Negative Pressure Irrigation System Research Articles

Outcome of nonsurgical management of large cyst-like periapical lesions using a modified apical negative pressure irrigation system: a case series study

ObjectiveTo assess the effectiveness of a self-constructed modified apical negative pressure irrigation (ANPI) system employing commonly used clinical instruments in nonsurgical root canal therapy (NSRCT) for large cyst-like periapical lesions (LCPLs).MethodsFrom 2017 to 2022, 35 patients diagnosed with LCPLs (5-15 mm) via preoperative clinical and radiographic evaluations of endodontic origin underwent NSRCT combined with ANPI. These patients were subjected to postoperative clinical and radiographic follow-up at 3 months, 6 months, 1 year, 2 years, 3 years, and 4 years, with a CBCT scan specifically conducted at 6-month follow-up. Through the reconstruction of three-dimensional cone beam computed tomography (CBCT) data, an early prognosis was facilitated by monitoring changes in lesion volume. Various treatment predictors—including sex, type of treatment, lesion size, preoperative pain, jaw, type of teeth involved, sealer extrusion, and the number of root canals—were meticulously analyzed. The evaluation of post-treatment outcomes leveraged both clinical observations and radiographic data collected during the follow-up periods. The Kruskal‒Wallis test and one-way ANOVA were also conducted to determine the independent factors influencing treatment outcomes. A significance level of 5% was established.ResultsThirty-five teeth from 35 patients with a median age of 28 years (range 24–34) were treated; the median follow-up duration was 19 months (range 12–26). The overall success rate was 91.4%, with a median lesion reduction of 77.0% (range 54.2–96.4%) at 6 months. Patients under 30 years of age exhibited a significantly greater success rate than older patients did (100.0% vs. 80.0%, p = 0.037). Other factors, such as sex, jaw, treatment type, preoperative pain, cyst size, tooth location, sealer extrusion, and the number of roots, did not significantly impact treatment outcomes.ConclusionsDespite limitations related to the observational case-series study design and relatively small sample size, our findings suggest that utilizing the ANPI in the NSRCT for LCPLs may hold promise. The notably higher success rate in patients younger than 30 years is worth noting.

Management of symptomatic irreversible pulpitis using irrigation agitation techniques in anterior teeth.

Endodontic pain, a common complication after root canal treatment, affects 2.5% to 60% of patients. Therefore, it is of interest to compare apical negative pressure irrigation (EndoVac) with conventional needle irrigation to assess their impact on postoperative pain in permanent anterior teeth with symptomatic irreversible pulpitis. Fifty patients were randomly assigned to either the EndoVac or needle irrigation group. Pre and post-operative pain levels were assessed using a Visual Analog Scale and the amount of Ibuprofen taken was recorded. At 12-, 24-, and 48-hour intervals, the EndoVac group reported significantly less pain than the needle irrigation group. The needle irrigation group also required more Ibuprofen. The apical negative pressure irrigation system (EndoVac) resulted in significantly less postoperative pain and reduced the need for analgesic medication than the conventional needle irrigation protocol.

The potential for mitigating greenhouse gas emissions and minimizing yield losses using the negative pressure irrigation system

Efficient strategies for reducing agricultural greenhouse gas (GHG) emissions without yield penalties are crucial for sustainable agricultural development in the context of population increases and global warming. This study investigates the efficacy of negative pressure irrigation (NPI) in mitigating GHG emissions, as well as its impact on crop yield, global warming potential (GWP), and GHG emission intensity (GHGI), using surface irrigation (CK) as the control. The NPI system operated at three water pressure levels: NPI1 (-2 kPa), NPI2 (-4 kPa), and NPI3 (-6 kPa). The results revealed a notable pattern under NPI: a single peak in GHG emissions that remained consistently, and much lower than CK for the majority of the vegetable season, directly results in the lower cumulative GHG emissions and GWP from NPI than those from CK. Notably, the central region, located near the emitter, exhibited significantly lower GWP compared to the edge region, accompanied by higher yields, leading to a lower GHGI. Based on the findings, the -2 kPa water pressure level demonstrated the optimal performance in sustaining crop yields for Chinese chives while effectively reducing GWP and GHGI. Additionally, regions situated 20 cm on both sides of the emitter under -2 kPa NPI were identified as suitable areas for crop cultivation, offering higher yields and lower GWP and GHGI compared to CK. These results emphasize the win-win situation by balancing vegetable yield while reduced GHG emissions.

