Conventional Irrigation Research Articles

Comparative Efficacy of Different Irrigant Activation Techniques for Irrigant Delivery Up to the Working Length of Mature Permanent Teeth: A Systematic Review and Meta-Analysis

This systematic review aims to establish whether various irrigant activation techniques (IATs) result in greater penetration of irrigant up to the working length. The MEDLINE, Scopus and Cochrane Library electronic databases were searched to determine the difference in irrigant penetration depth in the main canal following the use of manual dynamic activation (MDA), sonic irrigation (SI), passive ultrasonic irrigation (PUI), and apical negative pressure irrigation technique (ANP) in comparison with conventional needle irrigation technique (CNI) in mature permanent teeth. Meta-analysis was performed for straight canals as well as curved canals in addition to subgroup analyses for a) Individual IATs in comparison with CNI, b) Comparison of PUI v ANP and SI v ANP in the straight canals, c) comparison of different IATs performed in straight and curved canals. The outcome was presented as effect size: standardized mean difference (SMD) and percentage difference (% diff) of irrigant penetration up to the working length (WL) alongside 95% confidence intervals using chi-square analysis. Of the 840 records screened, 20 studies were included in the systematic review and 17 studies were included in the meta-analysis. It revealed IATs had significant improvement in irrigant delivery up to the WL in straight (% diff: 51.94%, 95% CI: 39.20-64.67%) and curved canals (SMD: 1.08, 95% CI: 0.64-1.52) over CNI. The subgroup analysis revealed ANP was the most effective and significant technique followed by PUI, SI and MDA techniques in straight canals (% diff: 91.70%, 95% CI: 75.63-107.77%) and curved canals (SMD: 1.45, 95% CI: 0.77-2.13). IATs improve irrigant penetration when compared to CNI technique. In both straight and curved canals, ANP is the most effective in delivering the irrigant up to the WL followed by PUI, SI and MDA techniques. Hence adaptation of recent IATs in routine endodontic practice is recommended. (EEJ-2022-03-036).

Solar Powered Smart Agriculturing

The greater usage of fossil fuels and increasedcarbon emissions, which hasten their rapid depletion, inducesconsumers to switch to renewable energy. Traditional irrigationtechniques may be expensive or environmentally harmful. Inlight of this, conversion to renewable energy sources, like solarenergy, can resolve this problem. Solar energy is widely usedin a wide range of applications since it is user-friendly andenvironmentally friendly. Yet, many rural areas of India continueto use conventional irrigation systems, such as diesel pumps,for irrigation. They are neither economical nor environmentally favourable. It releases a significant amount of hazardous gases,such as carbon dioxide. Farmers can operate a water pumpeffectively and sustainably by adopting a solar photovoltaic-based water pumping system. With the use of moisture sensors,scientific irrigation methodology is implemented, makingirrigation more efficient. In comparison to current technologies,this system is reliable, economical, and capable of increasingagricultural productivity levels. The requirement for labour is also decreased by irrigation automation and wireless control.In this, a permanent magnet DC (PMDC) motor-drive powersthe water pump. Outside in the field plains, moisture sensorsare being installed to keep track of the wetness in the soil. Themicrocontroller uses the information from the sensors to regulatethe pump’s operation.

Modeling of Sensor Enabled Irrigation Management for Intelligent Agriculture Using Hybrid Deep Belief Network

Artificial intelligence (AI) technologies and sensors have recently received significant interest in intellectual agriculture. Accelerating the application of AI technologies and agriculture sensors in intellectual agriculture is urgently required for the growth of modern agriculture and will help promote smart agriculture. Automatic irrigation scheduling systems were highly required in the agricultural field due to their capability to manage and save water deficit irrigation techniques. Automatic learning systems devise an alternative to conventional irrigation management through the automatic elaboration of predictions related to the learning of an agronomist. With this motivation, this study develops a modified black widow optimization with a deep belief network-based smart irrigation system (MBWODBN-SIS) for intelligent agriculture. The MBWODBN-SIS algorithm primarily enables the Internet of Things (IoT) based sensors to collect data forwarded to the cloud server for examination purposes. Besides, the MBWODBN-SIS technique applies the deep belief network (DBN) model for different types of irrigation classification: average, high needed, highly not needed, and not needed. The MBWO algorithm is used for the hyperparameter tuning process. A wide-ranging experiment was conducted, and the comparison study stated the enhanced outcomes of the MBWODBN-SIS approach to other DL models with maximum accuracy of 95.73%.

