Ethylenediaminetetraacetic Acid Irrigation Research Articles

Effect of Er:YAG Laser-Activated Irrigation with Side-Firing Spiral Endo Tip on Dentin Mineral Composition of Tooth Root Canals

Background: Treating tooth root canal systems with Er:YAG laser together with irrigants has been shown to be effective in reducing biofilms formed by Enterococcus faecalis. This study investigated whether laser-activated irrigation (LAI) with side-firing Endo tip (LiteTouch™; Light Instruments, Yokneam, Israel) affects dentin mineral composition when used with common endodontic irrigants. Methods: Root canals of extracted human teeth were treated with Er:YAG laser using a side-firing Endo tip combined with 17% ethylenediaminetetraacetic acid (EDTA) and/or 2.5% NaOCl in continuous or intermittent mode for 60 s. Dentin mineral composition (Ca, P, O) in coronal, middle, and apical regions of root canals was examined by energy dispersive X-ray spectroscopy. Results: The use of LAI with continuous EDTA resulted in the largest reduction in Ca and P levels. A final NaOCl rinse mitigated the EDTA-mediated mineral loss in all root canal regions and increased the O content. Likewise, the reduced Ca/O and Ca/P ratios caused by continuous EDTA irrigation were reversed when combined with a final NaOCl rinse. Conclusions: LAI with Er:YAG Endo tip using continuous EDTA irrigation followed by NaOCl caused minimal dentin mineral loss and can therefore be considered to be a safe treatment module for cleaning root canals.

Evaluation of Fracture Strength of Roots to Determine the Duration Limit of Activated Ethylene Diamine Tetraacetic Acid Irrigation for Intracanal Calcium Hydroxide Dressing Removal In Vitro

This study evaluated the effect of the use of EDTA solution at various intervals to remove intracanal calcium hydroxide medication on fracture resistance. One hundred and one extracted lower premolar teeth were randomly allocated into one control group (n = 5), two main experimental groups (CH(+), with calcium hydroxide dressing, and CH(−), without calcium hydroxide dressing), with four subgroups (EDTA intervals: 1 min, 3 min, 5 min, 10 min, n = 12). Ready-to-use injectable calcium hydroxide was used for the samples in the four CH(+) subgroups, and the samples were kept in an incubator at 37 °C and 100% humidity for seven days. All samples (CH(+), CH(−)) were irrigated with 17% EDTA, which was accompanied by activation with EndoActivator for 1, 3, 5, and 10 min, and then rinsed with 2.5% NaOCl in a standardized manner. The obturation was conducted using the warm obturation technique; experiments were conducted with a universal testing device, and their fracture strength was recorded. Compliance with the normal distribution was examined with ±2 skewness coefficients. Two-way ANOVA, Tukey’s, one-way ANOVA, and Dunnett’s tests were used for statistics (p < 0.050). A statistically significant difference was found between the mean values of the force between the groups (p = 0.009). The mean strength of the tooth at fracture that CH(−) was 401.7, CH(+) was 335.35. There was no statistically significant difference between the mean values of the forces according to time intervals (p = 0.387). While there was no significant difference among the experimental groups (p = 0.229), the mean fracture strength of the negative control group was found to be significantly higher (p < 0.001). The highest fracture resistance was observed in the nonprepared group. Irrigation with EDTA for up to 5 min showed more acceptable fracture resistance results than the other groups. Using calcium hydroxide significantly and negatively affected the root strength.