Matching water requirements of Chinese chives planted at different distances apart from the line emitter under negative pressure irrigation subsurface system

To supply water to crop in a proper way by using subsurface negative pressure irrigation (NPI), the distribution of soil moisture around the emitter with different water supply pressure (N1: −2 kPa, N2: −4 kPa, N3: −6 kPa) was investigated with surface irrigation as control (CK), to discuss the match degree of soil moisture to root distribution of Chinese chives planted at different distance apart from the NPI emitter. In the first growth season (FG), it took more than 15 days to form the stable wetting body of NPI due to the very low initial soil moisture, as a result the soil moisture and soil water storage (W) in NPI was lower than CK. In the second growth season (SG), the wetting body of NPI is almost invariable along time, and the soil moisture was much higher in NPI system with N1 significantly larger than CK. The yield showed a significant positive relation with soil moisture and W in both growth period (R was 0.942 and 0.849, respectively). As a result, the yield in NPI was significantly lower than CK in the FG and the yield in N1 was much higher than CK in the SG (p < 0.05). IWUE in NPI was significantly lower than CK in the FG while significantly larger than CK in the SG (p < 0.05). At the same water supply pressure, the soil moisture content was larger near the emitter, resulting better crop growth (p < 0.05). From the perspective of long-term irrigation, NPI could obtain a better yield and IWUE with less irrigation water amount (p < 0.05). The water supply pressure of − 2 kPa was more feasible to supply water for 6 lines of Chinese chives, with the same yield to CK and much higher IWUE (p < 0.05). The results indicated that planting crops in regions with proper soil moisture contents within the unique wetting body of NPI maintained high crop yield and improved crop IWUE, thus it is feasible to supply water for multiple rows of dense planted crops of Chinese chives with one linear emitter of the NPI subsurface system.

Comprehensive Assessment of Plant and Water Productivity Responses in Negative Pressure Irrigation Technology: A Meta-Analysis

Negative pressure irrigation (NPI) is an important water management strategy that can improve crop yields and water use efficiency (WUE). However, because NPI is affected by vital factors, such as negative pressure values, soil properties, and fertilization dosages, there is a lack of systematic analyses of the application effects of NPI on various crops. Hence, this study collected the results of 44 published studies and established the validity of 142 crop yields, 121 WUEs, 138 crop qualities, and 138 crop nutrient statuses in a database for NPI systems. The meta-analysis method was used to analyze NPI in comparison to conventional irrigation (CI) conditions. The results showed that the NPI yields and WUEs significantly improved by 17% and 63% compared to those of CI, respectively. Meanwhile, the negative pressure values were −2~−5 kPa; the improvement effects on yields were the best; and the WUEs exhibited the highest performance with negative pressure values of −6~−10 kPa. NPI promoted crop quality and plant nutrient uptakes under the appropriate NPI conditions. The synergistic impacts for sandy loam, alkalescent soils, and leafy vegetables were greater than for clay loam, neutral soils, and fruit vegetables under NPI conditions. Simultaneously, it was shown that the soil available phosphorus content and application of P fertilizer have a greater impact on NPI and CI crop yields. Therefore, the meta-analysis demonstrated the impacts of NPI on crop yields, WUEs, quality, and nutrient absorption, and quantified the effects of NPI on crop growth under various conditions, which provides an important water-saving technology for greenhouse production.

Study on Wetted Soil Geometry of a Negative Pressure Irrigation (NPI) System

The limited water resource is a main constraint on agricultural production in arid and semi-arid regions like Saudi Arabia. The Negative Pressure Irrigation (NPI) is one of the attractive irrigation systems since it consumes less water, leads irrigated water down up to root zone, minimizes evaporation and prevents deep percolation than other traditional irrigation systems. The aim of this paper is to get information on the soil water dynamics, which is very essential for the design and operation of the NPI system. With this view, the water balance experiment was carried out in the NPI system for different time intervals for three different negative pressures ( Pn = -0.02m, -0.07m and -0.10m). After finishing the experiment, the dry soil was removed from the column to measure the configuration of wet soil. This geometry of wetted soil represents the soil water dynamics and the wetted soil volume represents the water stored in soil at different negative pressures and elapsed time. A good relationship was obtained between the wetted soil geometry, time and negative pressure. This study reveals that for a certain negative pressure and time interval, the depth, width and volume of wetted soil can be predicted.

