Ethylenediaminetetraacetic Acid Group Research Articles

Design of multi-N-functional magnetic PVA microspheres for the rapid removal of heavy metal ions with different valence

In this study, magnetic polyvinyl acetate (MPVA) microspheres were prepared with the inverse suspension cross-linked method by adding magnetic nanoparticles (Fe3O4) into the PVA gel. Then, the resulting MPVA microspheres were modified with amino and ethylenediamine tetra acetic acid (EDTA) groups, which are both associated with nitrogen chelation. The final product, multi-N-functional MPVA (N-MPVA) microspheres, was characterized by scanning electron microscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, and vibrating sample magnetometer. Characterization results showed that the diameter of N-MPVA was about 10 μm; its saturation magnetization value was 4.89 emu g−1, and it possessed abundant amino and EDTA groups. A series of adsorption experiments were conducted to investigate the adsorption behavior, adsorption kinetics, and isotherms of different mono-, di-, and tri-valent heavy metals, i.e. Ag+, Cu2+, and Cr3+. Results showed that the adsorption capacity of heavy metals with different valences was Ag+ > Cu2+ > Cr3+. After three recycles, the loss of adsorption capacity did not exceed 25%. In addition, the chelating mechanism of the amino and EDTA groups with different valences was studied. This present work introduces the potential for using N-MPVA as an effective and recyclable adsorbent for the removal of heavy metal ions.

Evaluation of smear layer removal from ultrasonically prepared retrocavities by three agents.

Objectives:To evaluate the efficacy of 35% orthophosphoric acid, 24% ethylenediaminetetraacetic acid (EDTA) and 10% citric acid in the removal of smear layer from retrocavities prepared with ultrasonic retro-tips using scanning electron microscopy.Materials and Methods:Root canals of fifty single-rooted teeth were cleaned, shaped, and obturated with gutta-percha and AH plus sealer. The apical 3 mm of each root was sectioned with a diamond disc and retrograde cavities were prepared with Kis # 1 ultrasonic retro-tips to a depth of 3 mm. Retro cavities in Group I were treated with a gel of 35% orthophosphoric acid for 15 seconds, Group II were treated with a gel of 24% EDTA at neutral pH for 2 minutes, and Group III were treated with a gel of 10% citric acid for 2 minutes, followed by 1 minute rinsing with distilled water for all groups. The samples were prepared for scanning electron microscopic observation. Scoring was performed for the presence of the smear layer on the walls of the retrocavity.Results:In the orthophosphoric acid group, it was observed that all dentinal tubules were open in 70% of the samples. The majority of analyzed samples in EDTA and citric acid group showed dentinal tubules covered with the smear layer.Conclusions:Application of 35% orthophosphoric acid gel for 15 seconds on retrocavities prepared with ultrasonic retro-tips is the most effective means for removal of smear layer.

Comparative assessment of fluorosed and nonfluorosed fibroblast attachment on fluorosed and nonfluorosed teeth after scaling and root planning and ethylenediaminetetraacetic acid root biomodification

