Passive Irrigation Research Articles

Stormwater retention performance of tree integrated infiltration trenches designed for suburban streetscapes

The volume of stormwater generated by streetscapes in cities is a primary driver of urban stream degradation. Large infiltration trenches can be integrated into streetscapes to potentially retain large volumes of runoff and increase growth rates of nearby trees. To test this, a field study was conducted where three structural soil infiltration trenches receiving runoff (12 m long, 0.6 m wide and 0.6 deep) were installed alongside a carpark in Melbourne, Australia, with sizing determined by space constraints in a typical streetscape. The three structural soil trenches had raised outflow drainage, which created internal water storage for runoff received from a carpark. To separate the effects on tree growth of i) the presence of structural soil from ii) passive irrigation into the structural soil, three structural soil trenches (6 m long, 0.6 m wide and 0.6 deep) not receiving runoff and without outflow drainage were also installed. Runoff capture, exfiltration, outflow and tree growth was monitored over 19 months. Only one system performed close to the design intent and retained 18 % of runoff, due to slow soil exfiltration rates (<0.1 mm h−1). Compacted soil generated pervious-area runoff that filled the structural soil trenches not receiving impervious-area runoff from the carpark. Tree growth near these structural soil trenches was poor (59 % relative growth) compared with trees receiving runoff from the carpark (112 % relative growth), due to a lack of drainage, emphasising the need for drainage of stormwater systems in heavy textured soils to promote tree growth. This study highlights that options for creating storage for stormwater in streetscapes have the potential to meet local runoff infiltration targets. However, meeting local runoff volume reduction targets will require alternative ways to reduce surface runoff.

247 Novel Automated Active Irrigation With Drainage Leads to Significantly Faster Hematoma Clearance and Lower Catheter-related Infections Compared to Passive Drainage Alone for cSDHA Propensity Score-matched Comparative Study with Volumetric Analysis

INTRODUCTION: Passive drainage post-surgical evacuation of symptomatic chronic subdural hematoma (cSDH) is currently standard of care. High rates of infection, drain occlusion, and recurrence are associated complications. METHODS: A prospectively maintained database was retrospectively searched for consecutive patients presenting with cSDH. One-to-one PSM of covariates (including baseline comorbidities and presentation hematoma volume) in active and passive irrigation groups was performed to adjust for treatment selection bias. Rates of hematoma clearance, catheter-related occlusion, and infection; number of revisions; and length of hospital stay were recorded. RESULTS: This study included 55 patients: active continuous irrigation-drainage-21 (21 post-PSM); passive drainage-34 (21 post-PSM). For PSM groups, a significantly higher rate of hematoma clearance was obtained in the active irrigation-drainage group (0.5±0.4 vs. 0.4±0.5 ml/day in the passive drainage group; odds ratio [OR] = 1.291 (confidence interval [CI]:1.062-1.570, P = 0.002) and a significantly lower rate of catheter-related infections (OR = 0.051; CI: 0.004-0.697, P = 0.039). A non-significantly lower hematoma expansion rate at discharge was noted in the active irrigation-drainage group (4.8% vs. 23.8%; OR = 0.127; P = 0.186). No statistical difference in all-cause in-hospital mortality or discharge GCS score was observed between groups. CONCLUSIONS: Active and automated continuous irrigation plus drainage following cSDH surgical evacuation results in faster hematoma clearance and led to favorable clinical outcomes and low complication and revision rates compared to passive irrigation.