Negative Pressure Irrigation System Reduces Soil Nitrogen Loss for Lettuce during Greenhouse Production

Negative pressure irrigation (NPI) to grow crops reduces the application of fertilizer and water while also promoting yield and quality. However, plantation vegetables usually require a large input of nitrogen (N) fertilizer in a greenhouse setting, which will lower the soil quality and accelerate the emission of greenhouse gases. Therefore, the purpose of this research was to explore planting lettuce under an NPI system that retrenches N fertilizer application and mitigates N2O emissions compared with conventional irrigation (CI). This research proved that under NPI conditions, nitrate and ammonium fluctuated slightly in the soil, stabilizing in the range of 18–28 mg kg−1, while that of CI was 20–55 mg kg−1. The NPI alleviated N2O emissions, and NPI-N150 and NPI-N105 decreased them by 18% and 32%, respectively, compared with those for CI-N150. The main explanation was that the NPI inhibited the formation of NO3−-N, reduced the copies number of AOA and AOB as well as the abundance of Nitrospira in the soil, and weakened the soil nitrate reductase and urease activities. The results of this research provide a reliable scientific method for reducing the use of water and N fertilizer while cultivating lettuce, as well as for reducing N2O emissions from agricultural facilities.

Precise soil water control using a negative pressure irrigation system to improve the water productivity of greenhouse watermelon

A negative pressure irrigation system (NPIS) was tested in 2016 and 2018 to determine the optimum soil water control conditions to improve water productivity (WP) and fruit quality for greenhouse-grown watermelon. Four levels of negative water pressure (-5, -10, -15 and -20 kPa) were imposed continuously to a clay-made emitter buried 5 cm under the soil surface during three major stages of greenhouse-grown watermelon (I-VE: vine extension, 32 days; II-FF: flowering and fruit setting, 16 days; III-FM: fruit expansion to maturity, 28 days), which created soil water conditions around the emitter being 96%, 80%, 72% and 63% of field capacity, respectively. Except for the testing stages with the four levels of water treatments, the water supply during other stages was all set with a constant -10 kPa water pressure. A traditional furrow irrigation treatment was included to assess the water-saving effects of the NPIS. The irrigation timing used for the furrow irrigation treatment was decided based on the soil water contents corresponding to the -15 kPa treatment under NPIS. The results indicated that with an increase in the negative pressure imposed on the emitters, the average daily evapotranspiration linearly decreased for all three stages, with the largest decrease occurring during III-FM, but the watermelon yield decreased more with the decline in the water supply during vine extension due to the after-effects of the reduced vine growth. Water stress improved watermelon quality by increasing sugar contents during II-FF and reduced acid contents during III-FM. Moderate water stress resulted in the highest water productivity (WP) as well as protein and total soluble solid contents in the melon during all three stages. Comparing the NPIS with furrow irrigation, the water use of the former was 18.3–31.2% less, the yield was 6.2–12.0% higher, and the WP was improved by 36.6–53.8%. The results indicated that NPIS is a water-saving irrigation system, and the water pressure of NPIS can be set at -5 to -10 kPa for vine extension and fruit expansion to maturity stages; and -10 to -15 kPa for flowering and fruit setting stage to achieve good quality, high WP and relatively stable yield for greenhouse-grown melon.

Negative pressure irrigation increases vegetable water productivity and nitrogen use efficiency by improving soil water and NO3–-N distributions

Negative pressure irrigation (NPI), which is a new subsurface irrigation technique, promotes vegetable yield, water productivity (WP), and nitrogen use efficiency (NUE). However, it is not clear how NPI improves vegetable growth, especially in terms of water supply characteristics and uniformities of soil water and nitrogen. In this study, a cucumber pot experiment that had 0 kPa (PW1), –5 kPa (PW2), –10 kPa (PW3), –15kPa (PW4), and traditional irrigation (PCK) treatments under nitrogen application (N1) and no application (N0) was conducted to reveal the water supply characteristics of NPI and its effect on vegetable growth. There are two main water supply characteristics: 1) automatically supplying irrigation water based on the consumption of soil water, and 2) keeping soil water content stable during the vegetable growth period. In addition, the relationship between vegetable growth and soil water and NO3–-N distribution uniformities throughout the soil profile was investigated by carrying out two tomato field experiments. The treatments of one tomato experiment were NPI with –5 kPa (F1W) and furrow irrigation (F1CK). We also carried out NPI with –5 kPa (F2W), furrow irrigation (F2CK), and drip irrigation (F2D) in another tomato experiment. The results showed that cumulative water application under N1 was higher than under N0 in the PW1, PW2, and PW3 treatments in the cucumber experiment. Volumetric soil water content under the NPI system was more stable during the vegetative growth period than under traditional irrigation. The NPI system also increased yields under appropriate pressures (–10–0 kPa) compared to the PCK treatment in the cucumber experiment. The NPI in the two tomato experiments reduced fertilizer inputs and irrigation compared to furrow irrigation and drip irrigation. However, the irrigation method had no significant influence on the tomato yield in the two tomato experiments.

