Irrigation Delivery Research Articles

The synthesis of nano silver-graphene oxide system and its efficacy against endodontic biofilms using a novel tooth model

ObjectiveThe deleterious caustic effects of sodium hypochlorite (NaOCl) as a root canal irrigant makes it imperative that alternative methods are developed for root canal disinfection. The purpose of this study was to examine the antimicrobial efficacy of silver nanoparticles (AgNPs) synthesized on an aqueous graphene oxide (GO) matrix (Ag-GO), with different irrigant delivery methods to enhance the disinfection regimen, using a novel ex vivo infected tooth model. MethodsAgNPs were prepared by reducing AgNO3 with 0.01M NaBH4 in presence of GO. Elemental analysis was performed with scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and scanning transmission electron microscopy (STEM) was used for size and morphology analysis of GO and Ag-GO. Nutrient stressed, multi-species biofilms were grown in prepared root canals of single-rooted teeth. The irrigants used were sterile saline, 1% and 2.5% NaOCl, 2% chlorhexidine gluconate (CHX), 17% EDTA and an aqueous suspension of 0.25% Ag-GO. The antimicrobial efficacy of the irrigants were performed with paper point sampling and measurement of microbial counts. The biofilm disruption in dentine tubule surfaces was analysed with confocal laser scanning microscopy (CLSM). The acquisition of total biovolume (μm3/μm2) and biofilm viability was performed using software BioImage_L. Two-way analysis of variance (ANOVA) with post hoc Tukey tests was used for data analysis with level of statistical significance set at P<0.05. ResultsSEM/EDS analysis confirmed impregnation of Ag within the GO matrix. TEM images showed polygonal GO sheets and spherical AgNPs of diameter 20–50nm, forming a network on the surface of GO sheets. The use of ultrasonic activation enhanced the efficacy of Ag-GO compared to 1% NaOCl, 2% CHX, 17% EDTA and sterile saline (P<0.05). The microbial killing efficacy of 2.5% NaOCl was superior compared to the experimental groups. The maximum biofilm disruption, in dentine tubule surfaces, was achieved by 2.5% NaOCl, however Ag-GO caused a significant reduction of total biovolumes compared to the rest of the experimental groups (P<0.05%). SignificanceThe successful documentation of the microbial killing and biofilm disruption capacity of Ag-GO is a promising step forward to explore its unique properties in clinical applications and biomaterials in dentistry.

Effects of Fertilizer Placement on Greenhouse Gas Emissions from a Sun and Shade Grown Ornamental Crop1

Abstract The level to which ornamental plant production impacts rising atmospheric greenhouse gas (GHG) concentrations remains unknown. Research to date has focused on developing baseline estimations of GHG emissions from plant-pot production systems and their contribution to global warming potential. To date, pot size, irrigation delivery method and fertilizer application method have been evaluated in the production of common woody ornamental crops. In this study, two perennial herbaceous plants, full-sun-grown ‘Stella D'Oro' daylily (Hemerocallis × ‘Stella D'Oro' L.) and shade-grown ‘Royal Standard' hosta (Hosta × ‘Royal Standard') (Hosta plantaginea Aschers × Hosta sieboldiana N.Fujita) were grown utilizing one of three common fertilizer application methods (dibbled, incorporated or top-dressed). Plants were grown in 3.8 L (1 gal) nursery containers in a 6:1 pinebark:sand substrate with standard amendments. Gas samples were collected in situ according to standard GRACEnet protocols weekly for five months. Cumulative emissions for both CO2 and N2O were least for plant-pot systems using the dibbled fertilizer method, regardless of species. Cumulative CO2 emissions were highest for plants fertilized by incorporation, followed by those fertilized by top-dressing. No differences were observed between N2O efflux measurements for systems fertilized by either the incorporated or top-dressed methods. Results suggest that dibbling fertilizer could significantly decrease both CO2 and N2O emission. Index words: carbon dioxide, nitrous oxide, methane, trace gas. Species used in this study: ‘Stella D'Oro' daylily (Hemerocallis × ‘Stella D'Oro' L.); ‘Royal Standard' hosta [(Hosta × ‘Royal Standard') (Hosta plantaginea Aschers × Hosta sieboldiana N.Fujita)].