COMPARATIVE ASSESSMENT OF THE ROOT CANAL IRRIGATION QUALITY WITH EXPERIMENTAL INTRA-ROOT RESORPTION IN VITRO

Introduction. To date, intra-root resorption of teeth is poorly understood, although it is often encountered in dental clinics. This study aimed on assess and comparison of different methods of irrigation and antiseptic solutions activation used for root canal treatment, and focus on cleaning the area of simulated intra-root resorption. Methods. 24 extracted teeth were used, which the simulation of internal resorption was reproduced by dissection the inside of the root canal under the control of an electron microscope (Karl Kaps, Germany) in. Distilled water, sodium hypochlorite 5.25 %, sodium hypochlorite 3 %, chlorhexidine 2 % were used for comparative assessment of irrigation quality by staining with Indian Ink dye. Results. When using an endodontic needle and passive irrigation with the studied irrigation solutions, the dye remained on the inner surfaces of the root canal walls, which indicated their insufficient cleaning. The use of auxiliary cleaning methods - sound and ultrasonic irrigation nozzles - showed better cleaning of the root canal resorption zone. When using the sound activation of the irrigator with the EndoActivator device, the dye partially remained in the simulated resorption zone, while a significant part of the root canal system was cleaned. The use of ultrasonic activation of the irrigator with the P5 XS device showed that all dye-stained root canals of the samples were cleaned. Zones of simulated root resorption did not show any dye residues visually and under electron microscope control. Conclusions. The quality of root canal cleaning in case of intra-root resorption in terms of visual assessment of their transparency and under the control of an electron microscope was more pronounced when using methods of activating irrigation solutions with sound and ultrasonic activators.

Endodontic tooth treatment with internal root resorption: case report

INTRODUCTION: Internal tooth resorption is characterized by the destruction of dentin in the root canal wall due to an imbalance of clastic cell activity resulting mainly from trauma. Thus, endodontic treatment is indicated with the aim of removing the etiology of resorption by using intracanal medication to combat possible infection and thus provide tissue repair. OBJECTIVE: The aim of this study is to investigate the treatment of root resorption by conventional endodontic therapy by identifying internal resorption and highlighting the steps of endodontic treatment. CASE REPORT: The methodology adopted was a clinical study in which we selected a female patient who required endodontic treatment of tooth 12 with pulp necrosis and resorption in the middle third of the root. Thus, the endodontic treatment was performed according to the technique, through instrumentation of the root canal followed by irrigation with sodium hypochlorite 6%. After instrumentation, the PUI (Ultrasonic Passive Irrigation) was performed followed by irrigation with 6% sodium hypochlorite and EDTA solution. The root canal was also dried and filled, allowing the respective tooth to be provisionally restored with glass ionomer so that it could later be permanently restored according to the indication of the material. Therefore, internal tooth resorption causes irreversible damage to the individual, such as tooth loss, thus altering the functioning of the stomatognathic system. Thus, endodontic treatment has great advantages in the treatment of teeth with internal tooth resorption since it promotes stagnation of the resorption process and tissue repair. CONCLUSIONS: Therefore, the treatment of internal tooth resorption requires close attention by the dental surgeon due to careful evaluation throughout the entire clinical case.

Use of Novel Automated Active Irrigation With Drainage Versus Passive Drainage Alone for Chronic Subdural Hematoma-A Propensity Score-Matched Comparative Study With Volumetric Analysis.

Passive drainage post-surgical evacuation of symptomatic chronic subdural hematoma (cSDH) is currently standard of care. High rates of infection, drain occlusion, and recurrence are associated complications. To explore the use of a novel double-lumen active automated irrigation and aspiration system, IRRAflow (IRRAS), for patients with cSDH and compared procedural and clinical outcomes against passive drainage alone with propensity score matching (PSM) and volumetric analysis. A prospectively maintained database was retrospectively searched for consecutive patients presenting with cSDH. One-to-one PSM of covariates (including baseline comorbidities and presentation hematoma volume) in active and passive irrigation groups was performed to adjust for treatment selection bias. Rates of hematoma clearance, catheter-related occlusion, and infection; number of revisions; and length of hospital stay were recorded. This study included 55 patients: active continuous irrigation-drainage-21 (21 post-PSM) and passive drainage-34 (21 post-PSM). For PSM groups, a significantly higher rate of hematoma clearance was obtained in the active irrigation-drainage group (0.5 ± 0.4 vs 0.4 ± 0.5 mL/day) and in the passive drainage group; odds ratio (OR) = 1.291 (CI: 1.062-1.570, P = .002) and a significantly lower rate of catheter-related infections (OR = 0.051; CI: 0.004-0.697, P = .039). A nonsignificantly lower hematoma expansion rate at discharge was noted in the active irrigation-drainage group (4.8% vs 23.8%; OR = 0.127; P = .186). No statistical difference in all-cause in-hospital mortality or discharge Glasgow Coma Scale score was observed between groups. Active and automated continuous irrigation plus drainage after cSDH surgical evacuation resulted in faster hematoma clearance and led to favorable clinical outcomes and low complication and revision rates compared with passive irrigation.