In Vitro Assessment of Intracanal Calcium Hydroxide Removal Using Various Irrigation Systems: An SEM Study

The aim of this research was to assess the effectiveness of three different irrigation systems in elimination of calcium hydroxide [Ca(OH)2]from root canals. This in vitro research included ninety recently extracted mandibular premolar teeth with a solitary root. The sample teeth were subjected to disinfection employing sodium hypochlorite at 5.25%. The root canal preparation was performed followed by placement of premixed Ca(OH)2 within every canal. The sample teeth were then randomly allocated into one of the three experimental groups (each comprising 30 samples) as follows: Group 1, NaviTip FX irrigation system; group 2, Vibringe sonic irrigation system; and group 3, EndoVac apical negative pressure irrigation system. Following the preparation, each of the sample teeth was examined beneath a scanning electron microscope (SEM) at a magnification of 1000×. An intragroup comparative analysis revealed that the highest Ca(OH)2 elimination was seen at middle third (0.82 ± 0.09, 0.30 ± 0.11) in NaviTip FX irrigation system and Vibringe sonic irrigation system, respectively. Higher Ca(OH)2 was eliminated at the apical third (0.26 ± 0.02) by the EndoVac irrigation system. At coronal third, maximum Ca(OH)2 removal was seen in EndoVac irrigation system (0.49 ± 0.03). A statistically significant difference was noted amid Vibringe sonic irrigation and EndoVac irrigation systems. The intergroup evaluation of Ca(OH)2 elimination at coronal, middle, and apical third showed a statistically significant difference between NaviTip FX irrigation and Vibringe sonic irrigation as well as between NaviTip FX irrigation and EndoVac irrigation at a p value of 0.001. The difference between EndoVac irrigation and Vibringe sonic irrigation was not statistically significant. Amid the limitations of this research, this research concludes that none among the irrigation methods employed could totally eliminate the Ca(OH)2 off the root canals. Nevertheless, EndoVac apical negative pressure irrigation has slightly superior potential in eliminating Ca(OH)2 from the root canals in comparison with Vibringe sonic irrigation as well as the NaviTip FX irrigation system. Even though the Ca(OH)2 is largely suggested as medicament, its elimination at the point of canal obturation is likewise significant and complex as any remaining portion may avoid sealer diffusion inside the dentinal tubules, consequently substantially escalating the apical leakage of endodontically treated teeth.

Debridement Efficiency Of Different Irrigating Protocols In Truss Cavity Access Preparation

Minimal invasive dentistry and endodontic technological revolution used in endodontic treatment enable the application of conservative endodontic access(CEC)cavity to minimize tooth structure removal.This study examined the cleanliness of CEC.Methods:Eighty sound extracted upper first premolar divided into 4groups (n=20)according to the irrigation protocol G1:Conventional method with Irriflex irrigating needle;G2: ENDOVAC negative pressure irrigation system;G3: PUI with ED62 irrigation ultrasonic tip;G4: Er,Cr:YSGG Laser SWEEPS Mode. CEC done under high magnification.After instrumentation with M3ProGold rotary file to size 35/0.04 taper and irriganted, specimens examined under SEM, and cleanliness of pulp chamber and root canal walls at coronal,middle,apical third was measured. Data were measured, tabulated and statistically analyzed by ANOVA and t-student test (P

In Vitro Comparative Evaluation of Effectiveness of Sodium Hypochlorite with Conventional Irrigation Method versus EndoVac and Ultrasonic Irrigation in the Elimination of Enterococcus faecalis from Root Canals.