Background and Objectives: Fluorosis causes mineralization changes in the tooth and can lead to morphological alterations of fibroblasts. To evaluate the effect of fluorosis on periodontal healing, the initial step while healing such as, fibroblast attachment onto the root surface requires to be evaluated on the fluorosed and nonfluorosed tooth using nonfluorosed as well as fluorosed fibroblasts originated from the subjects influenced by high-water fluoride. Hence, the objective of the current study was to study and compare the attachment of nonfluorosed and fluorosed fibroblasts on the fluorosed and nonfluorosed root fragments. Materials and Methods: A total of 112 fluorosed and nonfluorosed, periodontally healthy and diseased tooth roots were obtained and allotted to eight groups : f0 luorosed healthy (FH) and non-FH (NFH) controls, fluorosed diseased (FD) and non-FD (NFD) controls, fluorosed and nonfluorosed teeth treated with scaling and root planning (SRP) (FD SRP and NFD SRP) and similar groups treated with SRP and ethylenediaminetetraacetic acid (EDTA) (FD SRP + EDTA and NFD SRP + EDTA) burnishing treatment with 24% EDTA gel for 2 min. After the respective treatment half of the root fragments in each group were incubated in the human periodontal ligament fibroblast cells obtained and cultured from freshly extracted FH and NFH human premolar tooth root. The nonfluorosed fibroblasts are elongated, flat cells thus they show increased attachment to root the surface. Results: When comparison was carried out between the attachment of fluorosed and nonfluorosed fibroblasts on NFD groups treated with scaling and EDTA, significant results were obtained with increased attachment seen on the group incubated with nonfluorosed fibroblasts (P = 0.029). While on comparison between the attachment of fluorosed and nonfluorosed fibroblasts on NFH group, NFD group treated with SRP and NFD group, no significant results were obtained (P > 0.05). On comparison between the attachment of fluorosed and nonfluorosed fibroblasts on FD group treated with SRP, highly significant results were obtained with increased attachment seen in the group incubated with nonfluorosed fibroblasts (P = 0.001). While the comparison of attachment of fluorosed and nonfluorosed fibroblasts on FH group, FD group treated with SRP + EDTA and FD group revealed no significant results (P > 0.05). Interpretation and Conclusion: SRP proves yet to be a standard requirement for fibroblast attachment to occur both in fluorosed and nonfluorosed teeth. Although, there is no significant difference in attachment between SRP and SRP + EDTA among fluorosed teeth, EDTA does not seem to be a promising agent for root biomodification in fluorosed teeth in given concentration and time of treatment.

An In Vitro SEM Study on the Effectiveness of Smear Layer Removal of Four Different Irrigations.

The aim of this study was to compare the smear layer removal efficacies of 3% sodium hypochlorite (NaOCl), 17% Ethylenediaminetetraacetic acid (EDTA), SmearClear and BioPure MTAD using a common irrigation protocol. Fifty freshly extracted human single rooted maxillary and mandibular teeth were prepared by a ProTaper rotary system up to an apical preparation file size F3. Prepared teeth were randomly divided into five groups (n=10); distilled water (Group A; negative control), EDTA (Group B), SmearClear (Group C), BioPure MTAD (Group D) and NaOCl (Group E). After final irrigation with tested irrigants the teeth were decoronated, split into two halves longitudinally and observed under a scanning electron microscope (SEM) for removal of the smear layer. The SEM images were then analyzed for the amount of smear layer present using a three score system. Data were analyzed using the Kruskal-Wallis test and Mann-Whitney U test. Intergroup comparison of groups B, C, and D showed no statistical significant differences in the coronal and middle thirds, however, in the apical third the canal surfaces were cleaner in samples from group D (P<0.05). BioPure MTAD was the most effective agent for the purpose of smear layer removal in the apical third of the root canals.

REMOVAL OF SMEAR LAYER BY TWO ENDODONTIC IRRIGATION SOLUTIONS AND ERBIUM: YTTRIUM, ALUMINUM, GARNET (ER: YAG) LASER. A SCANNING ELECTRON MICROSCOPE (SEM) STUDY

INTRODUCTION: The purpose of the present study was to determine the effect of 17% Ethylene,di-amine, tetra-acetic acid (EDTA), 6% phosphoric acid and Erbium: Yttrium, Aluminum, Garnet (Er:YAG) Laser in removing the smear layer by scanning electron microscopy. METHODS: In this study, 80 single-rooted human teeth were selected. Instrumentation was done by use of hand files and step-back technique up to file #40 at apical and file #80 at coronal area. During instrumentation, 1ml of 5.25% sodium hypochlorite (NaOCl) was used as irrigation between each file. The teeth were randomly divided into four groups with different methods of smear removal.17% Ethylene, di-amine, tetra-acetic acid was used in group 1, 6% Phosphoric acid in group 2, Erbium: Yttrium, Aluminum, Garnet laser in group 3, and no intervention in group 4 (as control). Roots were then longitudinally sectioned and prepared for scanning electron micrograph in cervical, middle and apical areas. Data were analyzed by Kruskal-Walis, Mann-Whitney, Friedman and Wilcoxson tests ( P <0.05). RESULTS: The results showed a significant difference in smear layer removal between three methods in favor of the EDTA ( P <0.001) and Phosphoric groups ( P <0.001) with no significant difference between them ( P =0.49). Although Er:YAG laser showed some limited ability to remove the smear layer, the effectiveness was not significantly different from the control group ( P =0.157). CONCLUSION: Based on the findings of this study, EDTA and Phosphoric acid were effective methods to remove smear layer from the root canal walls but Er:YAG laser showed less efficacy compared to the other experimental groups.

