Smear Layer Removal Research Articles

Effect of glycolic acid as single irrigant versus sodium hypochlorite and EDTA on enterococcus faecalis count and smear layer removal in single-rooted teeth (an in vitro study)

Aim: The study aimed to compare 10% Glycolic acid as a single irrigant versus 2.5% sodium hypochlorite followed by 17% Ethylenediaminetetraacetic acid (EDTA) in terms of E. faecalis count reduction and smear layer removal in single-rooted teeth.Methodology: Thirty human extracted mandibular premolars were prepared and inoculated with E. faecalis for one week to evaluate E. faecalis count reduction. Teeth were randomly assigned to two groups (n = 15) according to the irrigation protocol used. Group I: intervention (10% Glycolic acid) and Group II: Control group (Irrigation using 2.5% NaOCl followed by 17% EDTA). After 24 hours of incubation, bacterial count reduction using colony forming units CFUs/ml was determined. For evaluating the ability of irrigants to remove the smear layer, another twenty-two mandibular premolars were chosen and randomized into two groups (n = 11). During “chemo-mechanical” preparations, the root canals were irrigated with different irrigation protocols according to each group. Then, the roots were split longitudinally in the bucco-lingual direction into two halves. A smear layer assessment was conducted on the “coronal, middle, and apical thirds” of the root canal using an Environmental Scanning-Electron Microscope (ESEM) at 1000x magnification.Results: Regarding E. faecalis count reduction, there was “no significant” difference between the two groups (p = 0.14). Regarding the ability to remove the “smear layer”, there was no significant difference between the two groups at coronal, middle and apical. While comparing smear layer scores within the same group, the “apical third” showed a significantly higher smear layer score in the two groups.Conclusion: Glycolic acid can be used as a single irrigant owing to its antibacterial efficacy and the ability to remove the smear layer.

Efficacy of Diode Laser Activated Irrigation (980 nm) and Passive Ultrasonic Irrigation in terms of Smear Layer Removal in Oval-Shaped Canals: A Comparative In-Vitro Study.

Efficacy of Diode Laser Activated Irrigation (980 nm) and Passive Ultrasonic Irrigation in terms of Smear Layer Removal in Oval-Shaped Canals: A Comparative In-Vitro Study.

Comparative Evaluation of Antimicrobial Efficacy of New Herbal Preparation With and Without 17% Ethylenediamine Tetraacetic Acid as a Root Canal Irrigant in Human Root Dentin: A Systematic Review

The literature on conventional irrigants used as root canal disinfectants in endodontic is extensive. For smear layer removal, a number of chelating compounds comprising citric acid and ethylenediaminetetraacetic acid have been utilized. Both work by lowering the dentin complex’s calcium ion content, which changes its permeability. Although synthetic antibiotics have proven unsuccessful against a number of pathogenic species due to rising drug resistance, attention to antimicrobials derived from plants has been evident in the recent literature. As literature is boosting about the various time-tested herbs, there are still other heritage herbs that remain away from the limelight. Hence, this review focuses on various studies that highlighted the use of herbal irrigants in place of synthetic irrigants. Search methodology involved searching PubMed and Google Scholar databases for articles that were published between 2018 and 2022, following which 13 articles were recruited for the current review. After evaluation of the various studies, the review concluded that herbal irrigants are useful root canal irrigants that can replace synthetic irrigants for smear layer removal and antimicrobial efficiency against various microorganisms.

Influence of Sapindus mukorossi extract in comparison to 17% EDTA as final root canal irrigant on the sealer penetration and microleakage of dentinal tubules.

The study evaluated the effect of Sapindus mukorossi (SM) extract as a final root canal irrigant on sealer penetration (SP) in dentinal tubules and microleakage. Samples were selected based on inclusion and exclusion criteria. An access opening in all samples was performed and the working length was decided using pro taper for canal finishing along with constant irrigation. Specimens were randomly divided into 3 groups. Group 1 was irrigated with 3 ml of 17% EDTA; group 2 was irrigated with SM irrigant and group 3 samples were irrigated with 0.9% saline. After obturation, samples were vertically placed in 1% methylene blue dye cut in half longitudinally, and viewed under a stereomicroscope. Analysis of SP in the dentinal tubule was assessed using scanning electron microscopy (SEM). For microleakage assessment, mean and standard deviation were reported and One-Way ANOVA was applied. SP was compared using Kruskal-Wallis' test. For inspecting the interaction between SM/EDTA and NaOCl, Fisher's exact test was applied. No statistically significant difference between microleakage in any of the tested groups was observed. The control group showed minimum leakage as compared to EDTA and SM. The results displayed that there was no significant difference, (p=0.67), between dentinal tubule SP at 2 mm. A significant difference between dentinal tubule SP among groups at 5 mm was observed (p<0.05). SM ethanolic extract showed comparable outcomes of smear layer removal and sealer penetration to 17% EDTA, as a final irrigant in root canal cleaning. Therefore, SM has the potential to be used as an adjuvant final irrigant in conjunction with NaOCl.