ABSTRACTAim:The aim of this study was to compare the decrease in bacterial population in the root canals with 2.5% sodium hypochlorite (NaOCl) and three irrigation systems: Conventional Needle Irrigation, Passive Ultrasonic Irrigation, and EndoVac Apical Negative Pressure Irrigation systemMaterials and Methods:Access open was carried out in 48 extracted single-rooted maxillary and mandibular human premolar teeth. The canals were instrumented 1 mm short of apical foramen up to No. 50 size file; irrigated and apical foramen was sealed with cyanoacrylate. The teeth were mounted in plaster and autoclaved for 20 min at 121°C. The plaster blocks containing the teeth were inoculated with Enterococcus faecalis and incubated at 37°C for 24 h. The specimens divided randomly into four groups (n = 12) depending on the type of irrigation system used: Group 1: Conventional Irrigation Needle, Group 2: Ultrasonic system, Group 3: EndoVac Negative Pressure Irrigation system used with 2.5% NaOCl, and Group 4: Control group, normal saline irrigation. The normal saline is used as control. The samples were collected using 45 size sterile paper points and quantitative bacterial assessment was carried out by seeding each dilution on plates containing brain heart infusion broth. Then, incubated at 37°C for 7 days and colony-forming units were counted. Data obtained were statistically analyzed.Results:Statistically, EndoVac irrigation systems were more effective in reducing the number of bacteria than the other irrigation systems.Conclusion:EndoVac irrigation system was more effective in reducing bacterial numbers in infected root canals than the other two irrigation systems.

Efficacy evaluation of a cordless ultrasonic unit in achieving reduction of bacterial load within a root canal system as compared to a conventional ultrasonic unit and negative pressure irrigation

IntroductionIncrease in efficacy during root canal irrigation may contribute to better treatment outcomes. This study investigated the efficacy of ultrasonic and negative pressure irrigation systems using sodium hypochlorite (NaOCl) in the reduction of bacterial load in human teeth.One hundred thirty-one single-rooted teeth were cleaned and shaped, autoclaved, and incubated with E. faecalis. Teeth were randomly assigned to three experimental groups (n = 40) and treated in the presence of 1% sodium hypochlorite using EndoUltra cordless ultrasonic, conventional ultrasonic, and Endovac negative pressure irrigation. Syringe irrigation controls were treated with 1% sodium hypochlorite and phosphate-buffered saline via side-vented needle irrigation. All groups with NaOCl received 5% sodium thiosulfate neutralization for 5 min after treatment. Samples of root canal fluid and dentin chips were acquired from canals before and after treatment, incubated on BHI agar, and colony forming units categorized according to quantity. Wilcoxon rank-sum and Bonferroni tests were used for statistical analysis. p values less than 0.05 were considered significant.ResultsEndovac group was significantly better in eliminating bacteria from the root canals than 1% NaOCl (p = 0.006) and PBS syringe irrigation (p = 0.015). However, it was not significantly different from the two ultrasonic groups (p > 0.05). Both ultrasonic groups showed better performance than 1% NaOCl and PBS syringe irrigation, however, not statistically significant (p < 0.03). There was no significant difference between the two ultrasonic devices (p > 0.05).ConclusionEndoVac may be an important tool for bacterial load reduction in oval canals.

Investigation of different sodium hypochlorite volumes, concentrations and times of irrigation in endodontic therapy: a systematic review

Investigation of different sodium hypochlorite volumes, concentrations and times of irrigation in endodontic therapy: a systematic review

The Effect of Apical Positive and Negative Pressure Irrigation Methods on Postoperative Pain in Mandibular Molar Teeth with Symptomatic Irreversible Pulpitis: A Randomized Clinical Trial

IntroductionThis study compared the effect of conventional needle irrigation (positive pressure) and the EndoVac system (Discus Dental, Culver City, CA) (negative pressure) on postoperative pain in mandibular molar teeth with symptomatic irreversible pulpitis. MethodsOne hundred sixteen patients with symptomatic irreversible pulpitis were selected. Teeth were randomly assigned to 2 groups according to the irrigation methods performed during root canal preparation. In group 1, root canal irrigation was performed using a syringe and a 31-G side-port needle (NaviTip; Ultradent, South Jordan, UT). In group 2, the EndoVac system was used for irrigation. Teeth were then obturated with gutta-percha and a resin-based sealer using the cold lateral compaction technique. The presence of postoperative pain was assessed after 6, 24, 48, and 72 hours and 1 week. ResultsAt 6-, 24-, and 48-hour time intervals, group 1 patients reported more intense postoperative pain than patients in group 2 (P < .05). There was no significant difference between the 2 groups at the other time intervals (P > .05), and in both groups the intensity of postoperative pain decreased over time. ConclusionsApical positive pressure irrigation caused greater postoperative pain after endodontic therapy of mandibular molar teeth with symptomatic irreversible pulpitis compared with the apical negative pressure irrigation system.