Comparative Evaluation of the Microleakage of Self-etch Adhesives on the Pulp Chamber Dentin after Proanthocyanidin Application: An In vitro Study

ABSTRACT Background: The long-term success of adhesive restorations is contingent on minimizing microleakage, which can lead to postoperative sensitivity and secondary caries. Sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) irrigation are commonly employed during adhesive restorative procedures, but their impact on microleakage remains a concern. Proanthocyanidin (PA), a naturally derived agent, has shown potential in enhancing bond strength. Aim: This study aimed to compare and evaluate the effect of treatment with or without 30% PA of the pulp chamber dentin after 1% NaOCl and 17% EDTA irrigation on the microleakage of adhesive restorations. Materials and Methods: Forty caries-free, freshly extracted permanent human molars were used. The pulp chamber roof was removed, and the roots were resected. Canal orifices were enlarged and sealed. Specimens were divided into four groups based on adhesives (OptiBond All-In-One and Adper Easy One) and irrigation regimens. After irrigation, pulp chambers were restored with Filtek Bulk-Fill composite resin. Microleakage was assessed using methylene blue dye penetration. Results: Microleakage was observed in all groups, irrespective of irrigation protocol and adhesives. PA application showed reduced dye penetration compared to without PA, although not statistically significant. Statistical analysis was performed using Kruskal–Wallis and Mann–Whitney tests at P < 0.05. Conclusion: Irrigation protocols and the use of PA had no significant effect on the microleakage of self-etch adhesives to pulp chamber dentin. A 1-min application of 30% PA solution after NaOCl and EDTA irrigation did not improve the bonding of self-etch adhesives to pulp chamber dentin.

Effect of Dentin Conditioning with EDTA and Diode Lasers on Expression of Odontoblast-like Cell Markers of Dental Pulp Stem Cells.

Regenerative endodontic procedures rely on the delivery of mesenchymal stem cells into the root canal and on the effect of local growth factors from the dentin and blood clot. The aim of this study was to assess the effect of dentin conditioning with ethylenediamine tetraacetic acid (EDTA) and diode lasers with different wavelengths (808 nm and 980 nm) on the expression of odontoblast-like cell markers. Forty dentin cylinders were divided into four groups according to the irrigation protocol: EDTA, EDTA + 808 nm diode laser, EDTA + 980 nm diode laser, and phosphate-buffered saline as the control group. Dental pulp stem cells were seeded into the previously conditioned cylinders and incubated for 14 days. The quantitative real-time polymerase chain reaction was used to evaluate the expression of dentin sialophosphoprotein (DSPP), dentin morphoprotein-1 (DMP-1), and transforming growth factor-beta 1 (TGF-β1). Data analysis was performed using the Kruskal-Wallis test. The activation of EDTA with 980 nm and 808 nm diode lasers resulted in lower DSPP and DMP-1 expression than that for EDTA alone (p < 0.05 and p < 0.01, respectively). The expression of TGF was similar among all groups. The highest level of expression of odontoblast-like differentiation markers was observed with EDTA alone. However, the use of an 808 nm diode laser during EDTA irrigation reduced the expression of odontoblastic differentiation markers.

Morphological Analyses of Effects of Endodontic Irrigant Solutions Using a Root Canal Model and an Immersion Model.

This study aimed to compare an experimental model simulating clinical root canal irrigation (root canal model) with a conventional experimental model immersing dentin sample to irrigants (immersion model) to evaluate removal of the smear layer and decalcification of the root canal dentin using sodium hypochlorite (NaOCl) and two different concentrations of ethylenediaminetetraacetic acid (EDTA) solution. Forty-five single-rooted extracted human teeth were prepared using a Ni-Ti rotary file. EDTA, NaOCl, and citric acid were used in the root canal models and the immersion models. After the irrigation protocol, root canal surfaces were observed under scanning electron microscopy. Residual smear and decalcification of the root canal dentin were evaluated objectively by measuring the percentage of the area occupied by visible dentin tubules, the number of visible dentin tubules, and the mean area of a visible single dentin tubule. Root canal and immersion models with the same irrigation protocol showed significantly different results for smear residues and decalcification of root canal dentin. In the root canal model, neither different EDTA concentrations nor the order of EDTA and NaOCl applications significantly impacted smear residues or decalcification of root canal dentin. Furthermore, no erosion of the root canal dentin surface was observed in any experimental groups in the root canal model using EDTA and NaOCl compared to intact dentin. Experimental design affected results for residual smear layer and decalcification of root canal dentin. The order of EDTA and NaOCl use and the concentration of EDTA did not affect results. EDTA and NaOCl irrigation did not cause erosion in the root canal model in this study.