Effect of MTAD as a Final Rinse on Removal of Smear Layer in Ten-minute Preparation Time

IntroductionThe aim of this study was to evaluate the effect of MTAD as final rinse on removal of the smear layer subsequent to primary irrigation with 1.3% sodium hypochlorite (NaOCl) during 10-minute instrumentation periods. MethodsForty teeth were divided into 2 experimental groups, each containing 15 teeth, and 1 positive control group of 10 teeth. The canals were prepared with hand and rotary instruments. In the MTAD group, the root canals were flushed with 1.3% NaOCl solution during 10-minute instrumentation, and MTAD was used as the final rinse. In other experimental group, 5.25% NaOCl was used during instrumentation, and 17% ethylenediaminetetraacetic acid (EDTA) was used as the final rinse. In the positive control group, sterile distilled water was used for irrigation. The overall instrumentation period for each canal was 10 minutes. The amount of the smear layer and degree of erosion qualified according to the study by Torabinejad et al by using a scanning electron microscope. Data were analyzed by Kruskal–Wallis and Mann–Whitney tests. All statistical analyses were set with a significance level of α = 0.05. ResultsIn the positive control group, debris and heavy smear layer covered the root canal surface and the tubules. In MTAD group, moderate smear layer covered the root canal surface and the tubules. In EDTA group, there was no smear layer on surface of canals. There were significant differences between groups (α < 0.0001). Mann–Whitney test showed significant difference between experimental groups (α = 0.01). ConclusionsIn 10-minute instrumentation period, the use of 5.25% NaOCl during instrumentation and 17% EDTA as the final rinse is more effective than using 1.3% NaOCl as primary irrigation and MTAD as final rinse on removal of the smear layer.

The effect of using an alternative irrigant between sodium hypochlorite and chlorhexidine to prevent the formation of para‐chloroaniline within the root canal system

To determine if the formation of para-chloroaniline (PCA) can be avoided by using an alternative irrigant following sodium hypochlorite but before chlorhexidine. Fifty-five single-rooted teeth were decoronated, instrumented to size 40, .06 taper whilst being irrigated with 14% ethylene-diamine-tetra-acetic acid (EDTA) and 6% NaOCl. Samples were then randomly divided into three experimental and two control groups. Group 1 was irrigated with saline followed by 2% chlorhexidine gluconate (CHX). Group 2 was irrigated with 50% citric acid (CA) followed by 2% CHX. Group 3 was irrigated with 14% EDTA followed by 2% CHX. The chemical identity and quantification of the PCA in the formed precipitate was determined using gas chromatography/mass spectrometry (GC/MS). All experimental groups contained PCA. The mean level of PCA for group 1 (sterile saline) was 229 ng mL(-1), group 2 (citric acid) 72 ng mL(-1) and group 3 (EDTA) 400 ng mL(-1), respectively. A significant difference was found between the saline and EDTA groups and the negative control (P < 0.05). Although no statistical significance was found between the negative control and citric acid group, PCA was still present in this experimental group. Citric acid used as the intermittent irrigant had the least amount of PCA formation in the canal system. Until the threshold required to cause biological damage in humans is determined, the combination of NaOCl and CHX in root canal treatment should be avoided.

A comparative evaluation of the efficacy of Citric Acid, Ethylene Diamine Tetra Acetic Acid (EDTA) and Tetracycline Hydrochloride as root biomodification agents: An in vitro SEM study

Background and aims. Root conditioning is recommended as an adjunct to mechanical root surface debridement to remove smear layer and root associated endotoxins. The aim of this study was to compare the efficacy of citric acid, ethylenediaminetetraacetic acid (EDTA), and tetracycline hydrochloride as root biomodification agents. Materials and methods. Fifteen freshly extracted teeth were root planed and specimens obtained from the cervical twothirds of the root. Each tooth root provided four specimens to be treated by saline (used as control, citric acid, EDTA and tetracycline hydrochloride for a total of three minutes using the passive burnishing technique. The specimens were then observed under a scanning electron microscope (SEM). The specimens were evaluated for presence or absence of smear layer, total number of tubules visible, number of patent tubules and diameter of patent tubules. Statistical analysis was performed using paired -test. Results. All three test groups effectively removed the smear layer in comparison to the control. The number of patent tubules present in the citric acid and EDTA test groups was significantly higher than those in the tetracycline hydrochloride test group. However, the average diameter of the patent tubules was greater in the tetracycline hydrochloride group compared with citric acid and EDTA groups. Conclusion. All three agents are equally effective root biomodification agents. In clinical practice, EDTA might be more useful owing to its neutral pH.