Clustered Wireless Sensor Network in Precision Agriculture via Graph Theory

Food security and sustainable development is making a mandatory move in the entire human race. The attainment of this goal requires man to strive for a highly advanced state in the field of agriculture so that he can produce crops with a minimum amount of water and fertilizer. Even though our agricultural methodologies have undergone a series of metamorphoses in the process of a present smart-agricultural system, a long way is ahead to attain a system that is precise and accurate for the optimum yield and profitability. Towards such a futuristic method of cultivation, this paper proposes a novel method for monitoring the efficient flow of a small quantity of water through the conventional irrigation system in cultivation using Clustered Wireless Sensor Networks (CWSN). The performance measure is simulated the creation of edge-fixed geodetic clusters using Mat lab’s Cup-carbon tool in order to evaluate the suggested irrigation process model’s performance. The findings of blocks 1 and 2 are assessed. Each signal takes just a little amount of energy to communicate, according to the performance. It is feasible to save energy while maintaining uninterrupted communication between nodes and cluster chiefs. However, the need for proper placement of a dynamic control station in WSN still exists for maintaining connectivity and for improving the lifetime fault tolerance of WSN. Based on the minimum edge fixed geodetic sets of the connected graph, this paper offers an innovative method for optimizing the placement of control stations. The edge-fixed geodetic cluster makes the network fast, efficient and reliable. Moreover, it also solves routing and congestion problems.

Comparative antibacterial effects of ginger and marjoram extract versus conventional irrigants on mature Enterococcus faecalis biofilms: An in vitro study.

This study evaluated antibacterial effects of Ginger and Marjoram extract compared with Routine Intracanal Irrigants on Mature Enterococcus faecalis Biofilms. Sixty-six extracted human teeth, were randomly assigned to four groups 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), chloroform extract of marjoram (Origanum majorana), and oil extract of ginger (Zingiber officinale), and two positive and negative control groups (n=11). Samples were contaminated with E. faecalis, except the negative control group. Then the root canals were irrigated with solutions above, after which dental debris was collected from each tooth separately, followed by culturing on plates containing BHI agar. The bacterial counts were finally determined with a colony counting machine. No bacterial growth was detected in the NaOCl, CHX, and negative control groups. However, some bacterial growth was observed in the ginger and marjoram groups. All four solutions successfully eliminated E. faecalis biofilms compared to the positive control group. Significant difference in the median bacterial growth between the ginger and marjoram groups and the positive control group (P<0.001) has been shown. There was no significant difference in median bacterial growth between the ginger and marjoram groups (P=0.94). Chloroform extract of marjoram and oil extract of ginger were effective in eliminating 6-week-old biofilms of E. faecalis in vitro; however, their effect was not as favorable as CHX and NaOCl. These herbal extracts yielded promising results in the present study; therefore, they can be used as intracanal irrigants instead of chemical agents. Key words:Biofilm, Chlorhexidine, E. faecalis, Ginger, Marjoram, Sodium hypochlorite.