Farklı irrigasyon aktivasyon yöntemlerinin rezin siman kullanılarak yapıştırılan fiber postların bağlanma dayanımına etkileri

Amaç: Endodontik tedavili ve koronal harabiyeti fazla olan dişlerin restorasyonunda sıklıkla kullanılan fiber postların uzun dönem başarısında, postun dentine etkin bir şekilde bağlanması kritik önem taşır. Bu çalışmanın amacı, çeşitli irrigasyon aktivasyon yöntemlerinin post boşluğunun farklı bölgelerinde fiber postların bağlanma dayanımına etkisini araştırmaktır. Gereç ve yöntemler: Endodontik tedavileri yapılan 48 adet alt 1. premolar diş, post boşluğuna uygulanacak olan irrigasyon yöntemine göre 4 gruba ayrıldı (n=12): pasif irrigasyon (Pİ); manuel-dinamik irrigasyon (MDİ); sonik irrigasyon (Sİ), ultrasonik irrigasyon (Uİ). Fiber postlar, post boşluğuna kendinden adeziv rezin siman ile yapıştırıldı. Kökler, her biri 2 mm olacak şekilde koronal, orta ve apikal olmak üzere 3 enine kesite ayrıldı. Push-out bağlanma dayanımları universal test cihazı kullanılarak MPa cinsinden hesaplandı. Başarısızlık tipleri her bir örneğin stereomikroskop altında incelenmesi ile şu şekilde gruplandı: siman-dentin arası adeziv başarısızlık-Adeziv(S/D); siman-fiber post arası adeziv başarısızlık-Adeziv(S/F); ilk 2 başarısızlık tipinin beraber görüldüğü başarısızlık-karma. Bulgular: En düşük ortalama bağlanma dayanımı Pİ için elde edildi (p&amp;lt;0.05). Diğer gruplar arasında istatistiksel açıdan farklılık bulunmadı (p&amp;gt;0.05). Köklerden elde edilen kesitlerden koronal bölge, apikal bölgeden istatistiksel olarak anlamlı düzeyde yüksek bağlantı değeri gösterdi (p&amp;lt;0.05). MDİ,Sİ ve Uİ gruplarında karma hata dominant olarak gözlenirken adeziv (S/D) hatayı en fazla gösteren grup Pİ oldu. Sonuç: Post boşluğu hazırlandıktan sonra manuel-dinamik, sonik ve ultrasonik irrigasyon aktivasyon yöntemlerinden birinin kullanılması, fiber postların kök kanal dentinine olan bağlanma dayanımını arttırmaktadır. Uygulanan irrigasyon yönteminden bağımsız olarak fiber postun bağlanma dayanımı, koronal bölgede apikal bölgeden daha yüksektir.

