilidades de modificação dos diâmetros das tubulações da rede, de forma a minimizar o custo de investimento da reabilitação do sistema. O método foi testado para uma rede de distribuição que abastece um projeto de irrigação fictício, no qual existe deficiência de pressão em quase todos os pontos de consumo; enfim, o custo para a reabilitação da rede foi de 41% do custo original do sistema.This paper presents a method of economic optimization aiming the rehabilitation of pressurized branched networks of water distribution for irrigation projects, which have flow and pressure deficiency at the consumption points. The method can be applied to looped networks of urban water supply, on condition that they are changed into branched ones, through the fictitious sectioning method. The methodology used is based on the Granados method of economic optimization of pressurized networks, which is an iterative process that selects step by step the possibilities of changes of the network pipe diameters, so as to optimize the investment cost of the rehabilitation system. The method was tested for a distribution network that supplies a fictitious irrigation project, in which there is pressure deficiency in almost all the consumption points. The network rehabilitation cost was 41% of the original cost.

  20. EFFICACY OF DIFFERENT ENDODONTIC IRRIGATION PROTOCOLS IN CALCIUM HYDROXIDE REMOVAL

    Directory of Open Access Journals (Sweden)

    Elka N. Radeva

    2016-10-01

    Full Text Available Introduction: Calcium hydroxide is widely used in the field of endodontics as a temporary root canal filling. This medicament significantly increases pH and optimizes the treatment outcome. Its total removal before final obturation is very important. Otherwise it could affect the hermetic filling and respectively the endodontic success. Aim: To evaluate the most effective irrigation protocol of calcium hydroxide removal from root canals. Materials and methods: In this study 36 single root canal teeth were observed. They were randomly divided into three groups (n=10 each group according to the technique applied for calcium hydroxide removal - manual irrigation, irrigation and Revo-S rotary instrumentation; and passive ultrasonic irrigation, and a control group (n=6 – irrigation with distilled water only. After calcium hydroxide removals following the procedures above, teeth were separated longitudinally in a buccal-lingual direction and remnants of medicaments were observed in the apical, middle and coronal part of each tooth. Then all of the specimens were observed using scanning electron microscopy and evaluated by a specified scale. The results have undergone statistical analysis. Results: In the case of calcium hydroxide in the apex and in the middle with highest average is Revo-S, followed by Ultrasonic and irrigation. In the coronal part the highest average belongs to Revo-S, irrigation and Ultrasonic. In all groups the highest average is represented by control group. Conclusion: There is not a universal technique for removal of intracanal medicaments and applying more than one protocol is required.

  1. Corelation between Machines Assisted Endodontic Irrigant Agitation and Apical Extrusion of Debris and Irrigant: A Laboratory Study

    Directory of Open Access Journals (Sweden)

    Jatin Gupta

    2014-01-01

    Full Text Available Aims. To compare amount of root canal debris and irrigant extruded apically after irrigants agitation using closed and open chambers. Methods and Material. Sixty maxillary central incisors were selected, decoronated, and mounted in preweighed glass vials filled with distilled water. Biomechanical preparation was completed using ProTaper rotary files until number F4 and 1 mL of 3% NaOCl solution after each file use. Samples were randomly divided into closed or open chamber sets which were further subdivided into 6 groups, based on the agitation techniques: no agitation (control, canalBrush, lentulospiral, passive ultrasonic agitation (PUA, EndoActivator, and EndoVac. Canals were irrigated with 1 mL of 17% EDTA and agitated for 30 s and then flushed with 2 mL of distilled water. Apically extruded irrigant was measured and vials were kept in incubator for 5 days at 68°C for drying for weight calculation. Statistical Analysis. Analysis was done using Student’s t-test, one-way ANOVA, and post-hoc. Results. All agitation techniques showed apical extrusion of the debris and irrigant. The closed chamber apparatus showed significantly less extrusion of debris and irrigant than open chamber (P<0.05. Conclusions. EndoVac was found to be the safest agitation system among all test groups with regard to apical extrusion of debris and irrigant.

  2. Effectiveness of various irrigation activation protocols and the self-adjusting file system on smear layer and debris removal.

    Science.gov (United States)

    Çapar, İsmail Davut; Aydinbelge, Hale Ari

    2014-01-01

    The purpose of the present study is to evaluate smear layer generation and residual debris after using self-adjusting file (SAF) or rotary instrumentation and to compare the debris and smear layer removal efficacy of the SAF cleaning/shaping irrigation system against final agitation techniques. One hundred and eight maxillary lateral incisor teeth were randomly divided into nine experimental groups (n = 12), and root canals were prepared using ProTaper Universal rotary files, with the exception of the SAF instrumentation group. During instrumentation, root canals were irrigated with a total of 16 mL of 5% NaOCl. For final irrigation, rotary-instrumented groups were irrigated with 10 mL of 17% EDTA and 10 mL of 5% NaOCl using different irrigation agitation regimens (syringe irrigation with needles, NaviTip FX, manual dynamic irrigation, CanalBrush, EndoActivator, EndoVac, passive ultrasonic irrigation (PUI), and SAF irrigation). In the SAF instrumentation group, root canals were instrumented for 4 min at a rate of 4 mL/min with 5% NaOCl and received a final flush with same as syringe irrigation with needles. The surface of the root dentin was observed using a scanning electron microscope. The SAF instrumentation group generated less smear layer and yielded cleaner canals compared to rotary instrumentation. The EndoActivator, EndoVac, PUI, and SAF irrigation groups increased the efficacy of irrigating solutions on the smear layer and debris removal. The SAF instrumentation yielded cleaner canal walls when compared to rotary instrumentation. None of the techniques completely removed the smear layer from the root canal walls.

  3. Cavitation measurement during sonic and ultrasonic activated irrigation.

    Science.gov (United States)

    Macedo, Ricardo; Verhaagen, Bram; Rivas, David Fernandez; Versluis, Michel; Wesselink, Paul; van der Sluis, Luc

    2014-04-01

    The aims of this study were to quantify and to visualize the possible occurrence of transient cavitation (bubble formation and implosion) during sonic and ultrasonic (UAI) activated irrigation. The amount of cavitation generated around several endodontic instruments was measured by sonochemiluminescence dosimetry inside 4 root canal models of human dimensions and varying complexity. Furthermore, the spatial distribution of the sonochemiluminescence in the root canal was visualized with long-exposure photography. Instrument oscillation frequency, ultrasonic power, and file taper influenced the occurrence and amount of cavitation. In UAI, cavitation was distributed between the file and the wall extending beyond the file and inside lateral canals/isthmuses. In sonic activated irrigation, no cavitation was detected. Cavitation was shown to occur in UAI at clinically relevant ultrasonic power settings in both straight and curved canals but not around sonically oscillating instruments, driven at their highest frequency. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Application of the Viterbi Algorithm in Hidden Markov Models for Exploring Irrigation Decision Series

    Science.gov (United States)

    Andriyas, S.; McKee, M.

    2014-12-01

    Anticipating farmers' irrigation decisions can provide the possibility of improving the efficiency of canal operations in on-demand irrigation systems. Although multiple factors are considered during irrigation decision making, for any given farmer there might be one factor playing a major role. Identification of that biophysical factor which led to a farmer deciding to irrigate is difficult because of high variability of those factors during the growing season. Analysis of the irrigation decisions of a group of farmers for a single crop can help to simplify the problem. We developed a hidden Markov model (HMM) to analyze irrigation decisions and explore the factor and level at which the majority of farmers decide to irrigate. The model requires observed variables as inputs and the hidden states. The chosen model inputs were relatively easily measured, or estimated, biophysical data, including such factors (i.e., those variables which are believed to affect irrigation decision-making) as cumulative evapotranspiration, soil moisture depletion, soil stress coefficient, and canal flows. Irrigation decision series were the hidden states for the model. The data for the work comes from the Canal B region of the Lower Sevier River Basin, near Delta, Utah. The main crops of the region are alfalfa, barley, and corn. A portion of the data was used to build and test the model capability to explore that factor and the level at which the farmer takes the decision to irrigate for future irrigation events. Both group and individual level behavior can be studied using HMMs. The study showed that the farmers cannot be classified into certain classes based on their irrigation decisions, but vary in their behavior from irrigation-to-irrigation across all years and crops. HMMs can be used to analyze what factor and, subsequently, what level of that factor on which the farmer most likely based the irrigation decision. The study shows that the HMM is a capable tool to study a process

  5. Comparison of the Effectiveness of Four Different Types of Needles in Irrigating Endodontically Treated Teeth.

    Science.gov (United States)

    1980-02-08

    H. Ultrasonic disinfection of the root canal. Oral Surg 42(l):92-98, 1976. 12. Grossman, L.I. Endodontic Practice, Philadelphia, Lea and Febiger, 1976...different types of irrigating needles in the removal of contamination in vitro from the root canals of forty endodontically treated single-rooted...TYPES OF NEEDLES IN IRRIGATING ENDODONTICALLY TREATED TEETH E. Drobotij, DDS, MS Resident, Endodontics Dept. of Dentistry - PO Box 59 Madigan Army

  6. [The use of ultrasonic files in canal preparation].

    Science.gov (United States)

    Calas, P; Terrie, B

    1990-01-01

    The continuous high volume of irrigating solution delivered by the ultrasonic system facilitates the root canal debridement. An excellent cleaning of dentin wall is obtained even on surfaces unreached by the mechanical instrumentation. In order to obtain an efficacious preparation, the use of ultrasonic files were combined with instrumentation. This new technique is described in this article.

  7. Atrioventricular Canal Defect

    Science.gov (United States)

    ... doctor See your doctor if you or your child develops signs or symptoms of atrioventricular canal defect. Atrioventricular canal defect occurs before birth when a baby's heart is developing. Some factors, such as Down syndrome, might increase the risk of atrioventricular canal defect. ...

  8. The clinical success of different root canal treatments in primary molars

    Directory of Open Access Journals (Sweden)

    Çiğdem Güler

    2013-01-01

    Full Text Available

    Objectives: To examine the success rate of root canal treatment in primary molars with the use two different root canal instrumentation ways, irrigation solutions and root canal sealers.

    Materials and Methods: Root canal treatment was applied to 120 second primary molars of 69 children between 5-8 years old. The teeth were divided in 8 groups randomly according to instrumentation ways [conventional stainless-steel hand files / Nickel-titanium (Ni-Ti rotary files], irrigation solutions [0.5% sodium hypochlorite (NaOCl and 0.9% saline solution combination / 0.4% chlorhehexidine (CHX] and root canal sealers [Zinc oxide eugenol cement (ZOE and Apexit Plus (AP]. All teeth were restored with stainless steel crowns. The teeth were followed 12 months both clinically and radiographically. All data was analyzed statistically by χ2 and Wilcoxon test.

    Results: Statistical significance were found according to “age” and “root canal sealers” factors on success rate of root canal treatment (p<0.05. No statistical significance were found according to gender, jaw, tooth type, root canal instrumentation ways and irrigation solutions  on success rate of root canal treatment (p>0.05. The clinically and radiographically success rate of ZOE and AP were 98.3% and 68.3%, respectively.

    Conclusions: Root canal treatment is a successful treatment in primary molars. Ni-Ti rotary files and CHX can be a good alternative for root canal treatment in primary molars. The most effective factor to obtain clinical success of root canal treatment is properties of using root canal sealer.

  9. Irrigation Analysis Based on Long-Term Weather Data

    Directory of Open Access Journals (Sweden)

    James R. Mahan

    2016-08-01

    Full Text Available Irrigation management is based upon delivery of water to a crop in the correct amount and time, and the crop’s water need is determined by calculating evapotranspiration (ET using weather data. In 1994, an ET-network was established in the Texas High Plains to manage irrigation on a regional scale. Though producers used the ET-network, by 2010 public access was discontinued. Why did producers allow a valuable irrigation-management tool to be eliminated? Our objective was to analyze the effect of declining well capacities on the usefulness of cotton ET (ETc for irrigation. Thirty years (1975–2004 of daily ETc data were used to compare irrigation demand vs. irrigation responses at four locations, analyzed for multiple years and range of well capacities for three irrigation-intervals. Results indicated that when well capacities declined to the point that over-irrigation was not possible, the lower well capacities reduced the value of ETc in terms of the number of irrigations and total amount of water applied. At well capacities <1514 L·min−1 the fraction of irrigations for which ETc information was used to determine the irrigation amount was <35% across years and irrigation intervals. The value of an ETc-based irrigation may fall into disuse when irrigation-water supplies decline.

  10. Technical descriptions of ten irrigation technologies for conserving energy

    Energy Technology Data Exchange (ETDEWEB)

    Harrer, B.J.; Wilfert, G.L.

    1983-05-01

    Technical description of ten technologies which were researched to save energy in irrigated agriculture are presented. These technologies are: well design and development ground water supply system optimization, column and pump redesign, variable-speed pumping, pipe network optimization, reduced-pressure center-pivot systems, low-energy precision application, automated gated-pipe system, computerized irrigation scheduling, and instrumented irrigation scheduling. (MHR)

  11. In vitro Comparison of Debris Removal Using Various Adjunct Irrigation Devices

    Science.gov (United States)

    2016-06-01

    instrumentation and prior to adjunct irrigation and (b) immediately following adjunct irrigation. Canals were dried with sterile paper points prior to...Endod 2005; 31: 166–70. 14. Carver, K., Nusstein, J., Reader, A., and Beck, M. In vivo antibacterial efficacy of ultrasound after hand and rotary

  12. Influence of smear layer removal on the obturation of root canal ramifications

    Directory of Open Access Journals (Sweden)

    Elaine Vianna Freitas Fachin

    2009-06-01

    Full Text Available OBJECTIVE: This study evaluated whether smear layer removal has any influence on the filling of the root canal system, by examining the obturation of lateral canals, secondary canals and apical deltas. MATERIAL AND METHODS: Eighty maxillary and mandibular canines were randomly divided into two groups, according to their irrigation regimen. Both groups were irrigated with 1% NaOCl during canal shaping, but only the teeth in Group II received a final irrigation with 17% EDTA for smear layer removal. The root canals were obturated with lateral condensation of gutta-percha and the specimens were cleared, allowing for observation under the microscope. RESULTS: In Groups I and II, 42.5% and 37.5% of the teeth, respectively, presented at least one filled canal ramification. Although a larger number of obturated ramifications was found in Group I, there were no statistically significant differences between the two groups (p = 0.4957. CONCLUSIONS: Smear layer removal under the conditions tested in this study did not affect the obturation of root canal ramifications when lateral condensation of gutta-percha was the technique used for root canal filling.

  13. GIS-based analysis of the fate of waste-related pathogens Cryptosporidium parvum, Giardia lamblia and Escherichia coli in a tropical canal network.

    Science.gov (United States)

    Diallo, Mamadou B C; Anceno, Alfredo J; Tawatsupa, Benjawan; Tripathi, Nitin K; Wangsuphachart, Voranuch; Shipin, Oleg V

    2009-03-01

    Urban canals play a major socio-economic role in many tropical countries and, particularly, Thailand. One of the overlooked functions that they perform is a significant attenuation of waste-related pathogens posing considerable health risk, as well as pollution attenuation in general. The study dealt with a comparison of three canals receiving: (i) municipal, (ii) mainly industrial and (iii) mainly agricultural wastewater, listed in order of progressively decreasing organic loading. The occurrence and fate of waterborne Cryptosporidium parvum, Giardia lamblia and Escherichia coli were monitored in the canals by both real-time PCR and conventionally for 12 months. The pathogens are etiological agents of an estimated 38% and 47% of diarrhea cases worldwide and in Thailand, respectively. The geographic information system (GIS) was used to evaluate and map point and, particularly, non-point pollution sources which allowed differentiating the canal sections in terms of predominant pathogen sources. The flowthrough canals, which can be viewed as waste stabilization ponds, were found to be efficiently removing the pathogens at the following generalized specific rates: 0.3 (C. parvum), 1.2 (G. lamblia), 1.8 (E. coli) log10/km.d in the dry season. The rates decreased in the rainy season for E. coli and G. lamblia, but increased for C. parvum which indicated different removal mechanisms. Data suggest that E. coli and G. lamblia were mainly removed through sedimentation and sunlight (UV) irradiation, while the likely mechanism for C. parvum was predation. Overall, the specific pathogen removal rates positively correlated with the canal organic loading rates in the rainy season. As an important result, an estimate of the municipal pollution mitigation by over 2280 km canals in the Greater Bangkok suggests that concomitant to the pathogens at least 36-95 tons of BOD5 is being removed daily, thereby saving the receiving Chao Phraya River and Bight of Bangkok, by far exceeding

  14. Wall shear stress effects of different endodontic irrigation techniques and systems.

    Science.gov (United States)

    Goode, Narisa; Khan, Sara; Eid, Ashraf A; Niu, Li-na; Gosier, Johnny; Susin, Lisiane F; Pashley, David H; Tay, Franklin R

    2013-07-01

    This study examined débridement efficacy as a result of wall shear stresses created by different irrigant delivery/agitation techniques in an inaccessible recess of a curved root canal model. A reusable, curved canal cavity containing a simulated canal fin was milled into mirrored titanium blocks. Calcium hydroxide (Ca(OH)2) paste was used as debris and loaded into the canal fin. The titanium blocks were bolted together to provide a fluid-tight seal. Sodium hypochlorite was delivered at a previously-determined flow rate of 1 mL/min that produced either negligible or no irrigant extrusion pressure into the periapex for all the techniques examined. Nine irrigation delivery/agitation techniques were examined: NaviTip passive irrigation control, Max-i-Probe(®) side-vented needle passive irrigation, manual dynamic agitation (MDA) using non-fitting and well-fitting gutta-percha points, EndoActivator™ sonic agitation with medium and large points, VPro™ EndoSafe™ irrigation system, VPro™ StreamClean™ continuous ultrasonic irrigation and EndoVac apical negative pressure irrigation. Débridement efficacies were analysed with Kruskal-Wallis ANOVA and Dunn's multiple comparisons tests (α=0.05). EndoVac was the only technique that removed more than 99% calcium hydroxide debris from the canal fin at the predefined flow rate. This group was significantly different (p<0.05) from the other groups that exhibited incomplete Ca(OH)2 removal. The ability of the EndoVac system to significantly clean more debris from a mechanically inaccessible recess of the model curved root canal may be caused by robust bubble formation during irrigant delivery, creating higher wall shear stresses by a two-phase air-liquid flow phenomenon that is well known in other industrial débridement systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Effect of irrigation technique for removal of triple antibiotic paste on bond strength of MTA to root dentin.

    Science.gov (United States)

    Dumani, Aysin; Yilmaz, Sehnaz; Yoldas, Oguz; Bek, Zeliha Gonca

    2016-01-01

    This study evaluated the bond strength of mineral trioxide aggregate (MTA) to root canal dentin after the performance of various irrigation procedures to remove triple antibiotic paste (TAP). A total of 56 single-rooted human mandibular premolars were instrumented using a rotary system to size 40 and divided randomly into a control group (no intracanal dressing) and three experimental groups (TAP application for 28 days). TAP was then removed by rinsing with 10 mL 2.5% NaOCl using three irrigation systems (Vibringe sonic irrigation, CanalBrush, and syringe irrigation). The coronal and middle parts of root canals were then obturated with MTA. After storage for 1 week, each specimen was embedded in an acrylic block and sectioned horizontally (2-mm-thick slices) at two levels (coronal and middle). Bond strength of MTA to root canal dentin was assessed in 28 samples per group via push-out test using a universal testing machine. Data from the four groups were compared using one-way analysis of variance. Tukey's test was used for multiple comparisons. Push-out bond strength values were significantly higher in the control and Vibringe groups than in the CanalBrush and syringe irrigation groups (p irrigation system may increase the push-out bond strength of MTA compared with the use of the CanalBrush or syringe irrigation.

  16. Use of the SAR (Synthetic Aperture Radar) P band for detection of the Moche and Lambayeque canal networks in the Apurlec region, Perù

    Science.gov (United States)

    Ilaria Pannaccione Apa, Maria; Santovito, Maria Rosaria; Pica, Giulia; Catapano, Ilaria; Fornaro, Gianfranco; Lanari, Riccardo; Soldovieri, Francesco; Wester La Torre, Carlos; Fernandez Manayalle, Marco Antonio; Longo, Francesco; Facchinetti, Claudia; Formaro, Roberto

    2016-04-01

    , glaciers investigation, biomass monitoring, detection of buried targets. Its extension to non-civil application concerns sub-surface target detection and foliage penetration (FOPEN). In order to achieve the flexibility to face all the above mentioned fields of application, the CORISTA system has been designed as a multi-mode and multi-frequency radar. Multimode stands for the functionality of the system both as Sounder and Imager. In addition, P-band radar is a multi-frequency instrument, since it is designed to work in three different frequency bands, as mentioned above: lower frequency band is used in sounder operative mode, higher frequency in imager operative mode. In the Imager operative mode, low resolution and high resolution capabilities are implemented. The data collected by the radar system have been processed using a model-based microwave tomographic approach, recently developed by IREA-CNR, with the aim to enhance the interpretability of the raw-data radar images. Currently, the non-invasive SAR P band application is under evaluation for testing in the Northern Coast of Perù, in collaboration with the Museo Arqueológico Nacional Brüning. The project will aim to recognize the subsurface ancient Moche (100-700 d.C.) and Lambayeque (700-1375 d.C.) canal networks, whose water supply comes from the Canal Taymi, started to be dug by the Mochicas, still in use by local communities.

