Effect of ethylenediaminetetraacetic, etidronic, and peracetic acids with different concentrations on the removal of Enterococcus faecalis biofilms from root canal walls: an in vitro study.

Introduction: Bacteria play a key role in pulp and periapical disease, making their complete removal essential in endodontic treatment. Calcium hydroxide (Ca(OH)₂) is commonly used as an intracanal medicament due to its antimicrobial properties, but its remnants can hinder sealer adhesion and affect treatment outcomes. This study evaluated the effectiveness of 0.5% peracetic acid (PAA), 10% citric acid (CA), 1% PAA, 3% sodium hypochlorite (NaOCl), and 17% ethylenediamine tetraacetic acid (EDTA) with passive ultrasonic irrigation (PUI), in removing Ca(OH)₂ from root canals. Materials and Method: Sixty teeth that had single roots were chosen and decoronated to set the length of the root at 12 mm. Canals were irrigated, followed by filling up with Ca(OH)₂ after biomechanical preparation. The samples were divided into seven groups: Group 1: Control (positive); Group 2: Control (negative); Group 3: 5 ml of 17% EDTA + PUI; Group 4: 5 ml of 3 % NaOCl+ PUI; Group 5: 5 ml of 0.5% PAA + PUI; Group 6: 5 ml of 1% PAA + PUI; Group 7: 10% CA + PUI. The radicular portions of teeth were split longitudinally, followed by examination beneath a stereomicroscope with a magnification of 50×. Results: The obtained data was statistically analyzed using the Kruskal–Wallis test to find out significant differences between the study groups. Pair-wise comparison for mean scores was done using the Mann–Whitney test. Friedman’s test was used for intra group differences between regions. Small amounts of Ca(OH)₂ residue were observed in the 1% PAA group compared to other irrigants in the coronal, middle, and apical thirds of the root canals, and the difference was statistically significant (p < 0.05). Conclusion: About 1% PAA with PUI was superior in removing Ca(OH)₂ from root canals compared to other irrigants used in the present study.

To evaluate the nanohardness reduction and erosion in root canal dentine after application of 17% ethylenediaminetetraacetic acid (EDTA), 9% etidronic acid (HEBP) and 2% peracetic acid (PAA) either alone or combined with sodium hypochlorite (NaOCl). One hundred and sixty single-rooted teeth were decoronated and their root canals were chemomechanically prepared. For the nanohardness evaluation, 80 roots with instrumented canals were split longitudinally into two halves. Dentine blocks with a length of 7mm were obtained from the middle third of one half of each tooth and were embedded in epoxy resin blocks exposing the root canal walls. Initial nanohardness values of root canal dentine were measured for each specimen using a nanoindenter with a Berkovich tip. The specimens were divided into seven experimental (n=10) and one control (n=10) group according to the final irrigation regimens: Group 1: 2.5% NaOCl, Group 2: 17% EDTA, Group 3: 2.5% NaOCl-17% EDTA, Group 4: 2% PAA, Group 5: 2.5% NaOCl-2% PAA, Group 6: 9% HEBP, Group 7: 2.5% NaOCl+9% HEBP and Group 8: Distilled water (control). The measurement of the nanohardness values was repeated for each specimen after being exposed to the irrigants. The nanaohardness reduction of each sample was calculated and recorded. The other 80 instrumented root canals were used for scanning electron microscope (SEM) evaluation. First, they were irrigated with the same protocols stated above and longitudinally split into two halves. One half of each root canal was viewed using SEM for the amount of erosion. The erosion scores were recorded. Data were analysed statistically using Kruskal-Wallis and Bonferroni-adjusted Mann-Whitney U-tests with a significance level of 0.05. Use of etidronic acid and NaOCl+HEBP reduced the nanohardness values significantly more than the other experimental solutions (P<0.05). There was no significant difference between the values for the nanohardness reduction in the samples irrigated with a single chelator and chelator combined with NaOCl (P>0.05). Peritubular and intertubular erosion were observed in the samples irrigated with HEBP and NaOCl+HEBP. Final irrigation of root canals using etidronic acid alone or combined with NaOCl was associated with structural alterations in root canal dentine of extracted teeth.

