Aqueous Ethylenediaminetetraacetic Acid Research Articles

Evaluation of Paste and Aqueous Lubricants on the Incidence of File Breakage, Quality of Obturation and Postoperative Pain in Children after Pulpectomy in Primary Teeth: A Randomised Clinical Trial

Introduction: Pulpectomy in primary teeth involves various steps, including tooth isolation, access opening, canal instrumentation, and obturation. Lubricants are commonly used in the biomechanical preparation of root canals to suspend and emulsify debris generated by the mechanical action of hand and rotary files. While paste-type lubricants (Prime Dental RC Help) and aqueous lubricants (17% aqueous Ethylenediaminetetraacetic acid [EDTA]) are available for use, there is a lack of studies in the literature documenting the effects of these lubricants on file fracture, obturation quality, and postoperative pain. Aim: To compare the effects of paste-type lubricants with aqueous lubricants on file breakage, quality of obturation, and postoperative pain in children treated with pulpectomy in primary teeth. Materials and Methods: This randomised clinical trial involved 40 primary teeth, evenly distributed for instrumentation using Kedo-S Plus pediatric rotary files. In Group 1 (n=20), paste-type lubricant was used during canal preparation, while in Group 2 (n=20), aqueous lubricant was used. The clinician recorded data on file fractures, evaluated the quality of obturation using immediate postoperative radiographs, and measured postoperative pain using the Four-point facial pain intensity rating scale. Descriptive statistics were performed once the data was tabulated. Results: Total of 40 primary teeth were included, participants aged 4-9 years, 22 girls and 18 boys. There was no incidence of file fracture in the group-2 treated with aqueous lubricants. Regarding the quality of obturation, the group-1 treated with paste-type lubricant had a higher number of under-fill and over-fill cases (p=0.002, 0.001), while no statistically significant difference was observed between the groups in terms of optimal fill (p=0.661). At 6, 12, 24, and 48 hours, there was no difference in pain experienced by the participants in both groups (p>0.05). Conclusion: During rotary instrumentation in primary teeth, aqueous lubricants were found to be more effective than pastetype lubricants in preventing file breakage, providing optimal obturation quality, and reducing postoperative pain.

Spectrophotometric analysis of the color stability of white mineral trioxide aggregate in contact with four different irrigating solutions - An in vitro study

Aims:This study aims to compare the color stability of white mineral trioxide aggregate (wMTA) in contact with four irrigating solutions.Settings and Design:Original research study.Subjects and Methods:Fifty cylindrical discs of wMTA, 10 mm in diameter and 2 mm in height were prepared using a mold. Samples were incubated at a temperature of 37°C and at 100% humidity for the material to reach its optimal mechanical properties. The samples were divided into 6 groups: Group A: dry (n = 5); Group B: distilled water (DW) (n = 5); Group C: 5% sodium hypochlorite (NaOCl) (n = 10); Group D: 2% chlorhexidine gluconate (CHX) (n = 10); Group E: 17% aqueous ethylene diamine tetra-acetic acid (EDTA) (n = 10); Group F: 0.2% Chitosan (n = 10) Each disc was immersed into the irrigating solution for a period of 24 h. All the specimens were photographed using a digital camera before and after immersion. The assessment of color change of each disc of wMTA was conducted by a spectrophotometer. The Commission Internationale de l'eclairage system was used to calculate the differences in color.Statistical Analysis Used:Statistical Package for the Social Sciences version 16.0 (Chicago, IL, USA) at a significance level of P < 0.05 was used.Results:All groups except group A exhibited discoloration of wMTA. The mean values for change in color was highest with Group D, followed by Group C, F, E, B, and group A. Only Group B when compared to group A did not show any statistically significant difference (P = 0.948) whereas all the other four groups showed a highly statistically significant difference (P < 0.001).Conclusions:2% CHX causes maximum discoloration of wMTA followed by 5% NaOCl, 0.2% Chitosan and least discoloration with 17% aqueous EDTA and DW.