Influence of ethylenediaminetetraacetic acid irrigation on the regenerative endodontic procedure in an immature rat molar model.

To analyse the influence of ethylenediaminetetraacetic acid (EDTA) on the repair process in immature rat molars after a regenerative endodontic procedure (REP). The lower first molars of 12 4-week-old Wistar rats underwent pulpectomy in the mesial root and were divided into the following groups: sodium hypochlorite (NaOCl; n=6) - the mesial canals were irrigated with 2.5% NaOCl for 5min, and NaOCl-EDTA (n=6) - the canals were irrigated with 2.5% NaOCl, followed by 17% EDTA for 5min each. After evoking bleeding using a size 10K-file, the cavities were sealed. Three molars on the untreated side were randomly used as control (control-15 d; n=3), and three molars from the other three rats untreated were used as immediate control (n=3). After 15 days (NaOCl, NaOCl-EDTA and control-15 d groups) or immediately (control-immediate), the animals were euthanized, and the teeth were subjected to histologic evaluation of tissue regeneration and presence of collagen fibres. Mann-Whitney U-test was used (p < .05). The experimental groups had newly formed cementum-like tissue and increased root length and thickness. Half of the specimens in NaOCl-EDTA group showed apical foramen closure, whilst the NaOCl group had partial apical closure. The experimental groups showed inflammatory infiltrate extending mainly to the medium third of the root canal. These parameters were similar between experimental groups (p > .05). Newly formed connective tissue in the pulp space was significantly higher in the NaOCl-EDTA group than in NaOCl group (p < .05). Regarding the collagen fibres, the NaOCl-EDTA group had more collagen fibres in the root tip, but there was no significant difference compared to NaOCl group, and both groups showed greater amount of immature fibres in this area; in the centre of the apical third of root canal, there was equivalence between mature and immature fibres from both groups (p > .05). Ethylenediaminetetraacetic acid irrigation improved newly formed intracanal connective tissue after REP in immature molars of rats; however, EDTA did not influence cementum-like tissue formation, apical closure, inflammatory infiltrate and maturation of collagen fibres.

Comparison of Local and Systemic Ibuprofen for Relief of Postoperative Pain in Symptomatic Teeth with Apical Periodontitis.

BackgroundOne of the aims of endodontic treatment is to control preoperative and postoperative pain. The present study evaluated the effects of local and systemic ibuprofen on postoperative pain. It aimed to determine the most effective method for relieving postoperative pain due to chemomechanical preparation.Material/MethodsNinety patients with symptomatic apical periodontitis were randomly assigned to local ibuprofen, systemic ibuprofen, and control groups (n=30 each). Chemomechanical preparations were performed using a ProTaper Universal Ni-Ti rotary file under 2.5% sodium hypochlorite and 17% ethylenediaminetetraacetic acid irrigation. After the root canals were dried with sterile paper points, while Odontocide paste was applied into the root canals of the patients in the local ibuprofen group, calcium hydroxide paste was applied into the root canals of the patients in the systemic ibuprofen and control groups. Following completion of the endodontic treatment procedure, 200 mg ibuprofen was prescribed to patients in the systemic ibuprofen group. Friedman and Wilcoxon tests were used for statistical analysis.ResultsPosttreatment pain scores were recorded at 6, 12, 24, and 48 h using a visual analogue scale. Although there were no significant differences between the local ibuprofen group (Odontocide) and the control group (Ultracal) (P>0.05), pain scores in the systemic group (Ultracal+200 mg ibuprofen) were significantly lower than those in the other 2 groups (P<0.05).ConclusionsThese results indicate that systemic administration of ibuprofen is effective for postoperative pain relief.