Internet of things and agent-based system to improve water use efficiency in collective irrigation

The efficient management of water resources is a major issue in the field of sustainable development. Several models of solving this problem can be found in the literature, especially in the agricultural sector which represents the main consumer through irrigation. Therefore, Irrigation management is an important and innovative field that has been the subject of several types of research and studies to deal with the different activities, behaviors, and conflicts between the different users. This article introduces an intelligent irrigation system based on smart sensors that can be used moderately and economically to monitor farms by integrating some connected electronic devices and other advantageous instruments widely used in the field of IoT, it determines the water requirement of each farm according to the water loss due to the process of evapotranspiration. The water requirement is calculated from data collected from a series of sensors installed in the plantation farm. This project focuses on smart irrigation based on IoT and agent technology, it can be used by farmer associations whose endowments and irrigation planning are defined according to the need and quantity of water available in the rural municipality. The system includes a microcontroller with the integration of sensors, actuators, and valve modules where each node serves as an IoT device. Environmental parameters are monitored directly through a multi-agent system that facilitates the control of each node and the configuration of irrigation parameters. The amount of water calculated for irrigation is based on the Penman model for calculating the daily evapotranspiration baseline. Compared to the conventional irrigation method, it is expected that the proposed irrigation model would contribute to saving water use and distributing it impartially without compromising its production.

Effect of different managements with drip irrigation (tape)

Conventional irrigation methods to new methods have been altered with respect to reduction of water resources and climate change. Considering the corn cultivation development, applying modern irrigation methods namely drip irrigation with the aim of improving the efficiency of water consumption as well as the zone under cultivation has been investigated. In this research, the performance of corn (SC 704) in various managements of drip irrigation (by strip method) both in single-row and double-row planting patterns was considered with a variety of densities. This test was carried out on random complete blocks in the form of a 3-repetitive Split Design in Isfahan-Iran during the years 2018–2019. Four irrigation levels containing: 80, 100 and 120% of full water requirement with drip irrigation (strip) and 100% of water requirement with normal drip irrigation were utilized. The results indicated that applying the aforementioned drip tapes and different surface treatments with soil and water monitoring, the water consumption of corn seasonal irrigation can be saved by 81, 71, 61, 52 and 36% compared to normal drip irrigation without soil, water and root monitoring, respectively. Seasonal yield (Kc), the yield response coefficient (Ky), and pan coefficient (Kp) for corn were 0.80, 0.76 and 0.97, respectively.

Relationship between the Dynamic Characteristics of Tomato Plant Height and Leaf Area Index with Yield, under Aerated Drip Irrigation and Nitrogen Application in Greenhouses

The current study was undertaken to investigate the dynamic characteristics of the tomato crop, such as its plant height and leaf area index (LAI), based on the effective cumulative temperature. This was assessed under aerated drip irrigation (ADI) conditions and the application of a specific nitrogen (N) dose, and their relationship with the yield of the crop was formulated. The study was conducted in a greenhouse located in Zhengzhou, Henan province, China. The assessment conditions were the two irrigation methods, ADI and conventional drip irrigation (CK), and the three N application rates, i.e., 0, 140, and 210 kg ha−1. The logistic and Richards models were used to fit dynamic equations for plant height and LAI under the different treatments to quantify the characteristic parameters and understand their relationship with yield. The results revealed that the growth of the tomato plant fitted well with the logistic and Richards model at R2 &gt; 0.98 (p &lt; 0.01), regardless of the treatments. ADI and N application were found to significantly increase the maximum growth rate and average growth rate over the rapid growth period based on the tomato plant height and LAI. They were also noted to reduce the effective cumulative temperature at which plant height entered the rapid growth period (p &lt; 0.05), thereby increasing the time spent in the nutritional growth phase. This is an essential precursor for the better development of subsequent reproductive organs. Tomato yields also confirm it: the highest yield of 85.87 t ha−1 was obtained with 210 kg N ha−1 for the ADI treatment, with an increase of 13.8%, 12.2%, and 39.6% compared to the CK–210 kg N ha−1, ADI–140 kg N ha−1, and ADI–0 kg N ha−1 treatments, respectively (p &lt; 0.05). Grey correlation analysis showed that the characteristic parameters closely related to yield were all from the ADI and N application treatments. Furthermore, it was observed that the effective cumulative temperature and the maximum growth rate of the LAI at which the LAI entered the slow growth phase were the key growth characteristic parameters affecting tomato yield. This study provides a scientific basis for regulating the growth dynamics and yield of vegetables in greenhouse facilities under ADI and N application.