BackgroundTo determine the antibacterial effect of photodynamic Therapy on Enterococcus faecalis (E. faecalis) biofilms in experimentally infected human root canals in primary infections and endodontic retreatments.MethodsOne hundred and sixty single-rooted extracted teeth with one root canal were prepared using ProTaper instruments. Seventy specimens were left without root canal filling and autoclaved. The root canals of another 70 specimens were filled with Thermafil and AH Plus and the root canal fillings were removed after 24 hours using ProTaper D files and plasma sterilized. The specimens were infected with a clinical isolate of E. faecalis for 72 hours. Samples were taken using sterile paper points to determine the presence of E. faecalis in the root canals. The specimens were randomly divided into groups according to their treatment with 20 teeth each and a control. In the PDT group the teeth were treated using PDT, consisting of the photosensitizer toluidine blue and the PDT light source at 635 nm. In the NaOCl (sodium hypochlorite) group the root canals were rinsed with 10 mL of 3% NaOCl. In the NaOCl-PDT group the root canals were rinsed with 10 mL of 3% of sodium hypochlorite and then treated with PDT. Samples were taken after treatments using sterile paper points. Additionally, remaining root canal filling material was recovered from the root canal walls. Survival fractions of the samples were calculated by counting colony-forming units. A one-way analysis of variance (ANOVA) was applied to the data to assess the effect of different treatment techniques.ResultsAntimicrobial treatment of root canals caused a significant reduction of bacterial load in all groups. NaOCl irrigation eliminated E. faecalis most effectively. PDT alone was less effective compared to NaOCl irrigation and the combination of NaOCl irrigation and PDT. CFU levels recovered from the filling material after NaOCl irrigation of the root canals were 10fold higher compared to PDT and the combination of NaOCl irrigation and PDT.ConclusionsPhotodynamic therapy killed E. faecalis in experimental primary endodontic infections and retreated human root canals. PDT is an effective supplement in root canal disinfection, especially in endodontic retreatments.

The purpose of this study was to investigate the effects of different irrigation solutions on the smear layer removal and marginal adaptation of a resin-based sealer to root canal dentine. A total of 152 instrumented roots were irrigated with the following irrigants: 9,18% etidronic acid (HEBP), 0.5, 1,2% peracetic acid (PAA), 17% ethylenediaminetetraacetic acid (EDTA), saline. The amount of smear layer was evaluated using scanning electron microscope (SEM) in seventy root samples. Eighty-two roots were filled with AH Plus and gutta-percha. Slices obtained from apical third of each specimen were viewed with SEM to assess marginal adaptation. Use of 9% and 18% HEBP resulted in more efficient smear layer removal in the apical third than the other chelators (p < 0.05). Higher smear layer scores in the coronal and middle thirds were obtained from 0.5%, 1% PAA groups. Regarding marginal adaptation, 18% HEBP group showed the lowest gap size values (p < 0.05), and better marginal adaptation. Etidronic acid is a promising candidate for final irrigation of root canals.

Chelating substances bind to metals, forming stable complexes, rendering these essential ions unavailable for microbial metabolism and community stability in biofilms. This action can contribute to the disinfection in endodontic treatments. Through confocal laser scanning microscopy (CLSM), this study quantified the metal ion removal by chelating agents in Enterococcus faecalis biofilms and assessed the impact on community stability. E. faecalis biofilms were grown for 21days on acrylic coverslips, which the following were immersed in (n = 10): G1) saline solution (control, 5min); G2) 17% ethylenediaminetetraacetic acid (EDTA, 3min); and G3) 9% etidronic acid (Dual Rinse HEDP, 5min). Next, they were stained with Phen Green FL to identify metals, 4',6-diamidino-2-phenylindole (DAPI) to highlight bacterial DNA, and propidium iodide (PI) to mark nucleic acid in cells with damaged membranes. Images were captured (4/sample) by CLSM and analyzed by the software Leica Application Suite X. The individual and total volume of the biofilm-stained components (µm3) and their individual percentages in the biofilms were analyzed using one-way ANOVA with Tukey tests (α < 0.05). EDTA caused a higher metal removal (P < 0.05) that potentially destabilized biofilms, causing detachment of bacterial cells. Consequently, EDTA significantly reduced the total cubic volume of biofilms compared to other irrigants (P < 0.05), while control and etidronic acid groups exhibited similarity (P > 0.05). However, the percentages of nucleic acid and metals remained constant in all treatments (P > 0.05). In conclusion, strong chelating solutions, such as EDTA, can remove substantial amounts of metals from biofilms and affect the community stability.