The Smear Layer Removal Efficiency of Different Concentrations of EDTA in primary teeth: A SEM Study

Objectives: The present study aims to evaluate the effects of different concentrations of ethylenediamine tetraacetic acid (EDTA) on smear layer removal in primary teeth by using scanning electron microscopy (SEM). Materials and Methods: The present study was performed with 28 extracted upper primary incisors assigned into four main groups (n=7) as 5%, 10% and 17% EDTA, and 1% sodium hypochlorite (NaOCl). The root canal surfaces (coronal, middle and apical) were scanned by SEM and scores of smear layer removal were recorded and compared after the root canal irrigation procedures. The results were analyzed using Kruskal–Wallis, Friedman and Dunn tests. Results: In all the root portions, although EDTA groups removed the smear layer more effectively than NaOCl, a statistically significant difference was observed between 17% EDTA and 1% NaOCl only in middle third (p &amp;lt;0.05). Also, smear layer was removed more effectively in coronal than apical in most of the groups (10% EDTA, 17% EDTA and 1% NaOCl) (p &amp;lt;0.05). Erosive defects were mostly seen in 17% EDTA and less than 10% EDTA group. These findings were not detected in 5% EDTA and 1% NaOCl group. Conclusions: It is possible to recommend the use of 5% EDTA irrigation solution in root canal treatment of primary teeth due to its similar smear layer removal efficacy with NaOCl and high concentration EDTA groups, low erosive potential and low concentration for periapical safety.

Effect of 17% ethylenediaminetetraacetic acid irrigation on the dentin adhesion of Enterococcus faecalis

This work aims to uncover the promoting effect of 17% ethylenediaminetetraacetic acid (EDTA) irrigation on the dentin adhesion of Enterococcus faecalis (E. faecalis). Forty-eight half split samples and twelve dentin slices were randomly divided into three experimental groups and one control group. The experimental groups and the control group were soaked with EDTA in different time lengths and with normal saline, respectively. E. faecalis was inoculated, and its dentin adhesion was measured via scanning electron microscopy, confocal laser scanning microscopy (CLSM), colony forming unit counts, and histological Gram staining. According to histological Gram staining, the depth showed no statistically significant differences between 1 min group and the control group, 1 min group and 3 min groups (P>0.05). E. faecalis intruded in the dentine tubules (measured by CLSM), and the thickness of the biofilm on the dentin surface and the colony numbers of experimental groups were greater than those of the control group (P<0.05). The differences between the three experimental groups were statistically signi-ficant (P<0.05). EDTA (17%) irrigation can promote E. faecalis adhesion to dentin. This adhesion would in turn prolong EDTA treatment time.

Effect of ethylenediaminetetraacetic acid irrigation on immune‐inflammatory response in teeth submitted to regenerative endodontic therapy

To analyse longitudinally the immune-inflammatory response in teeth of mice that underwent a regenerative protocol with or without the use of ethylenediaminetetraacetic acid (EDTA) to irrigate the root canal system. First maxillary molars of mice were devitalized using size 10 and 15 files. Teeth were divided into the following groups: Empty - the canals were left empty; Blood Clot (BC) - the canals were filled with a blood clot; and EDTA+Blood - the canals were irrigated with 0.06mL of 17% EDTA for 1min and filled with a blood clot. Access cavities were restored with Coltosol® . Animals were sacrificed at 7, 14 or 21days after the operative procedures, and teeth were collected. RNA was extracted, mRNA expression of the cytokines IGF, NGF, IL-1α, IL-10, TGF and VEGF was assessed using real-time PCR, and the anova Kruskal-Wallis test was used. IL-1 mRNA expression was significantly higher in the EDTA+BC group than in the Empty and BC groups at the 7th and 14th days of evaluation (P<0.05). IL-10 mRNA expression was similar across the three groups at all time periods. TGF-β mRNA expression in the EDTA+BC group was significantly higher on the 7th and 21st days than on the 14th (P<0.05); at day 21, TGF-β mRNA expression was similar between the BC and EDTA+BC groups but significantly higher than in the Empty group (P<0.05). IGF mRNA expression was significantly higher in the EDTA+BC group than in the other groups at all time periods. VEGF mRNA expression remained unchanged throughout the experimental period in all groups (P>0.05). NGF mRNA expression was similar amongst all groups at the 7th and 21st days (P>0.05). At the 14th day, however, there was a significant increase in NGF mRNA expression in the EDTA+Blood group (P<0.05) when compared with the expression in the other groups. EDTA promoted increased expression of factors that have the potential to improve the outcome of regenerative endodontic treatment.