Evaluation of the Efficacy of Different Irrigation Systems on the Removal of Root Canal Smear Layer: A Scanning Electron Microscopic Study

Irrigation represents a crucial step in endodontics for bacteria disinfection and smear layer removal. Several irrigation strategies have been proposed, although their effects are controversial. This study aims to assess the comparison of four different irrigation systems on the smear layer removal utilizing scanning electron microscopy (SEM). Forty sound monoradicular teeth were collected and casually allocated into four groups (n = 10): Group A, conventional irrigation; Group B, IrriFlex irrigation; Group C, ultrasonic irrigation system; Group D, apical negative pressure irrigation. After chemo-mechanical preparation and longitudinal root separation, the three root thirds were analyzed by SEM. Micrographs were carried out at ×2000 to analyze the smear layer residual in each third of the root canal. Statistically significant differences were found between Group A and Group D (p &lt; 0.05). Groups B and C showed satisfactory results in the coronal and middle thirds, while Group D was the only system that achieved satisfactory results in the apical third. However, the complete smear layer removal in the root canal was never achieved with any of the four systems tested. In conclusion, among the four tested irrigation systems, the greatest efficacy on smear layer removal was reached by Group D.

Effectiveness of Passive Ultrasonic Irrigation Protocols in Simulated Complex Root Canal Cavities

This study aimed to evaluate the effectiveness of different Passive Ultrasonic Irrigation (PUI) protocols on debris removal and exposure of dentinal tubules in simulated complex root canal cavities. Twenty single-rooted human mandibular premolars with simulated root canal cavities were filled with the debris and randomly divided into ten groups based on the final irrigation protocol: 1—positive control; 2—negative control; 3—conventional irrigation (CI) with 2.5% sodium hypochlorite (NaOCl); 4—CI with 17% ethylenediaminetetraacetic acid (EDTA) followed by NaOCl; 5—three cycles of PUI for 20 s (NaOCl-NaOCl-NaOCl); 6—three cycles of PUI for 20 s (NaOCl-EDTA-NaOCl); 7—one 60 s PUI cycle (NaOCl); 8—one PUI 180 s cycle (NaOCl); 9—two cycles of PUI for 60 s (EDTA-NaOCl); and 10—two cycles of PUI for 60 s (NaOCl-EDTA). The groups were analyzed by SEM. The Kruskal-Wallis test was used at a 5% level. PUI showed a higher reduction of debris, similar to the positive control group (p &gt; 0.05) and higher than the CI and negative control groups (p &lt; 0.05). Regarding the exposure tubules, the CI groups were similar to the negative control group in all cavities (p &gt; 0.05). The PUI groups were similar to the positive control group (p &gt; 0.05). However, only groups 6, 7, and 10 were statistically different from the CI and negative control (p &lt; 0.05). The protocols using PUI, comprising groups with three cycles of 20 s (NaOCl-EDTA-NaOCl), two cycles of 60 s (EDTA-NaOCl), or one cycle of 60 s (NaOCl), were more effective at removing debris and increasing the exposure of dentinal tubules.

Continuous Chelation Concept in Endodontics

Background:Continuous chelation can be defined as the concept of using a single mix of a weak chelator with NaOCL throughout the entire root canal preparation procedure without causing a reduction in the antimicrobial and proteolytic activity of NaOCL. Etidronic acid, also known as "1-Hydroxyethylidene-1, 1-Bisphosphonate" HEBP, or HEDP, is a soft biocompatible chelator utilized in direct combination with sodium hypochlorite to form an all-in-one deproteinizing, disinfecting, and chelating solution. It's the only chelator available as a certified commercial product, "Dual Rinse HEDP," approved for endodontic usage. This review aims to analyze and bring up-to-date data about the continuous chelation protocol using a combination of HEDP with sodium hypochlorite in endodontic irrigation. Data: only papers that were published electronically were searched within the review. Sources: “Google Scholar”,” PubMed” websites were used for searching data by using the following keywords: : Bisphosphonates, Continuous chelation, Dual rinse HEDP, Etidronate, HEBP. The most relevant papers related to the topic were chosen, specifically the original articles and clinical studies, including only English-language articles from 2005 to September 2022. Conclusion:Combining a weak chelator with NaOCL solution, a single irrigation solution mixture with soft tissue dissolving ability and antibacterial properties with chelating capability can be created, which can be considered a good alternative to the conventional irrigation protocol (sequential irrigation) with NaOCL followed by using a strong chelator such as EDTA. The obvious benefit is that only one solution is required for root canal cleansing and decontamination, also decreasing the time for irrigation and providing better conditioning of root canal walls for root-filling materials