  17. Effect of diode laser and ultrasonics with and without ethylenediaminetetraacetic acid on smear layer removal from the root canals: A scanning electron microscope study

    Science.gov (United States)

    Amin, Khalid; Masoodi, Ajaz; Nabi, Shahnaz; Ahmad, Parvaiz; Farooq, Riyaz; Purra, Aamir Rashid; Ahangar, Fayaz Ahmad

    2016-01-01

    Aim: To evaluate the effect of diode laser and ultrasonics with and without ethylenediaminetetraacetic acid (EDTA) on the smear layer removal from root canals. Materials and Methods: A total of 120 mandibular premolars were decoronated to working the length of 12 mm and prepared with protaper rotary files up to size F3. Group A canals irrigated with 1 ml of 3% sodium hypochlorite (NaOCl) followed by 3 ml of 3% NaOCl. Group B canals irrigated with 1 ml of 17% EDTA followed by 3 ml of 3% NaOCl. Group C canals lased with a diode laser. Group D canals were initially irrigated with 0.8 ml of 17% EDTA the remaining 0.2 ml was used to fill the root canals, and diode laser application was done. Group E canals were irrigated with 1 ml distilled water with passive ultrasonic activation, followed by 3 ml of 3% NaOCl. Group F canals were irrigated with 1 ml EDTA with passive ultrasonic activation, followed by 3 ml of 3% NaOCl. Scanning electron microscope examination of canals was done for remaining smear layer at coronal middle and apical third levels. Results: Ultrasonics with EDTA had the least smear layer scores. Conclusion: Diode laser alone performed significantly better than ultrasonics. PMID:27656060

  18. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    We show that societies with a history of irrigation-based agriculture have been less likely to adopt democracy than societies with a history of rainfed agriculture. Rather than actual irrigation, the empirical analysis is based on how much irrigation potentially can increase yields.Irrigation...

  19. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    We show that societies with a history of irrigation-based agriculture have been less likely to adopt democracy than societies with a history of rainfed agriculture. Rather than actual irrigation, the empirical analysis is based on how much irrigation potentially can increase yields.Irrigation...

  20. Assessment of alternative water management options for irrigated agriculture

    NARCIS (Netherlands)

    Jhorar, R.K.; Smit, A.A.M.F.R.; Roest, C.W.J.

    2009-01-01

    A simulation study on alternative water management strategies was carried out for Sirsa Irrigation Circle in Haryana, covering an area of about 4800 km(2). Results showed that crop evapotranspiration and soil salinity development under reduction in canal water supply and increase in groundwater use,

  1. Effects of different sonic activation protocols on debridement efficacy in teeth with single-rooted canals

    Science.gov (United States)

    Niu, Li-na; Luo, Xiao-juan; Li, Guo-hua; Bortoluzzi, Eduardo A.; Mao, Jing; Chen, Ji-hua; Gutmann, James L.; Pashley, David H.; Tay, Franklin R.

    2014-01-01

    Objectives The effects of different EndoActivator® (EA) sonic activation protocols on root canal debridement efficacy were examined. Methods Root canals in 48 single-rooted teeth were instrumented, irrigated initially with NaOCl and divided into 6 groups (N=8) based on the application time of QMix (antimicrobial calcium-chelating irrigant), and the time and sequence of EA irrigant activation - Positive Control: 90 sec QMix; Negative Control: 90 sec saline; Group 1A: 15 sec QMix + 15 sec QMix with EA-activation; Group 1B: 30 sec QMix + 30 sec of QMix with EA-activation; Group 2A: 15 sec QMix with EA-activation + 15 sec QMix; Group 2B: 30 sec QMix with EA-activation + 30 sec QMix. Split roots were examined with scanning electron microscopy for assignment of smear and debris scores in locations along the coronal, middle and apical thirds of the canals. The overall cleanliness of pooled canal locations in the Positive Control and the 4 experimental groups were compared with chi-square tests. Results Significant differences were detected among the 5 groups (p 2A > 1A > Positive Control. Completely clean canals could not be achieved due to the absence of continuous irrigant flow for EA to clear intraradicular debris. Conclusions Irrespective of the sonic activation sequence, irrigant activation for 30 seconds during a 60-second period of QMix application appears to maximize the smear layer and debris removal potential of the EndoActivator® system. PMID:24878251

  2. Effectiveness of castor oil extract on Escherichia coli and its endotoxins in root canals.

    Science.gov (United States)

    Valera, Marcia Carneiro; Maekawa, Lilian Eiko; Chung, Adriana; de Oliveira, Luciane Dias; Carvalho, Claudio Antonio Talge; Koga-Ito, Cristiane Yumi; Jorge, Antonio Olavo Cardoso

    2012-01-01

    This in vitro study sought to evaluate the effectiveness of castor oil extract used as an irrigating solution on Escherichia coli and its endotoxins in root canals. Sixty single-rooted teeth were prepared (using castor oil extract as irrigating solution) and divided into five groups (n = 12): Group 1 samples were treated with calcium hydroxide (Ca(OH)2), Group 2 samples were treated with polymyxin B, Group 3 samples were treated with Ca(OH)2 and 2% chlorhexidine gel (CHX), and Group 4 samples were treated with castor oil extract. A control group used physiological saline solution as an irrigant. Canal content samples were collected at four different times: immediately after instrumentation, seven days after instrumentation, after 14 days of intracanal medication, and seven days after removal of intracanal medication. A plating method was used to assess antimicrobial activity and the quantification of endotoxins was evaluated by the chromogenic Limulus lysate assay. Data were submitted to ANOVA and a Dunn test (a = 5%). Irrigation with castor oil extract decreased E. coli counts but had no effect on the level of endotoxins. Samples taken seven days after removal of medication revealed a significant reduction in endotoxin levels in Groups 3 and 4. Compared to the saline solution irrigation, castor oil extract decreased microorganism counts in root canals immediately after canal preparation. None of the medications used completely eliminated endotoxins in the root canal.

  3. The ability of 5% Tamarindus indica extract as cleaner of the root canal wall smear layer

    Directory of Open Access Journals (Sweden)

    Erawati Wulandari

    2007-12-01

    Full Text Available Tamarindus indica is one of traditional medicines. Pulpa tamaridorum consist of organic acid that is usually used as irrigant and to remove root canal wall smear layer. The aimed of this study was to elucidate the ability of 5% Tamarindus indica extract as a root canal irrigant to remove root canal wall smear layer. Eighteen tooth samples were cut on cervical line and divided into 2 then groups were prepared with K file and irrigated. Group 1 was irrigated by sterile aquabidest and group 2 was irrigated by 5% Tamarindus indica extract. Samples were cut longitudinally and formed 7 × 2× 2 mm specimen. Each specimen was photographed by scanning electron microscope, scored and summed. The total score obtained is used as the hygiene value of root canal wall. The collected data were statistically analyzed by using independent t test at 0.05 level. The result of the study showed there was a significant difference between 5% Tamarindus indica extract and sterile aquabidest (p < 0.05, the hygiene value of 5% Tamarindus indica extract was higher than sterile aquabidest. The conclusion of this investigation showed that 5% Tamarindus indica extract remove root canal wall smear layer.

  4. Threshold Value Research about Catchment Area of Drainage Network of Hetao Irrigated Area%河套灌区排水网络集水面积闽值研究

    Institute of Scientific and Technical Information of China (English)

    周钧迪; 马锦; 宋密; 程一平; 张涛

    2012-01-01

    流域数字水系网络提取的精度,通常与所使用的数字高程图(DEM)的精度和集水面积阈值的大小有关。在给定的DEM图上,数字水系的精度基本上取决于集水面积阈值的设置。首先介绍了几种确定阈值大小的方法,然后应用其中的“河网密度”法来对河套灌区的排干沟的水系网络进行提取。结果表明,该方法能很好地应用于灌区水系网络的合理提取。%The accuracy extraction of basins stream cision and the the threshold value of catchment area. ital stream digital network basically depends on how digital network usually is related to the DEM pre- In a givend DEM map, the precision of the dig- to set the threshold value of the catchment area.This paper first introduces several determine method of t the threshold value , then apply the "river network density" method to the extraction of drainage network for hetao irrigated area . The results show that the method can be used in reasonable network extraction for drainage network of irrigation.

  5. Comparison of triple antibiotic paste removal by different irrigation techniques.

    Science.gov (United States)

    Aksel, Hacer; Küçükkaya Eren, Selen; Serper, Ahmet

    2017-05-31

    This study compared different irrigation techniques in triple antibiotic paste (TAP) removal from root canals. Fifty-six maxillaryanterior-teeth were filled with TAP for 28 days, and assigned into 5 experimental groups (n=10): Syringe irrigation (SI), NaviTip FX (NFX), Vibringe-Syringe irrigation (V-SI), NaviTip FX-Vibringe (V-NFX), passive ultrasonic irrigation (PUI) and positive and negative control groups (n=3 for each). Following the removal of the medicament, the remaining medicament was evaluated using 4-grade scoring-system. V-NFX and NFX showed similar performances (p>0.05) while V-NFX was significantly more efficient than SI and PUI (p0.05). Regarding different parts of the root canals, V-SI and PUI were significantly less efficient at the apical part (pirrigation delivery with and without sonic activation improved the removal of TAP from the root canals when compared to ultrasonic activation, syringe irrigation or sonic activation alone.

  6. Characteristics of inferior variation of water environment and regulating capacity of groundwater reservoir in Jinghui Canal Irrigation District of China%泾惠渠灌区水环境劣变特征及地下水调蓄能力分析

    Institute of Scientific and Technical Information of China (English)

    刘燕; 朱红艳

    2011-01-01

    为确保泾惠渠灌区水环境安全及地下水资源的可持续开发利用,该文通过对20世纪80年代以来泾惠渠灌区地表水和地下水环境劣变特征分析,重点指出了灌区地下水环境劣变的严重性,同时也证实了对地下水实施涵养调蓄的必要性.从取水条件、地下库容、蓄水水源和蓄水方式4个方面论证了灌区具备良好地下水调蓄能力,并利用体积疏干法对灌区各测站的地下调蓄库容进行计算,确定出灌区最大调蓄库容达6.46亿m3,年调蓄库容0.281亿m3.提出对灌区春、夏两季适当加大地表灌溉力度,并针对调蓄空间较大的石桥、泾阳等站进行优先调蓄,实现灌区“以井补渠,以渠养井”,即涵养了当地地下水资源,又有利于灌区水资源的可持续利用,最终保障了灌区的生态环境及粮食安全.%To ensure the safety of water environment and sustainable utilization of groundwater resource, the severity of inferior variation in Jinghui Canal Irrigation District was pointed out, and the necessity to carry out regulating capacity of groundwater reservior was confirmed by analyzing characteristics of inferior variation of water environment since 1980s. Irrigation district was verified to possess ability for regulating capacity of groundwater reservior by water intaking condition, groundwater reservior, water source for reserve and reserve pattern. The regulating capacity of groundwater reservoir of each observation station was calculated through capacity drainage method, 6.46 X 108m3 could be regarded as the maximal regulating capacity of groundwater reservoir, 0.281 X 108 m3 regulating capacity of groundwater reservoir per year. The results indicated that utilization of surface water should be intensified in Spring and Summer properly, Shiqiao and Jingyang stations should take precedence to reserve groundwater in view of larger regulating capacity of groundwater reservoir and water supply ability, and

  7. Evaluation and Comparison of Biological Cleaning Efficacy of Two Endofiles and Irrigants as Judged by Microbial Quantification in Primary Teeth — An In Vivo Study

    Science.gov (United States)

    Musani, Iqbal; Goyal, Varun; Singh, Asha; Bhat, Chetan

    2009-01-01

    The endodontic triad comprises of cleaning and shaping, disinfection and obturation. Success of root canal therapy is majorly achieved by proper cleaning and shaping. However, elimination of bacterial contaminants as well as necrotic debris of the canals requires the adjunctive use of irrigants. To achieve a satisfactory biological and mechanical preparation proper selection of endodontic instruments and irrigants is necessary. In this study we are comparing and evaluating cleaning efficacy of endofiles (K-files and handprotapers ) and root canal irrigants (sodium hypochlorite and chlorhexidine) by microbial quantification. Root canal samples were collected in autoclavable bottles containing transport media (nutrient broth) and samples were cultured in tryptose soya agar at incubation temperature of 37°C for 24-48 hours and colonies were counted with digital colony counter. The significance of this study is to help the clinician select proper instrument and irrigant which minimize the failure rate of root canal treatment for the benefit of patients. PMID:25206117

  8. Water quality of the Boca Raton canal system and effects of the Hillsboro Canal inflow, southeastern Florida, 1990-91

    Science.gov (United States)

    McKenzie, D.J.

    1995-01-01

    The City of Boca Raton in southeastern Palm Beach County, Florida, is an urban residential area that has sustained a constant population growth with subsequent increase in water use. The Boca Raton network of canals is controlled to provide for drainage of excess water, to maintain proper coastal ground-water levels to prevent saltwater intrusion, and to recharge the surficial aquifer system from which the city withdraws potable water. Most of the water supplied to the Boca Raton canal system and the surficial aquifer system, other than rainfall and runoff, is pumped from the Hillsboro Canal. The Biscayne aquifer, principal hydrogeologic unit of the surficial aquifer system, is highly permeable and there is a close relation between water levels in the canals and the aquifer. The amount of water supplied by seepage from the conservation areas is unknown. Because the Hillsboro Canal flows from Lake Okeechobee and Water Conservation Areas 1 and 2, which are places of more highly mineralized ground water and surface water, the canal is a possible source of contamination. Water samples were collected at 10 canal sites during wet and dry seasons and analyzed for major inorganic ions and related characteristics, nutrients, and trace elements. All concentrations were generally within or less than the drinking-water standards established by the Florida Department of Environmental Protection. The high concentrations of sodium and chloride that were detected in samples from the Boca Raton canal system are probably from the more mineralized water of the Hillsboro Canal. Other water-quality data, gathered from various sources from 1982 through 1991, did not indicate any significant changes nor trends. The effects of the Hillsboro Canal on the water quality of the Boca Raton canal system are indicated by increased concentrations of sodium, chloride, dissolved solids, and total organic carbon. Concentrations of the constituents in the canal water generally decrease with distance

  9. Antibacterial Efficacy of Calcium Hypochlorite with Vibringe Sonic Irrigation System on Enterococcus faecalis: An In Vitro Study

    OpenAIRE

    Dumani, Aysin; Guvenmez, Hatice Korkmaz; YILMAZ,Sehnaz; Yoldas, Oguz; Kurklu, Zeliha Gonca Bek

    2016-01-01

    Aim. The purpose of this study was to compare the in vitro efficacy of calcium hypochlorite (Ca[OCl]2) and sodium hypochlorite (NaOCl) associated with sonic (Vibringe) irrigation system in root canals which were contaminated with Enterococcus faecalis. Material and Methods. The root canals of 84 single-rooted premolars were enlarged up to a file 40, autoclaved, inoculated with Enterococcus faecalis, and incubated for 21 days. The samples were divided into 7 groups according to the irrigation ...

  10. Management Of Irrigation Water and its Impact on Agriculture Productivity

    Directory of Open Access Journals (Sweden)

    Asad Raza Abidi

    2013-10-01

    Full Text Available On the inflow side canal water in the canal command area of Mirwah is mismanaged by irrigation officials and head-end and influential farmers. Farmers in Sindh generally and Khairpur particularly irrigate their land without scientific techniques and there is no economic pricing of water that might encourage conservation. This, together with the lack of any adequate substitute in the form of administrative control of water and cropping patterns, has been responsible for the excessive water-coefficient of output, and the unequal distribution of water, which have been at the heart of the problem of mismanagement water on the inflow side. The need for restructuring the irrigation system in Sindh is urgent not only because of both allocation and distribution, because, over the years, the province has suffered from unequal distribution of water between big and small farmers, and between head-end and tail-end farmers.

  11. STUDY AND APPLICATION OF STEADY FLOW AND UNSTEADY FLOW MATHEMATICAL MODEL FOR CHANNEL NETWORKS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the Preissmann implicit scheme for the one-dimensional Saint-Venant equation, the mathematical model for one-dimensional river networks and canal networks was developed and the key issues on the model were expatiated particularly in this article. This model applies the method of three-steps solution for channel-junction-channel to simulate the river networks, and the Gauss elimination method was used to calculate the sparse matrix. This model was applied to simulate the tree-type irrigation canal networks, complex looped channel networks and the Lower Columbia Slough networks. The results of water level and discharge agree with the data from the Adlul and field data. The model is proved to be robust for simulating unsteady flows in river networks with various degrees of complex structure. The calculated results show that this model is useful for engineering applications in complicated river networks. Future research was recommended to focus on setting up ecological numerical model of water quality in river networks and canal networks.

  12. [Waterborne iron migration by groundwater irrigation pumping in a typical irrigation district of Sanjiang Plain].

    Science.gov (United States)

    Zou, Yuan-Chun; Yu, Xiao-Fei; Huo, Li-Li; Lü, Xian-Guo; Jiang, Ming

    2012-04-01

    The iron concentration in groundwater, iron's seasonal migration from groundwater to sun-basked pools, paddy fields and drainage canals, and its distribution in the sediments/soils were observed in the Jiansanjiang Branch Bureau, Heilongjiang Agricultural Cultivation Bureau. The results suggested that the total iron mass concentration of the studied area was (1.73 +/- 0.41) mg x L(-1), ranging from 0.01 to 11.4 mg x L(-1), with the variation coefficient of 1.29%. The annual iron input mass from groundwater to paddy fields and other surface water bodies was 4 976.40 t in 2010, according to the rice planting area and rating irrigation volume. Dissolved Fe2+, Fe3+ and iron, as well as the total iron (dissolved and particle) had seasonal variation, with greater values presented in June and July. These waterborne irons in paddy field waters were greater than those in sun-basked pools and drainage canals. Obvious enrichment effect was observed in sun-basked pools and paddy fields, with their total iron mass concentrations were 6.17 and 21.65 times greater than that in groundwater. Either the total iron or iron oxides in sun-baked pool sediments were greater than that in paddy field soils, field canal and main canal sediments. The differences of the total iron and iron oxides in paddy field soils, field canal and main canal sediments were not significantly different. Considerable irons were precipitated within sun-basked pools and paddy fields during the transfer from groundwater to surface water, with a part of irons exporting into canals through drainage and then precipitated there. Not only the change of total iron mass, but the transformation of iron chemical speciation was observed during the transfer, which was affected by paddy irrigation management directly. The long-term irrigation pumping could cause the substantial enrichment of iron in paddy soils and canal sediments, resulting in the increase of potential pollution risk.

  13. Uncontrolled Removal of Dentin during In Vitro Ultrasonic Irrigant Activation.

    Science.gov (United States)

    Boutsioukis, Christos; Tzimpoulas, Nestor

    2016-02-01

    The aim of this study was to evaluate uncontrolled removal of dentin during in vitro ultrasonic irrigant activation in prepared root canals using 2 different files. Fifty-four human single-rooted teeth with straight root canals were prepared to size 35/.06 taper. The specimens were randomly allocated to 3 groups (n = 18). Two milliliters of 2% sodium hypochlorite was delivered 3 times to each root canal by a syringe and an open-ended needle. After each delivery, the irrigant was ultrasonically activated for 10 seconds at 35% power either by a size 15 ultrasonic K-file (group A) or a size 20 Irrisafe file (Acteon Satelec, Merignac, France) (group B) placed at 2 mm short of the working length. The irrigant in the control specimens (group C) was not activated. Specimens were scanned by micro-computed tomographic imaging at 10-μm voxel size before preparation, after preparation, and after the final irrigation/activation sequence. Scans were coregistered and segmented, and the amount of dentin removed during the final step was quantified by morphologic operations. Results were analyzed by nonparametric statistical tests. The level of significance was set to P ultrasonic files removed significantly more dentin than irrigant delivery in the control group (P ≤ .005). K-files removed significantly more dentin than Irrisafe files in the apical third (P = .001). Ultrasonic irrigant activation may result in uncontrolled removal of dentin in straight root canals and at manufacturer-recommended power settings. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Grower demand for sensor-controlled irrigation

    Science.gov (United States)

    Lichtenberg, Erik; Majsztrik, John; Saavoss, Monica

    2015-01-01

    Water scarcity is likely to increase in the coming years, making improvements in irrigation efficiency increasingly important. An emerging technology that promises to increase irrigation efficiency substantially is a wireless irrigation sensor network that uploads sensor data into irrigation management software, creating an integrated system that allows real-time monitoring and control of moisture status that has been shown in experimental settings to reduce irrigation costs, lower plant loss rates, shorten production times, decrease pesticide application, and increase yield, quality, and profit. We use an original survey to investigate likely initial acceptance, ceiling adoption rates, and profitability of this new sensor network technology in the nursery and greenhouse industry. We find that adoption rates for a base system and demand for expansion components are decreasing in price, as expected. The price elasticity of the probability of adoption suggests that sensor networks are likely to diffuse at a rate somewhat greater than that of drip irrigation. Adoption rates for a base system and demand for expansion components are increasing in specialization in ornamental production: growers earning greater shares of revenue from greenhouse and nursery operations are willing to pay more for a base system and are willing to purchase larger numbers of expansion components at any given price. We estimate that growers who are willing to purchase a sensor network expect investment in this technology to generate significant profit, consistent with findings from experimental studies.