Efficacy of Laser-Activated Irrigation Versus Ultrasonic-Activated Irrigation: A Systematic Review.

This study aimed to conduct a systematic review and critical analysis of the evidence pertaining to the efficacy of laser-activated irrigation (LAI) versus ultrasonic-activated irrigation (UAI) in mature permanent teeth. A comprehensive literature search was performed using PubMed and Google Scholar. Additionally, a hand search was performed to identify relevant studies related to UAI and LAI. The search covered all articles published from January 1997 to December 2021. The identified studies were screened for eligibility using the inclusion and exclusion criteria. The included articles were then subjected to data extraction and analysis. The search yielded 1,637 results. Of these, 23 articles were included in this systematic review. All included articles were assessed for the outcomes of antimicrobial efficacy, smear layer, and dentin debris removal. The majority of the articles reported the superiority of LAI over UAI. Within the confines of this systematic review, the current evidence mandates that LAI has superior efficacy over UAI in the elimination of microorganisms, dentin debris, and smear layer from the root canal system.

The Effectiveness of Different Irrigation Techniques on Debris and Smear Layer Removal in Primary Mandibular Second Molars: An In Vitro Study.

The aim of the present in vitro study was to compare the effectiveness of passive ultrasonic irrigation (PUI), sonic irrigation, and mechanic dynamic activation on the removal of debris and smear layer from primary mandibular second molars during pulpectomy. Mesial roots of 48 primary mandibular second molars were prepared with an R-motion 21 mm file (30/0.04) (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland), irrigated with 1% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA), and divided into four groups (n = 24 canals) according to the final irrigation activation technique: control group without activation, PUI with Ultra-X (Eighteeth, Changzhou, China), mechanical activation with XP-endo Finisher (FKG), and sonic irrigation with EQ-S (Meta Biomed, Chungcheongbuk-do, Korea). The roots were split longitudinally and analyzed using scanning electron microscopy (SEM). The presence of debris and smear layer was assessed using a 5-grade scoring scale with 200× and 1000× magnification, respectively. The Kruskal-Wallis and Friedman tests were used for data analysis. The activation of the irrigant significantly improved debris and smear layer removal (p < 0.001). There was no significant difference between Ultra-X, XP-endo Finisher, and EQ-S (p > 0.05). No activation technique was able to completely eliminate debris and smear layer from the root canals of primary mandibular second molars. During pediatric pulpectomy, the irrigation protocol must include activation of the irrigation solutions using either ultrasonic, sonic, or mechanical activation techniques to enhance the removal of debris and smear layer for a better prognosis. During root canal treatment on primary teeth, the clinician must incorporate an activation technique in the irrigation protocol to enhance the removal of debris and smear layer and increase the success of the treatment.

Cleaning efficacy of EDDY versus ultrasonically-activated irrigation in root canals: a systematic review and meta-analysis

BackgroundUltrasonically-activated irrigation (UAI) is effective in root canal irrigation but may damage canal walls. EDDY is a sonic activation system with flexible working tips that cause no harm to dentinal walls. This review explores the intracanal cleaning efficacy of EDDY compared with UAI in vitro.MethodsThe systematic review was registered in the PROSPERO database (CRD42021235826). A literature search was conducted in six electronic databases. In vitro studies that compared the removal of smear layer, debris, soft tissue or microbes in root canals between EDDY and UAI were included. Data extraction and quality assessment were performed. Meta-analyses were conducted on smear layer removal and debris elimination with the standardized mean difference (SMD). Heterogeneity was measured using the I2 test and the Chi2 test. The random-effect model was used when I2 > 50%, or p < 0.1, otherwise the fixed-effect model was applied. The level of significance was set at p < 0.05.Results19 articles were included in this systematic review and 7 articles were included in meta-analyses. Meta-analyses on smear layer removal showed unimportant differences between EDDY and UAI at any canal third (coronal [SMD = 0.08, 95% confidence interval (95%CI): -0.29 to 0.45; p = 0.44, I2 = 0%]; middle [SMD = 0.02, 95% CI: -0.44 to 0.47; p = 0.94, I2 = 0%]; apical [SMD = 0.01, 95%CI: -0.35 to 0.38; p = 0.70, I2 = 0%]). Meta-analyses on debris removal evaluated by scanning electron microscope (coronal [SMD = 0.03, 95% CI: -0.41 to 0.46; p = 0.27, I2 = 23%]; middle [SMD = -0.24, 95% CI: -0.83 to 0.35; p = 0.80, I2 = 0%]; apical [SMD = 0.24, 95%CI: -0.20 to 0.67; p = 0.36, I2 = 2%]) and micro-CT (SMD = 0.36, 95% CI: -0.67 to 1.40; p = 0.03, I2 = 70%) both found insignificant differences. No meta-analysis was undertaken on soft-tissue removal and disinfection due to the various study designs, but the qualitative analyses implied that EDDY achieved similar performance to UAI in both aspects.ConclusionsLimited evidence indicated that EDDY was comparable to UAI in removing smear layer, debris, soft tissue and microbes ex vivo. Considering UAI may damage canal walls, EDDY might be a substitute for UAI in irrigation activation. But more randomized clinical trials are required to explore the clinical extrapolation of the results in this review.