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.

Cleaning Efficacy of Root Canal Irrigation with Positive and Negative Pressure System.

Introduction:The purpose of this study was to analyze the differences between irrigant replacement in the positive and negative pressure irrigation systems regarding root canal cleaning efficacy. Methods and Materials:A total of 27 extracted single-root mandibular premolars with 18-20 mm root canal length were decoronated and equally divided into three groups (n=9) based on the irrigation system used: positive irrigation with side-vented needle as the control group (C), positive irrigation with an open-ended needle as the first group (T1) and negative irrigation as the second group (T2). The root canals were irrigated with 2.5% NaOCl between each instrumentation, followed by a final irrigation with 5 mL of sterile distilled water. The irrigation replacements were monitored by means of computational fluid dynamic (CFD), while a scanning electrone microscope (SEM) was used to observe the smear layers and plug evaluations after the teeth had been sectioned longitudinally and buccolingually halves subsequently cut in apical third area. The result was analyzed using the Kruskal Wallis, Mann Whitney and Spearman correlation tests. The level of significance was set at 0.05. Result:Irrigant replacement in the negative pressure irrigation system tends to produce a greater effect in reaching the apical end compared to in the positive pressure irrigation system. This resulted in significantly superior smear layer removal in the apical third area (P<0.05). Conclusion: The irrigation solution exchange of the negative pressure irrigation system is more capable of reaching the apical end compared to the positive pressure irrigation system, resulting in a higher sanitation level in the apical third of the root canal.

Water and salt movement in different soil textures under various negative irrigating pressures

This study examined the effect of different negative pressures and soil textures on water and salt movement to improve the efficiency of negative pressure irrigation (NPI). Four soil textures of varying fineness (Loamy Sand, Loam, Silty Loam, and Sandy Loam) and three negative pressure values (0, –5, and –10 kPa) were used. As irrigation time increased, wetting front movement speeds decreased, and as negative pressure increased, wetting front size decreased. Coarse soils had the smallest wetting front under greater negative pressure. Next, water infiltration rate decreased as irrigation time increased, and coarse soils had the lowest average infiltration rate under greater negative pressure. Finally, salt content increased with distance from the irrigation emitter and with increased negative pressure. Further, coarse soils were found to have decreased desalination under greater negative pressure. Thus, soil texture has a strong effect on NPI efficiency. However, by adjusting pressure values in accordance with soil texture, soil water content can be controlled and maintained. These findings are important to the improvement of NPI systems, increasing their practicality for agricultural use.

New Technologies to Improve Root Canal Disinfection.

Effective irrigant delivery and agitation are prerequisites to promote root canal disinfection and debris removal and improve successful endodontic treatment. This paper presents an overview of the currently available technologies to improve the cleaning of the endodontic space and their debridement efficacy. A PubMed electronic search was conducted with appropriate key words to identify the relevant literature on this topic. After retrieving the full-text articles, all the articles were reviewed and the most appropriate were included in this review. Several different systems of mechanical activation of irrigants to improve endodontic disinfection were analysed: manual agitation with gutta-percha cones, endodontic instruments or special brushes, vibrating systems activated by low-speed hand-pieces or by sonic or subsonic energy, use of ultrasonic or laser energy to mechanically activate the irrigants and apical negative pressure irrigation systems. Furthermore, this review aims to describe systems designed to improve the intracanal bacterial decontamination by a specific chemical action, such as ozone, direct laser action or light-activated disinfection. The ultrasonic activation of root canal irrigants and of sodium hypochlorite in particular still remains the gold standard to which all other systems of mechanical agitation analyzed in this article were compared. From this overview, it is evident that the use of different irrigation systems can provide several advantages in the clinical endodontic outcome and that integration of new technologies, coupled with enhanced techniques and materials, may help everyday clinical practice.

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

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