Comparison of the efficacy of ethylenediaminetetraacetic acid and tetracycline hydrochloride as root conditioning agents: An in vitro study

Objective: Root surfaces of periodontitis-affected teeth are hypermineralized and contaminated with cytotoxic and other biologically active substances. Various root conditioning agents have been recommended as an adjunct to mechanical root surface debridement to expose dentin collagen and cementum bound proteins. The aim of the present in vitro study was to compare the efficacy of ethylenediaminetetraacetic acid (EDTA) and tetracycline hydrochloride (HCl) as root conditioning agents on planed root surfaces. Materials and Methods: A total of 20 human maxillary anterior teeth indicated for extraction due to chronic periodontitis were collected and root planed. The teeth were sectioned and specimens were divided into two groups - Group I and II. Group I dentin specimens were treated with EDTA and Group II specimens were treated with tetracycline HCl solution at a concentration of 10% by active burnishing technique for 3 min. The root surface samples were then examined by scanning electron microscope. Results: The results of this study showed that EDTA and tetracycline HCl were equally effective in removing the smear layer. It was observed that the total and patent dentinal tubules were more in number in teeth treated with tetracycline when compared to EDTA group. However, EDTA was found to be much more effective as root conditioning agent because it enlarged the diameter of dentinal tubules more than that of tetracycline HCl. Conclusion: The results of in vitro study showed that both the agents are good root conditioning agents if applied in addition to periodontal therapy. However, further studies are required to establish the in vivo importance of EDTA and tetracycline HCL as root conditioners.

Comparison of the Effect of Four Decalcifying Agents Combined with 60°C 3% Sodium Hypochlorite on Smear Layer Removal

IntroductionThe objective of this study was to compare the efficacy on smear layer removal of 4 decalcifying agents: 17% ethylenediaminetetraacetic acid (EDTA), 20% citric acid, BioPure MTAD, and SmearClear. MethodsForty-five single-rooted human teeth were used and prepared up to ProTaper F3. After each instrumentation, 1 mL of 3% NaOCl at 60°C was irrigated for 1 minute. All the samples were randomly divided into 5 groups according to the final irrigants: 17% EDTA, 20% citric acid, BioPure MTAD, SmearClear, and 3% NaOCl (control). The smear layer removal of all groups at the apical, middle, and coronal thirds was observed under the thermal field emission scanning electron microscope. ResultsThe EDTA group was significantly more effective than the SmearClear and MTAD groups (P < .05). The efficacy of all three thirds in the EDTA, MTAD, and SmearClear groups can be arranged as coronal, middle, and apical thirds (P < .05) from excellent to poor. However, in the citric acid group, the coronal two thirds were significantly better than the apical third (P < .05), and there was no statistical significance between the coronal and middle thirds (P > .05). ConclusionsThe 4 decalcifying agents could effectively, but not completely, remove the smear layer, especially in the apical third. The efficacy of 17% EDTA was better than that of MTAD and SmearClear.

A comparative scanning electron microscopy evaluation of smear layer removal with apple vinegar and sodium hypochlorite associated with EDTA