Effectiveness of ultrasonic activation associated to glycolic acid on smear layer removal, dentin structure and bond strength to root dentin

This study evaluated the effects of ultrasonic activation (US) associated to glycolic acid (GA) on smear layer, dentin structure and bond strength (BS) of filling/restorative material to root dentin. The roots were used for antimicrobial activity, dentin structure and BS evaluation, being distributed into seven groups, according to irrigation protocols: G1:DW+US; G2:17% EDTA; G3:QMix; G4:17% GA; G5:17% EDTA+US; G6:QMix+US; G7:17% GA+US. Scanning electronic microscopy, transmission electronic microscopy and push-out were performed, with specific statistical analysis for each evaluation. The highest smear layer removal occured in Groups 6 and 7 (p&lt;0.05), and the largest collagen dispersion in Group 7, being similar to Group 2 and 5 (p&gt;0.05). The highest BS of filling and restorative material occurred in Groups 6 and 7, and Groups 5, 6 and 7, respectively, being similars between them (p&gt;0.05). The use of GA+US promoted effective smear layer removal and dentin structure preservation, improving the BS of filling/restorative material to root dentin.

Formulation and Characterization of a Novel Palm-Oil-Based α-Mangostin Nano-Emulsion (PO-AMNE) as an Antimicrobial Endodontic Irrigant: An In Vitro Study

Aim: To formulate and characterize a palm-oil-in-water-based α-Mangostin nano-emulsion (PO-AMNE) endodontic irrigant, in order to evaluate its antibacterial efficacy against Enterococcus faecalis, Staphylococcus epidermidis, and Candida albicans biofilms, as well as its capacity to remove smear layer. Methods: The solubility of α-Mangostin in various oils was determined and selected, surfactants and co-surfactants were used for the nano-emulsion trial. PO-AMNE was prepared and optimized. The MIC was performed, and the antimicrobial efficacy was estimated against biofilms. The optimized 0.2% PO-AMNE irrigant antimicrobial efficacy in a tooth model was done using colony-forming units. The treated teeth were processed by scanning electron microscopic examination for debris and smear layer removal. An Alamar Blue assay was used to evaluate cell viability. The optimization of the PO-AMNE irrigant was performed using Box–Behnken statistical design. Results: The optimized 0.2% PO-AMNE irrigant was found to have a particle size of 340.9 nm with 0.246 PDI of the dispersed droplets, and a zeta potential (mV) of −27.2 ± 0.7 mV. The MIC values showed that 0.2% PO-AMNE (1.22 ± 0.02) were comparable to 2% CHX (1.33 ± 0.01), and 3.25% NaOCl (2.2 ± 0.09) had the least inhibition for E. faecalis. NaOCl (3.25%) showed the maximum inhibition of S. epidermidis (0.26 ± 0.05), whereas 0.2% PO-AMNE (1.25 ± 0.0) was comparable to 2% CHX (1.86 ± 0.07). For C. albicans, 2% CHX (8.12 ± 0.12) showed the least inhibition as compared to 0.2% PO-AMNE (1.23 ± 0.02) and 3.25% NaOCl (0.59 ± 0.02). The 0.2% PO-AMNE irrigant was then evaluated for its antimicrobial efficacy against the three biofilms, using colony-forming units. The 0.2% PO-AMNE was comparable to both 3.25% NaOCl and 2% CHX in inhibiting the growth of biofilms. The 0.2% PO-AMNE and 17% EDTA eliminated the smear layer with the lowest mean scores (p &lt; 0.001). Finally, 0.2% PO-AMNE was shown to be biocompatible when compared to 17% EDTA, 3.25% NaOCl, and 2% CHX in immortalized oral keratinocyte cells. Conclusion: Overall, the formulated 0.2% PO-AMNE irrigant was an effective antimicrobial and biocompatible which could combat endodontic-infection-related polymicrobial biofilms.