The Effect of High-Power Lasers on Root Canal Disinfection: A Systematic Review.

Introduction: In root canal therapy, the cleaning and shaping of canals are routinely applied by clinicians in order to remove microorganisms. Eradicating bacteria from the root canal system plays a crucial role in long-term success; however, it is not always easy to disinfect root canals properly because of their complicated anatomy and bacterial load. Achieving an optimally disinfected root canal environment requires adjunctive antibacterial therapeutic methods. High-power laser utilization as an adjunctive strategy to conventional treatment is a relatively new approach that helps clinicians. Methods: This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Online databases, namely Web of Science, PubMed/MEDLINE, Scopus, and Cochrane Library, were searched electronically regarding lasers and endodontic treatments. Appropriate studies were included according to the inclusion/exclusion criteria. Results: Among 504 obtained studies by search, 48 were considered for a detailed analysis. Ten articles performed in vivo evaluation, while nine assessed the effect of lasers on artificial models, and 29 conducted ex vivo experiments on extracted teeth. When the diode laser, the most frequently used laser, was utilized as an adjunct therapy after NaOCl irrigation, it killed more bacteria than conventional irrigation with NaOCl. Laser-activated irrigation (LAI) with the Er, Cr: YSGG laser and NaOCl disinfects the root canal effectively. Also, photon-induced photoacoustic streaming (PIPS) with Er: YAG and NaOCl exhibited a high bactericidal effect and deep tubular penetration. Conclusion: High-power laser utilization, considering proper case selection and method, can assist in root canal treatment of infected teeth.

The effect of different irrigation and disinfection methods on post-operative pain in mandibular molars: a randomised clinical trial

BackgroundTo examine post-operative pain (PP) after conventional irrigation and sonic activation methods, with and without laser disinfection in mandibular molars.MethodsEighty patients with symptomatic apical periodontitis were included in this randomized clinical study. There were four study groups. In group 1, conventional irrigation only was applied. In group 2, a sonic irrigation activation system (EDDY (VDW, Munich, Germany)), was applied. In groups 3 and 4, irradiation with a 980-nm diode laser was performed, following irrigation with the conventional method and sonic irrigation activation system, respectively. The patients were instructed to record their PP and analgesic intake using a numerical rating scale 8, 24, 48 h and 7 days post-procedure. A chi-square test, Fisher’s exact chi-square test and Fisher–Freeman–Halton exact test were used to assess qualitative data. Inter-group and intra-group parameters were assessed using the Kruskal–Wallis test and Wilcoxon’s test at a significance level of p < 0.05.ResultsThere was no statistically significant difference among the groups in terms of age, sex, pre-operative pain, PP and analgesic intake (p > 0.05).ConclusionsThe use of sonic irrigation activation system in the final irrigation protocol and irradiation with the 980-nm diode laser did not significantly reduce PP levels and analgesic intake.

Synchronized Microbubble Photodynamic Activation to Disinfect Minimally Prepared Root Canals