Effectiveness of Combination Irrigant Technique for Debris Removal in Simulated Canal Irregularities: An in vitro Study

Aim: To evaluate the debridement efficacy of different irrigation systems in simulated canal irregularities. Study Design and Setting: About sixty maxillary central incisors were selected and after chemomechanical preparation were split longitudinally into two halves. Each groove and depression were filled with dentine debris mixed with 2.5 % NaOCl to simulate a situation where dentine debris accumulates in the un-instrumented extensions of the root canal. Materials and Methods: The specimens were randomly divided into 4 experimental groups as follows: Group I - Conventional Needle Irrigation, Group II - Apical Negative Pressure Irrigation (EndoVac), Group III - Passive Ultrasonic Irrigation and Group IV - Combination Irrigation (EV+PUI). 9 ml of 2.5 % NaOCl, 9 ml of 17 % EDTA and 9 ml of saline was used for the final irrigation protocol. Images were taken before and after irrigation using PRIMA DNT surgical microscope with digital camera. Statistical Analysis: The intergroup and individual comparison of percentage reduction of debris in groove and depressions were carried out by using Kruskal-Wallis and Mann-Whitney U tests respectively. The intergroup comparison for different scoring criteria was compared using Pearson’s chi-square tests. Differences were considered statistically significant at P value &lt; 0.05. Results: The combination group, EV group and PUI group showed better removal of debris in Groove and Depressions than Conventional needle irrigation group. The Combination group had significant reduction of debris at 2 mm level when compared to all the other groups. Conclusion: The effectiveness of this combination irrigant delivery system for smear layer removal and antibacterial efficacy have to be evaluated further in future clinical studies

Effects of sphenoid surgery on nasal irrigation delivery.

Nasal irrigation is an important component of medical management in chronic rhinosinusitis. Nasal irrigations facilitate topical medication of therapies and lavage of mucin. In this study we aim to compare the influence of increasing surgical sphenoid openings on the distribution, force, and clearance of nasal irrigations. A study was performed on fresh-frozen adult cadaver heads. The surgical ostium was modified on one side via a simple sphenoidotomy, a sphenoid sinusectomy (type 1), and sphenoid sinusectomy (type 3a). The nasal cavity was irrigated using a 240-mL squeeze bottle with 0.1% fluoroscein. An endoscope passed through the contralateral side through the sphenoid septum recorded the irrigation. Videos were recorded and blindly assessed. The distribution was defined as either no irrigation, less than one third of the sinus, less than or equal to two thirds of the sinus, or the complete sinus. The force was defined as minimal, minor, or major. The clearance was defined as no residual, less than one third of volume, less than or equal to two thirds of volume, and more than two thirds volume. Ordinal correlation scores were assessed using the Kendall tau-B test. Nine specimens (sphenoid sinuses) were assessed (44.4% female; age, 75.0 ± 12.7 years). The use of a sphenoid sinusectomy or larger produced better distribution (percent specimens with more than one third: 100% vs 59%, p < 0.01), more force (percent major: 83% vs 29%, p < 0.01), and better clearance (percent with one third or less remaining: 56% vs 18%, p < 0.01). Increasing sphenoid ostial size improves nasal irrigation penetration. We propose that greater sphenoid sinusectomy size allows for improved lavage and irrigation penetration. Complete removal of the anterior face appears to mitigate pooling of irrigation.

A review of the prognostic value of irrigation on root canal treatment success.

The aim of this review is to discuss the requirements for effective irrigation of the root canal system and its role in treatment outcome. A review of the literature regarding irrigants, methods of irrigation and regimens was undertaken. It indicates that irrigation is comprised of a multitude of factors, and that effective irrigant delivery and agitation achieves mechanical, chemical and microbiological functions, which are prerequisites for obtaining a clean canal system. However, most studies are exvivo and assess intermediate outcome values rather than treatment success. Additionally, there is an absence of high-level evidence evaluating the effect of irrigation on the outcome of root canal treatment. Therefore, citing irrigation as a significant factor that affects root canal treatment success cannot be done. This highlights the need to further investigate the prognostic value of irrigation on root canal treatment success.