The purpose of this study was to evaluate the efficiencies of different irrigation protocols in the removal of triple antibiotic paste (TAP) from root canals. A total of 127 extracted human maxillary incisor teeth were prepared. Then, root-end resection of 3 mm was accomplished to simulate immature apex model. The root canals were filled with TAP, after 21 days, randomly divided into nine groups according to irrigation systems and solutions (n = 13). Conventional irrigation (CI) groups - Group 1: Root canal irrigation was performed with CI by Peracetic acid (PAA) solution, Group 2: Root canal irrigation was performed with CI by etidronic acid 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) + sodium hypochlorite (NaOCl) solution, Group 3: Root canal irrigation was performed with CI by ethylenediaminetetraacetic acid (EDTA)/NaOCl solutions. Vibringe system groups - Group 4: Root canal irrigation was performed with Vibringe system by PAA solution, Group 5: Root canal irrigation was performed with Vibringe system by HEBP + NaOCl solution, Group 6: Root canal irrigation was performed with Vibringe system by EDTA/NaOCl solution. EndoVac system groups - Group 7: Root canal irrigation was performed with EndoVac system by PAA solution, Group 8: Root canal irrigation was performed with EndoVac system by HEBP + NaOCl solution, Group 9: Root canal irrigation was performed with EndoVac system by EDTA/NaOCl solution. Control Group: (n = 0). Samples were sectioned vertically, and the amount of remaining medicament was scored for each root half and data were statistically analyzed. Among the irrigation systems, CI groups showed the highest scores at both apical and coronal parts (P < 0.05). In comparisons among the solutions, at the apical part, PAA groups showed the highest scores (P < 0.05). At the coronal part, EDTA + NaOCl groups showed the lowest score values (P < 0.05). The use of irrigation systems improved the removal of TAP from the simulated immature root canals. Also, as an irrigation solution EDTA gives more promising results than PAA and HEBP solutions.

Background: The elimination of pathogenic microorganisms is crucial in endodontic treatments, as Enterococcus Faecalis is involved in the majority of endodontic failures.This bacterium is known for its resilience and ability to persist within the root canal system, often leading to treatment complications.Purpose: The aim of this study was to compare the antibacterial efficiency of three different irrigation methods including passive ultrasonic, XP Endofinisher file,and Laser Diode 810 nm in infected roots with Enterococcus Faecalis (E.faecalis) biofilm. Materials and Method: In this experimental study, 48 anterior single-canal teeth were enrolled. After cutting their crowns, the teeth were cultured with E.faecalis and then randomly divided into four groups.Following preparation through the rotary system up to F4 at the working length, passive ultrasonic irrigation (Ultra X) was used inside the root canal in the first group.In the second group of the study, the XP Endofinisher file was applied to activate the irrigation solution, while in the third group, the Laser Diode 810 nm was used.The fourth group served as the control group and did not utilize any irrigation. The irrigation solution employed across all groups consisted of 1ml of 5.25%sodium hypochlorite (NaOCl), followed by a final irrigation with 5ml of 17% ethylenediaminetetraacetic acid (EDTA), 5ml of 5.25% NaOCl, and 5ml of sterile saline.After canal irrigation and sampling, bacterial colony counting was conducted, and the data were recorded. If the data were normally distributed,a variance test analysis was used; otherwise, the non-parametric Kruskal-Wallis test was applied. The tests were performed at a 5% significance level using SPSS software version 24.Results: The reduction in the number of bacterial colonies was significantly greater in all three methods compared to the control group. The obtained data revealed that the antibacterial effect ofLaser 810 nm was considerably (p< 0.05) higher than the other two groups and reduction in the number of colonies in Ultra X group was remarkably (p< 0.05) greater than the XP Endofinisher file group.Conclusion: All three mentioned methods were effective in reducing the number of bacteria in endodontic treatments. Notably, the antibacterial efficiency of the Laser Diode 810 nm was significantly greater than that of the other two methods.