ObjectiveThe purpose of this study was to evaluate by scanning electron microscopy (SEM) the removal of smear layer from the middle and apical root thirds after use of different irrigating solutions. Material and MethodsForty roots of permanent human teeth had their canals instrumented and were randomly assigned to 4 groups (n=10), according to the irrigating solution: apple vinegar (group A), apple vinegar finished with 17% ethylenediaminetetraacetic acid (EDTA) (group B), 1% sodium hypochlorite (NaOCl) finished with 17% EDTA (group C) and saline (group D - control). After chemomechanical preparation, the roots were cleaved longitudinally and their middle and apical thirds were examined by SEM at ×1,000 magnification. Two calibrated examiners (kappa=0.92) analyzed the SEM micrographs qualitatively attributing scores that indicated the efficacy of the solutions in removing the smear layer from the surface of the dentin tubules (1 - poor, 2 - good and 3 - excellent). Data from the control and experimental groups were analyzed by the Kruskal-Wallis and Dunn's test, while the Wilcoxon test was used to compare the middle and apical thirds of the canals within the same group (α=0.05). ResultsThe middle third presented less amount of smear layer than the apical third, regardless of the irrigant. There was statistically significant difference (p=0.0402) among the groups in the middle third. In the apical third, the apple vinegar/EDTA group showed the greatest removal of smear layer (p=0.0373). ConclusionApple vinegar associated or not with EDTA was effective in removing smear layer when used as an endodontic irrigant.

Effect of intracanal dentine wettability on human dental pulp cell attachment

To evaluate the effect of intracanal dentine wettability on human dental pulp cell (HDPC) attachment after application of endodontic irrigants. Twenty extracted human premolar teeth with straight canals were sectioned at the apical and coronal thirds of each root, and the remaining mid-root portions were bisected longitudinally. After polishing, the specimens were divided into two groups for wettability and cell attachment measurements, respectively. The intracanal surface wettability was assessed by atomic force microscopy after a rinse of H(2) O (control), 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) and MTAD (n = 5). Additionally, HDPCs were seeded onto the irrigated root canal dentine and the cell attachment was evaluated by calcein-CAM and propidium iodide (PI) dying under fluorescence microscope (n = 5). Data were analysed by means of one-way anova and LSD test. Compared with the control group, 5.25% NaOCl, 17% EDTA and MTAD treatment significantly increased surface wettability (P < 0.001). The rank order of adhesion force was MTAD >17% EDTA >5.25% NaOCl > H(2) O. The highest average numbers of viable HDPCs were observed on the root canals irrigated with MTAD, followed by the 17% EDTA group (P < 0.001), and the lowest average numbers of viable cells were detected in the 5.25% NaOCl and H(2) O groups. Surface wettability was affected by the irrigants. Increasing in wettability produced higher levels of HDPC attachment to irrigated dentine.

Synthesis of large surface area nano-sized BiVO 4 by an EDTA-modified hydrothermal process and its enhanced visible photocatalytic activity

In this work, monoclinic scheelite-type BiVO 4 nanoparticle with large surface area has been successfully synthesized, using Bi(NO 3) 3 and NH 4VO 3 as raw materials, through a hydrothermal process in the presence of ethylene diamine tetraacetic acid (EDTA). It is demonstrated that the nanoparticle size of as-prepared BiVO 4 becomes small by decreasing hydrothermal temperature, shortening hydrothermal reaction time and increasing EDTA amount used. The resulting BiVO 4 nanoparticle with large surface area exhibits a good photocatalytic performance for degrading phenol solution as a model organic pollutant under visible illumination. The key of this method is the chelating role of EDTA group in the synthetic process that it can greatly control the concentration of Bi 3+, leading to the growth inhibition of BiVO 4 crystallite. The work provides a route for the synthesis of Bi-containing nano-sized composite oxides with large surface area.

In vitro antimicrobial activity of maleic acid and ethylenediaminetetraacetic acid on endodontic pathogens

The aim of this study was to evaluate the antimicrobial efficacy of 7% maleic acid (MA) and 17% ethylenediaminetetraacetic acid (EDTA) in elimination of Enterococcus faecalis, Candida albicans, and Staphylococcus aureus at different time intervals. Transfer culture of microbial strains were used for inoculum preparation and determination of time-kill assay. The viability counts of 7% MA and 17% EDTA suspensions were performed at 0, 2, 4, 6, 12, and 24 hours. Assay results were analyzed by determining number of strains that yielded log(10) CFU/mL of -1 compared with counts at 0 hours, for test medicaments at time intervals. Medicaments were considered to be microbicidal at a minimum inhibitory concentration that reduced original inoculum by >3 log(10) CFU/mL (99.9%) and microbiostatic if inoculum was reduced by <3 log(10) CFU/mL. Statistical analysis was performed using chi-square and Fisher exact tests as well as Friedman test for comparison of the time interval within the MA and EDTA groups. At all time intervals, there was no significant difference between MA and EDTA for all of the organisms (P > .05). However, within the MA and EDTA groups at various time intervals, there were significant differences (P < .001). Equivalent antimicrobial activity was observed by MA and EDTA against all of the organisms tested at various periods.