IntroductionThe purpose of this study was to evaluate the antimicrobial efficacy of a novel irrigation strategy using synchronized microbubble photodynamic activation (SYMPA) in a minimally prepared single canal. MethodsSingle-canal mandibular incisors were inoculated with Enterococcus faecalis for 3 weeks and randomly allocated to 4 groups based on the irrigation protocols: (1) control (saline), (2) conventional needle irrigation (CI), (3) ultrasonic-assisted irrigation (UI), and (4) irrigation with SYMPA. The first 3 groups were instrumented to size 25.07v (WaveOne Gold Primary; Dentsply Sirona, Johnson City, TN), and the SYMPA group was minimally prepared to size 20.07v (WaveOne Gold Small, Dentsply Sirona). The apical 5 mm was resected for microbiological assessment using the culture technique (colony-forming unit), adenosine-5′-triphosphate–based viability assay (relative luminescence units), and the percentage of live bacteria using confocal laser scanning microscopy. ResultsLog colony-forming units from the UI (2.37 ± 0.66) and SYMPA (2.21 ± 0.86) groups showed a reduction compared with the control (5.16 ± 0.75) and CI (4.08 ± 1.19) groups. Relative luminescence unit reduction was significant for UI (619.08 ± 352.78) and SYMPA (415.25 ± 329.51) compared with the control (1213.2 ± 880.03) (P < .05). The percentage of live bacteria was significantly lower in the UI and SYMPA groups compared with the control and CI groups. Although higher microbial reduction was observed in SYMPA compared with UI, there was no statistical significance (P > .05). ConclusionSYMPA in minimally prepared canals showed significant antimicrobial efficacy. The novel irrigation strategy using SYMPA could be an effective disinfection strategy for minimally prepared root canals.

Comparison of sealer penetration of sonic activation versus conventional needle irrigation: a systematic review and meta-analysis of randomized controlled trials

BackgroundMost existing studies comparing the efficiency of sonic irrigation (SI) and conventional needle irrigation (CNI) in increasing the penetration of sealers into dentine tubules are controversial; and this study aimed to determine whether the use of SI can lead to greater sealing ability than CNI, during the root canal treatment.MethodsThe EMBASE, PubMed, and Cochrane Library databases were used to find confocal laser scanning microscopy studies evaluating percentage and maximum depth of sealer penetration following the use of SI or CNI in mature permanent teeth until October 2022. The critical estimative checklist of randomized controlled trials of the standardized Joanna Briggs Institute was adopted to independently score the quality of each study. The random-effect model for meta-analysis was used to analyse for each canal segment (apical, middle, coronal). The results are shown in the forest plots as weighted mean differences (WMDs) with 95% confidence intervals (95% CIs).ResultsNinety-seven articles were included in the preliminary screening, and nine of them were included in this study. Eight studies were included in the meta-analysis.The meta-analysis exhibited great increases in the coronal (WMD: 8.09, 95% CI 2.78–13.40/WMD: 165.32, 95% CI 128.85–201.80), and middle segments (WMD: 8.81, 95% CI 5.76–11.87/WMD: 132.98, 95% CI 68.71–197.25) for the percentage and maximum depth of sealer penetration, respectively. The percentage of sealer penetration in the apical thirds region was nonsignificant (WMD: 4.73, 95% CI − 2.34–11.80). However, the maximum depth of sealer penetration in the apical thirds region was significant (WMD: 121.46, 95% CI 86.55–156.38). Chi-squared analysis revealed heterogeneity scores of 0.0–70.0% and 44.0–90.0% for the percentage and maximum depth of sealer penetration, respectively.DiscussionThis review verified that SI significantly improves tubular dentin sealer penetration in most areas of the root canal; thus, SI may lead to better filling efficiency and anti-reinfection effects than CNI during and after the root canal therapy. Nevertheless, a large heterogeneity in the current data comparing the irrigation efficiency of SI versus CNI in the apical third of the root canal was found, implying the necessity to standardize root canal irrigation procedures and obtain more accurate results in this area.Trial Registration: INPLASY database (INPLASY202270116).