Therapeutic effect of ethylenediaminetetraacetic acid irrigation solution against wound infection with drug-resistant bacteria in a rat model: an animal study.

ObjectivesIrrigation is the cornerstone of treating skeletal infection by eliminating pathogens in wounds. A previous study shows that irrigation with normal saline (0.9%) and ethylenediaminetetraacetic acid (EDTA) could improve the removal of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) compared with normal saline (NS) alone. However, it is still unclear whether EDTA solution is effective against infection with drug-resistant bacteria.MethodsWe established three wound infection models (skin defect, bone-exposed, implant-exposed) by inoculating the wounds with a variety of representative drug-resistant bacteria including methicillin-resistant S. aureus (MRSA), extended spectrum beta-lactamase-producing E. coli (ESBL-EC), multidrug-resistant Pseudomonas aeruginosa (MRPA), vancomycin-resistant Enterococcus (VRE), multidrug-resistant Acinetobacter baumannii (MRAB), multidrug-resistant Enterobacter (MRE), and multidrug-resistant Proteus mirabilis (MRPM). Irrigation and debridement were repeated until the wound culture became negative. The operating times required to eliminate pathogens in wounds were compared through survival analysis.ResultsCompared with other groups (NS, castile soap, benzalkonium chloride, and bacitracin), the EDTA group required fewer debridement and irrigation operations to achieve pathogen eradication in all three models of wound infection.ConclusionIrrigation with EDTA solution was more effective than the other irrigation fluids used in the treatment of wound infections caused by drug-resistant pathogens.Cite this article: Z. Deng, F. Liu, C. Li. Therapeutic effect of ethylenediaminetetraacetic acid irrigation solution against wound infection with drug-resistant bacteria in a rat model: an animal study. Bone Joint Res 2019;8:189–198. DOI: 10.1302/2046-3758.85.BJR-2018-0280.R3.

Velocity and wall shear stress of 18% EDTA irrigation solution flow in the removal of Ca(OH)2 with computational fluid dynamic analysis

Introduction: Ethylene Diamine Tetra Acetic Acid (EDTA) 18% irrigation solution is one of the chelating agents that able to remove calcium hydroxide (Ca(OH)2) from the root canal wall. Failure of root canal treatment can be caused by the presence of residual calcium hydroxide in the root canal wall, thus blocking the bond between the medication and root canal filling material with the root canal wall. This study was aimed to observe the EDTA 18% flow in removing the Ca(OH)2 using CFD analysis. Methods: This research was descriptive. Cleanliness of the root canal wall from Ca(OH)2 medicament using EDTA 18% irrigation was analysed using the CFD method with test specimens in the form of resin blocks made according to the characteristics of the root canal. The irrigation needle used was side-vented with a position of 3 mm from the apical tooth. Stage analysis of root canal geometry was performed using Computational Fluid Dynamics (CFD) analysis to observe the characteristics of irrigation solutions in root canals in 3D. Results: The streamlined characteristics of EDTA 18% irrigation solution showed a unique behaviour due to the features of the side-vent shaped irrigation needle. Irrigation flow in the crown area of the inlet (side-vented irrigation needle) showed low velocity so that the fluid flow when exiting the inlet was more towards the apical than the outlet (root canal orifice). Conclusion: Velocity and wall shear stress of EDTA 18% showed the results validation conformity between experimental and CFD, that the maximum velocity of EDTA 18% is 19 ms-1 and EDTA 18% wall shear stress is 1.56 KPa for calcium hydroxide removal observed from the CFD study. Keywords: Computational fluid dynamics, EDTA 18%, calcium hydroxide (Ca(OH)2), velocity, wall shear stress