  15. Icogne irrigation-network hydro-power installation; Petite centrale hydro-electrique sur le reseau d'irrigation de la commune d'Icogne. Etude de faisabilite

    Energy Technology Data Exchange (ETDEWEB)

    Cordonier, N.; Rey, G. [Nicolas Cordonier et Gilles Rey SA, Sierre (Switzerland)

    2007-01-15

    This final report for the Swiss Federal Office of Energy (SFOE) presents the feasibility study for a hydro-power installation that uses an existing municipal irrigation scheme in the alpine region of Icogne, Switzerland. The report takes a look at the present situation which features, apart from the irrigation scheme itself, mountain torrents and artificial compensation lakes. The concept for the use of the available water pressure due to height-difference between these two lakes to drive a turbine and so generate electricity is described. Variants considered are reviewed. Investment and operating costs are examined as are the electricity production and the cost of the power generated. Finally, investments and other financial aspects are looked at and the further course of action is discussed.

  16. IN VITRO EVALUATION OF INTRACANAL BACTERIAL REDUCTION USING TWO DIFFERENT INSTRUMENTATION TECHNIQUES AND IRRIGATION REGIMENS

    Directory of Open Access Journals (Sweden)

    Senthilnayagam Kalyanasundaram

    2016-10-01

    Full Text Available BACKGROUND Enterococcus faecalis, a facultative anaerobic Gram-positive coccus is involved in the endodontic failures. The bacterial elimination from the infected root canal is often achieved by mechanical cleaning and shaping along with irrigants. This study compares the intracanal bacterial reduction using two instrumentation techniques and irrigation regimens. METHODS 50 extracted human mandibular bicuspid teeth with single canal were decoronated at cemento-enamel junction and pulpectomy done. Working length determined and apical foramen sealed with acrylic resin and specimens autoclaved at 1210 centigrade for 20 minutes. Samples were divided in to six groups. Group I - Hand instrumentation with 0.9% saline irrigant; Group II - Hand instrumentation with 5% sodium hypochlorite as irrigant; Group III - Rotary instrumentation with 0.9% saline irrigant; Group IV - Rotary instrumentation with 5% sodium hypochlorite as irrigant; Group V - Control-Only saline irrigation; Group VI - Samples taken immediately after sterilization. Sterilized teeth infected with E. faecalis and incubated for one day at 370 centigrade. Samples were collected from the canals before and after instrumentation and irrigation. The colony forming units were then counted and transformed to log numbers and analysed statistically. RESULTS The reduction in number of colony-forming units was statistically significant. Statistical analysis reveals bacterial reduction in the following order GIV>GIII>GII>GI>GV. CONCLUSION Bacterial reduction is higher with greater taper (0.06 mm/mm instrumentation and it is enhanced with the use of 5% sodium hypochlorite compared to 0.9% saline solution.

  17. MULTIPLE SPINAL CANAL MENINGIOMAS

    Directory of Open Access Journals (Sweden)

    Nandigama Pratap Kumar

    2016-10-01

    Full Text Available BACKGROUND Meningiomas of the spinal canal are common tumours with the incidence of 25 percent of all spinal cord tumours. But multiple spinal canal meningiomas are rare in compare to solitary lesions and account for 2 to 3.5% of all spinal meningiomas. Most of the reported cases are both intra cranial and spinal. Exclusive involvement of the spinal canal by multiple meningiomas are very rare. We could find only sixteen cases in the literature to the best of our knowledge. Exclusive multiple spinal canal meningiomas occurring in the first two decades of life are seldom reported in the literature. We are presenting a case of multiple spinal canal meningiomas in a young patient of 17 years, who was earlier operated for single lesion. We analysed the literature, with illustration of our case. MATERIALS AND METHODS In September 2016, we performed a literature search for multiple spinal canal meningiomas involving exclusively the spinal canal with no limitation for language and publication date. The search was conducted through http://pubmed.com, a wellknown worldwide internet medical address. To the best of our knowledge, we could find only sixteen cases of multiple meningiomas exclusively confined to the spinal canal. Exclusive multiple spinal canal meningiomas occurring in the first two decades of life are seldom reported in the literature. We are presenting a case of multiple spinal canal meningiomas in a young patient of 17 years, who was earlier operated for solitary intradural extra medullary spinal canal meningioma at D4-D6 level, again presented with spastic quadriparesis of two years duration and MRI whole spine demonstrated multiple intradural extra medullary lesions, which were excised completely and the histopathological diagnosis was transitional meningioma. RESULTS Patient recovered from his weakness and sensory symptoms gradually and bladder and bowel symptoms improved gradually over a period of two to three weeks. CONCLUSION Multiple

  18. Design of canals

    CERN Document Server

    Swamee, P K

    2015-01-01

    The book presents firsthand material from the authors on design of hydraulic canals. The book discusses elements of design based on principles of hydraulic flow through canals. It covers optimization of design based on usage requirements and economic constraints. The book includes explicit design equations and design procedures along with design examples for varied cases. With its comprehensive coverage of the principles of hydraulic canal design, this book will prove useful to students, researchers, and practicing engineers. End-of-chapter pedagogical elements make it ideal for use in graduate courses on hydraulic structures offered by most civil engineering departments across the world.

  19. Microbiological water quality in a large irrigation system: El Valle del Yaqui, Sonora México.

    Science.gov (United States)

    Gortáres-Moroyoqui, Pablo; Castro-Espinoza, L; Naranjo, Jaime E; Karpiscak, Martin M; Freitas, Robert J; Gerba, Charles P

    2011-01-01

    The primary objective of this study was to determine the microbial water quality of a large irrigation system and how this quality varies with respect to canal size, impact of near-by communities, and the travel distance from the source in the El Valle del Yaqui, Sonora, México. In this arid region, 220,000 hectares are irrigated with 80% of the irrigation water being supplied from an extensive irrigation system including three dams on the Yaqui River watershed. The stored water flows to the irrigated fields through two main canal systems (severing the upper and lower Yaqui Valley) and then through smaller lateral canals that deliver the water to the fields. A total of 146 irrigation water samples were collected from 52 sample sites during three sampling events. Not all sites could be accessed on each occasion. All of the samples contained coliform bacteria ranging from 1,140 to 68,670 MPN/100 mL with an arithmetic mean of 11,416. Ninety-eight percent of the samples contained less than 1,000 MPN/100 mL Escherichia coli, with an arithmetic mean of 291 MPN/100 mL. Coliphage were detected in less than 30% of the samples with an arithmetic average equal to 141 PFU/100 mL. Enteroviruses, Cryptosporidium oocysts, and Giardia cysts were also detected in the canal systems. No significant difference was found in the water quality due to canal system (upper or lower Yaqui Valley), canal-size (main vs. lateral), distance from source, and the vicinity of human habitation (presence of various villages and towns along the length of the canals). There was a significant decrease in coliforms (p < 0.011) and E. coli (< 0.022) concentrations as travel distance increased from the City of Obregón.

  20. The antimicrobial effect of iodine-potassium iodide after cleaning and shaping procedures in mesial root canals of mandibular molars.

    Science.gov (United States)

    Tello-Barbaran, Javier; Nakata, Hilda Moromi; Salcedo-Moncada, Doris; Bramante, Clovis M; Ordinola-Zapata, Ronald

    2010-01-01

    The aim of this study was to evaluate the antibacterial activity of 2% iodine potassium iodide (IKI) used as a final rinse after the cleaning and shaping procedures in mesial root canals of mandibular molars infected with Enterococcus faecalis. Seventy two mandibular first molars were used. The root canals were infected with Enterococcus faecalisfor 30 days. After the infection procedures, the root canals were cleaned and shaped by using the Pro Taper rotary system and manual files. The teeth were randomly assigned to four experimental groups (N = 18). In group 1, the root canals were irrigated with sterile distilled water (control). In group 2, the root canals were irrigated with 1% Sodium hypochlorite (NaOCl) during instrumentation. In group 3, root canals were irrigated with 1% NaOCl during instrumentation and a five minute final irrigation using 2% IKI. In group 4, the root canals were irrigated with 1% NaOCl during instrumentation and a 15 minutes final irrigation with 2% IKI. Bacteria colony-forming units (CFU) from root canals were semi-quantified and the presence of negative cultures among the groups was compared using Fisher's test (p < 0.05). The order of effectiveness was: 1% NaOCI plus 2% IKl for 15 minutes (95%), 1% NaOCl plus 2% IKl for 5 minutes (44%), 1% NaOCl (17%) and sterile distilled water (0%). Fisher's exact test showed a significant difference among the groups (p < 0.05). It was concluded that under in vitro conditions, IKI was able to eliminate the Enterococcus faecalis from infected dentin significantly in a 15-minute time frame after the cleaning and shaping procedures.

  1. Ghana - Agriculture - Irrigation

    Data.gov (United States)

    Millennium Challenge Corporation — The Millennium Development Authority (MiDA) financed the construction of a new irrigation scheme in Kpong and the renovation of two irrigation schemes in Botanga and...

  2. Efficiency of a semiconductor diode laser in disinfection of the root canal system in endodontics: An in vitro study

    Directory of Open Access Journals (Sweden)

    Mithra N Hegde

    2015-01-01

    Full Text Available Context: The success of endodontic treatment depends on the eradication of microbes from the rootcanal system and prevention of reinfection. The root canal is shaped with hand and rotary instruments under constant irrigation to remove the inflamed and necrotic tissue, microbes/biofilms, and other debris from the root canal space. The main goal of instrumentation is to facilitate effective irrigation, disinfection, and filling. Throughout the history of endodontics, endeavors have continuously been made to develop more effective irrigant delivery and agitation systems for root canal irrigation. Aim: The purpose of this study was to evaluate the efficacy of three different newer irrigation delivery techniques; namely Endovac, Stropko Irrigator, and laser disinfection with 5.25% sodium hypochlorite. Materials and Methods: Forty teeth after disinfection by Occupational Safety and Health Administration (OSHA regulations were instrumented and inoculated with bacterial strains of Enterococcusfaecalis. The teeth were divided into four groups, in the experimental group, the irrigants were delivered with the Endovac, Stropko Irrigator, and laser irradiation and the control group which received no irrigation. The samples were incubated in Muller-Hilton media plates and incubated for 24 h. Statistical analysis used: The colony forming units were determined and statistically analyzed using the chi-square test. Results: According to the results obtained, laser irradiation resulted in complete disinfection of the root canal system. The Endovac system resulted in significant disinfection as compared to the Stropko Irrigator system. Conclusion: Laser irradiation resulted in significantly higher antimicrobial effects compared with the Endovac and Stropko irrigation groups when in conjunction with sodium hypochlorite

  3. Complication of improper management of sodium hypochlorite accident during root canal treatment

    OpenAIRE

    Faras, Fatemah; Abo-Alhassan, Fawaz; Sadeq, Abdullah; Burezq, Hisham

    2016-01-01

    Sodium Hypochlorite (NaOCl) is a common irrigation solution used in root canal treatment. It has strong antibacterial and tissue dissolving properties. Nevertheless, it has some serious complications, some of which are life-threatening. A young male presented with severe chemical burn of the right infraorbital area and partial necrosis of the hard palate resulting from extrusion of NaOCl during root canal treatment of the upper right 2nd molar tooth. The patient had a facial scar, and mucosal...

  4. In vitro study of calcium hydroxide removal from mandibular molar root canals.

    Science.gov (United States)

    Ma, Jingzhi; Shen, Ya; Yang, Yan; Gao, Yuan; Wan, Pan; Gan, Yan; Patel, Payal; Curtis, Allison; Khakpour, Mehrzad; Haapasalo, Markus

    2015-04-01

    Previous studies have shown the difficulty in removing calcium hydroxide (Ca[OH]2) paste from the root canals before root filling. Mesial and distal canals of 30 mandibular molars were prepared with the WaveOne Primary (25/.08) and Large file (40/.08) (Dentsply Tulsa Dental Specialties, Tulsa, OK), respectively. All canals were then filled with Ca(OH)2. The teeth were divided into the following 3 treatment groups (each with n = 10): (1) instrumentation with needle irrigation, (2) instrumentation with irrigation and passive ultrasonic activation (PUI), and (3) the GentleWave system (Sonendo, Inc, Laguna Hills, CA) without instrumentation. The irrigation time in each group was 7.5 minutes. To further test the efficiency of the GentleWave system, shorter times of 90 seconds were tested using water alone. Reconstructed micro-computed tomographic scans were used to measure the volume of the canals and Ca(OH)2 after instrumentation, initial filling of Ca(OH)2, and after its removal. The percentage of Ca(OH)2 remaining in the canals was calculated. None of the 10 teeth (30 canals) in the conventional irrigation and PUI groups were completely cleaned of Ca(OH)2 in 7.5 minutes. In the apical third of mesial and distal canals, respectively, conventional irrigation removed 47.82% ± 16.36% and 77.68% ± 12.82%, PUI removed 61.66% ± 25.54% and 88.85 ± 12.06%, and the GentleWave system removed significantly more Ca(OH)2 (P < .05) with 100% and 98.78% ± 3.84%. Additional experiments in 10 teeth, using only water as the irrigant, revealed that the GentleWave system removed 99.85% and 99.97% of Ca(OH)2 within 90 seconds without the use of any instruments in the mesial and distal canals, respectively. The study confirms the difficulty to remove Ca(OH)2 from root canals using conventional methods. The GentleWave system removed the paste within 90 seconds using water irrigation alone. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights

  5. WATER REQUIREMENT OF IRRIGATED GARLIC

    Science.gov (United States)

    A replicated field trial was conducted on the West side of the San Joaquin Valley to determine the crop coefficient and water requirements of irrigated garlic. Irrigation systems used included flood irrigation, subsurface drip irrigation, and surface drip irrigation. Irrigation levels were set at 5...

  6. Water Requirements Of Irrigated Garlic

    Science.gov (United States)

    A replicated field trial was conducted on the West side of the San Joaquin Valley to determine the crop coefficient and water requirements of irrigated garlic. Irrigation systems used included flood irrigation, subsurface drip irrigation, and surface drip irrigation. Irrigation levels were set at 5...

  7. [Effect of different irrigants on radicular dentin cleansing and resin tag formation after post space preparation].

    Science.gov (United States)

    Mao, Cai-Yun; Gu, Xin-Hua

    2010-06-01

    To evaluate the effect of different root canal irrigants on smear layer removal and dentinal tubule opening of root canal surfaces after post space preparation. Thirty maxillary anteriors were endodontically treated. After post space preparation, the teeth were assigned to three groups with ten teeth each: group A, B, C. 3% H2O2, 15% ethylenediamine tetraacetic acid(EDTA), 15% EDTA and 3% NaClO were used as irrigant of group A, B, C. After post space irrigation, eight teeth of each group were examined under scanning electron microscope (SEM) for smear layer removal and dentinal tubule opening. The left two specimens were restored with fiber posts and prepared for evaluation of resin tag formation. The cleansing effectiveness of group A, B and C was respectively 3.89 +/- 0.36, 1.77 +/- 0.30, 1.25 +/- 0.21. The dentinal tubule opening of group A, B and C was respectively (2.53 +/- 0.19), (3 11 +/- 023) (3.83 +/- 0.52) microm. The cleansing effectiveness and dentinal tubule opening of root canal surfaces were significantly affected by different root canal irrigants (P irrigant groups, and group B showed excellent resin tag formation. Irrigation with 15% EDTA after post space preparation can excellently remove the smear layer and improve dentinal tubule opening, permitting well penetration of resin adhesive into the dentinal tubules and collagen fibrillar structure.

  8. Reimagining cost recovery in Pakistan's irrigation system through willingness-to-pay estimates for irrigation water from a discrete choice experiment

    Science.gov (United States)

    Bell, Andrew Reid; Shah, M. Azeem Ali; Ward, Patrick S.

    2014-08-01

    It is widely argued that farmers are unwilling to pay adequate fees for surface water irrigation to recover the costs associated with maintenance and improvement of delivery systems. In this paper, we use a discrete choice experiment to study farmer preferences for irrigation characteristics along two branch canals in Punjab Province in eastern Pakistan. We find that farmers are generally willing to pay well in excess of current surface water irrigation costs for increased surface water reliability and that the amount that farmers are willing to pay is an increasing function of their existing surface water supply as well as location along the main canal branch. This explicit translation of implicit willingness-to-pay (WTP) for water (via expenditure on groundwater pumping) to WTP for reliable surface water demonstrates the potential for greatly enhanced cost recovery in the Indus Basin Irrigation System via appropriate setting of water user fees, driven by the higher WTP of those currently receiving reliable supplies.

  9. Revestimiento de canales

    OpenAIRE

    Woll, A

    2017-01-01

    La maquinaria moderna alemana empleada para el revestimiento de canales de gran sección, presenta grandes ventajas de economía, rendimiento, regularidad e impermeabilidad de la construcción. Para la aplicación de esta maquinaria —inicialmente se ha procedido a la excavación del canal mediante el empleo de maquinaria ordinaria de desmonte y la maquinaria especial— comienza su trabajo con el enrase de las cotas previstas.

  10. Microporous, demineralized collagen matrices in intact radicular dentin created by commonly used calcium-depleting endodontic irrigants.

    Science.gov (United States)

    Tay, Franklin R; Gutmann, James L; Pashley, David H

    2007-09-01

    The use of calcium-depleting solutions in restorative dentistry results in demineralization of intact coronal dentin beneath smear layers. Likewise, application of calcium-depleting irrigants as final rinses might create demineralized collagen matrices in intact radicular dentin after removal of root canal wall smear layers created during canal shaping. These unsupported collagen matrices collapse on desiccation and might be difficult to detect in scanning electron microscopy dehydration techniques traditionally used in endodontic research. Demineralized collagen matrices were identified, by using a hexamethyldisilazane dehydration protocol, on the surface of smear layer-depleted radicular dentin when NaOCl was used as initial rinse, followed by the use of 17% ethylenediaminetetraacetic acid or BioPure MTAD as the final rinse. Compaction of conventional root filling materials over a demineralized collagen matrix in instrumented dentin is analogous to performing the same procedure against the predentin collagen network in the uninstrumented parts of root canals. The potential consequences of this process are, however, unknown.

  11. Irrigation System Design Based on ZigBee Network and D-S Data Fusion%基于ZigBee网络和D-S数据融合的灌溉系统设计

    Institute of Scientific and Technical Information of China (English)

    戴菲菲; 彭力

    2011-01-01

    To realize agricultural automation, this paper introduces design of an intelligent irrigation system consisting of a terminal node, a routing control node, a ZigBee total nodal and a central control system. This irrigation system realizes the real-time monitoring and the automatic control on the farmland soil moisture content. This system bases on ZigBee short-range wireless sensor network and GSM remote wireless sensor networks double communication network, and adopts the control method of combining automatic control and artificially remote mode. So it can not only solve the problems of the traditional automatic irrigation control system, such as high cost, the difficulty of power supply, the inaccurate algorithm and the inconvenience of expansion, etc, but also lay the .foundation of optimizing decisions because of its powerful information processing function.%为推进农业自动化,这里设计了一种由终端节点、路由控制节点、ZigBee总节点以及中央监控系统组成智能灌溉系统,实现了对农田土壤墒情的实时监测和自动控制.本系统通过基于ZigBee协议短程无线传感网络和基于GSM的远程无线传感网络的双层通信网络,采用自动控制和人工远程模式相结合的控制方式,不仅能够解决传统自动灌溉控制系统成本高、供电难、算法不准确以及扩展不便等问题,其强大的信息处理功能也为优化决策奠定了基础.

  12. Root canal irrigation%根管冲洗

    Institute of Scientific and Technical Information of China (English)

    王茜; 李淑华

    2014-01-01

    根管冲洗是根管预备中的重要环节.根管冲洗的主要目的是去除根管内容物、溶解病理组织、清除病原微生物、去除玷污层,避免根管预备过程中将感染物质推向深部或推出根尖孔.根管冲洗能否达到目的有赖于冲洗剂及冲洗技术的选择.本文主要介绍临床常用的根管冲洗剂及冲洗技术,旨在为临床操作提供理论依据.

  13. 根管冲洗%Irrigation of the root canal

    Institute of Scientific and Technical Information of China (English)

    Edgar Sch(a)fer; 刘洋

    2010-01-01

    在根尖周炎的病例中,微生物定植根管系统.目前,通过机械的方法尚不能将根管内的所有微生物彻底清除.因此,要想根除根管内的感染,冲洗是十分必要的.本文对最常用的冲洗剂的不同作用以及它们之间的相互作用进行了讨论,并对临床提出指导性建议.要减少根管内的微生物,至少应用两种不同的冲洗剂才能获得最好的效果.

  14. Assessment of smear layer removal protocols in curved root canals.

    Science.gov (United States)

    Yeung, William; Raldi, Denise Pontes; Cunha, Rodrigo Sanches; Mello, Isabel

    2014-08-01

    This study sought to assess if the final rinse protocol interferes with the smear layer removal in the apical area of curved canals. Sixty-four extracted human mandibular molars with curved mesial roots were instrumented with rotary files and divided into six experimental groups for final rinse: 1EDTA (syringe irrigation with 1 mL of 17% ethylenediaminetetraacetic acid (EDTA) ), 5EDTA (syringe irrigation with 5 mL of 17% EDTA), 1EDTA-P (syringe irrigation with 1 mL of 17% EDTA + pumping with gutta-percha point), 5EDTA-P (syringe irrigation with 5 mL of 17% EDTA + pumping with gutta-percha point), 1EDTA-EA (syringe irrigation with 1 mL of 17% EDTA + EndoActivator) and 5EDTA-EA (syringe irrigation with 5 mL of 17% EDTA + EndoActivator). Final rinsing was carried out over 3 min. The specimens were split lengthwise and observed under a scanning electron microscope using a score criterion. Comparison among the groups showed statistically significant difference only between the 5EDTA-EA group and the other groups (Kruskal-Wallis and Dunn's post-hoc tests, P protocols used.