Shock wave enhanced emission photoacoustic streaming (SWEEPS): An alternative to conventional irrigation in endodontic treatment

Background: Irrigation is an essential step in root canal treatment (RCT). However, the complex structure of the root canal can limit the penetration of irrigants, causing RCT failure. Shock wave enhanced emission of photoacoustic streaming (SWEEPS) has been developed to improve root canal cleaning by increasing the penetration of irrigants. SWEEPS utilized the Er:YAG laser to generate micropulse, producing bubbles delivered in liquid, causing powerful photodynamic streaming. However, its superiority compared to conventional irrigation remains unclear. Thus, we aim to review the available evidence to assess the benefits of SWEEPS over conventional irrigation. Purpose: This study aims to review the available evidence to assess the benefits of SWEEPS over conventional irrigation. Reviewa: Article searches were conducted on Pubmed, ScienceDirect, EBSCOhost, and ProQuest using SWEEPS and root canal irrigation as keywords. Articles were included if they aim to assess the benefits of SWEEPS over conventional irrigation in removing smear layer, debris, pulp tissues, or bacteria. A total of 833 articles were initially retrieved from systemic search of literature and 6 articles following inclusion criteria were included in the review. Out of 6 articles, 4 articles suggested that SWEEPS could increase the removal of smear layer, debris, pulp tissues, and bacteria in the root canal compared to conventional irrigation. However, 2 articles found contradictory results, in which SWEEPS and conventional irrigation had similar outcomes in terms of penetration depth and could not completely eradicate biofilm. Conclusion: This review suggests that SWEEPS offers more benefits over conventional irrigation since it can improve the removal of smear layer, debris, pulp tissues, and bacteria in the root canal.

An environmental and economic assessment of sustained cleaner production for double rice from the combination of controlled-released urea and water-saving irrigation

Controlled-released urea (CRU) and water-saving irrigation are being extensively used to obtain higher rice (Oryza sativa) yields with lower greenhouse gas emissions. However, the environmental impact potential of their combined impacts is still unknown. Two-factor experiments, nitrogen practices with urea and CRU while irrigation practices with conventional irrigation (CI) and alternate wetting-drying water-saving irrigation (AWD), were used to clarify the potential impacts in the Jianghan Plain in China. Life cycle assessment (LCA) methodology was used to examine seven environmental impact categories, including non-renewable energy depletion, global warming potential (GWP), acidification potential, eutrophication potential (EP), human toxicity potential, freshwater toxicity potential (FTP) and soil toxicity potential in addition to an economic assessment. The largest contribution allocated to the comprehensive environmental impact indices included the GWP, EP (>26.28%) and FTP (>62.14%), while the other four indices contributed little, and CRU + AWD had the lowest weighting value (0.7981). The EP was affected by N fertilizer off and on the farm (7% and 68%–71%), nitrous oxide emissions from the planting season and winter fallow (7%–12% and 8%–12%) and the FTP differed slightly among the four treatments. Net ecosystem economic benefits (NEEB) (approximately 15,541 CNY ha−1) and benefit-cost ratio (52%) of CRU + AWD was similar to those of CRU + CI, and were increased by 18%–47% and 11%–41% compared with U + CI and U + AWD, respectively. Trade-off results found the combination of CRU and AWD had the lowest environmental load with a high grain yield, economic benefits and soil organic carbon storage to enable the sustainable production of rice.

An in vitro scanning electron microscopic study: smear layer removal by chelat activation methods

Background: The process of mechanical root canal preparation creates smear layer. The smear layer can prevent the penetration of intracanal medicaments into dentinal tubules and influence the adaptation of filling materials to canal walls. The purpose of this study is to compare the smear layer removal ability of root canal irrigation methods with chelat solution. Materials and Methods: 45 extracted human premolar roots were selected and randomly divided into 3 groups (n=15) based on root canal irrigation methods with 17% EDTA solution: (1) Conventional needle irrigation, (2) Ultrasonic activation, (3) Sonic activation. The roots were prepared with Reciproc Blue 25 file and was removed smear layer by 3 different methods of irrigation. The study sample was then sectioned longitudinally with a diamond cutting disc, randomly selecting half of the root. After undergoing sample processing, the half roots were observed and evaluated for the presence of smear layer under a scanning electron microscope with a magnification of 1000 times according to Torabinejad (2003). Results: In cervical, the average smear layer score of the 3 study groups was not statistically significant (p&gt;0.05). In the middle, apical and over the root canal, the average smear layer score of the sonic activation method was lower than that of the other 2 groups. Conclusion: Sonic irrigation is more effective in removing smear layer than conventional needle irrigation and ultrasonic irrigation activation. Key words: smear layer, ultrasonic, sonic.