Streamline characteristics using the computational fluid dynamic analysis in the flow of 18% EDTA irrigation solution to remove Ca(OH)2

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.

In vitro evaluation of bond strength of sealers after using various irrigants and Erbium-Yttrium-Aluminum-Garnet laser irradiation on radicular dentin surface: A SEM study

Aim: The aim of this in vitro study was to evaluate and compare the push-out bond strength of Adseal and mineral trioxide aggregate (MTA) Fillapex sealer after using various irrigants and Erbium-Yttrium-Aluminum-Garnet (Er:YAG) laser irradiation on radicular dentin surface. Materials and Methods: A total of 80 freshly extracted human permanent maxillary anterior teeth were sectioned transversally below the cemento-enamel junction. The remaining root portion was sectioned to get 4-mm thick dentin disc from coronal end of the root, with straight handpiece, and diamond disc. Root canal of specimens was prepared with bur to create space for sealer placement. Specimens were divided into eight groups of 10 samples each, as per irrigants and sealer used. In Group 1, 3, 5, and 7 specimens irrigated with distilled water, NaOCl, Ethylenediaminetetraacetic acid (EDTA), and Er:YAG laser, respectively, and obturated with Adseal sealer. In Group 2, 4, 6, and 8 irrigated with distilled water, NaOCl, EDTA, and Er:YAG laser, respectively, and obturated with MTA Fillapex sealer. After sealer setting, the force used to remove the sealer was evaluated using universal testing machine. Recorded force used to calculate the push-out bond strength in Megapascals and scanning electron microscopy examination was done for specimens. Results: Adseal sealer had significantly higher bond strength than MTA Fillapex sealer, irrespective of irrigant used. The highest bond strength was seen in specimens irrigated with EDTA and obturated with Adseal sealer and least in specimens irrigated with distilled water and obturated with MTA Fillapex sealer. Conclusion: Adseal sealer had significantly higher bond strength than the MTA Fillapex sealer. EDTA irrigation showed better smear layer removal, followed by Er:YAG laser irradiation, then NaOCl, least by distilled water.

Effect of Laser-Activated Irrigation with Ethylene Diaminetetraacetic Acid and Phytic Acid on the Removal of Calcium Hydroxide and Triple Antibiotic Paste from Root Dentin.

This study assessed the efficacy of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser-activated irrigation (LAI) of ethylene diaminetetraacetic acid (EDTA) and phytic acid on the removal of calcium hydroxide (CH) and triple antibiotic paste (TAP) from root canals. Although some studies investigated the efficacy of LAI of EDTA irrigation, no study has been conducted to investigate the efficacy of LAI of phytic acid in the removal of CH and TAP from root dentin. Root canals of extracted maxillary incisors (n = 80) were instrumented using rotary files and thereafter were split longitudinally. Following preparation of a standardized groove in the apical region of one root half, the roots were randomly divided into two groups according to the intracanal medicaments placed into the grooves: (1) CH and (2) TAP. The roots were reassembled, and the specimens were further assigned into four groups (n = 10/group) defined by the final irrigation solution (EDTA and phytic acid) and irrigation technique (needle irrigation and LAI) used for removal of the medicaments. The data were analyzed statistically using Kruskal-Wallis and Mann-Whitney U tests. For both EDTA and phytic acid, LAI was more efficient than needle irrigation in removing both CH and TAP (p < 0.05), but none of the tested techniques completely removed CH. Irrespective of the tested irrigation solutions and techniques, significantly less TAP remained in canals (p = 0.0001), with TAP being completely removed by LAI. Irrigation with phytic acid showed better removal efficacy than EDTA in the absence of statistical significance. Er,Cr:YSGG LAI of EDTA and phytic acid completely removed TAP and effectively reduced CH on root dentin.