  15. Cytotoxic effect of endodontic irrigants in vitro.

    Science.gov (United States)

    Bajrami, Donika; Hoxha, Veton; Gorduysus, Omer; Muftuoglu, Sevda; Zeybek, Nacije Dilara; Küçükkaya, Selen

    2014-03-10

    Cytotoxicity of root canal irrigants is important due to their close contact with host tissues. The aim of this study was to assess the cytotoxic effect of NaOCl 3%, Chx 2%, and MTAD on rat periodontal ligament fibroblasts, at 0.1 and 100 µl/mL, using WST-1 colorimetric method. Rat ligamental fibroblasts were exposed to the irrigants and their viability was assessed after 1, 24, 48, and 72 h. The measurements were determined using WST-1 assay, using a micro ELISA reader. At 100 ml/L all 3 irrigants were strongly cytotoxic, although CHX was less so than NaOCl and MTAD. At the 0.1 ml/L concentration, NaOCl and MTAD were only moderately cytotoxic, whereas Chx was highly deleterious to cell viability at all time points. There was a significant influence of the dilution rate of the substance, because the odds ratio for cell viability being over 50% was increased 51 times between the 100 ml/L and 0.1 ml/L dilutions. It seems that irrigating solutions should be used at lower concentrations to enhance cell viability.

  16. Comparative anti-microbial efficacy of Azadirachta indica irrigant with standard endodontic irrigants: A preliminary study

    Directory of Open Access Journals (Sweden)

    Arindam Dutta

    2014-01-01

    Full Text Available Objective: The anti-microbial efficacy of 2.5% sodium hypochlorite (SHC and 0.2% chlorhexidine gluconate were compared with an experimental irrigant formulated from the Neem tree, Azadirachta indica A. Juss. Materials and Methods: A sample of 36 single rooted anterior teeth with periapical radiolucency and absence of response to vitality tests that required root canal treatment were selected for this study. The test irrigants and their combinations were assigned to five different groups and saline served as the control. Access cavities were prepared using an aseptic technique and samples collected for both anaerobic culture and Gram stained smears, followed by irrigation and sample collection again. The number of organisms were expressed in colony forming units/ml after 72 h of incubation; the smears were analyzed for their microbial loads and tissue clearance and assessed as per defined criteria. Results: Our results found the maximum reduction in microbial loads, when analyzed by culture method, with a combination of SHC and the experimental neem irrigant. Maximum tissue clearance on the Gram Stained smears was also found with the same combination. Conclusion: Neem irrigant has anti-microbial efficacy and can be considered for endodontic use.

  17. Antibiofilm and antibacterial activities of farnesol and xylitol as potential endodontic irrigants.

    Science.gov (United States)

    Alves, Flávio R F; Neves, Mônica A S; Silva, Marlei G; Rôças, Isabela N; Siqueira, José F

    2013-01-01

    This study investigated the antibiofilm and antibacterial effects of farnesol and xylitol in a series of experiments in order to evaluate their potential use as root canal irrigants. The following substances were tested: 0.2% farnesol; 5% and 20% xylitol; 0.2% farnesol plus 20% xylitol; and saline (control). For comparison with an established endodontic irrigant, 2.5% NaOCl was included in each test. Three experiments were conducted: the crystal violet assay, to evaluate the effects on the biofilm biomass; the dentin disinfection test, to evaluate the effects on bacterial viability in biofilms; and the root canal disinfection test, to simulate the use in the root canal environment. Farnesol was the most effective substance in reducing the biofilm biomass, followed by 20% xylitol. All substances affected bacterial viability in biofilms; farnesol showed the best results followed by the farnesol/xylitol combination. Irrigation with all substances significantly reduced the bacterial load (pendodontics in certain situations.

  18. Decalcifying efficacy of different irrigating solutions: effect of cetrimide addition

    Directory of Open Access Journals (Sweden)

    POGGIO Claudio

    2014-09-01

    Full Text Available The objective of the present study was to evaluate and compare the influence of cetrimide on decalcifying capability of different irrigating solutions. Fifteen maxillary central incisor teeth has been collected. The canals were prepared in order to obtain four samples from each root. The specimens were randomly divided into 6 experimental groups (n=10 according to tested irrigating agents. Irrigating agents consisted in different composition of EDTA and citric acid solutions, addicted or not with cetrimide. Each specimen was submitted to three successive 5-min immersions in each solution. After exposures, the concentration of Ca2+ extracted was measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES. Data were analysed by means of Kruskal Wallis and Mann Whitney tests. Significance was predetermined at p < 0.05. For all irrigants, the amounts of Ca2+ extracted from root canal dentin samples at 10 minutes were not significantly different from values reported after 15 minutes respectively. Therefore, for all irrigants tested, 10 minutes of application are sufficient to obtain maximum Ca2+ release. Moreover citric acid based agents observed a higher release of Ca2+. The addition of cetrimide did not affect the decalcifying capability of the EDTA and citric acid solutions.

  19. Discordance between presumed standard of care and actual clinical practice: the example of rubber dam use during root canal treatment in the National Dental Practice-Based Research Network

    Science.gov (United States)

    Gilbert, Gregg H; Riley, Joseph L; Eleazer, Paul D; Benjamin, Paul L; Funkhouser, Ellen

    2015-01-01

    Objectives Use of a rubber dam during root canal treatment is considered the standard of care because it enhances patient safety and optimises the odds of successful treatment. Nonetheless, not all dentists use a rubber dam, creating disconnect between presumed standard of care and what is actually done in clinical practice. Little is known about dentists’ attitudes towards use of the rubber dam in their practices. The objectives were to: (1) quantify these attitudes and (2) test the hypothesis that specific attitudes are significantly associated with rubber dam use. Setting National Dental Practice-Based Research Network (NationalDentalPBRN.org). Participants 1490 network dentists. Outcome measures Dentists completed a questionnaire about their attitudes towards rubber dam use during root canal treatment. Three attitude scales comprised 33 items that used a 5-point ordinal scale to measure beliefs about effectiveness, inconvenience, ease of placement, comparison to other isolation techniques and patient factors. Factor analysis, cluster analysis and multivariable logistic regression analysed the relationship between attitudes and rubber dam use. Results All items had responses at each point on the 5-point scale, with an overall pattern of substantial variation across dentists. Five attitudinal factors (rubber dam effectiveness; inconvenient/time-consuming; ease of placement; effectiveness compared to Isolite; patient factors) and 4 clusters of practitioners were identified. Each factor and cluster was independently and strongly associated with rubber dam use. Conclusions General dentists have substantial variation in attitudes about rubber dam use. Beliefs that rubber dam use is not effective, inconvenient, time-consuming, not easy to place or affected by patient factors, were independently and significantly associated with lower rubber dam use. These attitudes explain why there is substantial discordance between presumed standard of care and actual practice

  20. Canals, Bypass Canal, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2002. It is described as 'Bypass Canal'. Data by this publisher are often provided in...

  1. Irrigation analysis based on long-term weather data

    Science.gov (United States)

    Irrigation-management is based upon delivery of water to a crop in the correct amount and time, and the crop’s water need is determined by calculating evapotranspiration (ET) using weather data. In 1994 an ET-network was established in the Texas High Plains to manage irrigation on a regional scale. ...

  2. Antimicrobial activity of a new nanobased endodontic irrigation solution: In vitro study

    Directory of Open Access Journals (Sweden)

    Leila Moghadas

    2012-01-01

    Full Text Available Aims: The purpose of this study was to introduce a nanosilver particle based endodontic irrigation solution and to evaluate its antimicrobial efficacy in comparison to 5.25% NaOCl. Materials and Methods: In an in vitro experiment the effect of the new irrigant against Enterococcus faecalis (ATCC: 29212 and Staphylococcus aureus (ATCC 25923, two most commonly isolated species of root canal space, was studied in different time intervals of 3, 5 and 15 minutes. Results: No growth of E. faecalis and S. aureus was observed in any of irrigant groups and any of different time intervals. Conclusion: These results indicate that the new irrigant is as effective as NaOCl in preventing the bacterial growth of common root canal bacteria.

  3. Irrigation water as a source of drinking water: is safe use possible?

    DEFF Research Database (Denmark)

    Hoek, Wim van der; Konradsen, F; Ensink, J H;

    2001-01-01

    was used (relative risk 1.68; 95% CI 1.31-2.15). For people with less water available the direction of the association between water quality and diarrhoea was different (relative risk 0.80; 95% CI 0.69-0.93). This indicates that good quality drinking water provides additional health benefits only when...... and have a continuous water supply for sanitation and hygiene. Irrigation water management clearly has an impact on health and bridging the gap between the irrigation and drinking water supply sectors could provide important health benefits by taking into account the domestic water availability when......BACKGROUND: In arid and semi-arid countries there are often large areas where groundwater is brackish and where people have to obtain water from irrigation canals for all uses, including domestic ones. An alternative to drawing drinking water directly from irrigation canals or village water...

  4. Irrigation water quality in southern Mexico City based on bacterial and heavy metal analyses

    Science.gov (United States)

    Solís, C.; Sandoval, J.; Pérez-Vega, H.; Mazari-Hiriart, M.

    2006-08-01

    Xochimilco is located in southern Mexico City and represents the reminiscence of the pre-Columbian farming system, the "chinampa" agriculture. "Chinampas" are island plots surrounded by a canal network. At present the area is densely urbanized and populated, with various contaminant sources contributing to the water quality degradation. The canal system is recharged by a combination of treated-untreated wastewater, and precipitation during the rainy season. Over 40 agricultural species, including vegetables, cereals and flowers, are produced in the "chinampas". In order to characterize the quality of Xochimilcos' water used for irrigation, spatial and temporal contaminant indicators such as microorganisms and heavy metals were investigated. Bacterial indicators (fecal coliforms, fecal enterococcus) were analyzed by standard analytical procedures, and heavy metals (such as Fe, Cu, Zn and Pb) were analyzed by particle induced X-ray emission (PIXE). The more contaminated sites coincide with the heavily populated areas. Seasonal variation of contaminants was observed, with the higher bacterial counts and heavy metal concentrations reported during the rainy season.

  5. Irrigation water quality in southern Mexico City based on bacterial and heavy metal analyses

    Energy Technology Data Exchange (ETDEWEB)

    Solis, C. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apdo Postal 20-364, 01000 Mexico, DF (Mexico)]. E-mail: corina@fisica.unam.mx; Sandoval, J. [Instituto de Ecologia, Universidad Nacional Autonoma de Mexico, Apdo Postal 70-275, 04510 Mexico, DF (Mexico); Perez-Vega, H. [Ciencias Agropecuarias, Universidad Juarez Autonoma de Tabasco, Ave. Universidad S/N. Zona de la Cultura, 86040 Villa Hermosa, Tabasco (Mexico); Mazari-Hiriart, M. [Instituto de Ecologia, Universidad Nacional Autonoma de Mexico, Apdo Postal 70-275, 04510 Mexico, DF (Mexico)

    2006-08-15

    Xochimilco is located in southern Mexico City and represents the reminiscence of the pre-Columbian farming system, the 'chinampa' agriculture. 'Chinampas' are island plots surrounded by a canal network. At present the area is densely urbanized and populated, with various contaminant sources contributing to the water quality degradation. The canal system is recharged by a combination of treated-untreated wastewater, and precipitation during the rainy season. Over 40 agricultural species, including vegetables, cereals and flowers, are produced in the 'chinampas'. In order to characterize the quality of Xochimilcos' water used for irrigation, spatial and temporal contaminant indicators such as microorganisms and heavy metals were investigated. Bacterial indicators (fecal coliforms, fecal enterococcus) were analyzed by standard analytical procedures, and heavy metals (such as Fe, Cu, Zn and Pb) were analyzed by particle induced X-ray emission (PIXE). The more contaminated sites coincide with the heavily populated areas. Seasonal variation of contaminants was observed, with the higher bacterial counts and heavy metal concentrations reported during the rainy season.

  6. Comparative evaluation of canal cleaning ability of various rotary endodontic filesin apical third: A scanning electron microscopic study

    Science.gov (United States)

    Jadhav, Ganesh Ranganath; Mittal, Priya; Kulkarni, Anish; Syed, Shibli; Bagul, Ravikiran; Elahi, Saina; Kalra, Dheeraj

    2016-01-01

    Background: The purpose of this study was to evaluate the canal cleaning ability of three novel endodontic rotary instruments and compare with ProTaper files as a control in apical third of root canals under scanning electron microscopy (SEM). Materials and Methods: Eighty freshly extracted mandibular premolars were selected according to inclusion criteria. Buccal cusp tips were ground to ensure having a flat coronal reference point with a total tooth length of 16 mm for all samples. Teeth were divided equally into four groups: Group I (ProTaper group), Group II (ProTaper next group), Group III (variable taper group), and Group IV (self-adjusting file [SAF] group). Using SEM, the dentinal surfaces were observed and rated at apical thirds with a magnification of ×1000 for the presence/absence of smear layer and debris. Descriptive analysis was performed, and analysis of variance with Bonferroni post hoc test was carried out for comparison between the groups, at a significance level of 0.05. Results: There was statistically significant difference between Group II and Group IV for debris (P = 0.047) and smear layer (P = 0.037). Conclusion: In apical third of root canal, SAF showed statistically significant canal cleaning ability due to combined effect of continuous streaming irrigation with effectively replacing the irrigant from the apical portion of the root canal, irrigants activation through the creation of turbulence, and its self-adapting design to root canal anatomy with a scrubbing motion on the canal walls. PMID:28182065

  7. Love canal questions

    Science.gov (United States)

    Bell, Peter M.

    The Environmental Protection Agency (EPA) conducted a 3-month monitoring study of the Love Canal area near Niagara Falls, N.Y., after the federal government pronounced that a potential health risk existed due to chemical waste dumps. In 1982 the Department of Health and Human Services (HHS) decided that the area was habitable, subject to implementation of effective safeguards against leakage from the canal and to cleaning up of the contaminants. Now, the Congressional Office of Technology Assessment (OTA) has announced that, with the information available, it is not possible to demonstrate with certainty that unsafe levels do not exist within the so-called “emergency declaration area” (EDA).

  8. Influence of Ultrasonic Irrigation and Chloroform on Cleanliness of Dentinal Tubules During Endodontic Retreatment-An Invitro SEM Study

    Science.gov (United States)

    Singhal, Anurag; Gurtu, Anuraag; Vinayak, Vineet

    2015-01-01

    Background Ultrasonic irrigation has been proved for its remarkable cleaning efficiency in the field of endodontics. But its role in endodontic re-treatment has been understated. There is not much data available to understand the effect of ultrasonic irrigation for the evaluation of cleanliness of dentinal tubules when it is used with or without chloroform, a gutta percha solvent during endodontic retreatment. Aim To compare the influence of ultrasonic irrigation with syringe irrigation on cleanliness of dentinal tubules after gutta perch removal for endodontic retreatment with or without the use of chloroform a gutta percha solvent using scanning electron microscope (SEM). Materials and Methods Freshly extracted 45 human mandibular premolar teeth for periodontal and orthodontic reasons were taken and were occlusally adjusted to a working length of 19 mm. The root canals of all teeth were prepared chemo mechanically to a master apical file size 40 and were divided in various groups. In Group 1 (n = 5; control group), the canals remained unfilled. In Groups 2 and 3 (n = 20 each), the canals were filled using lateral compaction with gutta-percha and AH plus sealer, removal of root fillings was undertaken after 2 weeks using Gates Glidden drills and H files without chloroform in Group 2 and with chloroform in group 3. The specimen of Group 2 and 3 were further divided into two subgroups I and II (n=10). In subgroup I, irrigation was done using side vented needles and sodium hypochlorite. In subgroup II irrigation was done using passive ultrasonic irrigation with sodium hypochlorite. Thereafter, the roots were split and the sections were observed under SEM. The number of occluded dentinal tubules /total number of dentinal tubules were calculated for the coronal, middle and apical third of each root half. Statistical analysis was performed using one-way ANOVA followed by Tukey’s test using standardized technique. Result Results indicated that the cleanest dentinal

  9. Ex vivo microbial leakage after using different final irrigation regimens with chlorhexidine

    Directory of Open Access Journals (Sweden)

    Esther NAVARRO-ESCOBAR

    2013-01-01

    Full Text Available Objective To assess the influence of final irrigation protocols with chlorhexidine in the coronal leakage of Enterococcus faecalis in filled root canals. Material and Methods Seventy single-root canals from extracted teeth were prepared using ProTaper instruments. The irrigation protocol accomplished an alternating irrigation with 5 mL of 2.5% sodium hypochlorite (NaOCI and 17% EDTA between each file. The teeth were randomly divided into four experimental groups (n=15 according to the final irrigation regimen: group 1, without final irrigation; group 2, irrigation with 10 mL 2.0% chlorhexidine (CHX; group 3, with a final application of EC40™; and group 4, irrigation with the combination (1:1 of 0.2% CHX + 0.1% cetrimide (CTR. All the teeth were mounted in a two-chamber apparatus and the coronal access was exposed to E. faecalis. The presence of turbidity in the BHI broth over a period of 180 days was observed. The Friedman test was used for statistical analysis. Results EC40™ varnish showed the least leakage at 180 days, and was statistically similar to 2% CHX. No significant differences were observed between the group without final irrigation and the 2% CHX group or 0.2% CHX + 0.1% CTR. Conclusions In this ex vivo study, EC40™ showed the longest delayed coronal leakage of E. faecalis, although without significant differences from 2% CHX.

  10. Which is the most effective disinfection method in primary root canals

    African Journals Online (AJOL)

    2014-12-23

    Dec 23, 2014 ... entire model system was then sterilized in ethylene oxide gas for a 12‑h cycle. .... antimicrobial effectiveness of NaOCl in root canals is reported to be a function of ... irrigating agent with antimicrobial action. The antimicrobial.

  11. Nutrient canal of the fibula

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joo-Hyuk; Ehara, Shigeru; Tamakawa, Yoshiharu [Departments of Radiology, Iwate Medical University School of Medicine, Morioka (Japan); Horiguchi, Masahura [Department of Anatomy I, Iwate Medical University School of Medicine, Morioka (Japan)

    2000-01-01

    Objective. To investigate the radiological features of the nutrient canal in the fibula.Design and patients. One hundred and seventy-nine dried fibulae were studied regarding the type, number, location, and direction of the nutrient canal. They were classified into a usual type (type I: a radiolucent line confined to the cortex) and an atypical type (type II: a radiolucent line extending beyond the cortex).Results. Among the total of 230 nutrient canals seen on radiography, 197 (86%) were type I and 33 (14%) were type II. On CT scans, the ossified rim of the canal extended into the medullary cavity in type II canals. The most common site was the posteromedial aspect in both type I and type II canals. Type II canals were significantly more common in fibulae with two or three nutrient canals. The frequency of the upward direction was more common in type II canals.Conclusion. Nutrient canals with extension of the ossified rim into the medullary canal are the cause of linear lucency that may simulate a fracture. Their features are slightly different from those of usual canals. (orig.)

  12. [Endodontics in motion: new concepts, materials and techniques 4. Root canal disinfection in 2015].

    Science.gov (United States)

    van der Waal, S V; de Soet, J J

    2015-12-01

    Apical periodontitis is an inflammatory response around the root tip of a tooth to microbial infection of the root canal system. Therefore, disinfection of the root canal system is the most important aim of root canal treatment. There are various mechanical and chemical ways to clean and disinfect. Most methods, however, cannot be relied upon to fully decontaminate in all cases. There are problems, for example, with the proper concentrations of disinfectant agents, like sodium hypochlorite. But the more recent agents, like ethylenediaminetetraacetic acid, calcium hydroxide or antibiotic pastes also have disadvantages, which are mostly a result of poor access of the irrigant to the biofilm bacteria in the affected root canals. Currently, a new strategy with a modified salt solution is under investigation that offers the prospect of being used as a root canal irrigant. At this moment the preferred treatment still seems to be to remove infected tissue as much as possible and to create access for irrigation procedures. The best results are achieved with 1-2% sodium hypochlorite as a disinfectant, possibly alternating with ethylenediaminetetraacetic acid as a cleansing agent. There is no scientific evidence for the successful use of calcium hydroxide.

  13. A quantitative and qualitative analysis of ultrasonic versus sonic endodontic systems on canal cleanliness and obturation.

    Science.gov (United States)

    Kanter, Valerie; Weldon, Emily; Nair, Uma; Varella, Claudio; Kanter, Keith; Anusavice, Kenneth; Pileggi, Roberta

    2011-12-01

    The purpose of this study was to compare 2 irrigation techniques by evaluating canal cleanliness and obturation of lateral/accessory canals. Seventy-five extracted canines were instrumented to a size #40/0.06 taper. The EndoActivator (EA) was compared with an ultrasonic unit for final irrigation. Each unit was used for 1 minute each with 6.15% NaOCl and 17% EDTA. A control group received syringe irrigation. Thirty teeth were sectioned and evaluated for debris removal and open dentinal tubules at 3/5 mm from the apical foramen with a scanning electron microscope. Forty-five teeth were examined for obturation of lateral canals. The EA was significantly better in removing debris at all levels when compared with other treatment groups (P < .05) and resulted in obturation of significantly more numbers of lateral canals (P < .01.) The EA provided better obturation of lateral and accessory canals and resulted in less remaining debris. Copyright © 2011 Mosby, Inc. All rights reserved.