Activated Irrigation vs. Conventional non-activated Irrigation in Endodontics - A Systematic Review.

Objective:Irrigant activation has been claimed to be beneficial in in vitro and clinical studies. This systematic review aims to investigate the clinical efficiency of mechanically activated irrigants and conventional irrigation.Methods:A literature search (PROSPERO registration number: CRD42018112595) was undertaken in PubMed, Cochrane and hand search. The inclusion criteria were clinical trials, in vivo/ex vivo on adult permanent teeth involving an active irrigation device and a control group of conventional irrigation. The exclusion criteria were studies done in vitro, animals and foreign language. Adult patients requiring endodontic treatment of permanent dentition and irrigant activation during the treatment were chosen as the participants and intervention respectively.Results:After removal of duplicates, 89 articles were obtained, and 72 were excluded as they did not meet the selection criteria. 6 devices (EndoVac, EndoActivator, Ultrasonic, MDA (manual dynamic agitation), CUI (Continuous Ultrasonic Irrigation) and PUI (Passive Ultrasonic Irrigation)) and 6 variables of interest (Post-operative pain, periapical healing, antibacterial efficacy, canal and/or isthmus cleanliness, debridement efficacy and delivery up to working length) were evaluated in the 17 included articles. The risk of bias and quality of the selected articles were moderate. Results showed that mechanical active irrigation reduces post-operative pain. It improved debridement, canal/isthmus cleanliness. It also improved delivery of irrigant up to working length. Bacterial count was more with active irrigation, though not significant. There is no effect on long-term periapical healing.Conclusion:It may be concluded that mechanical active irrigation devices are beneficial in reducing post-operative pain and improving canal and isthmus cleanliness during Endodontics.

Comparative Evaluation of the Efficacy of Irrigation Delivery Systems on Enterococcus faecalis

Attaining a sterile root canal system is important since microorganisms can cause persistent inflammation in the periradicular tissues. Objectives: This study sought to evaluate the efficacy of two irrigation delivery systems; the EndoVac and semiconductor diode laser irradiation with 5.25% sodium hypochlorite and 2% chlorhexidine. Methods: Fifty teeth were disinfected according to the Occupational Safety and Health Administration regulations. The teeth were then instrumented, followed by inoculation with bacterial strains of Enterococcus faecalis (ATCC 29212). The teeth were randomly assigned to five groups, Group I: Control group; Group II: Teeth irrigated with 5.25% NaOCl + Endovac; Group III: Teeth irrigated with 2% Chlorhexidine + Endovac; Group IV: Teeth irrigated with 5.25% NaOCl + laser irradiation; and Group V: Teeth irrigated with 2% Chlorhexidine laser irradiation. All samples were incubated on Muller–Hilton media plates for a period of 24 h. We determined the colony-forming units and analyzed them statistically using Fisher’s exact test. Results: Laser irradiation completely disinfected the root canal system. The EndoVac system produced significant disinfection but was comparatively less effective than laser irradiation. Conclusion: Laser irradiation had a significantly greater bactericidal effect than the EndoVac system, used in conjunction with sodium hypochlorite and chlorhexidine.

Draf IIB with superior septectomy: finding the "middle ground".

Previous studies have demonstrated a high failure rate of endoscopic sinus surgery (ESS) with Draf IIa in patients with diffuse polyposis, asthma, and aspirin-exacerbated respiratory disease. A high percentage of these patients progress to endoscopic modified Lothrop procedure (EMLP). We describe a modification of the Draf IIb with a superior septectomy (IIb+SS), which may provide similar therapeutic benefit as demonstrated by the distribution of sinus irrigations in the sinus cavity with ESS with IIb+SS vs ESS with EMLP. ESS with IIb+SS was performed on 6 cadaver heads. Fluorescein-dyed irrigations were performed on each head and penetration was recorded using video endoscopy. EMLP was subsequently performed on each head with repeat dye-irrigation and video endoscopy. The videos were reviewed by 4 blinded fellowship-trained rhinologists, and irrigant penetration of the maxillary, ethmoid, frontal, sphenoid sinuses, and olfactory cleft was graded 0 to 3 (3 implying complete staining). The mean scores when comparing IIb+SS to EMLP were as follows: overall 1.99 vs 1.97 (p = 0.816), maxillary sinus 2.67 vs 2.38 (p = 0.128), ethmoid sinus 1.88 vs 1.98 (p = 0.536), sphenoid sinus 2.58 vs 2.50 (p = 0.467), frontal sinus 1.13 vs 1.38 (p = 0.073), and olfactory cleft 1.71 vs 1.63 (p = 0.529). There was no significant difference between subsites. Interrater reliability was good (Cronbach's alpha = 0.781). Performing ESS with IIb+SS provides similar irrigation delivery benefits to ESS with EMLP, without the need for altering natural sinus outflow and creating circumferential scarring. Further studies evaluating its use in patients that are high risk for revision surgery are needed.