Determination of five tetracyclines and their epimers by LC-MS/MS based on a liquid-liquid extraction with low temperature partitioning

ABSTRACTAn LC-MS/MS method is presented for screening five tetracyclines and their epimers in a broad range of food products. The scope of matrices includes meat-, fish-, seafood-based products, various dairy ingredients, infant formulae and fats. The method principle is based on a liquid–liquid extraction with aqueous ethylenediaminetetraacetic acid (EDTA) and acetonitrile followed by a freezing step to promote phase separation at low temperature. After defatting with hexane, sample extracts were evaporated and reconstituted before injection onto the LC-MS/MS system. The addition of oxalic acid in the aqueous mobile phase was mandatory to maintain good peak shape and sensitivity over the run. The screening is based upon a double preparation of each sample, one ‘as such’ and a second one with the analytes spiked in the sample, in order to mitigate the risk of false negative response. The method was validated according to the European Community Reference Laboratories Residues Guidelines. A total of 93 samples were included in the validation by two independent laboratories giving both false-negative and false-positive rates at 0% for all compounds. Over the last two years, 2600 samples were analysed routinely and only one chicken sample was found above the regulatory limit.

Effects of Different Final Irrigating Solutions on Depth of Sealer Penetration into Dentinal Tubules: An in vitro Confocal Laser Microscopic Study

ABSTRACT Aim To evaluate the maximum depth of sealer penetration into dentinal tubules at the coronal, middle, and apical third of root canals, following the use of different final irrigation solutions. Materials and methods Eighty freshly extracted mandibular premolars were selected for the study. After decoronation, instrumentation of samples was done using Protaper universal rotary file system till F4. During shaping and cleaning of root canal, 5.25% concentration of sodium hypochlorite (NaOCl) was used for irrigation. The samples were then randomly divided into four groups (n = 20) depending on the final irrigating solution used. Group I: 17% aqueous ethylenediaminetetraacetic acid (MA) (aq. EDTA); group II: 10% citric acid (CA); group III: 5% maleic acid; group IV: 5.25% conc. NaOCl. Passive ultrasonic irrigation (PUI) was used to activate each final irrigating solution. The samples were obturated using warm lateral condensation technique with guttapercha coated with AH plus sealer mixed with rhodamine B dye. Confocal laser scanning microscopy (CLSM) examined the sealer penetration depth. Results The Kruskal-Wallis analysis results showed that there was a significant difference in the maximum depth of sealer penetration among all groups in all sections (p &lt; 0.05). The coronal sections of the root canals in each group showed a significantly higher depth of sealer penetration than did the apical and middle sections (p &lt; 0.05). Conclusion A combination of 17% aq. EDTA and PUI used for final irrigation proved to be more effective for sealer penetration into the dentinal tubules. Clinical significance Final irrigation protocol followed is of paramount importance in achieving complete disinfection within the root canal, and also the penetration of sealer serves as an indicator of the extent to which the smear layer was removed. How to cite this article Shetty MA, Hegde V. Effects of Different Final Irrigating Solutions on Depth of Sealer Penetration into Dentinal Tubules: An in vitro Confocal Laser Microscopic Study. J Oper Dent Endod 2017;2(2):69-73.

Real-Time Dynamics of Galvanic Replacement Reactions of Silver Nanocubes and Au Studied by Liquid-Cell Transmission Electron Microscopy.

We study the galvanic replacement reaction of silver nanocubes in dilute, aqueous ethylenediaminetetraacetic acid disodium salt (EDTA)-capped gold aurate solutions using in situ liquid-cell electron microscopy. Au/Ag etched nanostructures with concave faces are formed via (1) etching that starts from the faces of the nanocubes, followed by (2) the deposition of an Au layer as a result of galvanic replacement, and (3) Au deposition via particle coalescence and monomer attachment where small nanoparticles are formed during the reaction as a result of radiolysis. Analysis of the Ag removal rate and Au deposition rate provides a quantitative picture of the growth process and shows that the morphology and composition of the final product are dependent on the stoichiometric ratio between Au and Ag.