Rotasyon ve resiprokasyon hareketi ile çalışan farklı eğe sisteminin apikal transportasyon ve kanal düzleşmesine etkisinin karşılaştırılması

Background: The effective bonding of fiber posts which are recommended in the restoration of endodontically treated teeth with excessive coronal damage is of critical importance for the long-term success. The aim of this study was to investigate the effect of various irrigation activation protocols on the push-out bond strength of fiber posts in different parts of the post space.Methods: Forty-eight endodontically treated mandibular first premolar teeth were divided into 4 groups according to irrigation protocol (n=12): passive irrigation(PI); manual-dynamic irrigation(MDI); sonic irrigation(SI), ultrasonic irrigation(UI). Fiber posts were bonded with a self-adhesive resin cement. Three transvers sections, were obtained from the coronal, middle, and apical regions of the root, in 2 mm thich each. Push-out bond strength in each section was calculated in MPa using a universal-testing machine. Each sample was examined under a stereomicroscope and failure types were classified as follows: adhesive failure between cement and dentin-Adhesive(C/D); adhesive failure between cement and fiber post-Adhesive(C/F); the combination of both adhesive failure types-mix.Results: The lowest bond strength was obtained for PI group (p&amp;lt;0.05). There was no statistically significant difference between the other groups (p&amp;gt;0.05). Coronal region showed higher bond strength than the apical region regardless of test group (p&amp;lt;0.05). While mixed failure was observed dominantly in the MDI, SI and UI groups, PI was the group that showed the adhesive(C/D) failure type in most.Conclusion: After preparing the post space, the use of any of the manual-dynamic, sonic or ultrasonic irrigation activation methods increases the bond strength of fiber posts to root canal dentin compared to passive irrigation. Regardless of the irrigation method applied, the bond strength of the fiber post to the root canal was higher in the coronal region compared to the apical region.

Influence of Needle Design and Irrigant Flow Rate on the Removal of Enterococcus faecalis Biofilms In Vitro.

This study aimed to evaluate the influence of needle design and irrigant flow rate on the removal of Enterococcus faecalis mature biofilms during sodium hypochlorite irrigation. Forty-eight single-rooted human teeth were instrumented (ProTaper F3), autoclaved and inoculated with Enterococcus faecalis to establish a two-week-old biofilm. E. faecalis biofilms were treated with Sodium hypochlorite that was injected in the root canals using three types of needles (NaviTip, ProRinse, IrriFlex). For the IrriFlex needle, one, two, or four bars of pressure was applied to the irrigating solution to increase flow rates. Bacteria were labeled with the LIVE/DEAD BacLight Bacterial Viability kit, and viability was assessed by flow cytometry (FCM). Results were statistically analyzed using one-way ANOVA and Tukey multiple comparison intervals (α = 0.05). Bacterial viability was significantly reduced after sodium hypochlorite passive irrigation but the number of viable bacteria retrieved from root canal specimens irrigated with the Pro-Rinse needle was significantly higher compared to NaviTip and IrriFlex needles (p < 0.05). When the irrigant flow rate was increased, the viability of bacterial biofilms was significantly reduced compared to passive irrigation using the IrriFlex needle (p < 0.05). Applying higher flow rates during irrigation using the IrriFlex needle did not further reduce bacterial viability.

Enhanced Passive Stormwater Infiltration Improves Urban Melia Azedarach Functioning in Dry Season

Urban water management projects involving stormwater harvesting, detention, and infiltration are being increasingly combined with urban greening to support adaptation and resilience to the changing climate. A novel stormwater harvesting device, the TREENET Inlet, intercepts stormwater runoff from roads and soaks it into the soil through a leaky well to provide passive irrigation directly into street tree root zones. This study investigated the effects of stormwater harvesting through these inlet systems on the growth, water-use, leaf-level gas exchange and productivity of white cedar (Melia azedarach) street trees in a semi-arid climate in South Australia. The results indicated that mature trees with TREENET Inlets and leaky wells transpired 17% more water per unit of canopy area per day, on average for about a year, and 21% more during the dry season. White cedar saplings with stormwater harvesting grew 65% more in height and 60% more in diameter at breast height over a 3-year period than saplings without stormwater harvesting. This is consistent with observed 106% greater stomatal conductance and up to 169% greater photosynthesis rate in the dry season for saplings supported by harvested stormwater. This study shows that stormwater harvesting and infiltration by TREENET Inlets provides significant benefit to white cedar trees growing in a suburban street.