The effect of irrigation service delivery and training in agronomy on crop choice in Tajikistan

The aim of this paper is to analyze the effect of irrigation delivery services and agricultural extension services on crop choice in southern Tajikistan. This analysis is motivated by the government’s recent efforts to address the country’s severe malnutrition problem by supporting changes in irrigation service delivery and agronomy to increase diversity in agricultural production and consumption, in an environment where the cultivation of cotton had, until recently, been mandatory. Water management in Tajikistan has largely been transferred to the community through the creation of water users’ associations (WUAs), which were established between 2011 and 2013. While all WUAs received training to improve irrigation delivery services, some also received training in cultivating alternative crops and improving cultivation practices through agricultural extension services. Through specific empirical analysis conducted on a primary panel dataset of 1855 farms in southern Tajikistan, we identify the extent to which improvements in irrigation services, and agronomy training through extension services affect decisions pertaining to cultivated areas of cotton and wheat (the traditional crops) and the cultivated area and number of (newer) high-value crops. We also examine the effect of water delivery and agricultural extension services on crop diversity and cropping intensity (how often land is used in a calendar year). We find that improvements in irrigation delivery services affect cultivated areas of cotton and wheat. Cultivation of high value crops is significantly influenced by agricultural extension services. While cropping intensity depends on water delivery services, crop diversity depends on extension services. From a policy perspective, these results highlight the importance of agricultural programs for stimulating agricultural value added in landscapes historically characterized by limited crop choice and a collapse of the agricultural sector.

Effect of simulated intraosseous sinusoidal pressure on NaOCl extrusion

IntroductionThe present study examined the effects of irrigant flow rate and simulated intraosseous sinusoidal pressure on the rate of NaOCl extrusion from the apical terminus of a faux root canal. MethodsAn extrusion setup was designed to enable irrigant extrusion to be opposed by 30 mm Hg simulated intraosseous pressure. The faux canal apex was opposed by atmospheric + 30 mm Hg pressure (experimental) or atmospheric pressure only (control group). Using five irrigant delivery rates (15.6 8.0, 4.0, 3.4 or 3.0 mL/min), the extrusion rates of 2% NaOCl from the faux apex were measured in both groups (n = 16). Data were analysed with two-factor ANOVA and pairwise comparisons at α = 0.05. Correlation between NaOCl delivery rates and extrusion rates in both groups were analysed with the Pearson product-moment procedure. ResultIrrespective of the presence or absence of simulated sinusoidal pressure, NaOCl extrusion rates were positively-correlated with irrigant flow rates. For the factor “irrigant flow rates”, significant differences in NaOCl extrusion rates were identified among all flow rates (p < 0.05), except for the pairwise comparison between 4.0 and 3.4 mL/min in the control. For all irrigant flow rates, NaOCl extrusion rate was significantly lower in the presence of 30 mm Hg simulated sinusoidal pressure than that obtained in the absence of opposing pressure (p < 0.05). ConclusionIn the presence of 30 mm Hg simulated intraosseous pressure, NaOCl delivered via a side-vented needle inserted to 1 mm short of working length may be prevented from extrusion when its flow rate is ≤ 3.0 mL/min. Clinical SignificanceWhen opposed by intraosseous sinusoidal pressure, NaOCl delivered via a side-vented needle inserted to 1 mm short of working length may be prevented from extrusion when its flow rate is ≤ 3.0 mL/min.