The success of endodontic treatment depends on the thorough removal of microorganisms from the root canal system. The search for new ways to eliminate the microorganisms is therefore justified. Nd:YAP is a laser that uses yttrium aluminum perovskite, doped with neodymium crystal, as active laser medium. We used the Nd:YAP laser in an in vitro experiment to evaluate the bactericidal effect of three parameters of Nd:YAP laser-activated irrigation on biofilms of Enterococcus faecalis in root canals. The canals of 45 extracted human single-root teeth were prepared on a #35 Mtwo instrument and contaminated with E. faecalis for 14days. Forty infected single-root teeth were then randomly divided into four groups according to the irrigation agitation protocols as follows: 5.25% sodium hypochlorite (NaOCl), Nd:YAP laser (180mJ) + NaOCl, Nd:YAP laser (280mJ) + NaOCl, and Nd:YAP laser (360mJ) + NaOCl. The remaining bacteria were counted immediately using the cell count method. Teeth were firstly spilt and one half examined by scanning electron microscopy (SEM). The other half involved examination of bacterial colonization in dentinal tubules using confocal laser scanning microscopy (CLSM). Nd:YAP laser (280mJ) + NaOCl and Nd:YAP laser (360mJ) + NaOCl completely removed the E. faecalis biofilms from the root canal walls and made it the cleanest among the treatment groups. Bacterial reductions in the treatment groups for dentinal tubules are presented in a descending order as follows: Nd:YAP laser (360mJ) (53.7%), Nd:YAP laser (280mJ) (51.5%) > Nd:YAP laser (180mJ) (45.3%) > 5.25% NaOCl (31.9%) > control (19.3%) (p < 0.05). Nd:YAP laser of 280mJ and 360mJ showed effective bactericidal effect in removing E. faecalis biofilm from the root canal walls and dentinal tubules.

Background: Enterococcus faecalis (E. faecalis) is a prototypical resistant bacterium in root canal infections and a leading cause of endodontic treatment failure. German chamomile (Matricaria chamomilla) flower extract has been used as a traditional medicine to treat infections. The aim of this study was to investigate the antimicrobial efficacy of chamomile extract on the removal of E. faecalis root canal biofilm. Materials and Methods: Chamomile flower extract was prepared and subjected to detailed chemical analysis. For the in vitro biofilm model, human mandibular premolars (n=48) with 18-20mm working length were used. Root canal preparation was performed using the ProTaper® Next system. Each sample was split longitudinally and reassembled within a pre-prepared silicone matrix, and a mature E. faecalis biofilm was grown for seven days. Samples were randomised into four groups (n=12 for each arm) based on the type of irrigant protocol comprising normal saline, 3% sodium hypochlorite (NaOCl), dual irrigation with 17% ethylenediaminetetraacetic acid (EDTA) and 3% NaOCl, and chamomile extract. After irrigation, residual biofilms were measured in (n=9/group) using densiometric measurements. Observational analysis of residual biofilm was performed in (n=3/group) using Scanning Electron Microscopy (SEM). Results: Phytochemical investigations showed that chamomile extract is rich in antimicrobial components such as flavonoids, polyphenolic compounds, tannins, and others. Spectrophotometry analysis showed a statistically significant difference between the normal saline group with mean optical density (OD)= 0.63044; ±0.106 and each of EDTA and NaOCl group (mean OD=0.35922; ±0.091), chamomile group (mean OD=0.37611; ±0.106) at p&lt;0.001, and the NaOCl group (mean OD=0.46344; ±0.096) at p&lt;0.01. No statistically significant difference between chamomile group and NaOCl and the dual EDTA and NaOCl irrigation protocol. SEM images showed removal of E. faecalis biofilm and smear layer was in the order: dual EDTA and NaOCl irrigation&gt;chamomile extract&gt;NaOCl. Conclusions: Chamomile flower extract has an apparent removal efficacy of E. faecalis biofilm from root canals. It may be a promising antimicrobial material to be used as a natural endodontic irrigation solution.