An in vitro radiological evaluation of irrigant penetration in the root canals using three different irrigation systems: Waterpik WP-100 device, passive irrigation, and manual dynamic irrigation systems.

Background:Instrumentation and irrigation of the root canal facilitating effective debridement is considered the most important single factor in the prevention and treatment of endodontic diseases.Aim:The aim of the study was to evaluate the depth of penetration of the irrigant depending on the final activation using Waterpik device modified with NaviTip needle, passive irrigation, and manual dynamic activation using the radiopaque solution in conjunction with digital dental radiography.Materials and Methods:Ninety freshly extracted single-rooted mandibular premolars based on the inclusion and exclusion criteria were used for this study. Access cavity preparation was done for all the samples, and the working length of each sample was determined using a size 10-k file. The radiopaque solution (Urografin) was delivered into (Groups A, B, and C) prepared canal of samples at the rate of 1 ml in 30 s with up-and-down motion.Results:The test results showed that Waterpik WP-100 group showed significantly high infiltration index values as compared to passive irrigation and manual irrigation group at P < 0.002 and P = 0.007, respectively.Conclusion:Sonic irrigation using a Waterpik device modified with a NaviTip needle permits better infiltration of the irrigant.

Supporting Growth and Transpiration of Newly Planted Street Trees With Passive Irrigation Systems

AbstractSolutions that use stormwater runoff to rapidly establish tree canopy cover in cities have received significant attention. Passive irrigation systems that direct stormwater to trees have the potential to increase growth and transpiration and may limit drought stress. However, little data from the field demonstrates this, and we lack robust and reliable designs which achieve it. Here, we quantified growth and transpiration for trees: (a) in infiltration pits receiving stormwater, with a raised underdrain and internal water storage (drained), (b) next to infiltration pits receiving stormwater but without an underdrain and internal water storage (adjacent), and (c) planted in standard pits, not receiving stormwater (control). Trees in drained pits grew twice as fast as control trees in the first 2 years, but fast initial growth rates were not sustained in years three and four. Trees outgrowing the small infiltration pits, rather than a lack of water, was most likely responsible for growth rates slowing down. Despite this, rapid initial growth for trees in drained pits meant trees were larger by year three and transpired more than twice as much (5.1 L d−1) as trees adjacent to pits (2.4 L d−1) or control trees (2.3 L d−1). No trees showed drought stress during the study. However, some trees planted adjacent to infiltration pits showed waterlogging stress, suggesting caution installing infiltration pits adjacent to establishing trees in fine‐textured soils. Overall, our results suggest passive irrigation systems can substantially increase initial tree growth, thereby facilitating greater cooling and runoff reduction through increased transpiration.

IMPROVEMENT OF HYDROPON INSTALLATIONS

Hydroponics is a promising area of development of modern agriculture, which provides long-term cultivation of basic vegetables and greenery in small areas with minimal consumption of water and fertilizers. This technology allows you to get a fairly large harvest of fresh vegetables within large cities, including office and residential premises. Entrepreneurs and researchers are paying close attention to developing more efficient hydroponics methods and equipment to implement them in order to reduce usable space, save water, nutrients and increase air supply and plant capacity. Several hydroponics systems are known: static solution culture, continuous flow solution (NFT) culture, deep water culture, passive irrigation, underwater and drainage irrigation systems, wastewater drainage system, deep-water fertilized culture, rotary system, aeroponics, wick system. The first three of the above methods were used commercially and industrially. The system of static culture solution does not provide the necessary saturation of plant roots with air. With the implementation of the method of continuous solution culture, minor buffering is possible due to interruptions in the flow (power outage), flooding of water in some canals, in addition, there are restrictions on the maximum length of canals (12 - 15 m). The system of deep-water culture on an industrial scale is used mainly for growing lettuce. Other mentioned systems are not efficient enough in terms of commercial use. The improved hydroponic installations presented in the article were developed taking into account the following requirements: universality of use (possibility of growing different types of plants); harmonization of optimal supply of crops with water, nutrients, light and air; maximum use of space; increasing the area for each plant and maintaining its stems and shoots. Also in the article the equation for definition of the basic parameters of the developed installations is given.