Size of septectomy does not affect distribution of nasal irrigation after endoscopic modified Lothrop procedure

The endoscopic modified Lothrop procedure (EMLP) is commonly performed in recalcitrant frontal sinusitis, in part to achieve better penetration of medicated irrigations postoperatively. Although EMLP requires a septectomy for exposure, it is unknown whether septectomy size affects delivery of irrigations. In this study we evaluated the role of septectomy in delivery of irrigations to the EMLP cavity. EMLP was performed on fresh human cadavers with sequentially increasing septectomy (minimal septectomy: drilling across septum to combine frontal sinuses; standard septectomy: 1.5 cm anterior to middle turbinate and inferiorly to the midlevel of the turbinate; large septectomy: extension to nasal floor). Irrigation with fluorescein-labeled water was performed with a 240-mL irrigation bottle in the vertex position and recorded with a 30° endoscope fixed in a 4-mm trephine in the paramedian EMLP cavity. Two blinded reviewers scored irrigation distribution recordings (0 = nasal cavity only; 1 = frontal recess; 2 = medial distribution; 3 = lateral distribution; 4 = entire sinus lavage). Distribution scores were assessed with Wilcoxon rank sum analysis. Six specimens (mean age, 75.2 ± 2.4; 50% female) were assessed. Interobserver scores were highly concordant (Kendall's W = 0.86, p < 0.01), internally validating the experiment. Distribution scores did not vary significantly when comparing minimal septectomy with standard or large septectomy (Z = 0.55, p = 0.58, Z = 0.37, p = 0.71). Increasing septectomy does not improve irrigation delivery in patients undergoing EMLP. These results suggest that a limited septectomy for access to the bilateral frontal sinuses is all that is required for effective drug delivery postoperatively. This strategy may reduce morbidity associated with larger septectomies.

Greenhouse Gas Emissions from an Ornamental Crop as Impacted by Two Best Management Practices: Irrigation Delivery and Fertilizer Placement1

Abstract Agriculture is one of the largest contributors of greenhouse gas (GHG) emissions. To date, much work on reducing GHG emissions has centered on row crops, pastures, forestry, and animal production systems, while little emphasis has been placed on specialty crop industries such as horticulture. In this horticulture container study, Japanese boxwood (Buxus microphylla Siebold &amp; Zucc.) was used to evaluate the interaction of irrigation (overhead vs drip) and fertilizer placement (dibble vs incorporated) on GHG emissions (CO2, N2O, and CH4). Plants were grown in 11.4 L (#3) containers with a 6:1 pine bark:sand substrate with standard amendments. All containers received 6.35 mm (0.25 in) water three times daily. Gas samples were collected in situ using the static closed chamber method according to standard protocols and analyzed using gas chromatography. Total cumulative CO2 loss was not affected by differences in irrigation or fertilizer placement. Total cumulative N2O efflux was least for drip-irrigated plants, regardless of fertilizer placement. For overhead-irrigated plants, N2O efflux was greatest for those with incorporated fertilizer. Efflux of CH4 was generally low throughout the study. Findings suggest that utilizing drip irrigation could decrease N2O emissions, regardless of fertilizer placement. However, when limited to overhead irrigation, dibbled fertilizer placement could decrease N2O emissions. Index words: carbon dioxide, methane, nitrous oxide, trace gas Species used in this study: Japanese boxwood (Buxus microphylla Siebold &amp; Zucc.)

Operational performance improvements in irrigation canals to overcome groundwater overexploitation