  14. Root Zone Sensors for Irrigation Management in Intensive Agriculture

    Directory of Open Access Journals (Sweden)

    Jochen Hemming

    2009-04-01

    Full Text Available Crop irrigation uses more than 70% of the world’s water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of efficient irrigation systems, which includes the implementation of a suitable method for precise scheduling. At the farm level, irrigation is generally scheduled based on the grower’s experience or on the determination of soil water balance (weather-based method. An alternative approach entails the measurement of soil water status. Expensive and sophisticated root zone sensors (RZS, such as neutron probes, are available for the use of soil and plant scientists, while cheap and practical devices are needed for irrigation management in commercial crops. The paper illustrates the main features of RZS’ (for both soil moisture and salinity marketed for the irrigation industry and discusses how such sensors may be integrated in a wireless network for computer-controlled irrigation and used for innovative irrigation strategies, such as deficit or dual-water irrigation. The paper also consider the main results of recent or current research works conducted by the authors in Tuscany (Italy on the irrigation management of container-grown ornamental plants, which is an important agricultural sector in Italy.

  15. Study on the influence of refreshment/activation cycles and irrigants on mechanical cleaning efficiency during ultrasonic activation of the irrigant

    NARCIS (Netherlands)

    L.W.M. van der Sluis; M.P.J.M. Vogels; B. Verhaagen; R. Macedo; P.R. Wesselink

    2010-01-01

    Introduction: The aims of this study were to evaluate dentin debris removal from the root canal during ultrasonic activation of sodium hypochlorite (2% and 10%), carbonated water, and distilled water and to determine the influence of 3 ultrasonic refreshment/activation cycles of the irrigant by usin

  16. Study on the Influence of Refreshment/Activation Cycles and Irrigants on Mechanical Cleaning Efficiency During Ultrasonic Activation of the Irrigant

    NARCIS (Netherlands)

    van der Sluis, Lucas W. M.; Vogels, Maikel P. J. M.; Verhaagen, Bram; Macedo, Ricardo; Wesselink, Paul R.

    2010-01-01

    Introduction: The aims of this study were to evaluate dentin debris removal from the root canal during ultrasonic activation of sodium hypochlorite (2% and 10%), carbonated water, and distilled water and to determine the influence of 3 ultrasonic refreshment/activation cycles of the irrigant by usin

  17. Study on the influence of refreshment/activation cycles and irrigants on mechanical cleaning efficiency during ultrasonic activation of the irrigant

    NARCIS (Netherlands)

    van der Sluis, L.W.M.; Vogels, M.P.J.M.; Verhaagen, B.; Macedo, R.; Wesselink, P.R.

    2010-01-01

    Introduction: The aims of this study were to evaluate dentin debris removal from the root canal during ultrasonic activation of sodium hypochlorite (2% and 10%), carbonated water, and distilled water and to determine the influence of 3 ultrasonic refreshment/activation cycles of the irrigant by

  18. Study on the Influence of Refreshment/Activation Cycles and Irrigants on Mechanical Cleaning Efficiency During Ultrasonic Activation of the Irrigant

    NARCIS (Netherlands)

    van der Sluis, Lucas W.M.; Vogels, Maikel P.J.M.; Verhaagen, B.; Macedo, Ricardo; Wesselink, Paul R.

    2010-01-01

    Introduction The aims of this study were to evaluate dentin debris removal from the root canal during ultrasonic activation of sodium hypochlorite (2% and 10%), carbonated water, and distilled water and to determine the influence of 3 ultrasonic refreshment/activation cycles of the irrigant by using

  19. Study on the Influence of Refreshment/Activation Cycles and Irrigants on Mechanical Cleaning Efficiency During Ultrasonic Activation of the Irrigant

    NARCIS (Netherlands)

    van der Sluis, Lucas W. M.; Vogels, Maikel P. J. M.; Verhaagen, Bram; Macedo, Ricardo; Wesselink, Paul R.

    Introduction: The aims of this study were to evaluate dentin debris removal from the root canal during ultrasonic activation of sodium hypochlorite (2% and 10%), carbonated water, and distilled water and to determine the influence of 3 ultrasonic refreshment/activation cycles of the irrigant by

  20. Study on the Influence of Refreshment/Activation Cycles and Irrigants on Mechanical Cleaning Efficiency During Ultrasonic Activation of the Irrigant

    NARCIS (Netherlands)

    Sluis, van der Lucas W.M.; Vogels, Maikel P.J.M.; Verhaagen, Bram; Macedo, Ricardo; Wesselink, Paul R.

    2010-01-01

    Introduction The aims of this study were to evaluate dentin debris removal from the root canal during ultrasonic activation of sodium hypochlorite (2% and 10%), carbonated water, and distilled water and to determine the influence of 3 ultrasonic refreshment/activation cycles of the irrigant by using

  1. 加快建设沈家河灌区末级渠系改造配套工程的重要性%The Importance of Accelerating the Construction of Transformation and Supporting Project of End-canal System of Shenjiahe Irrigation Area

    Institute of Scientific and Technical Information of China (English)

    李国会

    2012-01-01

    The main reasons of restricting agricultural economic development of Shenjiahe irrigation area are followings: water conservancy facilities are imperfect, the project is beat up, irrigation area operation management system is not perfect, waste of water resources is serious, irrigation water use is low, irrigated area is reducing and efficiency of irrigation area is inefficient, therefore, it is imperative to build transformation and supporting project of end梒anal system of Shenjiahe irrigation area.%制约沈家河灌区农业经济发展的主要原因是水利设施配套不完善,工程年久失修,灌区运行管理制度不够完善,水资源浪费严重,灌溉水利用率低,灌溉面积减少,灌区效益低下,所以建设沈家河灌区末级渠系改造配套工程势在必行.

  2. Water used to visualize and remove hidden foreign bodies from the external ear canal.

    Science.gov (United States)

    Peltola, T J; Saarento, R

    1992-02-01

    Small foreign bodies lodged anteriorly in the tympanic sulcus are usually not visible, due to the curve of the external ear canal. Such objects can be seen with the aid of an otomicroscope and micromirror or with an endoscope, and removed by irrigation. If irrigation fails, epithelial migration on the tympanic membrane may remove lodged foreign bodies, although this may take months. Our new method, which uses water to locate small objects lodged in the tympanic sulcus, includes irrigation of the ear, adjustment of the water level to the middle curve of the external ear canal, and use of the water surface as a concave lens, making the tympanic sulcus visible. With otomicroscopy a curved ear probe can then be used to remove lodged foreign bodies from behind the curve.

  3. Irrigation and avifaunal change in coastal Northwest Mexico: has irrigated habit attracted threatened migratory species?

    Directory of Open Access Journals (Sweden)

    Sievert Rohwer

    2015-08-01

    Full Text Available Irrigation in desert ecosystems can either reduce or increase species diversity. Groundwater pumping often lowers water tables and reduces natural wetlands, whereas canal irrigation often creates mesic habitat, resulting in great increases in avian diversity from irrigation. Here we compare a dataset of potential natural vegetation to recent datasets from areal and satellite imagery to show that 60% of the land in the coastal plain of southern Sonora and northern Sinaloa lying below 200 m elevation has been converted by irrigation to more mesic habitats. We then use the record of bird specimens in the world’s museums from this same region of Mexico to examine the avian community before and after the development of extensive irrigation. In general these museum records show an increase in the abundance and diversity of breeding birds associated with mesic habitats. Although thorn forest birds have likely decreased in total numbers, most are common enough in the remaining thorn forest that collection records did not indicate their probable decline. Four migrants having most of their breeding ranges in the US or Canada, Yellow-billed Cuckoo, Cliff Swallow, Bell’s Vireo, and Orchard Oriole, apparently have increased dramatically as breeders in irrigated habitats of NW Mexico. Because these species have decreased or even largely disappeared as breeding birds in parts of the US or Canada, further research should assess whether their increases in new mesic habitats of NW Mexico are linked to their declines as breeding birds in Canada and the US For Bell’s Vireo recent specimens from Sinaloa suggest its new breeding population in NW Mexico may be composed partly of the endangered Least Bell’s Vireo.

  4. Irrigation water quality assessments

    Science.gov (United States)

    Increasing demands on fresh water supplies by municipal and industrial users means decreased fresh water availability for irrigated agriculture in semi arid and arid regions. There is potential for agricultural use of treated wastewaters and low quality waters for irrigation but this will require co...

  5. Irrigation Systems. Student's Guide.

    Science.gov (United States)

    Amarillo Coll., TX.

    This guide is intended for use by individuals preparing for a career in commercial and residential irrigation. The materials included are geared toward students who have had some experience in the irrigation business; they are intended to be presented in 10 six-hour sessions. The first two sections deal with using this guide and preparing for the…

  6. Irrigation Systems. Instructor's Guide.

    Science.gov (United States)

    Amarillo Coll., TX.

    This guide is intended for use by licensed irrigators who wish to teach others how to design and install residential and commercial irrigation systems. The materials included in the guide have been developed under the assumption that the instructors who use it have little or no formal training as teachers. The first section presents detailed…

  7. Irrigation Without Waste

    Science.gov (United States)

    Shea, Kevin P.

    1975-01-01

    A new means of irrigation, called the drip or trickle system, has been proven more efficient and less wasteful than the current system of flood irrigation. As a result of this drip system, fertilizer-use efficiency is improved and crop yield, though never decreased, is sometimes increased in some crops. (MA)

  8. Sodium hypochlorite accident resulting in life-threatening airway obstruction during root canal treatment: a case report

    Directory of Open Access Journals (Sweden)

    Al-Sebaei MO

    2015-03-01

    Full Text Available Maisa O Al-Sebaei,1 Omar A Halabi,2 Ibrahim E El-Hakim3 1Department of Oral and Maxillofacial Surgery, King Abdulaziz University – Faculty of Dentistry, Jeddah, Kingdom of Saudi Arabia; 2Saudi Board of Oral and Maxillofacial Surgery, Al-Noor Specialist Hospital, Makkah, Kingdom of Saudi Arabia; 3Department of Oral and Maxillofacial Surgery, Riyadh Colleges of Dentistry and Pharmacy, Riyadh, Kingdom of Saudi Arabia Aim: This case report describes a serious and life-threatening complication of the use of sodium hypochlorite as an irrigation solution in root canal therapy. Summary: This case report describes a hypochlorite accident that occurred in a healthy 42-year-old female who was undergoing routine root canal therapy for the lower right central incisor (tooth #41. After approximately 1 hour of irrigation with 3% sodium hypochlorite (for a total of 12 cc, the patient complained of severe pain and burning in the lip. The swelling progressed over the next 8 hours to involve the sublingual and submental fascial spaces with elevation of the tongue and resultant upper airway obstruction. The patient was intubated and remained on mechanical ventilation for 3 days. She recovered without any skin necrosis or nerve deficits. Key learning points: This case report highlights the importance of carefully performing root canal irrigation with sodium hypochlorite to avoid complications. Careful injection without pressure, the use of proper rubber dam isolation, and the use of the endodontic needle are necessary to avoid this type of complication. Although it is a safe root canal irrigation solution, its use may lead to life-threatening complications. Early recognition and management of the untoward effects of sodium hypochlorite are vital for the patient's safety. Keywords: complications of root canal, facial edema, root canal irrigation, root canal therapy, sodium hypochlorite, upper airway obstruction

  9. Curved canals: Ancestral files revisited

    Directory of Open Access Journals (Sweden)

    Jain Nidhi

    2008-01-01

    Full Text Available The aim of this article is to provide an insight into different techniques of cleaning and shaping of curved root canals with hand instruments. Although a plethora of root canal instruments like ProFile, ProTaper, LightSpeed ® etc dominate the current scenario, the inexpensive conventional root canal hand files such as K-files and flexible files can be used to get optimum results when handled meticulously. Special emphasis has been put on the modifications in biomechanical canal preparation in a variety of curved canal cases. This article compiles a series of clinical cases of root canals with curvatures in the middle and apical third and with S-shaped curvatures that were successfully completed by employing only conventional root canal hand instruments.

  10. The role of energy audits in irrigated areas. The case of Fuente Palmera irrigation district (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo-Cobo, M. T.; Rodriguez-Diaz, J. A.; Camacho-Poyato, E.

    2010-07-01

    In recent years, energy consumption for irrigation has grown rapidly. Actually, nowadays energy represents a significant percentage on the total water costs in irrigation districts using energy to pressurize water. With the aim of improving energy efficiency in the Fuente Palmera irrigation district, was applied the protocol for conducting energy audits in irrigation districts developed by Spanish Institute for Diversification and Energy Savings (IDAE). The irrigated area organized in two independent sectors according to a homogeneous elevation criterion is analyzed and simulated. The potential energy savings derived from this measure was evaluated. For this purpose, a model based on the hydraulic simulator EPANET has been carried out. Its energy demand was estimated in 1,360 kWh ha-1 and its overall energy efficiency in 56%. The district was globally classified in group C (normal). Results show potential energy savings of up to 12% were obtained when the network was divided in sectors and farmers organized in two irrigation shifts. Further energy savings could be achieved by improving the hydraulic structures, such as the pumping station or the network layout and dimensions. (Author) 26 refs.

  11. Assessment of Root Canal Filling Removal Effectiveness Using Micro-computed Tomography: A Systematic Review.

    Science.gov (United States)

    Rossi-Fedele, Giampiero; Ahmed, Hany Mohamed Aly

    2017-04-01

    The removal of obturation materials from the root canal system is a primary objective in root canal retreatment procedures. This systematic review aims to discuss the effectiveness of different instrumentation procedures in removing root-canal filling materials assessed by micro-computed tomography. An electronic search in PubMed and major endodontic journals was conducted using appropriate key words to identify investigations that examined the effectiveness of obturation material removal assessed by micro-computed tomography. Among 345 studies, 22 satisfied the inclusion criteria. Seven studies compared hand instrumentation with Nickel-Titanium rotary or reciprocating systems. Three studies investigated rotary systems, and another three studies explored reciprocation. Eight studies compared rotary systems and reciprocation in removing filling materials from the root canal system. Other factors, such as the role of solvents and irrigant agitation, were discussed. The application of different instrumentation protocols can effectively, but not completely, remove the filling materials from the root canal system. Only hand instrumentation was not associated with iatrogenic errors. Reciprocating and rotary systems exhibited similar abilities in removing root filling material. Retreatment files performed similarly to conventional ones. Solvents enhanced penetration of files but hindered cleaning of the root canal. The role of irrigant agitation was determined as controversial. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. Mapping Soil hydrologic features in a semi-arid irrigated area in Spain

    Science.gov (United States)

    Jiménez-Aguirre, M.° Teresa; Isidoro, Daniel; Usón, Asunción

    2016-04-01

    The lack of soil information is a managerial problem in irrigated areas in Spain. The Violada Irrigation District (VID; 5234 ha) is a gypsic, semi-arid region in the Middle Ebro River Basin, northeast Spain. VID is under irrigation since the 1940's. The implementation of the flood irrigation system gave rise to waterlogging problems, solved along the years with the installation of an artificial drainage network. Aggregated water balances have been performed in VID since the early 1980's considering average soil properties and aggregated irrigation data for the calculations (crop evapotranspiration, canal seepage, and soil drainage). In 2008-2009, 91% of the VID was modernized to sprinkler irrigation. This new system provides detailed irrigation management information that together with detailed soil information would allow for disaggregated water balances for a better understanding of the system. Our goal was to draw a semi-detailed soil map of VID presenting the main soil characteristics related to irrigation management. A second step of the work was to set up pedotransfer functions (PTF) to estimate the water content and saturated hydraulic conductivity (Ks) from easily measurable parameters. Thirty four pits were opened, described and sampled for chemical and physical properties. Thirty three additional auger holes were sampled for water holding capacity (WHC; down to 60 cm), helping to draw the soil units boundaries. And 15 Ks tests (inverse auger hole method) were made. The WHC was determined as the difference between the field capacity (FC) and wilting point (WP) measured in samples dried at 40°C during 5 days. The comparison with old values dried at 105°C for 2 days highlighted the importance of the method when gypsum is present in order to avoid water removal from gypsum molecules. The soil map was drawn down to family level. Thirteen soil units were defined by the combination of five subgroups [Typic Calcixerept (A), Petrocalcic Calcixerept (B), Gypsic

  13. Response of selenium concentrations in groundwater to seasonal canal leakage, lower Gunnison River Basin, Colorado, 2013

    Science.gov (United States)

    Linard, J.I.; McMahon, P.B.; Arnold, L.R.; Thomas, J.C.

    2016-05-23

    Selenium is a water-quality concern in the lower Gunnison River Basin because irrigation water interacting with seleniferous soils derived from the Mancos Shale Formation has mobilized selenium and increased its concentrations in surface water. Understanding the occurrence of elevated selenium concentrations in groundwater is necessary because groundwater discharge is an important source of selenium in surface water in the basin. In 2013, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation and the Colorado Water Conservation Board, began a study to understand how changes in groundwater levels attributed to canal leakage affected the concentrations and speciation of dissolved selenium in groundwater. The purpose of this report is to characterize the groundwater adjacent to an unlined leaky canal. Two locations, near the East Canal (W-N1 and W-N2) and farther from the East Canal (W-M1 and W-M2), were selected for nested monitoring well installations. The pressure exerted by changes in canal stage was more readily transferred to the deep groundwater measured in the W-N1 near the canal than the shallow groundwater at the W-N2 well. No definitive relation could be made between canal water-level elevation and water-level elevations in monitoring wells farther from the canal (W-M1 and W-M2). 

  14. Reduction of Enterococcus faecalis in curved root canals after various sizes and tapers of canal preparation

    Directory of Open Access Journals (Sweden)

    Amir Abbas Moshari

    2015-01-01

    Full Text Available Aims: The aim of this study was to evaluate the reduction of Enterococcus faecalis in curved root canals after various sizes and tapers of the canal preparation. Materials and Methods: Mandibular first molars (n = 103 with curved mesiobuccal canals were divided into one control (n = 5 and 7 experimental (n = 14 groups, were inoculated with E. faecalis (ATTC 29212 and prepared with the following RaCe files (FKG Dentaire as master apical file: Groups: 25.04, 25.06, 30.04, 30.06, 35.04, 35.06 and 40.06. All the experimental groups were irrigated with 2 mL of 1% sodium hypochlorite during instrumentation and finally rinsed with 17% ethylenediaminetetraacetic acid (EDTA (2 mL followed by 5.25% NaOCl (2 mL and sterile distilled water. Colony counting was performed after incubation. Statistical Analysis Used: Resulting data were analyzed using one-way ANOVA and Tukey′s post-hoc test, (P < 0.05. Results and Conclusions: All the experimental groups showed significant bacterial reduction (P < 0.001. Although the greater the size/taper or both led to more decreased amount of bacteria, differences between the groups with the identical size and different tapers, and among the groups with the same taper and different sizes were not significant. Based on this study, 25.04 along with using 2 mL of 1% NaOCl during instrumentation, and using 17% EDTA and 5.25% NaOCl as final rinse successively after the termination of preparation, can effectively reduce intra-canal bacteria and preserve root structure.

  15. Local irrigation management institutions mediate changes driven by external policy and market pressures in Nepal and Thailand.

    Science.gov (United States)

    Bastakoti, Ram C; Shivakoti, Ganesh P; Lebel, Louis

    2010-09-01

    This article assesses the role of local institutions in managing irrigation water use. Fifty irrigation systems in each country were studied in Nepal and Thailand to compare the influence of local institutions on performance of irrigation systems amid changes in external policy and market pressures. Nepal's new irrigation policy after the re-instatement of multiparty democracy in 1990 emphasized participatory irrigation management transferring the management responsibility from state authorities to water users. The water user associations of traditional farmer-managed irrigation systems were formally recognized by requiring registration with related state authorities. In Thailand also government policies encouraged people's participation in irrigation management. Today water users are directly involved in management of even some large irrigation systems at the level of tertiary canals. Traditional communal irrigation systems in northern Thailand received support for system infrastructure improvement but have faced increased interference from government. In Thailand market development supported diversification in farming practices resulting in increased areas under high water-demanding commercial crops in the dry season. In contrast, the command areas of most irrigation systems in Nepal include cereal-based subsistence farming with only one-third having commercial farming. Cropping intensities are higher in Nepal than in Thailand reflecting, in part, differences in availability of land and management. In both countries local institutions play an important role in maintaining the performance of irrigation systems as external drivers and local contexts change. Local institutions have provided alternative options for irrigation water use by mediating external pressures.

  16. Local Irrigation Management Institutions Mediate Changes Driven by External Policy and Market Pressures in Nepal and Thailand

    Science.gov (United States)

    Bastakoti, Ram C.; Shivakoti, Ganesh P.; Lebel, Louis

    2010-09-01

    This article assesses the role of local institutions in managing irrigation water use. Fifty irrigation systems in each country were studied in Nepal and Thailand to compare the influence of local institutions on performance of irrigation systems amid changes in external policy and market pressures. Nepal’s new irrigation policy after the re-instatement of multiparty democracy in 1990 emphasized participatory irrigation management transferring the management responsibility from state authorities to water users. The water user associations of traditional farmer-managed irrigation systems were formally recognized by requiring registration with related state authorities. In Thailand also government policies encouraged people’s participation in irrigation management. Today water users are directly involved in management of even some large irrigation systems at the level of tertiary canals. Traditional communal irrigation systems in northern Thailand received support for system infrastructure improvement but have faced increased interference from government. In Thailand market development supported diversification in farming practices resulting in increased areas under high water-demanding commercial crops in the dry season. In contrast, the command areas of most irrigation systems in Nepal include cereal-based subsistence farming with only one-third having commercial farming. Cropping intensities are higher in Nepal than in Thailand reflecting, in part, differences in availability of land and management. In both countries local institutions play an important role in maintaining the performance of irrigation systems as external drivers and local contexts change. Local institutions have provided alternative options for irrigation water use by mediating external pressures.