Objective: The purpose of this study was to evaluate mineral content and surface morphology of root canals coated with Enterococcus faecalis biofilm after treatment with several endodontic irrigation solutions, with and without Er:YAG laser-activated irrigation (LAI). LAI has been introduced as a powerful method for root canal irrigation resulting in smear-layer removal from the root canal wall. Distal and palatal roots from 60 freshly extracted human molars were used in this study. The coronal of each tooth was removed. Roots were split longitudinally and placed in an ultrasonic bath to remove the smear layer, creating conditions for the formation of E. faecalis biofilm. After incubation, the two halves were reassembled in impression material to simulate clinical conditions. Specimens were divided into two main groups: roots rinsed with irrigation solutions and roots subjected to laser irradiation combined with irrigation solutions. Solutions tested were 2% chlorhexidine and 17% ethylenediaminetetraacetic acid (EDTA) and saline. Surface morphology: 17% EDTA irrigant solution combined with Er:YAG laser showed the best results for removing bacteria from the root canal walls. Chemical analysis: all samples treated with combined laser irradiation and irrigation solution had low surface levels of Ca compared with samples treated with irrigation alone. The Ca/P ratio was highest in the laser-EDTA group. Overall, mineral changes caused by laser with irrigation solutions were minimal, and statistically nonsignificant. In vitro irrigation solutions, combined with Er:YAG laser irradiation, were effective in removing E. faecalis biofilm from root canal walls. Irrigation solutions without laser irradiation were less effective, leaving a layer of biofilm on the dentin surface.

To observe the antimicrobial effect of strong acid electrolytic water (SAEW) against an Enterococcus faecalis (E. faecalis) biofilm when used as a root canal irrigant. The effect of SAEW, sodium hypochlorite (5.25%; NaOCl) and sodium chloride (0.9%; normal saline) on E. faecalis biofilm vitality on coverslips was observed by confocal laser scanning microscopy (CLSM). Thirty-five root canals from extracted human teeth were sterilized prior to contamination with E. faecalis for four weeks. Bacterial samples were collected with sterile paper points and plated onto BHI agar plates for 48 h. Root canal walls were observed by scanning electron microscopy before and after instrumentation, together with root canal irrigation with SAEW, NaOCl or normal saline, with or without ultrasonic vibration. Antimicrobial effectiveness was established by counting colony-forming units and analysed by two-way anova. Confocal laser scanning microscopy revealed that SAEW decreased E. faecalis biofilm vitality, and the proportion of dead bacteria increased in accordance with increasing treatment time. Most bacteria in the biofilms were killed after 10-min treatment. No significant difference was observed between SAEW and NaOCl groups at the same treatment time (P > 0.05) or in the susceptibility of E. faecalis to SAEW and NaOCl (P > 0.05) in extracted human teeth with or without ultrasonic activation. SAEW and NaOCl were more effective against E. faecalis biofilm than normal saline, and antimicrobial efficacy was significantly enhanced by ultrasonic vibration (P < 0.05). Strong acid electrolytic water effectively killed E. faecalis in a biofilm both on coverslips and in the root canals of extracted human teeth.

To assess the efficiency of ethylenediaminetetraacetic acid (EDTA), etidronic (HEBP), and peracetic (PAA) acids agitated with ultrasonic energy or diode laser on removing calcium hydroxide (CH) dressings from root canal walls. Single root canals of eighty extracted human teeth were chemomechanically instrumented and filled with CH. Sixty teeth were divided into six experimental groups (n = 10) according to the applied irrigation regimens for the removal of CH: Group 1: 5.25% NaOCl-17% EDTA, Passive ultrasonic irrigation (PUI); Group 2: 5.25% NaOCl + 9% HEBP, PUI; Group 3: 5.25% NaOCl-2% PAA, PUI; Group 4: 5.25% NaOCl-17% EDTA, Diode laser-activated irrigation (LAI); Group 5: 5.25% NaOCl + 9% HEBP, LAI; Group 6: 5.25% NaOCl-2% PAA, LAI. The other 20 teeth were served as negative (n = 10) and positive controls (n = 10). The residuary amount of CH was scored in coronal, middle, and apical thirds of the root canals by using scanning electron microscope. The data were statistically analyzed using Kruskal-Wallis H with Bonferroni adjusted Mann-Whitney U test with a significance level of 0.05. Etidronic acid activated with ultrasonics or diode laser removed the highest amount of CH from the middle third of root canals, compared to the other irrigation regimens (P < 0.001). Although the residual CH scores of PAA-PUI, PAA-LAI, and EDTA-PUI, EDTA-LAI groups were not statistically different from each other (P > 0.05), lower amount of CH was observed in the PAA-PUI and PAA-LAI groups. Use of etidronic acid activated with ultrasonics or diode laser can be an appropriate irrigation regimen for CH removal from root canal system.