Comparison of the Impact of Long-Term Applications of MTAD and EDTA Irrigation Agents on Dentin Structure: A Scanning Electron Microscope Study

Aim: The purpose of this study was to compare the effects of 20-min applications of MTAD and 15% ethylenediaminetetraacetic acid (EDTA) solutions during final irrigation on the demineralization of root canal dentin.&#x0D; Methodology: Forty mandibular and maxillary single-rooted teeth were randomly divided into two groups. During initial irrigation following the use of each file, 2 mL of 2.5% sodium hypochloride (NaOCl) solution was applied to all teeth. During final irrigation, 5 mL of EDTA solution was applied to the teeth in Group 1 and 5 mL MTAD solution was applied to the teeth in Group 2. Both solutions were applied for 20 min. All teeth were then washed with 5 mL distilled water and dried with paper points. The teeth were buccolingually bisected along the long axes using hammers and chisels. Scanning electron microscopic (SEM) images were then obtained and scored.&#x0D; Results: Mann–Whitney U tests revealed significant differences between the MTAD and EDTA groups (p &lt; 0.001).&#x0D; Conclusions: The EDTA solution produced more demineralized areas in the dentin tubules than the MTAD solution.&#x0D; How to cite this article: Kaya S, Ayaz SG, Uysal İ, Akkuş Z. Comparison of the Impact of Long-Term Applications of MTAD and EDTA Irrigation Agents on Dentin Structure: A Scanning Electron Microscope Study. Int Dent Res 2011;2:60-64.&#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Effects of Reducing Agents on Birefringence Dentin Collagen after Use of Different Endodontic Auxiliary Chemical Substances

Introduction The aim of this study was to evaluate the effect of 10% ascorbic acid or 10% sodium ascorbate on organic matrix collagen of bovine dentin root canal walls after irrigation with 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA), or 0.9% sodium chloride. Methods Eighty bovine incisors were randomly divided into 8 groups (n = 10): group 1, 0.9% sodium chloride (control); group 2, 5.25% NaOCl + 17% EDTA (NaOCl + EDTA); group 3, 5.25% NaOCl + 17% EDTA + 10% ascorbic acid (NaOCl + EDTA + AA); group 4, 5.25% NaOCl + 17% EDTA + 10% sodium ascorbate (NaOCl + EDTA + SA); group 5, 5.25% NaOCl (NaOCl); group 6, 17% EDTA; group 7, 10% ascorbic acid (AA); and group 8, 10% sodium ascorbate (SA). Teeth were chemomechanically prepared, submitted to histologic processing, and stained with Sirius Red dye to be analyzed under polarized light microscopy. Absorbance assay was also performed to confirm the loss of collagen. Results NaOCl + EDTA and NaOCl groups presented a significantly different birefringence pattern compared with the control group ( P < .05). The measurement of the optical retardations of NaOCl + EDTA + SA indicated that this group was not statistically different from the control group. Although the measurement of the optical retardations of NaOCl + EDTA + AA was statistically different from the control group, the results were significantly higher than for NaOCl + EDTA. The birefringence of EDTA, AA, and SA groups was not statistically different from that of control group. The absorbance assay of NaOCl + EDTA and NaOCl groups confirmed the loss of collagen ( P < .05). Conclusions It is possible to conclude that 5.25% NaOCl, whether associated or not with 17% EDTA, causes birefringence alterations and loss of dentin collagen. These alterations reduced the ability of Sirius Red to bind with collagen fiber molecules. The reductions in the optical retardation values could be reversed by the application of either 10% ascorbic acid or 10% sodium ascorbate after 5.25% sodium hypochlorite and 17% EDTA irrigation.