  17. Managing curved canals

    Directory of Open Access Journals (Sweden)

    Iram Ansari

    2012-01-01

    Full Text Available Dilaceration is the result of a developmental anomaly in which there has been an abrupt change in the axial inclination between the crown and the root of a tooth. Dilaceration can be seen in both the permanent and deciduous dentitions, and is more commonly found in posterior teeth and in maxilla. Periapical radiographs are the most appropriate way to diagnose the presence of root dilacerations. The controlled regularly tapered preparation of the curved canals is the ultimate challenge in endodontics. Careful and meticulous technique will yield a safe and sufficient enlargement of the curved canals. This article gives a review of the literature and three interesting case reports of root dilacerations.

  18. The power of the bubble: comparing ultrasonic and laser activated irrigation

    Science.gov (United States)

    De Moor, Roeland J. G.; Meire, Maarten A.; Verdaasdonk, Rudolf M.

    2014-01-01

    The major problem of irrigation is the fluid motion within the confined geometry of the root canal : efficient dispersion of the liquid is difficult, conventional irrigation is limited due to the absence of turbulence over much of the canal volume, vapour lock may limit apical cleaning and disinfection, there is also a stagnation plane beyond the needle tip. The best way to improve irrigant penetration and biofilm removal is achieved by means of the agitation of the fluid. Today ultrasonic activation appears to be the best way to activate and potentiate irrigants among the present-day used means and marketed systems. Another way to activate irrigation solutions is the use of lasers: laser activated irrigation or photon-initiated acoustic streaming have been investigated. Based on present-day research it appears that the efficacy of laser activation (especially with Erbium lasers) can be more efficient thanks to the induction of specific cavitation phenomena and acoustic streaming. Other wavelengths are now explored to be used for laser activated irrigation.

  19. Comparative antibacterial efficacies of hydrodynamic and ultrasonic irrigation systems in vitro.

    Science.gov (United States)

    Cachovan, Georg; Schiffner, Ulrich; Altenhof, Saskia; Guentsch, Arndt; Pfister, Wolfgang; Eick, Sigrun

    2013-09-01

    To ensure root canal treatment success, endodontic microbiota should be efficiently reduced. The in vitro bactericidal effects of a hydrodynamic system and a passive ultrasonic irrigation system were compared. Single-rooted extracted teeth (n = 250) were contaminated with suspensions of Enterococcus faecalis ATCC 29212, mixed aerobic cultures, or mixed anaerobic cultures. First, the antibacterial effects of the hydrodynamic system (RinsEndo), a passive ultrasonic irrigation system (Piezo smart), and manual rinsing with 0.9% NaCl (the control) were compared. Colony-forming units were counted. Second, the 2 systems were used with 1.5% sodium hypochlorite (NaOCl) alone or NaOCl + 0.2% chlorhexidine (CHX). The colony-forming units in the treated and untreated roots were determined during a period of 5 days. Both irrigation systems reduced bacterial numbers more effectively than manual rinsing (P ultrasonic activated irrigation reduced bacterial counts significantly better than hydrodynamic irrigation (P = .042). The NaOCl + CHX combination was more effective than NaOCl alone for both systems (P ultrasonic irrigation system. Both irrigation systems, when combined with NaOCl + CHX, removed bacteria from root canals. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  20. SCADA OPERATOR TRAINING TOOL APPLIED TO THE CENTRAL ARIZONA IRRIGATION AND DRAINAGE DISTRICT

    Science.gov (United States)

    Many irrigation districts use Supervisory Control and Data Acquisition (SCADA) software to manage their canal systems. Whether homegrown or commercial, these programs require a significant amount of training for new operators. While some SCADA operators are hired with extensive field experience, o...

  1. The Influence of the Ultrasonic Intensity on the Cleaning Efficacy of Passive Ultrasonic Irrigation

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Verhaagen, Bram; Versluis, Michel; Langedijk, Jelmer; Wesselink, Paul; van der Sluis, Lucas W. M.

    Introduction: It is not clear whether increasing the ultrasonic intensity would enhance the cleaning efficacy of passive ultrasonic irrigation (PUI) inside a root canal. The aim of this study was to evaluate the effect of the ultrasonic intensity on PUI to remove dentin debris and whether there is

  2. The Influence of the Ultrasonic Intensity on the Cleaning Efficacy of Passive Ultrasonic Irrigation

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Verhaagen, B.; Versluis, Andreas Michel; Langedijk, Jelmer; Wesselink, Paul; van der Sluis, Lucas W.M.

    2011-01-01

    Introduction It is not clear whether increasing the ultrasonic intensity would enhance the cleaning efficacy of passive ultrasonic irrigation (PUI) inside a root canal. The aim of this study was to evaluate the effect of the ultrasonic intensity on PUI to remove dentin debris and whether there is

  3. The influence of the ultrasonic intensity on the cleaning efficacy of passive ultrasonic irrigation

    NARCIS (Netherlands)

    Jiang, L.M.; Verhaagen, B.; Versluis, M.; Langedijk, J.; Wesselink, P.; van der Sluis, L.W.

    2011-01-01

    Introduction: It is not clear whether increasing the ultrasonic intensity would enhance the cleaning efficacy of passive ultrasonic irrigation (PUI) inside a root canal. The aim of this study was to evaluate the effect of the ultrasonic intensity on PUI to remove dentin debris and whether there is

  4. Subsurface drainage pilot area experiences in three irrigated project commands of Andhra Pradesh in India

    NARCIS (Netherlands)

    Satyanarayana, T.V.; Boonstra, J.

    2007-01-01

    The introduction of irrigated agriculture in arid and semi-arid regions of India has resulted in the development of the twin problems of waterlogging and soil salinization, as a result of which considerable areas of canal commands have either gone out of production or experienced reduced crop yields

  5. The Influence of the Ultrasonic Intensity on the Cleaning Efficacy of Passive Ultrasonic Irrigation

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Verhaagen, Bram; Versluis, Michel; Langedijk, Jelmer; Wesselink, Paul; van der Sluis, Lucas W. M.

    2011-01-01

    Introduction: It is not clear whether increasing the ultrasonic intensity would enhance the cleaning efficacy of passive ultrasonic irrigation (PUI) inside a root canal. The aim of this study was to evaluate the effect of the ultrasonic intensity on PUI to remove dentin debris and whether there is a

  6. Canal Wall Reconstruction Mastoidectomy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To investigate the advantages of canal wall reconstruction (CWR) mastoidectomy, a single-stage technique for cholesteatoma removal and posterior external canal wall reconstruction, over the open and closed procedures in terms of cholesteatoma recurrence. Methods: Between June 2002 and December 2005, 38 patients (40 ears) with cholesteatoma were admited to Sun Yat-Sen Memorial Hospital and received surgical treatments. Of these patients, 25 were male with ages ranging between 11 and 60 years (mean = 31.6 years) and 13 were female with ages ranging between 20 and 65 years (mean = 38.8 years). Canal wall reconstruction (CWR)mastoidectomy was performed in 31 ears and canal wall down (CWD) mastoidectomy in 9 ears. Concha cartilage was used for ear canal wall reconstruction in 22 of the 31 CWR procedures and cortical mastoid bone was used in the remaining 9 cases. Results At 0.5 to 4 years follow up, all but one patients remained free of signs of cholesteatoma recurrence, i.e., no retraction pocket or cholesteatoma matrix. One patient, a smoker, needed revision surgery due to cholesteatoma recurrence 1.5 year after the initial operation. The recurrence rate was therefore 3.2% (1/31). Cholesteatoma recurrence was monitored using postoperative CT scans whenever possible. In the case that needed a revision procedure, a retraction pocket was identified by otoendoscopy in the pars flacida area that eventually evolved into a cholesteatoma. A pocket extending to the epitympanum filled with cholesteatoma matrix was confirmed during the revision operation, A decision to perform a modified mastoidectomy was made as the patient refused to quit smoking. The mean air-bone gap in pure tone threshold was 45 dB before surgery and 25 dB after (p < 0.05). There was no difference between using concha cartilage and cortical mastoid bone for the reconstruction regarding air-bone gap improvement, CT findings and otoendoscopic results. Conclusion CWR mastoidectomy can be used for

  7. Evaluation of U.S. Geological Survey Monitoring-well network and potential effects of changes in water use, Newlands Project, Churchill County, Nevada

    Science.gov (United States)

    Maurer, Douglas K.; Seiler, Ralph L.; Watkins, Sharon A.

    2004-01-01

    Domestic wells tapping shallow ground water are an important source of potable water for rural residents of Lahontan Valley. For this reason, the public has expressed concern over the acquisition of water rights directed by Public Law 101-618. The acquisition has resulted in removal of land from irrigation, which could cause shallow domestic wells to go dry and adversely affect shallow ground-water quality. Periodic water-level measurements and water-quality sampling at a monitoring-well network developed by the U.S. Geological Survey (USGS) provided data to evaluate the potential effects of changes in water use. The USGS, in cooperation with Churchill County, analyzed these data and the monitoring-well network to determine if the network provides an adequate means to measure the response of the shallow aquifer to changes in water use, and to determine if measurable changes have taken place. To evaluate the USGS monitoring-well network, wells were characterized by their distance from active canals or ditches, and from currently (2003) or formerly irrigated land. An analysis of historical data showed that about 9,800 acres of land have been removed from irrigation, generally from the late 1990's to 2003. Twenty-five wells in the network are within about 1 mile of fields removed from irrigation. Of the 25 wells, 13 are within 300 feet of canals or ditches where seepage maintains stable water levels. The 13 wells likely are not useful for detecting changes caused by reductions in irrigation. The remaining 12 wells range from about 400 to 3,800 feet from the nearest canal and are useful for detecting continued changes from current reductions in irrigation. The evaluation showed that of the 75 wells in the network, only 8 wells are likely to be useful for detecting the effects of future (after 2003) reductions in irrigation. Water levels at most of the monitoring wells near irrigated land have declined from 1998 to 2003 because of drought conditions and below normal

  8. Sustainable crop intensification through surface water irrigation in Bangladesh? A geospatial assessment of landscape-scale production potential.

    Science.gov (United States)

    Krupnik, Timothy J; Schulthess, Urs; Ahmed, Zia Uddin; McDonald, Andrew J

    2017-01-01

    Changing dietary preferences and population growth in South Asia have resulted in increasing demand for wheat and maize, along side high and sustained demand for rice. In the highly productive northwestern Indo-Gangetic Plains of South Asia, farmers utilize groundwater irrigation to assure that at least two of these crops are sequenced on the same field within the same year. Such double cropping has had a significant and positive influence on regional agricultural productivity. But in the risk-prone and food insecure lower Eastern Indo-Gangetic Plains (EIGP), cropping is less intensive. During the dryer winter months, arable land is frequently fallowed or devoted to lower yielding rainfed legumes. Seeing opportunity to boost cereals production, particularly for rice, donors and land use policy makers have consequently reprioritized agricultural development investments in this impoverished region. Tapping groundwater for irrigation and intensified double cropping, however, is unlikely to be economically viable or environmentally sound in the EIGP. Constraints include saline shallow water tables and the prohibitively high installation and energetic extraction costs from deeper freshwater aquifers. The network of largely underutilized rivers and natural canals in the EIGP could conversely be tapped to provide less energetically and economically costly surface water irrigation (SWI). This approach is now championed by the Government of Bangladesh, which has requested USD 500 million from donors to implement land and water use policies to facilitate SWI and double cropping. Precise geospatial assessment of where freshwater flows are most prominent, or where viable fallow or low production intensity cropland is most common, however remains lacking. In response, we used remotely sensed data to identify agricultural land, detect the temporal availability of freshwater in rivers and canals, and assess crop production intensity over a three-year study period in a 33,750

  9. Analysis of sedimentation of canals

    Directory of Open Access Journals (Sweden)

    Agunwamba, J.C.,

    2013-03-01

    Full Text Available The dredged canals in the Niger Delta coastal flood plain are being threatened by siltation. This study is limited to those canals in Rivers State of Nigeria, which are under the influence of tidal waves. A total of eight canals were considered with four each from Ekulama and Cawthorne Channel. Different approaches were used to carry out this study, which includes field reconnaissance survey, hydrographic survey, soil sample analysis and collection of all available data and information. The typical bed materials size (D50 is approximately 0.01mm; which gives a settling velocity of 0.09mm/sec using stroke’s law. Hydrographic survey of the canals from 1992 to 1996 revealed an average siltation rate of 2.35m/yr. A regression equation was also derived which relates the cost of dredging to canal area, rate of siltation and average aggregation. A plot of canal centre profile; entrance, middle and end cross sections showing sediment distribution along the canal profile, shows that majority of the particles that form the sediment enter the canal from the rivers. The sedimentation is caused by the reduction in water current, which has average value of 0.0145m/sec. The bathyorographical check on the canals revealed that the sum of the two exterior angles of the canal with the river at the point of connection has to lie within 1800 + 50 for an effective flow that will minimize settlement of particles. In addition, the canals should be constructed to start and terminate on a moving water body, to avoid dead ends. A regression equation was determined which relates the cost of dredging to canal area, rate of siltation and average aggradations.

  10. Irrigation ponds:Possibility and potentials for the treatment of drainage water from paddy fields in Zhanghe Irrigation System

    Institute of Scientific and Technical Information of China (English)

    BROWN; Larry

    2009-01-01

    Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and unrecycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China. With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious. Traditional irrigation and drainage systems only focus on issues concerning water quantity, i.e. the capacity of irrigation in drought and drainage in waterlogging period, yet have no requirement on water quality improvement. how to clean the water quality of farmland drainage through remodeling the existing irrigation and drainage systems has a very important realistic meaning. Pond is an important irrigation facility in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use. Such water storage features of pond provide the possibility and potential capacity for drainage water treatment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system. To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site. The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water. Other issues, e.g. how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.

  11. Irrigation ponds: Possibility and potentials for the treatment of drainage water from paddy fields in Zhanghe Irrigation System

    Institute of Scientific and Technical Information of China (English)

    DONG Bin; MAO Zhi; BROWN Larry; CHEN XiuHong; PENG LiYuan; WANG JianZhang

    2009-01-01

    Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and un-recycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China.With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious.Traditional ir-rigation and drainage systems only focus on issues concerning water quantity, i.e.the capacity of irri-gation in drought and drainage in waterlogging period, yet have no requirement on water quality im-provement, how to clean the water quality of farmland drainage through remodeling the existing irriga-tion and drainage systems has a very important realistic meaning.Pond is an important irrigation facil-ity in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use.Such water storage features of pond provide the possibility and potential capacity for drainage water treat-ment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system.To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site.The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water.Other issues, e.g.how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.

  12. Vision of irrigation

    Directory of Open Access Journals (Sweden)

    Fernando Braz-Tangerino

    2014-08-01

    Full Text Available Irrigation not only has been a key factor for the development and maintenance of human societies but it still plays this role now and it is foreseen that in the future as well. Its evolution has been constrained to the advance in knowledge on matters regarding Agronomy and Water Engineering and in technology however, many challenges deserve further research. It is worth to note that Brazil has strongly promoted irrigation in the last decade. Within the limited extension of this article, some current topics in irrigation, some of them are innovative such us the research line studying water flow in soil-plant in Mediterranean plants and its consequences on water use,. and future challenges are presented with the purpose of stimulate publication of Irrigation papers in the journal “Ingeniería del Agua” among Portuguese and Spanish language communities.

  13. Effect of irrigation management on soil salinization in Manas River Valley,Xinjiang,China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The irrigated area of Manas River Valley in Northwest China is an example of the successful reclamation of massive land affected by shallow ground water levels and salinization.To determine the effect of irrigation management practices on soil salinization,soil profiles representing various soil types were sampled.The historical records on the characteristics of irrigation management practices,groundwater level and soil salts accumulation in this region at four key periods,namely:flood irrigation without drainage;flood irrigation with drainage but of low efficiency;irrigation in combination with lined irrigation canals and exploitation of groundwater;and irrigation with the application of water-saving irrigation techniques,were analyzed emphatically.In addition,the salinization status of cultivated land in 2010 and 2020 was also predicted by using analogism according to the relationship between soil salinization and irrigation practices.The results revealed that the application of the traditional irrigation methods,such as flood irrigation and ridge irrigation,resulted in a rapid rising of groundwater level and salts accumulation in soil surface layers.However,with the way of well irrigation and well drainage,the groundwater level and the desalinization in soil layers apparently lowered,leading to a substantial increase of crop yield.Currently,the application of drip irrigation under mulch decreased the salts concentration in soil layers and increased the crop yield.With the continuous application of drip irrigation,the average soil desalinization efficiency in soil layers may increase.It is predicted that the percentage of salinized land would be reduced to 35%-40% when irrigation water is utilized reasonably in 2010.With the high efficient utilization of irrigation water after 2020,the salinized land would remain below 30%.It is concluded that with the improvement of irrigation management,an obvious desalinization would appear in the soil surface layers and the

  14. Irrigation et paludisme : un couple infernal?

    Directory of Open Access Journals (Sweden)

    Mergeai, G.

    2016-01-01

    water basins, as natural transmission of the disease was low in these places. There are many possible ways of attenuating the negative effects of irrigation, while maintaining agricultural productivity, such as: alternate wetting and drying of rice paddies, rotation of rice cultivation with non-irrigated crops, proper maintenance of irrigation canals, in order to prevent the formation of ponds caused by leaks, using farm animals to attract mosquitos and keeping mosquito breeding sites away from alternative food sources, such as maize pollen, on which they feed. When irrigation projects are first planned, it is vital that measures are devised, in order to limit the spread of malaria, together with systems aimed at monitoring their impact on health. As well as the above-mentioned production techniques, this also applies to initiatives in the field of education, access to mosquito nets, cautious use of pesticides, diagnosis and early treatment of disease. It is important that all stakeholders in agricultural development are made more aware of these problems. The creation of affordable health insurance systems for farmers is also a solution that will rapidly get malaria victims back on their feet. Hoping to have sensitized to this important problematic all those of you who are concerned, I wish you an excellent reading of this issue.

  15. Advances in Irrigation

    Science.gov (United States)

    Gardner, W. R.

    This is the first volume of Advances in Irrigation, a new serial publication by the publishers of Advances in Agronomy and Advances in Hydroscience and designed to follow the same format. The editor is a well-known researcher and writer on irrigation and related subjects and has assembled a collection of highly regarded and respected authors for the initial volume. The readership for this volume will probably be mainly specialists and students interested in irrigation and an occasional design engineer.The seven contributions in this volume fall roughly into two classes: research and practice. Three papers (“Conjunctive Use of Rainfall and Irrigation in Semi-arid Regions,” by Stewart and Musik, “Irrigation Scheduling Using Soil Moisture Measurements: Theory and Practice,” by G. S. and M. D. Campbell, and “Use of Solute Transport Models to Estimate Salt Balance Below Irrigated Cropland,” by Jury) cover topics that have been the subject of a number of reviews. The contributions here provide brief, well-written, and authoritative summaries of the chosen topics and serve as good introductions or reviews. They should lend themselves well to classroom use in various ways. They also should be helpful to the nonspecialist interested in getting a sense of the subject without going into great detail.

  16. Comparison of efficacy of pulverization and sterile paper point techniques for sampling root canals.

    Science.gov (United States)

    Tran, Kenny T; Torabinejad, Mahmoud; Shabahang, Shahrokh; Retamozo, Bonnie; Aprecio, Raydolfo M; Chen, Jung-Wei

    2013-08-01

    The purpose of this study was to compare the efficacy of the pulverization and sterile paper point techniques for sampling root canals using 5.25% NaOCl/17% EDTA and 1.3% NaOCl/MTAD (Dentsply, Tulsa, OK) as irrigation regimens. Single-canal extracted human teeth were decoronated and infected with Enterococcus faecalis. Roots were randomly assigned to 2 irrigation regimens: group A with 5.25% NaOCl/17% EDTA (n = 30) and group B with 1.3% NaOCl/MTAD (n = 30). After chemomechanical debridement, bacterial samplings were taken using sterile paper points and pulverized powder of the apical 5 mm root ends. The sterile paper point technique did not show growth in any samples. The pulverization technique showed growth in 24 of the 60 samples. The Fisher exact test showed significant differences between sampling techniques (P technique showed no difference between irrigation regimens. However, 17 of the 30 roots in group A and 7 of the 30 roots in group B resulted in growth as detected by pulverization technique. Data showed a significant difference between irrigation regimens (P = .03) in pulverization technique. The pulverization technique was more efficacious in detecting viable bacteria. Furthermore, this technique showed that 1.3% NaOCl/MTAD regimen was more effective in disinfecting root canals. Published by Elsevier Inc.

  17. Residual activity of cetrimide and chlorhexidine on Enterococcus faecalis-infected root canals

    Institute of Scientific and Technical Information of China (English)

    Carmen Mara Ferrer-Luque; Mara Teresa Arias-Moliz; Matilde Ruz-Linares; Mara Elena Martnez Garca; Pilar Baca

    2014-01-01

    Effective final irrigation regimen is an important step in order to achieve better disinfection and ensure residual antimicrobial effects after root canal preparation. The aim of this study was to compare the residual antimicrobial activity of 0.2%cetrimide, and 0.2%and 2%chlorhexidine in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown on uniradicular roots for 4 weeks. After root canal preparation, root canals were irrigated with 17%ethylenediaminetetraacetic acid (EDTA) to remove the smear layer. The roots were randomly divided into three experimental groups (n526) according to the final irrigating solution:Group I, 5 mL 0.2%cetrimide;Group II, 5 mL 0.2%chlorhexidine;and Group III, 5 mL 2%chlorhexidine. Samples were collected for 50 days to denote the presence of bacterial growth. The proportion of ungrown specimens over 50 days was evaluated using the nonparametric Kaplan-Meier survival analysis. Differences among groups were tested using the log-rank test and the level of statistical significance was set at P,0.05. The highest survival value was found with 2%chlorhexidine, showing statistically significant differences from the other two groups. At 50 days, E. faecalis growth was detected in 69.23%specimens in Groups I and II, and in 34.61%specimens of Group III. There were no significant differences between 0.2%cetrimide and 0.2%chlorhexidine. Final irrigation with 2%chlorhexidine showed greater residual activity than 0.2%chlorhexidine and 0.2%cetrimide in root canals infected with E. faecalis.