The remaining calcium hydroxide (Ca(OH)2) medicaments in the root canal wall can block the penetration of filling medicaments to the dentine tubule and cause the failure in the root canal treatment. One of the ways in cleaning the root canal wall from the remains of (Ca(OH)2) is by using 18% Ethylene Diamine Tetra Acetic Acid (EDTA) irrigation solution. The cleanliness of the root canal can be examined using the Computational Fluid Dynamics (CFD) analysis. The aim of this research was to see the description of the cleanliness of the root canal wall from the (Ca(OH)2) medicament with 18% EDTA irrigation by means of CFD analysis. This is a descriptive-explorative research. Having been validated with the experimental research using test specimen in the form of block resin made in accordance with the characteristics of root canal, the description of the cleanliness of the root canal wall from the (Ca(OH)2) medicament with the 18% EDTA irrigation was analyzed using CFD method. The irrigation needle used was the side-vented type with the position of 3 mm from the tooth apical. The results of the research showed the conformity between the result of experimental research and CFD research. One of the results of this research was the characteristics of streamline of 18% EDTA in the root canal showing a unique behavior due to the characteristics of the form of side vent irrigation needle. The irrigation flow in the coronal area of the inlet (side vent irrigation needle) showed a low velocity causing the more fluid flowing out from the inlet went to apical rather to the outlet (root canal orifice). In conclusion, this research showed that 18% EDTA solution indicated the conformity of validation results between experimental research and CFD research in the frames of 5, 10, 15, and 20 secs observed from experimental research with the of frame 0,010, 0,099, 0,150 and 0,410 secs as observed from CFD research.

The aim of this study was to evaluate the bactericidal effects of Nd:YAG laser on biofilm of Enterococcus faecalis. It is difficult to eliminate bacterial biofilms with routine endodontic preparation techniques. It might be possible to eliminate biofilms remaining in the root canals of teeth with lasers. The root canals of 60 extracted teeth were prepared and E. faecalis biofilms were formed within the root canals. Then the teeth were randomly divided into four groups of 15. Group 1 samples did not undergo any interventions, to serve as controls. Group 2 samples underwent a 3-W laser beam for 10 sec. The root canals in group 3 were irrigated with 1% sodium hypochlorite for 15 min and then irradiated with a 3-W laser beam for 10 sec. The root canals in group 4 were irrigated with 1% sodium hypochlorite for 15 min. Dentin chips were collected from the root canal walls and weighed. Then the chips were used to prepare a suspension. The classic colony-forming unit (CFU) counting technique was used to determine remaining bacterial counts. The bacterial counts in groups 2 and 4 had decreased to 54% and 2.39% of the control group, respectively. In group 3 no bacterial growth was observed. There were no significant differences between groups 1 and 2 (p>0.05). Based on the results of the present study, the effect of Nd:YAG laser beam on E. faecalis biofilm is less than that of sodium hypochlorite solution. A combination of laser and sodium hypochlorite results in complete elimination of E. faecalis biofilm.

The purpose of this study was to evaluate the effect of laser-activated irrigations (LAI) by using the Erbium: Yttrium Aluminum Garnet (Er:YAG) laser and the Erbium Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser on removing smear layer (SL) from the root canal wall. LAI has been proposed as an adjuvant to conventional protocols of endodontic treatment to enhance the disinfection, which is a promising protocol for SL removal. SL was generated by preparing the root canals of extracted human teeth to a #35/.04 M3 instrument. The SL then received treatments of one of the following: (A) NaOCl, 5.25% sodium hypochlorite (NaOCl) for 60 sec; (B) EDTA, 17% ethylenediamine tetraacetic acid (EDTA) for 60 sec; (C) NaOCl+EDTA, NaOCl, and EDTA for 30 sec each; (D) LAI+NaOCl, LAI with NaOCl for 60 sec; (E) LAI+EDTA, LAI with EDTA for 60 sec; and (F) LAI+NaOCl+EDTA, LAI with NaOCl, and EDTA for 30 sec each. Efficacies of SL removal were evaluated by using a five-grade scoring system under scanning electron microscopy. The laser activations significantly enhanced the effect of the NaOCl, EDTA, and NaOCl+EDTA irrigations in removing SL. The efficacies of SL removal were presented in a descending order of LAI+NaOCl+EDTA, LAI+EDTA>LAI+NaOCl, NaOCl+EDTA>EDTA>NaOCl. Among the treatments, the LAI+NaOCl+EDTA was the most effective protocol in removing SL from the entire root canal wall, which may be effective for root canal treatment.