Groundwater overexploitation due to unsustainable agricultural development is a widespread problem in irrigation districts relying on conjunctive use of surface and groundwater resources. Nearly 90% of global groundwater supported irrigated areas have conjunctive use of both surface and groundwater. A major driver behind the use of groundwater in these regions, in addition to surface water scarcity, is the poor operational performance of the irrigation schemes. The lack of reliability of water deliveries at farm gates forces farmers to increasingly turn to groundwater. Therefore, they intensively extract water and continuously deteriorate groundwater aquifers. This case study investigates the potential impact of improved water distribution and delivery through implementing canal automation techniques. These techniques can enhance the reliability of irrigation deliveries to the endpoint, resulting in reduction of groundwater extraction and associated benefits in decreasing energy consumption and CO2 emissions. The current study focuses on six main irrigation districts located in the Zayandeh-Rud River Basin (ZRB) in central Iran, where a total area of 200,000 ha is irrigated using surface water in conjunction with groundwater. To improve the performance of the irrigation networks for each of these districts, three operational model alternatives, including fully automated systems, were considered. Each of these models was designed and run for each of the six districts separately. The results showed a reduction of operational water losses in the range of 15% –25% depending on the implemented operational model. These potential water savings are then available to be used in the agricultural sector and can result in a reduction in groundwater extraction of up to 300 Million Cubic Meters (MCM). The associated reduction in energy consumption and carbon emission was about 450 GWh and 57,500 t each year, respectively. The results of this study can be employed in designing a centralized configuration of automated systems that enable water managers to reduce pressure on groundwater resources.

Antimicrobial efficacy of an apical negative pressure root canal irrigation system against intracanal microorganisms

ObjectivesThe effect of irrigation time on the antimicrobial efficacy of an apical negative pressure irrigation system was examined in vitro, followed by validation of the antimicrobial effect in vivo using the identified optimal irrigation time. MethodsFor the in vitro experiment, 44 extracted premolars were decoronated, instrumented, autoclaved and inoculated with Enterococcus faecalis (ATCC 29212) for 21 days. Four teeth were used as positive control, without irrigation. Each of the remaining 40 teeth was irrigated with 2.5% NaOCl, delivered via the EndoVac MacroCannula for 10 s, and subsequently via the EndoVac MicroCannula for 15, 30, 45, 60 or 90 s per canal, respectively (N = 8). After irrigation, microbial samples were collected, transferred to BHI broth and incubated for counting of bacterial colony forming units (CFUs). Based on the in vitro results, 8.25% NaOCl was delivered via the EndoVac MicroCannula for 60 s, during root canal treatment of 20 human subjects presented with apical periodontitis. Microbial samples retrieved in vivo prior to canal instrumentation (S0), after chemomechanical debridement (S1) and after irrigation with EndoVac (S2) were cultured in an anaerobic chamber for 7 days for CFU evaluation. ResultsCompared with the control, irrigation significantly reduced bacterial populations (p < .05). Irrigation delivery via the EndoVac demonstrated improved antibacterial efficacy with increased irrigation time (p < .05). Samples retrieved from canals after NaOCl delivery in vivo with the EndoVac for 60 s were all culture-negative. ConclusionsMicrobial elimination may be achieved with 8.25% NaOCl delivered via the EndoVac apical negative pressure irrigation device for 60 s. Clinical significanceWith the use of the EndoVac apical negative pressure irrigant delivery system, optimal elimination of the intracanal bacterial load can only be achieved when sodium hypochlorite is delivered via the MicroCannula for at least 60 s per canal.

Comparison of the Volume of Root Canal Irrigant Collected by 2 Negative Pressure Needles at Different Flow Rates of Delivery

IntroductionA greater irrigant volume improves the effectiveness of root canal irrigation. The purpose of this study was to compare 2 negative pressure systems regarding the volume of irrigant collected from the apical area in moderately curved canals at 3 different flow rates of delivery in vitro. MethodsThe mesiobuccal canals of 30 molars with a curvature between 20° and 40° were prepared to size #40.04 taper. A closed system was created. The canals were irrigated at 3, 6, and 12 mL/min for 30 seconds using EndoVac (SybronEndo, Orange, CA) and the INP needle (Mixnus Fine Engineering Co Ltd, Nagano, Japan) (both independent variables). A recovery trap was used to collect the irrigant aspirated by the negative pressure needles. Irrigant volume (dependent variable) was measured in milliliters. Data were analyzed using mixed analysis of variance. ResultsThere was a statistically significant interaction between the negative pressure system and the irrigant volume collected (P < .0005). The mean irrigant volume collected by the different negative pressure systems was greater for INP at 3 (P < .001), 6 (P < .001), and 12 mL/min (P < .001) flow rate. Both negative pressure needles showed statistically significant differences (P < .001) between mean irrigant volume collected at different flow rates. ConclusionsA greater volume was collected by increasing the flow rate of irrigant delivery for both EndoVac and INP. The INP needle could collect a greater volume of irrigant from the apical third compared with EndoVac at all 3 different flow rates.