Selecting tree species with high transpiration and drought avoidance to optimise runoff reduction in passive irrigation systems

Rainfall in cities can generate large volumes of stormwater runoff which degrades receiving waterways. Irrigating trees with runoff (passive irrigation) has the potential to increase transpiration and contribute to stormwater management by reducing runoff received by downstream waterways, but the stochastic nature of rainfall may expose trees with high transpiration to drought stress. We hypothesized that for success in passive irrigation systems, tree species should exhibit i) high maximum transpiration rates under well-watered conditions, ii) drought avoidance between rainfall events, and iii) high recovery of transpiration with rainfall following a drought. We assessed 13 commonly planted urban tree species in Melbourne, Australia against three metrics representing these behaviours (crop factor, hydroscape area, and transpiration recovery, respectively) in a glasshouse experiment. To aid species selection, we also investigated the relationships between these three metrics and commonly measured plant traits, including leaf turgor loss point, wood density, and sapwood to leaf area ratio (Huber value). Only one species (Tristaniopsis laurina) exhibited a combination of high crop factor (>1.1 mm mm−1 d−1) indicating high transpiration, small hydroscape area (<3 MPa2) indicating drought avoidance, and high transpiration recovery (>85%) following water deficit. Hence, of the species measured, it had the greatest potential to reduce runoff from passive irrigation systems while avoiding drought stress. Nevertheless, several other species showed moderate transpiration, hydroscape areas and transpiration recovery, indicating a balanced strategy likely suitable for passive irrigation systems. Huber values were negatively related to crop factor and transpiration recovery and may therefore be a useful tool to aid species selection. We propose that selecting tree species with high transpiration rates that can avoid drought and recover well could greatly reduce stormwater runoff, while supporting broader environmental benefits such as urban cooling in cities.

Smear layer removal and sealer penetration with different tapers after using photon-initiated photoacoustic streaming technique

To evaluate the effect of the photon-initiated photoacoustic streaming (PIPS) technique on irrigation performance with different instrumentation tapers in root canals regarding smear layer removal and subsequent sealer penetration. One hundred twenty human mandibular molars were divided into three equal groups according to the apical preparation taper (25/4%, 25/6%, and 25/8%). Each group was divided into two equal subgroups, one received passive irrigation (PI) while the other received PIPS activation of 2.5% sodium hypochlorite and 17% EDTA. Half the samples were evaluated using electron microscope images to assess smear layer removal. The other half was obturated using gutta-percha and rhodamine B-labeled AH Plus sealer before being sectioned horizontally at different root levels (coronal, middle, and apical) to evaluate the percentage of sealer penetration using CLSM. Mann-Whitney U and Friedman tests were used to analyze smear layer scores, while sealer penetration data were analyzed using the three-way analysis of variance (ANOVA) and Tukey's post hoc test. Statistical analysis showed significantly better smear layer removal and better sealer penetration after PIPS activation when corresponding root thirds were compared (P<0.001). Only exception was sealer penetration in the apical third with root canal preparation of 25/4% where the difference between the irrigation methods was statistically insignificant (P>0.05). The use of PIPS activation in the final irrigation protocol enhanced smear layer removal and sealer penetration into dentinal tubules if the taper of the prepared canal was at least 6%. Increasing apical preparation taper significantly enhances PIPS performance in terms of irrigation activation thus enhancing smear layer removal and subsequent sealer penetration in dentinal tubules.

Evaluation and comparison on the wettability of three root canal sealers after three different irrigant activation techniques: An in vitro study.