Effect of time and ultrasonic activation on ethylenediaminetetraacetic acid on smear layer removal of the root canal.

The aim of this study was to assess the effect of time and the ultrasonic activation of ethylenediaminetetraacetic acid (EDTA) in removing the smear layer of at root canal. A total of 60 bovine inferior incisors were transversely sectioned and instrumented; A smear layer was added in the root dentin surface. The specimen were then divided into six groups according to the following final irrigation protocols: Group (G) 1: conventional irrigation with sodium hypochlorite (NaOCl); G2: conventional irrigation with NaOCl + EDTA for 20 s; G3: conventional irrigation with NaOCl + EDTA for 60 s; G4: passive ultrasonic irrigation (PUI) with NaOCl; G5: PUI with NaOCl + PUI with EDTA for 20 s; G6: PUI + NaOCl and PUI with EDTA for 60 s. Samples were analyzed by scanning electron microscope (SEM) at ×500 increase. The images were measured by three blinded evaluators and classified in scores ranging from 1 to 5. The results were analyzed by the Pearson correlation test and the ANOVA nonparametric Kruskal-Wallis and Dunn's tests were used for the comparisons. Irrigated samples only with NaOCl (G1 and G4) had higher scores when compared with other groups. G5 and G6, irrigated with 17% EDTA and ultrasonic irrigation had lower scores. However, there was no statistically significant difference in G2 and G3, where there was no irrigation. It was concluded that irrigation with 17% EDTA for 20 s promoted the effective removal of smear layer, regardless of ultrasonic irrigation.

Effect of irrigating solutions used for postspace treatment on the push-out bond strength of glass fiber posts.

Aim:To evaluate the effect of different irrigating solutions on postspace treatments on the push-out bond strength of glass fiber posts.Materials and Methods:Thirty mandibular premolar roots were decoronated and endodontically treated. Postspaces were prepared and roots were divided into three groups: In group 1: 2.5% sodium hypochlorite irrigation (control), group 2: 17% ethylenediaminetetraacetic acid (EDTA) with hand activation, group 3: 17% EDTA irrigation with photon-induced photoacoustic streaming (PIPS) has been done to the postspaces. Scanning electron microscope (SEM) analysis has been made for two samples of each group. Fiber posts were then luted with resin cement. Each root was prepared for push-out test. Data have been statistically analyzed.Results:SEM results showed clean postwalls with both group 2 and group 3, whereas group 1 showed adhesion of resin cement to intraradicular dentine. When all groups were compared, the bond strength values are higher with group 2 followed by group 3.Conclusion:Within the limitations of the study, clean postwalls and the highest bond strength values were obtained from 17% EDTA with hand activation and 17% EDTA with PIPS.

Efficacy of Er,Cr:YSGG laser in removing smear layer and debris with two different output powers.

The purpose of this study was to evaluate the effectiveness of the erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser in removing debris and the smear layer using two different output powers on the apical, middle, and coronal segments of root canal walls. Previous literature has failed to evaluate the exclusive effect of Er,Cr:YSGG laser on the quality of smear layer and debris removal in all three segments of the root canal space. Sixty extracted teeth were included in the study. After instrumentation, samples were divided into three experimental groups and one positive control group with no further treatment. In group 1, a final irrigation was performed using ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl), sequentially. In group 2, the samples were treated with a 2.78 μm Er,Cr:YSGG laser with an output power of 1.5 W. The same laser was used in group 3, but with an output power of 2.5 W. Scanning electron microscope (SEM) images from the coronal, middle, and apical thirds of the roots were prepared and evaluated for both smear layer and debris removal by three blinded observers. The results showed no differences between groups 1 and 2 regarding the quality of smear layer removal in all areas. However, the 2.5 W laser failed to remove the smear layer effectively. Regarding debris removal, the EDTA and NaOCl irrigation showed significantly better outcomes (adjusted p<0.05) in all areas. This study raises questions about the overall cleaning abilities of Er,Cr:YSGG lasers.