Effectiveness of ultrasonically activated irrigation on root canal disinfection: a systematic review of in vitro studies.

Reduction of microbial load from the root canal systems is a pre-requisite for healing of lesions of endodontic origin. Such microbial reduction is influenced by the method of irrigant delivery and activation. The aim of this systematic review was to compare the effect of ultrasonically activated irrigation (UAI) with other irrigation techniques on the reduction of microorganisms during root canal disinfection. The research question was created based on the PICO strategy. Two reviewers independently performed a comprehensive literature search in electronic databases. Following application of inclusion and exclusion criteria to the selected articles, a systematic data extraction sheet was constructed. The selected articles were assessed using methodological quality scoring protocol. The risk of bias in selected studies was critically assessed by two reviewers. A total of 15 articles were included for the systematic review. The included studies were heterogeneous in study design; hence, meta-analysis was not performed. The overall risk of bias for the selected studies was moderate. Overall, UAI showed superior reduction of microbial counts, resulting in better disinfection compared to other irrigation systems chosen for comparison in this review. The use of UAI can bring about superior microbial reduction within the root canal system compared to other irrigant activation techniques. Activation of irrigants with ultrasonic brings about significant bacterial reduction from the root canal systems compared to other methods of irrigant activation and conventional syringe irrigation. This might help in improving the outcome of root canal treatment.

Size of Master Apical File and Optimal Irrigation of the Apical Zone: A Systematic Review.

To determine what would be the minimal apical diameter for optimal chemomechanical preparation in the root canal system in terms of debridement and/or irrigation delivery, in patients undergoing nonsurgical root canal treatment. Randomized controlled clinical trials, cohorts, cross-over studies from peer-reviewed journals published in English from January 1950 to June 2018 which reported outcome in terms of healing, microbial reduction and/or effectiveness of irrigation delivery to the apical third of the root canal system. Two reviewers conducted a comprehensive literature search. There were no disagreements between the two reviewers. The articles that met the inclusion criteria went through a predefined review process. Due to the variety of methodologies and different techniques used to measure outcome for master apical file enlargement, it was not possible to standardize the research data and to perform meta-analysis. Twelve clinical articles were identified that met the inclusion criteria. The overall level of evidence on this topic was moderate (fair). From this systematic review, the majority of the studies collected and referred to recommend sizes higher than #30 as the minimal size in order to adequately prepare the apical region of the root canals. Only 2 out of 12 studies suggested the size #25 as acceptable. From this systematic review it may be concluded that a larger MAF preparation above size 30 aids chemomechanical action.

A Subsurface Drip Irrigation System for Weighing Lysimetry

Abstract. Large, precision weighing lysimeters can have accuracies as good as 0.04 mm equivalent depth of water, adequate for hourly and even half-hourly determinations of evapotranspiration (ET) rate from crops. Such data are important for testing and improving simulation models of the complex interactions of surface water and energy balances, soil physics, plant growth, and biophysics that determine crop ET in response to rapid microclimate dynamics. When crops are irrigated with sprinkler systems or other rapid additions of water, the irrigation event is typically short enough that not much ET data are compromised by the lysimeter mass change due to irrigation. In contrast, subsurface drip irrigation (SDI) systems may take many hours to apply an irrigation, during which time the lysimeter mass change is affected by both ET rate and irrigation application rate. Given that irrigation application rate can be affected by pressure dynamics of the irrigation system, emitter clogging and water viscosity changes with temperature over several-hour periods, it can be difficult to impossible to separate the ET signal from the interference of the irrigation application. The inaccuracies in the data can be important, particularly for comparisons of sprinkler and SDI systems, since they are of the order of 8 to 10% of daily ET. We developed an SDI irrigation system to apply irrigations of up to 50 mm to large weighing lysimeters while limiting the period of lysimeter mass change due to irrigation delivery to approximately ten minutes by storing the water needed for irrigation in tanks suspended from the lysimeter weighing system. The system applied water at the same rate as the SDI system in the surrounding field, allowed irrigation over periods of any duration, but often exceeding 12 h, without directly affecting lysimeter mass change and the accuracy of ET rate determinations, and allowed irrigation overnight without compromising lysimeter daily ET measurements. Errors in lysimeter ET measurements using the previous SDI system, which was directly connected to the field irrigation system, were up to 10% of daily ET compared with negligible error using the new system. Errors using the previous, directly connected, SDI system varied over time due to variable system pressure, and possibly due to water temperature (viscosity) changes and emitter clogging. With the new system, all of the water transferred to the lysimeter weighing system was eventually applied by the SDI system regardless of temperature, pressure, or emitter clogging. Differences between planned and applied irrigation depth were less than 2% over the irrigation season. Keywords: Evapotranspiration, ET, Subsurface drip irrigation, SDI, Weighing lysimeter.