Preparation of DNA-immobilized magnetic particles and their utilization as an accumulative material of metal ions

Abstract

SEPARATION OF FOUR CATIONIC SURFACTANTS ON SILICA GEL 60 F254 HIGH PERFORMANCE THIN-LAYER CHROMATOGRAPHIC PLATES

The chromatography of four cationic surfactants was performed on silica high performance thin-layer plates with mixed solvent system of methanol and ethylenediaminetetraacetic acid (EDTA). The resolution of a mixture of Benzyltrimethylammonium chloride (BTAC), Dodecyltrimethylammonium chloride (DTAC), Tetrabutylammonium bromide (TBAB), and Methyltrioctylammonium bromide (MTOB) was achieved by using methanol:5% aqueous EDTA (7:3,v/v) as a solvent system. The effect of concentration of EDTA on the mobility of all the four cationic surfactants was examined. The limit of detection of BTAC, DTAC, TBAB, and MTOB estimated was 0.65, 0.15, 0.15, and 0.31 µg/zone, respectively. The developed method was utilized to identify these surfactants in different spiked water samples after their preliminary separation.

The Impact of Three Different Canal Lubricants on Fracture, Deformity and Metal Slivering of ProTaper Rotary Instruments.

The aim of this in vitro study was to evaluate the effect(s) of three canal lubricants i.e. sodium hypochlorite, RC-Prep as the paste form of ethylenediaminetetraacetic acid (EDTA) and aqueous EDTA on the occurrence/incidence of fracture, deformity and metal slivering of ProTaper rotary instruments. A total of 120 mesial canals (i.e. mesiobuccal and mesiolingual) of first mandibular molars or buccal canals (i.e. mesiobuccal and distobuccal) of first maxillary molars, with curvatures of 10-20 degrees were selected and randomly divided into three groups of forty samples each. These selected canals all had approximate 19-21 mm working length and apical diameter equal to a #15 K-file. In each group, the root canals were prepared using ProTaper rotary instruments with an electric motor using one of the three aforementioned irrigants. Subsequently, samples were compared to each other at different magnifications (16×, 20×, 40× and 57×) for any fracture, deformity or metal slivering, by the Cox regression analysis. The fractures rate of samples in RC-Prep group was significantly higher compared to other groups (P=0.01). No evidence of instrument deformity was detected in any groups. A statistically significant reverse relation between metal slivering and instrument fracture was observed. Application of aqueous EDTA and/or sodium hypochlorite as intracanal lubricants caused less fracture of ProTaper instruments compared to canal lubrication with RC-Prep.

Three-Liquid-Phase Extraction and Separation of Ti(IV), Fe(III), and Mg(II)

Three-liquid-phase extraction has been considered to be a promising method for isolation and separation of multicomponents. Selective extraction-separation of Ti(IV), Fe(III), and Mg(II) in the three-liquid-phase system containing trialkylphosphine oxide (TRPO), poly(ethylene glycol) with an average molecular mass of 2000 (PEG 2000), and (NH(4))(2)SO(4) was achieved by adding a water-soluble complexing agent, ethylenediaminetetraacetic acid (EDTA). The simple and environmentally benign complexing method was proved to be an effective strategy for enhancing the selectivity of the PEG-2000-rich middle phase for Fe(III) without reducing the affinity of the TRPO-rich top phase to Ti(IV). The related chemistry was detailed, and effects of some important parameters such as the aqueous phase pH, EDTA amount, mixing time, and temperature were examined. It revealed that Ti(IV) and Fe(III) could be enriched respectively into the TRPO-rich top phase and the PEG-2000-rich middle phase through optimization of the aqueous pH and the EDTA amount. Ti(IV) was extracted into the top phase with a slow kinetics and a positive enthalpy change (Delta H), whereas Fe(III) was rapidly transferred to the middle phase as Fe(III) EDTA complexes formed by an exothermic reaction. Mg(II) tended to remain in the bottom phase.

Fabrication of Covalently Crosslinked and Amine-Reactive Microcapsules by Reactive Layer-by-Layer Assembly of Azlactone-Containing Polymer Multilayers on Sacrificial Microparticle Templates.