Background:Wettability of root canal sealers to the root canal wall plays a significant role in the attainment of a fluid-tight seal.Aims:This study aimed to evaluate and compare the wettability of three different root canal sealers on the root canal walls after three different irrigant activation techniques using the contact angle meter.Subjects and Methods:Thirty-six single-rooted mandibular premolars after decoronation and cleaning and shaping up to size #35 were randomly divided into three groups with 12 samples in each group (n = 12) based on the different activation techniques: Group I (passive irrigation with side-vented needle), Group II (manual dynamic agitation), and Group III (passive ultrasonic irrigation). Root segments were split longitudinally and were subdivided into three subgroups based on the root canal sealers tested with four samples in each subgroup (n = 4): Subgroup A (Tubliseal EWT), Subgroup B (AH Plus), and Subgroup C (Endosequence BC sealer). A controlled volume droplet of sealer was placed on each specimen and was subjected to the contact angle meter.Statistical Analysis:Data were statistically analyzed using the one-way ANOVA and Tukey’s post hoc test at a significance level of 0.05 (P < 0.05).Results:A statistically significant difference was seen among all the groups and subgroups with the highest contact angle value for Group III and Subgroup C and the least value for Group I and Subgroup A.Conclusions:Passive irrigation with side-vented needle and Tubli-Seal EWT showed better wettability on dentin.

Ecohydrology of urban trees under passive and active irrigation in a semiarid city.

The infiltration of stormwater runoff for use by urban trees is a major co-benefit of green infrastructure for desert cities with limited water resources. However, the effects of this passive irrigation versus regular, controlled moisture inputs, or active irrigation, is largely unquantified. We monitored the ecohydrology of urban mesquite trees (Prosopis spp.) under these contrasting irrigation regimes in semiarid Tucson, AZ. Measurements included soil moisture, sap velocity, canopy greenness, and leaf-area index. We expected both irrigation types to provide additional deep (>20 cm) soil moisture compared to natural conditions, and that trees would depend on this deep moisture for transpiration and phenological activity. Results show that active irrigation supported higher soil moisture throughout the study than passive irrigation. Passive irrigation only provided additional deep moisture when green infrastructure features received impervious runoff from a city street. Sap velocity and greenness were similar under both irrigation types, outside of isolated periods of time. These differences occurred during the extremely wet summer 2017 when passively irrigated trees exhibited a greenness peak, and the dry conditions of spring when actively irrigated trees had higher sap flow and relative greenness. Finally, it was not determined that deep soil moisture had a stronger relationship with mesquite productivity than shallow moisture, but both relationships were stronger in the spring, before summer rains. This study aims to contribute empirical observations of green infrastructure performance for urban watershed management.

Effects of Endodontic Irrigants on Material and Surface Properties of Biocompatible Thermoplastics.

Passive irrigation is an efficient method for a successful endodontic treatment. During sonic activation biocompatible polymer tips are used to activate irrigants. Compared to ultrasonic activation with metallic tips, polymer tips have the advantage of a reduced risk of fracture and minimise dentine damage. Hence, two polymers, polyether ether ketones (PEEK) and polyamide (PA6), were identified for the manufacturing of novel irrigation tips. The chemical resistance against the irrigants ethylenediaminetetraacetic acid (EDTA) 20%, chlorhexidine gluconate (CHX) 2% and sodium hypochlorite (NaOCl) 5.25% was analysed. Using microindentation, the change of hardness, elasticity, surface roughness and appearance of the polymers was determined. PA6 had a high absorption of irrigant compared to PEEK. PEEK was resistant to the investigated irrigants and showed no significant alteration of surface and mechanical properties, whereas PA6 slightly increased its hardness, elastic modulus and surface roughness during long-term exposure at 37 °C. However, PA6 tips seem to be a promising disposable product due to the material’s high deformability and low manufacturing costs. Particularly with regard to structural-dynamic properties and high chemical resistance, PEEK can be considered as a material for reusable irrigation tips.