Correlation between sealer penetration and microleakage following the use of MTAD as a final irrigant

The relationship between sealer penetration and apical microleakage following the use of MTAD as an irrigant in root canal procedures was evaluated. A collection of 120 human teeth was divided into three groups of 40 in each group. The final rinse was varied as follows: group 1 - the final rinse was saline solution, group 2 - ethylene diamine tetraacetic acid and for group 3 - MTAD. Each group was then divided into two subgroups (20 teeth) and filled with gutta percha and either AH Plus or Dorifill sealer. Half of the teeth were selected for dye penetration testing and the sealer penetration in the remaining teeth was evaluated using scanning electron microscope. There were no significant differences between the three irrigants, but there was less dye penetration in teeth sealed with AH Plus than Dorifill. Penetration of the sealer was better in the MTAD and ethylene diamine tetraacetic acid groups than in the saline group. Statistically, there was no significant difference between the sealer penetration into the dentinal tubules and the dye penetration.

Effects of EDTA on the Hydration Mechanism of Mineral Trioxide Aggregate

Ethylenediaminetetraacetic acid (EDTA) is commonly used during the preparation of obstructed root canals that face a high risk of root perforation. Such perforations may be repaired with mineral trioxide aggregate (MTA). Due to EDTA's ability to chelate calcium ions, we hypothesized that EDTA may disrupt the hydration of MTA. Using scanning electron microscopy and energy-dispersive x-ray spectroscopy, we found that MTA specimens stored in an EDTA solution had no crystalline structure and a Ca/Si molar ratio considerably lower than those obtained for specimens stored in distilled water and normal saline. Poor cell adhesion in EDTA-treated MTA was also noted. X-ray diffraction indicated that the peak corresponding to portlandite, which is normally present in hydrated MTA, was not shown in the EDTA group. The microhardness of EDTA-treated specimens was also significantly reduced (p < 0.0001). These findings suggest that EDTA interferes with the hydration of MTA, resulting in decreased hardness and poor biocompatibility.

Effect of endodontic irrigation on bonding of resin cement to radicular dentin

The influence of endodontic irrigation on shear bond strengths of resin cement to radicular dentin was investigated. Human radicular dentin blocks were divided into four groups and subjected to one of four endodontic irrigations: ethylenediaminetetraacetic acid (EDTA) group, 17% EDTA for 60 s; EDTA/sodium hypochlorite (NaOCl) group, 17% EDTA for 60 s followed by 10 ml of 5% NaOCl for 15 s; NaOCl group, 10 ml of 5% NaOCl for 15 s; and control group, no treatment. Morphological changes of dentin surface after endodontic irrigation were observed by scanning electron microscopy (SEM). A resin block was bonded to the radicular dentin after irrigation using resin cement with either wet-bonding (Uni-Etch/One-Step; Bisco) or self-etching (Tyrian SPE/One-Step Plus; Bisco) adhesives. Shear bond strengths were measured and the penetration of resin tags into dentinal tubules at resin-dentin interface was observed by SEM. With the wet-bonding system, the shear bond strengths for the EDTA/NaOCl group, in which dentinal tubules openings and uniform resin tag penetration into dentinal tubules were observed, were significantly higher than the EDTA and control groups. With the self-etching system, the shear bond strengths were significantly lower in the EDTA group compared with the NaOCl and control groups. The effects of endodontic irrigation on the bonding of resin cement to radicular dentin depended on the dentin bonding system used.

Effects of EDTA (Ethylene Diamine Tetra Acetic Acid) in Propofol on Serum Electrolyte, BUN and Creatinine during Long Time Neurosurgical Operation

Background: EDTA was added to the formulation of propofol to inhibit microbial growth due to accidental extrinsic contamination. This study was conducted to determine whether the EDTA in the propofol would affect the ionized calcium homeostasis, other electrolyte balance, blood urea nitrogen (BUN) and creatinine (Cr) in long time craniotomy patients. Methods: Forty two patients undergoing surgery for clipping of a cerebral aneurysm were randomly assigned to receive either propofol without EDTA (propofol group; n = 20), or propofol with EDTA (propofol EDTA group; n = 22). The ionized calcium, total calcium, total magnesium, phosphate, potassium, sodium, BUN and Cr in the blood were measured at before anesthetic induction, 4 hours after induction and 1 hour after the operation. Results: There were no significant differences in the ionized calcium, other electrolytes, BUN and Cr between the two groups. Conclusions: The addition of EDTA into propofol appears to have no significant effects on the electrolyte balance, BUN and Cr concentration.