We report on the fabrication of covalently crosslinked and amine-reactive hollow microcapsules using 'reactive' layer-by-layer assembly to deposit thin polymer films on sacrificial microparticle templates. Our approach is based on the alternating deposition of layers of a synthetic polyamine and a polymer containing reactive azlactone functionality. Multilayered films composed of branched poly(ethylene imine) (BPEI) and poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) were fabricated layer-by-layer on the surfaces of calcium carbonate and glass microparticle templates. After fabrication, these films contained residual azlactone functionality that was accessible for reaction with amine-containing molecules. Dissolution of the calcium carbonate or glass cores using aqueous ethylenediamine tetraacetic acid (EDTA) or hydrofluoric acid (HF), respectively, led to the formation of hollow polymer microcapsules. These microcapsules were robust enough to encapsulate and retain a model macromolecule (FITC-dextran) and were stable for at least 22 hours in high ionic strength environments, in low and high pH solutions, and in several common organic solvents. Significant differences in the behaviors of capsules fabricated on CaCO(3) and glass cores were observed and characterized using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Whereas capsules fabricated on CaCO(3) templates collapsed upon drying, capsules fabricated on glass templates remained rigid and spherical. Characterization using EDS suggested that this latter behavior results, at least in part, from the presence of insoluble metal fluoride salts that are trapped or precipitate within the walls of capsules after etching of the glass cores using HF. Our results demonstrate that the assembly of BPEI/PVDMA films on sacrificial templates can be used to fabricate reactive microcapsules of potential use in a wide range of fields, including catalysis, drug and gene delivery, imaging, and biomedical research.

Calcium Niobate Nanosheets Prepared by the Polymerized Complex Method as Catalytic Materials for Photochemical Hydrogen Evolution

The Dion-Jacobson phase niobate perovskite, KCa2Nb3O10, was prepared by the polymerized complex (PC) method. The corresponding proton-exchanged material, HCa2Nb3O10, was then exfoliated by reaction with tetra(n-butyl)ammonium hydroxide (TBA+OH−), yielding unilamellar colloidal nanosheets whose lateral dimensions increased with the final calcination temperature in the PC synthesis. By restacking the TBA+-stabilized nanosheets with hydrochloric acid, aggregates of HCa2Nb3O10 nanosheets were obtained and tested as photocatalytic materials. The rate of H2 production from aqueous methanol solution under band gap irradiation (λ > 300 nm) was dependent on the calcination temperature. The best materials, prepared by the PC method at the intermediate calcination temperature of 1273 K, had higher activity than those made by a conventional solid state reaction. In contrast, the rate of visible-light hydrogen evolution (λ = 450 ± 20 nm) from aqueous ethylenediaminetetraacetic acid (EDTA) solution with materials sensitized by [Ru(bpy)2(4,4′-(PO3H2)2bpy)](PF6)2 (abbreviated RuP2+) was essentially insensitive to the preparation conditions. These results suggest that increasing the crystallinity of the nanosheets enhances their activity under band gap irradiation, where catalytic reactions compete with electron−hole recombination within the nanosheet. In contrast, the quantum yield for sensitized H2 production is primarily governed by electron injection efficiency from the excited-state sensitizer into the nanosheet.

Destruction of EDTA by mediated electrochemical oxidation process: Monitoring by continuous CO 2 measurements

The mediated electrochemical oxidation (MEO) process with cerium(IV) in nitric acid as the oxidizing medium was employed for the destruction of ethylenediaminetetraacetic acid (EDTA) in batch and continuous feeding modes. A complete mineralization of EDTA to CO 2 and water was achieved. The system parameters studied were the temperature (343, 353 and 368 K), concentration of nitric acid (2, 3 and 4 M), Ce(IV) concentration (0.7–0.95 M), aqueous EDTA concentration (67–268 mM) , flow rate of EDTA addition (3.0–7.5 ml/min), and feeding time (30 min and 2 h). The batch process CO 2 pattern clearly showed two distinct kinetic regimes. Accordingly the overall CO 2 formation rate constants were evaluated for fast and slow processes using pseudo first-order kinetics. In case of continuous organic feeding, the CO 2 formation rate constant was obtained using a new proposed mathematical procedure based on geometrical progression. The only parameter in the calculations was the first-order rate constant. The theoretical CO 2 evolution pattern was fitted on to the experimental data to obtain the formation rate constants. The activation energy was calculated based on the CO 2 formation constants and presented. The application of mathematical procedure predicted a steady-state attainment of CO 2 evolution for the destruction process during a long-term organic feeding and observed experimentally.