A COMPARATIVE EVALUATION OF EFFICACY OF TETRACYCLINE HCL, EDTA &amp; HYALURONIC ACID GEL AS ROOT BIOMODIFICATION AGENTS. -AN IN-VITRO SEM STUDY

Background: Scaling and Root Planing alone leaves a smear layer on the root surface which may interfere with reattachment of cells to root surface during regenerative periodontal therapy. Root bio-modification has been advocated for smear layer removal which may enhance regeneration. Objective: To evaluate and compare effect of 17% Ethylenediamine Tetra Acetic acid (EDTA), Tetracycline HCL and 1% Hyaluronic Acid gel as root conditioning agents on periodontally involved root surfaces of extracted teeth using a scanning electron microscope (SEM). Materials And Method: Freshly extracted 10 single rooted human teeth were sectioned into 30 samples and were segregated into 3 groups: 1. Group â… - tetracycline HCl (pH 1.6), 2. Group â…¡ – EDTA 17% (pH 7.3), 3. Group III – HA gel 2%. The samples were treated with respective agents and were viewed under 4000X magnification using a SEM. The specimens were assessed for the Residual smear layer score, Number of patent tubules, Total number of dentinal tubules, Proportion of patent to total number of dentinal tubules and Mean Diameter of dentinal tubules. Results: Group I and Group II were significantly better than Group III for all the measured parameters. However, the number of patent dentinal tubules, total number of dentinal tubules and mean diameter of dentinal tubules were significantly superior in Group II as compared to Group I. Conclusion: Tetracycline HCL was found to be the most effective root conditioning agent amongst the 3 groups, for the assessed parameters.

To evaluate and compare the effect of 17% EDTA, 10% citric acid, 7% maleic acid on the dentinal tubule penetration depth of bio ceramic root canal sealer using confocal laser scanning microscopy: an in vitro study.

Background: The main factors that affect the success of an endodontic infection are effective cleaning and shaping of the root canal system including complete disinfection by using chemical irrigating solutions and obturation with an endodontic sealer to provide a fluid-tight seal. Using rotary and hand instruments for shaping and cleaning the root canal along with irrigants produces a smear layer on the surface of the root dentin affecting the penetration of the endodontic sealer into the dentinal tubules. This smear is difficult to remove with the use of only endodontic irrigants, hence, chelating agents were introduced in adjunct with irrigating solutions for irrigation protocol for effective removal of smear layer which affect the penetration of endodontic sealers into the dentinal tubules. Methods: 32 mandibular premolar teeth were used. The biomechanical preparation was done till Protaper F3 size. Irrigation was done with 2.5 mL sodium hypochlorite (NaOCl) solution after each instrumentation change for 1 min. Samples were then divided into 4 groups according to the irrigating solution used as the final rinse used with passive ultrasonic agitation. The groups were: Group I: 5 ml of saline, Group II: 5ml of 17% ethylenediaminetetraacetic acid, Group III: 5 ml of 10% citric acid, Group IV: 5 ml of 7% maleic acid each for one minute. All the canals were obturated with BioRoot tmRCS with gutta-percha using the ultrasonic condensation technique. For staining the samples for Confocal LASER microscopy, BioRoot tmRCS was mixed with Rhodamine B dye. Results: The maximum penetration of bio-ceramic sealer was observed in the coronal region. At the apical third, the maximum sealer penetration was seen with 7% maleic acid. Conclusions: Maximum sealer penetration was seen in the coronal section followed by the middle and apical section. Maximum sealer penetration was seen with 7 % maleic acid at the apical third.

Efficacy of Smear Layer Removal at the Apical One-Third of the Root Using Different Protocols of Erbium-Doped Yttrium Aluminium Garnet (Er:YAG) Laser.