Street tree stormwater control measures can reduce runoff but may not benefit established trees

Directing stormwater runoff to irrigate urban trees has the potential to simultaneously: (i) reduce the volume of runoff generated by impervious surfaces and (ii) reduce tree drought stress and increase growth. Many papers promote this concept, but few have quantified both potential benefits. In this study, we quantified both the runoff retention performance of infiltration trenches retrofitted alongside established street trees and tree drought stress and growth. We compared retention for different soil types, tree phenological types and inlet designs over a period of 18 months. Retention was low on average (18.3%) but was highly variable among infiltration trenches (5.2–43.7%), driven by variation in inlet capacity due to blockages, as well as the flow velocity of runoff leading to the inlet. With appropriately designed inlets, street tree stormwater control measures have significant potential to retain runoff. We observed no clear reduction in tree drought stress or increase in tree growth. This suggests that the established trees in our study already had access to adequate soil water within their rooting volumes, supplemented by nearby irrigated private gardens, or leaky water infrastructure. We suggest that i) mature trees surrounded by greater impervious surface area, ii) newly planted trees, or iii) trees growing in hotter, drier climates, may respond more positively to similar passive irrigation systems. The evolving practice of passive irrigation of street trees with stormwater requires innovative design to maximise runoff capture efficiency under typical sediment and debris loads.

Effect of the irrigation protocols on the elimination of dentin debris from simulated lateral canals

Objective: Computed microtomography was used to evaluate the capacity of debris removal from simulated lateral canals, in conventional irrigation, passive ultrasonic irrigation (PUI), continuous passive irrigation (CUI), Endoactivator and EasyClean, for both types of motion (continuous and reciprocating). Material and Methods: Sixty acrylic incisors with 3 simulated lateral canals per tooth (cervical, middle and apical third) were instrumented with Reciproc 40/06 and then filled with dentin debris. The teeth were scanned and divided into 6 groups (n = 10) according to the irrigation protocol: G1 - conventional, G2 - PUI, G3 - CUI, G4 - Endoactivator, G5 - EasyClean continuous rotation and G6 - EasyClean reciprocating. After the irrigation protocols, the samples were scanned again. The initial and final volume images were analyzed and the percentage of debris removal were found for each group in all levels. Results: There were significant differences between the initial and final volume of debris after the protocols, with the exception of conventional irrigation group in the apical and cervical thirds, EasyClean reciprocating in the middle and cervical thirds, and CUI in the middle third. In the analysis between the groups: in the apical third, Endoactivator and PUI removed more debris than CUI (p &lt; 0.05); in the middle and cervical thirds, PUI was more efficient than conventional irrigation, EasyClean reciprocating and CUI (p &lt; 0.05). Conclusion: No method completely removed the debris. PUI was the method that showed greater effectiveness in cleaning the lateral canals.KeywordsRoot canal therapy; Microct; Dentin; Ultrasonic therapy.

Tree pits to help mitigate runoff in dense urban areas

Tree pits are attractive stormwater control measures (SCMs) for implementation in dense urban areas because of their small footprint, their potentially low cost and the co-benefits they may bring through improved street tree growth. While they provide street trees with passive irrigation, it remains to be determined if tree pits may achieve meaningful reductions in stormwater runoff. We undertook a streetscape experiment to quantify runoff retention of tree pits in a heavy clay soil with low-rates of exfiltration. We calibrated and validated a water balance model using the field experiment data to identify tree pit characteristics driving runoff retention performance. We then applied the model to different implementation scenarios to ascertain how useful these tree pits may be at reducing runoff to return a more natural flow regime in dense urban areas. The main drivers of runoff retention were identified as exfiltration rates from the tree pits and the connected impervious catchment size. Our results show that it is possible, even in dense urban streetscapes with low conductivity (heavy-clay) soils, to achieve a 90% reduction in annual runoff and to reduce days of runoff to just 15 days per year. However, to achieve this, tree pits need to be sized between 2.5% and 8% of the impervious catchment area, depending on pit exfiltration rates. In practice, achieving these tree pit to catchment area ratios for a dense urban streetscape will require consideration in the planning stages of development works and is expected to be most feasible through implementation of tree pits alongside a suite of other complementary SCMs.