Enhanced Irrigant Delivery to the Ethmoid Sinuses Directly Following Ethmoid Punch Sinusotomy.

Ethmoid punch sinusotomy (EPS) is a feasible treatment for ethmoid sinusitis in a subset of chronic rhinosinusitis (CRS) patients per a recent report. This adjunctive work investigates the technical characteristics of EPS and determines if EPS measurably alters the topical delivery of irrigant into the ethmoid sinuses in a cadaveric model. The sinonasal cavities of 10 human cadaver heads were irrigated with a solution containing methylene blue and radio-opaque contrast prior to and following EPS. Procedural characteristics and irrigant distribution were assessed by endoscopy and computed tomography. Forty EPS procedures were performed through the ethmoid bulla and basal lamella. Compared to controls, EPS enhanced dye distribution into the anterior (90% vs 35%, P < .004) and posterior (90% vs 35%, P < .002) ethmoid sinuses, representing a 157% increase for each of these sites. Contrast was detected in a higher proportion of anterior (65% vs 5%, P < .001) and posterior (60% vs 0%, P < .001) ethmoid sinuses. Endoscopically guided catheter instillation of contrast through the EPS sites achieved radiotracer distribution throughout the ethmoid complex. Ethmoid punch sinusotomy sites can be reliably created via micro-minimally invasive procedures. Ethmoid punch sinusotomy improves irrigant delivery to the ethmoid sinuses, providing mechanistic understanding for the clinical outcomes observed in CRS patients.

Surge Irrigation Reduces Irrigation Requirements for Soybean on Smectitic Clay‐Textured Soils

Core Ideas Surge irrigation reduced the amount of water applied per irrigation event by 22% Surge irrigation reduced the total amount of seasonal irrigation water application by 24% Surge irrigation increased irrigation water use efficiency by 29% The Mississippi River Valley Alluvial Aquifer is declining precipitously due to irrigation withdrawal for row crop production. Currently, 25% of the soybean (Glycine max L.) acres in the Mid‐South are planted on clay‐textured soils and furrow‐irrigated using conventional continuous flow (CONV), the least efficient irrigation delivery system. The objective of this research was to determine the effect of surge irrigation (SURGE) on amount of water applied, soybean grain yield, irrigation water use efficiency (IWUE), and net return above irrigation costs when implemented on clay‐textured soils. The research was conducted during the 2013 through 2015 growing seasons in Stoneville, MS and consisted of paired fields, with the same cultivar, soil texture, planting date, and management practices used on both sites. Paired fields were randomly assigned as SURGE or CONV. Water applied to each field was monitored with flowmeters, and irrigations were initiated based on soil moisture sensor thresholds. Relative to CONV, SURGE reduced the amount of water applied per irrigation event by 22% and total water applied in season by 24% (P ≤ 0.0349). Soybean grain yield averaged 66 bu/acre and was not different between delivery systems (P = 0.7711), but SURGE increased IWUE by 29% compared with CONV (P = 0.0076). Net return above irrigation cost was not different between CONV and SURGE, regardless of diesel price or pumping depth (P ≥ 0.1149). Results from this research indicate that soybean producers in the Mid‐South and other regions that irrigate using lay‐flat polyethylene tubing can adopt SURGE for soybean on clay‐textured soils without adversely affecting yield or on‐farm profitability while concurrently decreasing the demand on depleted groundwater resources.