  18. Controversy at Love Canal.

    Science.gov (United States)

    Paigen, B

    1982-06-01

    A cancer researcher reviews the events surrounding the toxic waste contamination at Love Canal with emphasis on the political nature of the controversy about its health impact. Antagonism between the community and the New York State Department of Health was fueled by several factors: the state's awareness that it gained from delay in investigation, disagreement on health problems to be studied, control over the information gathering process, silencing of opposition opinion, and the violation of norms of scientific behavior. The author calls for the establishment of standards of ethical behavior for scientists in such situations, standards for conflict resolution, and means of appeal for those injured.

  19. Comparison of the Antimicrobial Efficacy of Octenidine Dihydrochloride and Chlorhexidine with and Without Passive Ultrasonic Irrigation - An Invitro Study.

    Science.gov (United States)

    Cherian, Bastin; Gehlot, Paras Mull; Manjunath, Mysore Krishnaswamy

    2016-06-01

    Elimination of microorganisms from infected root canals is a complicated task. Numerous measures have been described to reduce the microbial load in the root canal system, including the use of various instrumentation techniques, irrigation regimens and intracanal medicaments. The drawbacks of few commonly used irrigants include toxic and harmful side effects, microbial resistance to antimicrobial agents and staining. Hence there is a need for alternative agents which are nontoxic, effective and safe. To compare and evaluate antimicrobial effects of 2% Chlorhexidine (CHX) versus 0.1% Octenidine Dihydrochloride (OCT) as root canal irrigant with and without passive ultrasonic irrigation against Enterococcus faecalis (E. faecalis) in vitro and to evaluate the depth of penetration of irrigant solution into the dentinal tubules at the junction of middle and apical third. Forty eight freshly extracted, single rooted human mandibular premolars were decoronated and root specimen standardized to 14mm. Biofilm of E. faecalis (strain ATCC 29212) was grown for seven days and the specimens were divided into four groups (n=12) based on irrigation protocol : Group I- Conventional Syringe Irrigation (CSI) with 2% CHX, Group II- CSI + 0.1% OCT, Group III-Passive Ultrasonic Irrigation (PUI) + 2% CHX and Group IV- PUI+ 0.1% OCT. Dentin shavings were collected at two depths (200μm and 400μm) and total number of colony forming units were determined. The data were statistically analyzed using ANOVA, Scheffes multiple comparison of means and paired t-test (pOctenidine (0.1%) was more effective than 2% Chlorhexidine against E. faecalis both at 200μm and 400μm. Passive ultrasonic irrigation proved to enhance the antimicrobial action of the irrigants.

  20. Comparison of the Antimicrobial Efficacy of Octenidine Dihydrochloride and Chlorhexidine with and Without Passive Ultrasonic Irrigation - An Invitro Study

    Science.gov (United States)

    Cherian, Bastin; Manjunath, Mysore Krishnaswamy

    2016-01-01

    Introduction Elimination of microorganisms from infected root canals is a complicated task. Numerous measures have been described to reduce the microbial load in the root canal system, including the use of various instrumentation techniques, irrigation regimens and intracanal medicaments. The drawbacks of few commonly used irrigants include toxic and harmful side effects, microbial resistance to antimicrobial agents and staining. Hence there is a need for alternative agents which are nontoxic, effective and safe. Aim To compare and evaluate antimicrobial effects of 2% Chlorhexidine (CHX) versus 0.1% Octenidine Dihydrochloride (OCT) as root canal irrigant with and without passive ultrasonic irrigation against Enterococcus faecalis (E. faecalis) in vitro and to evaluate the depth of penetration of irrigant solution into the dentinal tubules at the junction of middle and apical third. Materials and Methods Forty eight freshly extracted, single rooted human mandibular premolars were decoronated and root specimen standardized to 14mm. Biofilm of E. faecalis (strain ATCC 29212) was grown for seven days and the specimens were divided into four groups (n=12) based on irrigation protocol : Group I- Conventional Syringe Irrigation (CSI) with 2% CHX, Group II- CSI + 0.1% OCT, Group III-Passive Ultrasonic Irrigation (PUI) + 2% CHX and Group IV- PUI+ 0.1% OCT. Dentin shavings were collected at two depths (200μm and 400μm) and total number of colony forming units were determined. The data were statistically analyzed using ANOVA, Scheffes multiple comparison of means and paired t-test (pfaecalis both at 200μm and 400μm. Passive ultrasonic irrigation proved to enhance the antimicrobial action of the irrigants. PMID:27504415

  1. Effectiveness of different irrigation protocols on calcium hydroxide removal from simulated immature teeth after apexification

    Directory of Open Access Journals (Sweden)

    Evren Ok

    2015-01-01

    Full Text Available Aim: To evaluate the effectiveness of different irrigation solutions and ultrasonic activation of the irrigation solutions on the removal of calcium hydroxide (Ca(OH2 from the simulated immature root canals after apexification. Materials and methods: One-hundred and one single-rooted teeth were used. The root canals were shaped with ProTaper rotary files up to F5. Simulation of roots with immature apices was carried out using size 4 Unicore drills. An injectable Ca(OH2 was injected into each root canal, and packed to the working length. Then, cotton pellets were placed over canal orifices, and apical and coronal parts of the roots were sealed with resin-modified glass ionomer cement, and light cured. Specimens were stored in distilled water for 3 months at 37°C. After 3 months, the temporary coronal seal was removed and the samples were randomly divided into: (a saline (n = 20, (b ultrasonic activation of saline (n = 20, (c sodium hypochlorite (NaOCl (n = 20, (d ultrasonic activation of NaOCl (n = 15, (e chlorhexidine digluconate (CHX (n = 20 and one positive control group (n = 3 and one negative control group (n = 3. The amount of remaining Ca(OH2 on the canal walls was measured under stereomicroscope with 30× magnification. Comparisons between groups were made by the non-parametric Kruskal-Wallis test and Dunn post-test at a significance level of p  0.05 groups. Conclusions: Irrigation solutions and ultrasonic activation of the irrigation solutions could not completely remove Ca(OH2 from the simulated immature root canals.

  2. Viability and antibacterial efficacy of four root canal disinfection techniques evaluated using confocal laser scanning microscopy

    Directory of Open Access Journals (Sweden)

    Joan Mathew

    2014-01-01

    Full Text Available Background: Several disinfection techniques have been recently introduced with the main objective of improving root canal disinfection in the inaccessible areas of the root canal system. This in vitro study was done to evaluate the antimicrobial effect and viability of Enterococcus faecalis biofilms using conventional irrigation, EndoActivator (Dentsply, Tulsa Dental, USA, diode laser irradiation and photon-initiated photoacoustic streaming (PIPS. Materials and Methods: Root canals of 130 single rooted mandibular premolars, standardized to a uniform length of 20 mm were instrumented until finishing file, F1 (Universal Protaper Rotary System, Dentsply, Tulsa Dental Specialties, USA. After smear layer removal and sterilization, five teeth were randomly selected to assure sterility before bacterial inoculation. The remaining 125 samples were contaminated with E. faecalis suspension, incubated for 21 days and divided into five groups (n = 25. In Group 1; untreated group (positive control, the root canals were not subjected to any disinfection procedure. Sampling was performed within the canals and the colony-forming unit count was evaluated for 20 samples. Five samples were selected to visualize the pattern of colonization at Level 1 (4 mm from the apex and Level 2 (1 mm from the apex by confocal laser scanning microscopy. Samples in Groups 2-5 namely conventional needle irrigation, EndoActivator, diode laser and PIPS were subjected to their respective disinfection procedures. Postdisinfection sample evaluation criteria was followed for all groups as same as that for Group 1. Results: Diode laser displayed the highest antibacterial efficacy and least viable bacteria than the other three disinfection techniques. Conclusion: Diode laser group showed better antibacterial efficacy and least viable bacteria when compared to conventional needle irrigation, PIPS and EndoActivator groups in minimally instrumented, experimentally infected root canals.

  3. Spinal canal stenosis; Spinalkanalstenose

    Energy Technology Data Exchange (ETDEWEB)

    Papanagiotou, P.; Boutchakova, M. [Klinikum Bremen-Mitte/Bremen-Ost, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Bremen (Germany)

    2014-11-15

    Spinal stenosis is a narrowing of the spinal canal by a combination of bone and soft tissues, which can lead to mechanical compression of spinal nerve roots or the dural sac. The lumbal spinal compression of these nerve roots can be symptomatic, resulting in weakness, reflex alterations, gait disturbances, bowel or bladder dysfunction, motor and sensory changes, radicular pain or atypical leg pain and neurogenic claudication. The anatomical presence of spinal canal stenosis is confirmed radiologically with computerized tomography, myelography or magnetic resonance imaging and play a decisive role in optimal patient-oriented therapy decision-making. (orig.) [German] Die Spinalkanalstenose ist eine umschriebene, knoechern-ligamentaer bedingte Einengung des Spinalkanals, die zur Kompression der Nervenwurzeln oder des Duralsacks fuehren kann. Die lumbale Spinalkanalstenose manifestiert sich klinisch als Komplex aus Rueckenschmerzen sowie sensiblen und motorischen neurologischen Ausfaellen, die in der Regel belastungsabhaengig sind (Claudicatio spinalis). Die bildgebende Diagnostik mittels Magnetresonanztomographie, Computertomographie und Myelographie spielt eine entscheidende Rolle bei der optimalen patientenbezogenen Therapieentscheidung. (orig.)

  4. 典型小型灌区渠系老化对农田灌溉的影响——以贵州省乌中灌区为例%The Effects of Typical Small Irrigation District System Aging in Wuzhong Irrigation District on Farmland Irrigation

    Institute of Scientific and Technical Information of China (English)

    刘浏; 张和喜; 蔡长举; 王鹏

    2012-01-01

    Wuzhong Irrigation District is one of the biggest irrigation districts in Guizhou Province. The irrigation project was constructed from1950s to 1970s. l Jp to now, most of irrigation canals can not work well because of aging, the average aging rate of canal system is 0. 55, so that irrigation area and water efficiency of irrigation declines sharply. The present effective irrigation area accounts for 37 %-54% of the designed irrigation area. Utilization coefficient of irrigation water is low in between 0. 39-0. 42. In this study, five typical irrigation districts are investigated and the impact of irrigation district system aging on farmland irrigation is analyzed.%乌中灌区是贵州省的大型灌区之一,灌区工程多修建于20世纪50-70年代。至今,大多渠道老化难以正常工作,渠系老化率平均达0.55;灌区有效灌溉面积锐减,现状有效灌溉面积为设计灌溉面积的37%~54%,其中改种.占相当比例;灌溉水利用系数较低,在0.39~0.42之间。以5个典型样点灌区为例,分析渠系老化对农田灌溉的影响。

  5. 全国纯井灌区类型构成对灌溉水有效利用系数的影响分析%Influence Analysis of Irrigation Area Composition of Well-irrigation District on Irrigation Water Use Efficiency in China

    Institute of Scientific and Technical Information of China (English)

    冯保清; 崔静

    2013-01-01

    Multivariate regression analysis was conducted to identify the relationship between irrigation area composition of different irrigation types and irrigation water use efficiency,and irrigation water use efficiency model was established using 2007-2012 nationwide well irrigation data.The results showed that the influence degree of five irrigation types on irrigation water use efficiency in the decreasing order was micro-irrigation,sprinkler irrigation,pipeline water system,surface irrigation of lining canal,surface irrigation of earth canal.Errors between simulated and measured water use efficiency of well irrigation district in each province and in China were within ±10%,2% respectively.%对2007-2012年全国纯井灌区不同类型有效灌溉面积占纯井灌区有效灌溉面积的比例与纯井灌区灌溉水有效利用系数进行多元回归分析,建立了灌溉水有效利用系数模型.结果表明,5种灌溉类型灌溉面积占比对纯井灌区灌溉水有效利用系数的影响程度为:微灌>喷灌>管道输水地面灌>防渗渠道地面灌>土质渠道地面灌;各省、全国纯井灌区灌溉水有效利用系数模拟值与实测值误差分别在土10%、2%以内.

  6. Assessment of the wetting behavior of three different root canal sealers on root canal dentin

    Directory of Open Access Journals (Sweden)

    Muralidhar Tummala

    2012-01-01

    Full Text Available Aim: The objective of the present study was to evaluate and compare the wetting behavior of three different root canal sealers on the root canal dentin surface treated with irrigants and their combination. Materials and Methods: Decoronation and apical third resections of 27 extracted single-rooted human mandibular premolars were done. The roots were then split longitudinally into two halves, and randomly assigned into three treatment groups (n=18. The root dentin surfaces in Group1, Group 2 and Group 3 were treated with 17% ethylene diamine tetra acetic acid (EDTA, 3% sodium hypochlorite (NaOCl and combination of 17% EDTA and 3% NaOCl, respectively. Each group was subdivided into three subgroups of 6 specimens each, depending on the the sealer used, i.e. sub group A. zinc oxide (ZnOE, sub group B. AH plus, subgroup C. Guttaflow sealer, respectively. The contact angle was measured using First Ten Angstroms (FTA 200 dynamic contact angle analyzer. Results: The contact angle values for AH Plus sealer were significantly lower when compared to the other two sealer groups. Conclusion: The wettability of AH Plus sealer on the root surface dentin was found to be better than Gutta-Flow and ZnOE sealer.

  7. The origin of the Dargom canal in the oasis of Samarkand (Uzbekistan). A new scenario from geoarcheological data

    Science.gov (United States)

    Marconi, V.; Mantellini, S.; Picotti, V.; Gabbianelli, G.; Tosi, M.

    2009-04-01

    As the main oases developed in the arid regions of Central Asia, the region of Samarkand is the outcome of large hydraulic works carried out since the past times. The main result of such a great landscape transformation is a complex irrigation network formed by several artificial channels and useful for both urban water supply and irrigation purposes. Within the framework of the Italo-Uzbek Archaeological Project begun in 2001, a specific study was aimed to reconstruct the history of Dargom, the primary canal on the South of the city, and its relationships with the settlement dynamics. According to the most accepted theories, the Dargom was dug during the Achaemenid Age (6th-4th c. BC) as a consequence of a master plan linked to a strong central political power. The new investigations carried out by a joined team of Archaelogists and Geologists from the University Bologna allowed a new hypothesis on the way of digging and the chronology of the Dargom itself. The analyses on the historical settlement patterns seem to suggest a low development of Samarkand's territory during the Achaemenid times, whilst the increasing of sites during the Early Middle Age (5th-8th c.) can be explained throughout the rich trades along the Silk Road as well as the development of irrigated agriculture. The present-day Dargom is a high sinuosity channel deeply incised into the bedrock flowing to the east, strongly resembling a natural channel. It has been excavated for around 70 km along an apron of alluvial fans sourced by a southern mountain range. Its morphology clearly document a natural evolution after excavation: incision and meandering took place, likely due to the increasing gradient related to the headward migration of lowering of the base-level and the decrease of the bed load through time. Field survey around the fortress of Kafir Kala, the main archeological site geographically linked to the Dargom, allowed reconstructing the original bed of the canal, marked by a layer of

  8. Irrigant transport into dental microchannels

    NARCIS (Netherlands)

    Verhaagen, B.; Boutsioukis, C.; Sleutel, C. P.; Kastrinakis, E.; van der Sluis, L. W. M.; Versluis, M.

    2014-01-01

    The root canal system of a tooth is a complex geometrical entity, consisting not only of the main root canal, but also of accessory and lateral canals. Bacteria can reside up to hundreds of micrometers inside those channels and may be difficult to reach for the antimicrobial agents with which root c

  9. Effect of intracanal cryotherapy on pain after single-visit root canal treatment.

    Science.gov (United States)

    Keskin, Cangül; Özdemir, Özgür; Uzun, İsmail; Güler, Buğra

    2016-10-04

    The purpose of this study was to evaluate the effect of 2.5°C cold saline irrigation as final irrigant on postoperative pain after single-visit root canal treatment of teeth with vital pulps. One-hundred and seventy patients were assessed as eligible and included to the study. The teeth were randomly divided into two groups (n = 85) (i.e. the control group and the cryotherapy group). In the cryotherapy group, final irrigation with 2.5°C 0.9% physiological saline solution for 5 min was performed following completion of biomechanical preparation, whereas in control group same solution stored at the root temperature was used. Treatments were performed in a single visit. Participants were asked to rate the intensity of their postoperative pain using visual analogue scale at 24 and 48 h. Data were analysed by Mann-Whitney U test and Student's t test. In the cryotherapy group level of reported postoperative pain was significantly lower than the control group (P < 0.05, Mann-Whitney U test). The outcome of this investigation indicates that 2.5°C cold saline irrigation as final irrigant can result a significant reduction in postoperative pain levels in comparison to the control group. Cryotherapy is a simple, cost-effective, and non-toxic option for postoperative pain control in single visit root canal treatment.

  10. Antibacterial Efficacy of Calcium Hypochlorite with Vibringe Sonic Irrigation System on Enterococcus faecalis: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Aysin Dumani

    2016-01-01

    Full Text Available Aim. The purpose of this study was to compare the in vitro efficacy of calcium hypochlorite (Ca[OCl]2 and sodium hypochlorite (NaOCl associated with sonic (Vibringe irrigation system in root canals which were contaminated with Enterococcus faecalis. Material and Methods. The root canals of 84 single-rooted premolars were enlarged up to a file 40, autoclaved, inoculated with Enterococcus faecalis, and incubated for 21 days. The samples were divided into 7 groups according to the irrigation protocol: G0: no treatment; G1: distilled water; G2: 2.5% NaOCl; G3: 2.5% Ca(OCl2; G4: distilled water with sonic activation; G5: 2.5% NaOCl with sonic activation; and G6: 2.5% Ca(OCl2 with sonic activation. Before and after decontamination procedures microbiological samples were collected and the colony-forming units were counted and the percentages of reduction were calculated. Results. Distilled water with syringe irrigation and sonic activation groups demonstrated poor antibacterial effect on Enterococcus faecalis compared to other experimental groups (p<0.05. There was no statistically significant difference between syringe and sonic irrigation systems with Ca(OCl2 and NaOCl. Conclusion. The antimicrobial property of Ca(OCl2 has been investigated and compared with that of NaOCl. Both conventional syringe irrigation and sonic irrigation were found effective at removing E. faecalis from the root canal of extracted human teeth.

  11. Using hydraulic modeling to simulate human interactions with water resources in an Omani irrigation system

    Science.gov (United States)

    Xanthopoulou, Themis; Ertsen, Maurits; Düring, Bleda; Kolen, Jan

    2017-04-01

    In the dry Southern Oman, more than a thousand years ago, a large water system that connected the mountain mass with the coastal region was constructed. Its length (up to 30 km) and the fact that the coastal region has a rich groundwater aquifer create confusion as to why the system was initially built. Nonetheless, it was abandoned a couple of centuries later only to be partially revived by small farming communities in the 17th to 18th century. The focus of our research is one of the irrigation systems that used the water conveyed from the large water system. Not much is known about these small irrigation systems functioning in the Wadi Al Jizzi of the greater Sohar region. There are no written records and we can only make guesses about the way the systems were managed based on ethnographical studies and the traditional Omani techniques. On the other hand, the good preservation state of the canals offers a great opportunity for hydraulic reconstruction of irrigation events. More than that, the material remains suggest and at the same time limit the ways in which humans interacted with the system and the water resources of the region. All irrigation activities and some daily activities had to be realized through the canal system and only if the canal system permits it these actions would have been feasible. We created a conceptual model of irrigation that includes the human agent and feedback mechanisms through hydraulics and then we simulated irrigation events using the Sobek software. Scenarios and sensibility analysis were used to address the unknown aspects of the system. Our research yielded insights about the way the farming community interacted with the larger water system, the levels of co-ordination and co-operation required for successful irrigation and the predisposition of conflict and power relations.

  12. Micro-computed tomography evaluation of the removal of calcium hydroxide medicament from C-shaped root canals of mandibular second molars.