Evaluation and optimization of surge and alternate furrow irrigation performance in maize fields using the WinSRFR software

Low efficiency of irrigation is a major problem with surface irrigation methods, mainly due to poor management and improper design. The objective of this study was to evaluate and improve the performance of different surge and alternate furrow irrigation methods. A field experiment was conducted during the grain maize growing season in the Jayedar Plain of Poldokhtar City (southwest of Iran) in the years 2020 and 2021. Five different furrow irrigation methods including conventional furrow irrigation (CFI), surge irrigation with on/off cycle ratios of 1 and 0.5 (SFI1–1 and SFI1–2, respectively), fixed alternate irrigation (FFI) and variable alternate irrigation (AFI) were investigated. A total of 15 irrigation evaluations were performed at the initial, middle, and end of the growing season by measuring inflow rate, cutoff time, outflow rate, infiltration and advance time. The length and spacing of experimental furrows were 120 and 0.75 m, respectively, and the inflow rate of furrows and the flow cutoff times at the initial (3rd irrigation), middle (6th irrigation), and end (9th irrigation) of the season were 0.28 L/s and 240 min, 0.42 L/s and 360 min, 0.35 L/s and 300 min, respectively. The WinSRFR 3.1 software was calibrated and applied using field data based on the zero-inertia model. The results of the furrow irrigation sensitivity analysis with WinSRFR 3.1 software demonstrated that furrow irrigation in the studied area was most sensitive to the inflow rate, cutoff time and infiltration parameters, respectively. There were high correlations between the measured and simulated values of runoff, infiltration and advance time (coefficient of determination of 1.0, 0.94, and 0.97, respectively). The relative error values in estimating runoff, infiltration and advance time were 5.60 %, 5.09 %, and 2.14 %, respectively. Mean performance indices of different furrow irrigation methods under field experiments showed that the highest values of Application Efficiency (78.7 %), Potential Application Efficiency of the minimum (69.5 %), and Potential Application Efficiency of low-quarter (74.1 %) were observed under the AFI method. By optimizing the inflow rate and flow cutoff time, application efficiencies of 66.6–80.7 % were obtained for different irrigation methods. The results of this study show that AFI is a more suitable method for maize irrigation in the study area.

Effectiveness of ultrasonic activation over glycolic acid on microhardness, cohesive strength, flexural strength, and fracture resistance of the root dentin.

The aim of this study was to evaluate the effectiveness of ultrasonic activation (US) over glycolic acid on microhardness, cohesive strength, flexural strength, and fracture resistance of root dentin, comparing with conventional final irrigation protocols. Samples were obtained from 140 extracted bovine teeth and distributed into four test groups: microhardness (50 teeth), cohesive strength (15 teeth), flexural strength (15 teeth), and fracture resistance (60 teeth). In all four tests, specimens were subdivided into five groups, according to final irrigation protocols: G1: distilled water (DW); G2: 17% ethylenediaminetetraacetic acid (EDTA); G3: 17% glycolic acid (GA); G4: 17% EDTA + US; and G5: 17% GA + US. The duration time of each protocol was set in 1min. After irrigation protocols, the Vickers tester was used to evaluate microhardness and the universal testing machine was used to evaluate the cohesive strength, flexural strength, and fracture resistance of the root dentin. One-way ANOVA test and the Tukey HSD were used for multiple comparison tests in all evaluations (α = 5%). In general, groups 2 (EDTA), 4 (EDTA + US), and 5 (GA + US) promoted the highest reduction of microhardness, being statistically different from other groups (p < 0.05). Cohesive strength, flexural strength, and fracture resistance data revealed that no differences between groups were observed (p > 0.05). The association of GA and US results in microhardness reduction, with no influence on cohesive strength, flexural strength, and fracture resistance of the root dentin. The use of US over GA has no influence on some mechanical properties of root dentin.