STRIPPING OF Zn(II), Cu(II), Co(II), AND Cd(II) FROM DEHPA USING EDTA IN A HOLLOW-FIBER MEMBRANE MODULE

The equilibrium behavior of liquid-liquid extraction of Zn(II), Cu(II), Co(II), and Cd(II) from DEHPA (di(2-ethylhexyl)phosphoric acid) with EDTA (ethylenediamine-tetraacetic acid) was studied. A concentration of 0.003M EDTA was able to extract simultaneously 83, 70, 88 and 54% of the cadmium, cobalt, copper and zinc, respectively at a pH between 1.6 and 1.8. The non-equilibrium liquid-liquid extraction behavior was studied using a polysulfonic hollow fiber membrane module with 1 mm ID and 5,000 molecular weight cut-off. The aqueous feed solution and EDTA was passed through the tubeside of the two membrane modules, and the organic DEHPA solution was circulated through the shellside. The optimum flow rate for the organic solution was 77ml/min and that of the aqueous feed and strip solutions were 78ml/min. The shellside pressure was maintained at 1.0–1.2 psig and that of the tubeside was kept at atmospheric pressure so that a stable organic interface was achieved. Under these conditions, 77, 63, 93, and 56% of cadmium, cobalt, copper and zinc were extracted from DEHPA, respectively.

The determination of fumonisin B1 in human faeces: a short term marker for assessment of exposure

Fumonisin B1 (FB1) is a compound that occurs frequently in rural foods and feeds, creating health hazards. When ingested, FB1 does not appear to change in structure and is mostly excreted unchanged in faeces within 24 h. Twenty human stool samples obtained from rural school children of Vulamehlo, south of Durban (South Africa), were analysed for FB1, as well as 23 urban control samples obtained from various households within the Durban metropolitan area. The samples were freeze-dried and ground to a fine powder. A fraction of each sample was extracted three times with aqueous ethylenediaminetetraacetic acid at pH 5.2. The pooled extracts were purified using reversed phase C18 solid phase extraction cartridges. Analytical high performance liquid chromatography was used to quantitate the amount of FB1 as an o-phthaldialdehyde (OPA) derivative in the extracts. The rural (35%) and the urban samples (9%) showed the presence of FB ranging from 790 to 19 560 ng g-1 of freeze dried stool. It was concluded that this method could be used as a routine biomarker for short term human exposure to FB1 in contaminated food.

Determination of lead in frying oils by direct current plasma atomic emission spectrometry

AbstractTwo methods for determination of lead in frying oils by direct current plasma‐atomic emission spectrometry were investigated. The first method is based on the formation of an oil‐water emulsion followed by aspiration of the sample directly into the plasma. The second method involves extraction of lead from oil into an aqueous ethylene diamine tetraacetic acid phase before measurement. The methods were applied to the determination of lead in used frying oil samples collected from different parts of Cairo, Egypt.

Determination of bismuth in geological materials by flame atomic absorption spectrometry using a selective extraction technique

An investigation has been carried out to establish a rapid method for the determination of bismuth in geological samples (especially geochemical exploration samples) by flame atomic absorption spectrometry using a boosted-output hollow cathode lamp. Bismuth iodide is first extracted into isobutyl methyl ketone and then bismuth is stripped into an aqueous ethylenediaminetetraacetic acid solution for nebulization into an air–acetylene flame. In order to determine the accuracy of the method, geochemical exploration reference samples issued by the US Geological Survey and other international reference samples were analysed using the proposed method and the results obtained were compared with those obtained using other atomic absorption spectrometric procedures. The proposed method can be applied to a variety of geological samples for the determination of bismuth at levels as low as 0.4 ppm.

The extraction of chromium (iii) from aqueous edta by solutions of tetra- n-hexylammonium chloride in dichloroethane

When a solution of chromium (III) in aqueous ethylenediaminetetraacetic acid (H 4Y) is equilibrated with a solution of the liquid anion-exchanger tetra n-hexylammonium chloride in 1,2-dichloroethane, only the violet complex CrY(H 2O) − is extracted as the ion pair NR 4 +CrY(H 2O) − (where R = n-hexyl) over the pH range 3.6–6.0. Maximal extraction occurs at pH 4.7 and the extraction constant ▪ The formally neutral species CrHY(H 2-O) and the anionic species CrY(OH) 2- and CrY(OH) 2 3- are not extractable.