    Science.gov (United States)

    Ma, J Z; Shen, Y; Al-Ashaw, A J; Khaleel, H Y; Yang, Y; Wang, Z J; Peng, B; Haapasalo, M

    2015-04-01

    To use micro-computed tomography (μ-CT) to evaluate the amount of calcium hydroxide [Ca(OH)2 ] remaining in the C-shaped root canals of mandibular second molars after attempting to remove it with passive ultrasonic and sonic irrigation. Thirty mandibular second molars, 15 in C1 and 15 in C2 configurations as first identified by μ-CT, were divided into three groups (five C1 and five C2 in each group) for the three irrigation methods. All teeth were prepared to ProTaper Universal F2 and filled with Ca(OH)2 paste. The Ca(OH)2 was removed with F2 files and irrigation without agitation or with agitation using either EndoActivator or ultrasonics. μ-CT was used to measure the initial amount of Ca(OH)2 present. After removal of Ca(OH)2, μ-CT imaging was used to assess the percentage of volume of residual Ca(OH)2 in the canal. Data were analysed using one-way anova test. There was no significant difference in the mean volume of the root canal systems after instrumentation amongst the three groups. The three irrigation techniques left 2-17% of Ca(OH)2 in the root canals after removal. The mean volume of the remaining Ca(OH)2 was higher in the group without agitation than in the groups with sonic or ultrasonic agitation (P < 0.05). In the apical third, 68% of the canal space remained occupied by Ca(OH)2 when no agitation was used, whereas 28% and 31% remained filled by Ca(OH)2 in the EndoActivator and ultrasonic groups, respectively. There was no significant difference in the amount of residual Ca(OH)2 between the EndoActivator and ultrasonic groups. The proportion of remaining Ca(OH)2 in the apical canals was higher than in the middle and coronal canals in all groups (P < 0.05). A considerable proportion of the apical canal space remained filled with Ca(OH)2 in the C-shaped root canals after instrumentation and conventional needle irrigation. Although combining rotary instrumentation and irrigation with sonic or ultrasonic agitation reduced the amount of residual Ca

  13. A novel model for testing the efficiency of removal of calcium hydroxide from complex root canal anatomies.

    Science.gov (United States)

    Küçükkaya Eren, Selen; Aksel, Hacer; Parashos, Peter

    2017-04-01

    The purpose of this study was to evaluate the efficacy of several irrigation protocols in the removal of calcium hydroxide [Ca(OH)2 ] from simulated internal root resorption cavities in a complex root canal anatomy model. The 20° to 35° curved mesiobuccal roots of 94 maxillary molars were sectioned longitudinally; internal resorption cavities were prepared in the apical third of the canal walls. Calcium hydroxide was placed into the cavities and the root halves reassembled. Four teeth were used as controls, and 90 teeth were randomly divided into six experimental groups (n = 15), according to the irrigation protocols used: syringe irrigation; H2 O2 (HP); Navitip FX; Vibringe-syringe; Vibringe-NaviTip FX; ultrasonically activated irrigation (UAI) using an ultrasonic K-file. In the HP group, 2.5% NaOCl and 3% H2 O2 were used, while 2.5% NaOCl and 17% EDTA were used in the remaining groups. Stereomicroscope images and radiographs were used to measure the remaining Ca(OH)2 . The model proved to be suitable for simulating complex anatomy. Positive correlation was found between stereomicroscope and radiographic analyses (P efficient protocol (P < 0.05). It would appear that a reliable model has been developed that simulates complex root canal anatomy. Irrigant activation protocols enhanced Ca(OH)2 removal. © 2017 Australian Society of Endodontology Inc.

  14. Debris removal from artificial grooves using different endodontic irrigation activation techniques: ex vivo

    Directory of Open Access Journals (Sweden)

    Mügem Aslı Ekici

    2016-12-01

    Full Text Available Objective: The aim of this study was to compare the debris removal efficiency of different irrigation activation techniques from artificially formed endodontic grooves. Materials and Method: Crowns of twenty maxillary incisor teeth were removed and the root canals were prepared. Specimens were embedded in acrylic resin and placed into teflon molds. Acrylic resin blocks were removed from the molds and split longitudinally into equal two halves. A standardized artificial groove (4 mm x 0.2 mm x 0.5 mm was prepared at 2 mm distance from the apex and filled with dentinal debris. Acrylic resin blocks were placed into the teflon mold again and compressed. Four different irrigation activation techniques; Manual Dynamic Irrigation (MDI, Passive Ultrasonic Irrigation (PUI, Sonic Irrigation (SI and Apical Negative Pressure Irrigation (ANPI were used for debris removal. Conventional Irrigation (CI was applied as control. For standardization, each specimen was cleaned and reused (n=20. Before and after irrigation, images of the grooves were taken by using an operating microscope at x30 magnification. Amount of remaining debris was evaluated by using a scoring system. Data were analyzed by using Kruskall-Wallis and Mann-Whitney U tests (α=0.05. Results: There were statistically significant differences between the experimental groups (p0.05. Conclusion: PUI yielded the lowest debris scores. A simple and low-cost technique, MDI, yielded similar results with PUI.

  15. A Comparative Evaluation on Antimicrobial Effect of Honey, Neem Leaf Extract and Sodium Hypochlorite as Intracanal Irrigant: An Ex-Vivo Study.

    Science.gov (United States)

    Sundaram, Divya; Narayanan, Retna Kumari; Vadakkepurayil, Kannan

    2016-08-01

    The major determinant of the success of root canal treatment depends on meticulous disinfection of the root canal using intracanal irrigants. The most commonly used root canal irrigant is sodium hypochlorite which has disadvantages of cytotoxicity and unpleasant taste. So there is a need to identify a more biocompatible root canal irrigant. The aim of this ex-vivo study was to evaluate the efficacy of 40% honey, 100% neem leaf extract and 5.25% sodium hypochlorite as an intracanal irrigant against the isolated microorganisms from infected root canal. The samples were collected from infected root canals of 60 primary molar teeth indicated for pulpectomy. Alpha hemolytic Streptococci, gram negative bacilli, Candida, Staphylococci, Lactobacilli, Enterococci, Spore bearing gram positive bacilli and Micrococci were the microorganisms isolated from the samples. The zone of inhibition against the microbial growth was measured by agar well diffusion method. Statistical analysis was done by Repeated Analysis of Variance (ANOVA) and Bonferroni method. Statistical analysis showed that the means of the zones of inhibition measured in this study were 18.56mm, 2.09mm and 1.62mm for sodium hypochlorite, 100% neem leaf extract and 40% honey respectively. The significance was greater between sodium hypochlorite and the other two agents as p-value was neem leaf extract and 40% honey. It was also observed that 100% neem leaf extract has greater antimicrobial effect than 40% honey.

  16. SEDIMENT CONTROL FOR IRRIGATION INTAKES

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The analysis of the sediment problems in irrigation engineeringwas carried out, and the layout, the method as well as the effect of sediment control for irrigation intake structures in China were briefly introduced.

  17. Influence of instrumentation techniques and irrigating solutions on bond strength of glass fiber posts to root dentin.

    Science.gov (United States)

    Marques, Eduardo Fernandes; Bueno, Carlos Eduardo da Silveira; Veloso, Heloisa Helena Pinho; Almeida, Gustavo; Pinheiro, Sergio Luiz

    2014-01-01

    This study sought to evaluate how instrumentation techniques and irrigating solutions affected the bond strength of glass fiber posts. For this study, 80 human maxillary central incisors were selected. Endodontic access was obtained, root canal length was measured, and the coronal third was prepared using Gates-Glidden drills. The specimens were embedded in acrylic resin and randomly assigned to 8 groups (n = 10): manual instrumentation only (Group 1), rotary instrumentation only (Group 2), irrigation with 2.5% sodium hypochlorite (NaOCl) (Group 3), irrigation with 2% chlorhexidine (CHX) (Group 4), manual instrumentation and irrigation with 2.5% NaOCl (Group 5), manual instrumentation and irrigation with 2% CHX (Group 6), rotary instrumentation and irrigation with 2.5% NaOCl (Group 7), and rotary instrumentation and irrigation with 2% CHX (Group 8). Specimens in Groups 5-8 also received a 1 minute final rinse with ethylenediaminetetraacetic acid. Canals were filled and the specimens stored for 30 days in distilled water. The restoration material was removed down to the apical 4 mm of the root canal. The glass fiber posts were luted with resin cement and stored for 24 hours at 37°C. Specimens were subjected to a tensile strength test at a constant speed of 1.0 mm/minute and a load of 2,000 kgf. The results were analyzed by analysis of variance and Tukey's test. Irrigation with 2.5% NaOCl reduced the bond strength of fiber posts significantly (P 0.05). It was concluded that irrigation with 2.5% NaOCl has a negative effect on micromechanical retention of glass fiber posts, whether manual or rotary instrumentation is used.

  18. Fluid Dynamics and Biofilm Removal Generated by Syringe-delivered and 2 Ultrasonic-assisted Irrigation Methods: A Novel Experimental Approach.

    Science.gov (United States)

    Layton, Gillian; Wu, Wen-I; Selvaganapathy, Ponnambalam Ravi; Friedman, Shimon; Kishen, Anil

    2015-06-01

    Thorough understanding of fluid dynamics in root canal irrigation and corresponding antibiofilm capacity will support improved disinfection strategies. This study aimed to develop a standardized, simulated root canal model that allows real-time analysis of fluid/irrigation dynamics and its correlation with biofilm elimination. A maxillary incisor with an instrumented root canal was imaged with micro-computed tomography. The canal volume was reconstructed in 3 dimensions and replicated in soft lithography-based models microfabricated from polyethylene glycol-modified polydimethylsiloxane. Canals were irrigated by using a syringe (SI) and 2 ultrasonic-assisted methods, intermittent (IUAI) and continuous (CUAI). Real-time fluid movement within the apical 3 mm of canals was imaged by using microparticle image velocimetry. In similar models, canals were inoculated with Enterococcus faecalis to grow 3-week-old biofilms. Biofilm reduction by irrigation with SI, CUAI, and IUAI was assessed by using a crystal violet assay and compared with an untreated control. SI generated higher velocity and shear stress in the apical 1-2 mm than 0-1 and 2-3 mm. IUAI generated consistently low shear stress in the apical 3 mm. CUAI generated consistently high levels of velocity and shear stress; it was the highest of the groups in the apical 0-1 and 2-3 mm. Biofilm was significantly reduced compared with the control only by CUAI (two-sample permutation test, P = .005). CUAI exhibited the highest mechanical effects of fluid flow in the apical 3 mm, which correlated with significant biofilm reduction. The soft lithography-based models provided a novel model/method for study of correlations between fluid dynamics and the antibiofilm capacity of root canal irrigation methods. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Planning for an Irrigation System.

    Science.gov (United States)

    Turner, J. Howard; Anderson, Carl L.

    The publication, with the aid of tables and colored illustrations and diagrams, presents information to help the farmer who is considering the installation of an irrigation system determine whether or not to irrigate, the type of system to use, and the irrigation cost and return on investment. Information is presented on the increase in yield to…

  20. Planning for an Irrigation System.

    Science.gov (United States)

    Turner, J. Howard; Anderson, Carl L.

    The publication, with the aid of tables and colored illustrations and diagrams, presents information to help the farmer who is considering the installation of an irrigation system determine whether or not to irrigate, the type of system to use, and the irrigation cost and return on investment. Information is presented on the increase in yield to…

  1. Hood Canal Steelhead - Hood Canal Steelhead Supplementation Experiment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Hood Canal Steelhead Project is a 17-year before-after-control-impact experiment that tests the effects of supplementation on natural steelhead populations in...

  2. The influence of the ultrasonic intensity on the cleaning efficacy of passive ultrasonic irrigation.

    Science.gov (United States)

    Jiang, Lei-Meng; Verhaagen, Bram; Versluis, Michel; Langedijk, Jelmer; Wesselink, Paul; van der Sluis, Lucas W M

    2011-05-01

    It is not clear whether increasing the ultrasonic intensity would enhance the cleaning efficacy of passive ultrasonic irrigation (PUI) inside a root canal. The aim of this study was to evaluate the effect of the ultrasonic intensity on PUI to remove dentin debris and whether there is any lateral effect beyond the ultrasonic tip. Each of 15 in vitro root canal models with four standard depressions in the apical part of one canal wall were filled with dentin debris and received PUI repeatedly. The most apical depression was localized apically from the ultrasonic tip. The highest intensity was applied in group 1, the lowest intensity was applied in group 3, and syringe irrigation was performed in group 4 as a control. Before and after irrigation, images of the canal wall with depressions were taken and compared. The removal of dentin debris in the depression was categorized as clean or not clean. The data were analyzed by means of the chi-square test. The oscillation amplitude of the ultrasonic file at each intensity was recorded in vitro using time-resolved high-speed imaging. Group 1 (highest intensity) exhibited significantly better cleaning than all the other groups (P ultrasonic intensity resulted in a higher amplitude of the oscillating file and, consequently, enhanced the cleaning efficacy of PUI. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  3. Evaluating two irrigation controllers under subsurface drip irrigated tomato crop

    Directory of Open Access Journals (Sweden)

    Hussein M. Al-Ghobari

    2016-12-01

    Full Text Available Smart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water.

  4. Review on Trickle Irrigation Application in Groundwater Irrigation Schemes

    Directory of Open Access Journals (Sweden)

    Prastowo

    2006-04-01

    Full Text Available The Government of Indonesia has developed groundwater irrigation schemes in some province e.g. East Java, Central Java, Yogyakarta, Wast Java, Bali, West Nusa Tenggara and East Nusa Tenggara. However, not all regions were able to optimally utilize it. The irrigation effeciency of groundwater irrigation scheme was about 59%, while the wells-pumping efficiencies were varied from 28 to 98 %. In thefuture, the irrigation effieciency should be increased to anticipate water deficit during dry season. The application of trickle irrigation in indonesia has not been widely developed. Although trickle system has been used, however, it is still limited for few commercial agribusinesses. Trickle irrigation systems have a prospect to be developed in some regions having limited water resources. For preliminary stage, the systems could be applied in groundwater irrigation schemes that have been developed either by farmers or government.

  5. Evaluation of an Indigenously Prepared Herbal Extract (EndoPam) as an Antimicrobial Endodontic Irrigant: An Ex Vivo Study

    Science.gov (United States)

    Mathew, Jain; Pathrose, Sonia; Kottoor, Jojo; Karaththodiyil, Ranjith; Alani, Mathew; Mathew, Joy

    2015-01-01

    Backgroundg: Root canal irrigation plays a pivotal role in endodontics. Constant increase in antibiotic resistance and side effects caused by synthetic irrigants has shifted the research toward developing herbal alternatives. The current study aims to assess the ex vivo effectiveness of an indigenously prepared herbal extract “EndoPam” and compare it with the conventional endodontic irrigants for disinfection of root canals infected with Enterococcus faecalis. Materials and Methods: As a preliminary study of the antimicrobial efficacy of the test irrigants, an Agar diffusion study was conducted, and zone of inhibition measured. Forty extracted mandibular premolars with straight root canals were selected and standardized to 12 ± 1 mm in length. Root canals were prepared using rotary ProTaper system until F3 instrument and were infected with the culture of E. faecalis for three weeks. Specimens were divided into four groups (n = 10). Group 1: EndoPam ( Ingredients: Syzigium aromaticum, Eucalyptus globulus, Cinnamomum zeylanicum and Mentha piperita), Group 2: 2% chlorhexidine, Group 3: 5.25% Sodium hypochlorite, Group 4: Normal Saline. Irrigation was performed for each group. Samples were inoculated and incubated for 24 h at 37°C for qualitative analysis qualitative analysis. Results: In the preliminary Agar diffusion study, EndoPam exhibited a zone of inhibition comparable to that of sodium hypochrorite. The diameter of the inhibition zone was in the following order: 2% chlorhexidine gluconate > EndoPam > 5.25% NaOCl > Normal Saline. The qualitative assay done by culturing the bacteria after a period of 3 weeks showed no bacterial growth in any of the tested irrigants, except in normal saline. Conclusion: It was found that the experimental product was as effective as conventional irrigants in reducing the microbial count. PMID:26124607

  6. Effectiveness of various irrigation protocols for the removal of calcium hydroxide from artificial standardized grooves.

    Science.gov (United States)

    Gokturk, Hakan; Ozkocak, Ismail; Buyukgebiz, Feyzi; Demir, Osman

    2017-01-01

    The aim of this study was to investigate the ability of laser-activated irrigation (LAI), XP-endo Finisher, CanalBrush, Vibringe, passive ultrasonic irrigation (PUI), and conventional syringe irrigation systems on the removal of calcium hydroxide (CH) from simulated root canal irregularities. The root canals of one hundred and five extracted single-rooted teeth were instrumented using Reciproc rotary files up to size R40. The teeth were split longitudinally. Two of the three standard grooves were created in the coronal and apical section of one segment, and another in the middle part of the second segment. The standardized grooves were filled with CH and the root halves were reassembled. After 14 days, the specimens were randomly divided into 7 experimental groups (n=15/group). CH was removed as follows: Group 1: beveled needle irrigation; Group 2: double side-vented needle irrigation; Group 3: CanalBrush; Group 4: XP-endo Finisher; Group 5: Vibringe; Group 6: PUI; Group 7: LAI. The amount of remaining CH in the grooves was scored under a stereomicroscope at 20× magnification. Statistical evaluation was performed using Kruskal-Wallis and Bonferroni-Correction Mann-Whitney U tests. Groups 1 and 2 were the least efficient in eliminating CH from the grooves. Groups 6 and 7 eliminated more CH than the other protocols; however, no significant differences were found between these two groups (P>.05). Nevertheless, none of the investigated protocols were able to completely remove all CH from all three root regions. LAI and PUI showed less residual CH than the other protocols from artificial grooves.

  7. The Love Canal: Beyond science?

    Science.gov (United States)

    Bell, Peter M.

    When in 1978, the New York State Department of Health issued the report, ‘Love Canal—Public Health Time Bomb,’ the serious effects of chemical waste contamination in the Love Canal area became an issue of national concern. A few ‘studies’ since then have produced results in concert with those of initial reports that described ‘conditions of acute health effects’ as being linked to hazardous wastes incorporated in landfill in the Love Canal site near Niagara Falls, New York. Now that a ‘blue ribbon’ panel of experts from the medical sciences has reviewed the problems of Love Canal, however, a different view has emerged. The ‘Report of the Governors' Panel to Review Scientific Studies and the Development of Public Policy on Problems Resulting from Hazardous Wastes,’ transmitted in October of this year, identifies the following factors about the health effects at Love Canal:

  8. Phytic acid: an alternative root canal chelating agent.

    Science.gov (United States)

    Nassar, Mohannad; Hiraishi, Noriko; Tamura, Yukihiko; Otsuki, Masayuki; Aoki, Kazuhiro; Tagami, Junji

    2015-02-01

    The objectives of this study were to investigate the effect of phytic acid, inositol hexakisphosphate (IP6), as a final rinse on the surface of instrumented root canals and smear-layered flat dentin surfaces treated with sodium hypochlorite (NaOCl) and to evaluate its effect on the viability and alkaline phosphatase activity of osteoblast-like cells (MC3T3-E1). The universally accepted chelating agent EDTA was used as the control in all conducted experiments. Root canals of human canines were instrumented with rotary files and irrigated with 5% NaOCl, followed by a final rinse of 17% EDTA (1 minute), 1% IP6 (1 minute or 30 seconds), or distilled water. NaOCl-treated flat coronal dentin surfaces were also treated with 17% EDTA (1 minute), 1% IP6 (1 minute or 30 seconds), or distilled water. The presence or absence of smear layer was evaluated with scanning electron microscopy. Cell viability and alkaline phosphatase assays were performed to evaluate the effect of IP6 and EDTA on cultured MC3T3-E1 cells. The results demonstrated the ability of IP6 to remove the smear layer from instrumented root canals and flat coronal dentin surfaces. When compared with EDTA, IP6 was less cytotoxic and did not affect the differentiation of MC3T3-E1 cells. IP6 shows the potential to be an effective and biocompatible chelating agent. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. Geminated Maxillary Lateral Incisor with Two Root Canals

    Science.gov (United States)

    Romano, Nayara; Souza-Flamini, Luis Eduardo; Mendonça, Isabela Lima; Silva, Ricardo Gariba

    2016-01-01

    This paper reports a case of gemination in a maxillary lateral incisor with two root canals and crown-root dilaceration. A 16-year-old male patient was referred for endodontic treatment of the maxillary left lateral incisor and evaluation of esthetic and functional complaints in the anterior region. The patient reported trauma to the anterior primary teeth. There was no spontaneous pain, but the tooth responded positively to the vertical percussion test and negatively to the pulp vitality test. Clinical examination showed esthetic and functional alterations and normal periodontal tissues. CBCT imaging confirmed the suspicion of gemination and crown-root dilaceration and also revealed the presence of two root canals and periapical bone rarefaction. The root canals were instrumented with Reciproc R40 and 1% NaOCl irrigation and were filled by lateral condensation of gutta-percha and AH Plus sealer. The tooth was definitely restored with composite resin to recover esthetics. Continued follow-up over 6 months has shown absence of pain or clinical alterations as well as radiographic image suggestive of apical repair. PMID:28119787

  10. Antibacterial Efficacy of Super-Oxidized Water on Enterococcus faecalis Biofilms in Root Canal

    Science.gov (United States)

    Zan, Recai; Alacam, Tayfun; Hubbezoglu, Ihsan; Tunc, Tutku; Sumer, Zeynep; Alici, Oguzhan

    2016-01-01

    Background The success of endodontic treatment depends on a few crucial factors. One of these factors is the complete chemomechanic preparation of root canal against various bacteria. In particular, the effect of resistant bacteria may cause intense pain with flare-up and formation of periapical lesions. Therefore, the strong effect of irrigants plays an important role in terms of the complete elimination of these bacteria to achieve long-term successful treatment. Objectives The aim of this study was to investigate the antibacterial effects of super-oxidized water (SPO) in root canals infected with Enterococcus faecalis biofilms. Methods One hundred twenty single-root, premolar teeth were selected. Initially, the teeth were prepared and then disinfected. E. faecalis were inoculated and kept at 37°C for 24 hours in the root canals. The re-inoculation procedure was repeated on the first, fourth, seventh, and tenth days. The infected root canals were divided into one negative (saline) and one positive (sodium hypochlorite) control group and four experimental groups (super-oxidized water: 1, 2, 3, or 5 minutes) (n = 20). Paper points were placed in the root canals to control and evaluate the biofilm formation. Biofilms were counted on blood agar plates, and data was evaluated and statistically analyzed using one-way ANOVA and Tukey’s test. Results Although sodium hypochlorite (NaOCl) showed no statistically significant difference when compared with three and f