Disinfection efficacy of photon-induced photoacoustic streaming on root canals infected with Enterococcus faecalis: An ex vivo study

In 2010, one of the authors proposed that lasers could be used to enhance the decontaminating action of sodium hypochlorite (NaOCl). The authors conducted a study to compare the disinfection efficacy of laser-activated irrigation (LAI) by using a photon-induced photoacoustic streaming (PIPS) tip with conventional irrigation and specifically LAI's ability to remove bacterial film formed on root canal walls. The authors shaped 26 human anterior teeth to a master apical file size of International Organization for Standardization 25/06 (size 25 tip and size .06 taper) and then sterilized the teeth, infected them with Enterococcus faecalis and incubated them for four weeks. The authors used two irrigation protocols. Group A received two cycles of 30 seconds each of 5 percent NaOCl laser activation and one cycle of 30 seconds with laser activation involving the use of 17 percent ethylenediaminetetraacetic acid (EDTA). The erbium:yttrium-aluminum-garnet (Er:YAG) laser's settings were 20 millijoules, 15 hertz, 50-microsecond pulse duration, and it had a 600-micrometer PIPS tip. Group B received two cycles of 30 seconds each of 5 percent NaOCl and 17 percent EDTA irrigation alone, delivered via a syringe with a 25-gauge needle. The authors found that group A had significantly better disinfection compared with group B (P < .05). The results of cultures obtained after 48 hours showed that disinfection was maintained better in group A compared with group B (P < .0001). Scanning electron microscopic images showed absence of bacterial biofilm remaining after LAI using PIPS. Er:YAG laser activation of 5 percent NaOCl and 17 percent EDTA was more effective than conventional irrigation for eradicating E. faecalis and preventing new bacterial growth ex vivo. Additional clinical studies are needed to clarify the effect on endodontic treatment outcomes. PIPS appears to be effective in enhancing the effect of the irrigants commonly used in endodontics.

Adhesive bonding to pulp chamber dentin after different irrigation regimens.

The aim of the present study was to determine the effect of ethylenediaminetetraacetic acid (EDTA) and NaOCl irrigation on the microleakage and interfacial morphology of adhesives bonded to pulp chamber dentin. The pulp chamber roof of 72 extracted permanent molars was removed. Samples were equally divided into six groups. Pulp chamber dentin was bonded with either Adper Easy One (group 1), Adper Prompt L-Pop (group 2), or Adper Single Bond 2 (Group 3), after irrigation with either normal saline (groups 1a, 2a, 3a) or 17% EDTA and 5.25% NaOCl (groups 1b, 2b, 3b). Composite resin restorations were placed in the pulp chamber. Ten samples per group were subjected to microleakage test and scanning electron microscopic analysis was done in two samples from each group. Data were statistically analyzed using Mann-Whitney and Kruskal Wallis tests at a significance level of P<0.05. EDTA and NaOCl irrigation of the pulp chamber significantly reduced microleakage in Adper Easy One. However, it had no significant effect on the microleakage of Adper Prompt L-Pop and Adper Single Bond 2. EDTA and NaOCl irrigation of the pulp chamber was not deleterious to the bonding of any of the adhesives tested. While this irrigation regimen had no significant effect on the microleakage of Adper Prompt L-Pop and Adper Single Bond 2, it significantly reduced the microleakage scores in Adper Easy One.