Background and Objectives: Smear layer forms during cleaning and shaping can obstruct the entry of both irrigant and sealant into the dentinal tubules, resulting in the accumulation of the bacteria and their byproducts. To ensure effective adhesion and better periapical healing, it is strongly advised to remove the smear layer before proceeding with root canal obturation. This study was designed to compare the efficiency of laser-activated irrigation (LAI) in removing the smear layer and debriding the most apical third of the root canal. Materials and Methods: Sixty-five extracted human teeth with straight single roots were randomly and equally divided into four laser and one control groups. Root canals in all samples were shaped using prime size TruNatomy rotary files. During preparation, each canal was irrigated with 3 mL of 3% NaOCl and 3 mL of 17% EDTA alternately, followed by the irrigation with 10 mL of distilled water to avoid the prolonged effect of EDTA and NaOCl solutions. Final irrigation of 5 mL of 17% EDTA of the root canal was done to eliminate the smear layer and was subsequently activated by an endodontic ultrasonic tip for 20 s three times (control group), a flat-end laser tip (test groups 1 and 3) or a taper-end laser tip (test groups 2 and 4) for two cycles. The time of each cycle activation was 10 s (groups 1 and 2) or 20 s (groups 3 and 4) in which the Er:YAG laser of 2940 nm was used. The laser operating parameters were 15 Hz and 50 μs pulse duration. The samples were then split longitudinally and subjected to scanning electron microscopy (SEM). Results: The remaining smear layer at the apical part of the root canals was statistically significant between the control group and the laser groups 1 (p = 0.040) and 2 (p = 0.000). Within the laser groups, the exposed tubules count was greater in the laser with the flat tip as compared with the tapered tip (Laser 1 > Laser 2 and Laser 3 > Laser 4). Finally, no significant differences in the count of debris between the laser groups and control group were observed, except for laser 4 (p < 0.05), which had the highest count of debris. Conclusion: LAI to remove debris and smear layer at the apical third of the root canal is inferior to the current ultrasonic technique. However, when using the Er:YAG LAI, it is recommended to use a flat tip design for 10 s for two cycles to ensure maximum debridement of the apical dentin surface.

A Comparative Evaluation of Smear Layer Removal by Using 0.2% Chitosan, 17% Edta,10% Citric Acid as Final Root Canal Irrigation: Invitro A Scanning Electron Microscopic Study

A Comparative Evaluation of Smear Layer Removal by Using 0.2% Chitosan, 17% Edta,10% Citric Acid as Final Root Canal Irrigation: Invitro A Scanning Electron Microscopic Study

Comparative evaluation of canal cleanliness at apical third using Self-Adjusting File and Wave One File with different irrigants: an in vitro scanning electron microscopic study.

To evaluate the cleaning ability of two single-file rotary systems- Self-Adjusting File (SAF) and Wave one (WO) systems in removing the smear layer using sodium hypochlorite (NaOCl) + ethylene diamine tetraacetic acid (EDTA) and NaOCl + Qmix as irrigants at apical one-third of the root canal. Forty extracted human mandibular premolars were selected and working length was determined. The canal was manually instrumented up to a number 25 size K-file. The roots were divided into the following groups with 10 samples each - Group 1 using SAF: Group 1a- 3% NaOCl + 17% EDTA, Group 1b- 3% NaOCl + Qmix. Group2 using WO: Group 2a- 3% NaOCl + 17% EDTA, Group 2b- 3% NaOCl + Qmix. In the SAF group, the irrigation was performed continuously using the special irrigation apparatus. In the WO group, syringe irrigation was done followed by final irrigant activation using passive ultrasonic irrigation (PUI). The roots were sectioned longitudinally and subjected to scanning electron microscopic (SEM) examination. The amount of smear layer was evaluated using a five score index at the apical third level. Statistical analysis was performed using the Chi-square test. Group 1 (SAF) showed better canal cleanliness at apical third compared to Group 2 (WO) with both irrigant combinations and the results were statistically significant (p<0.05). 3% NaOCl + Qmix was equally as effective as 3% NaOCl + 17% EDTA in removing the smear layer with no significant difference between them. Within the limitation of this study, SAF in combination with 3% NaOCl + Qmix or 3% NaOCl + 17% EDTA should be used for removing smear layer in critical areas of the root canal.

Impact of Endodontic Irrigant Activation on Smear Layer Removal and Surface Disintegration of Root Canal Dentine In Vitro.

The objective of this study was to compare the ability of different endodontic irrigation activation methods to enable irrigant penetration, remove the smear layer from root canal walls after preparation, and investigate surface effects on dentine. Root canals of 90 single-rooted teeth were prepared and irrigated with EDTA (17%) and sodium hypochlorite (5%), where both irrigants or sodium hypochlorite only were activated as follows: conventional needle irrigation, ultrasonic activation, sonic activation (EDDY), or laser-based activation (photon-induced photoacoustic streaming/PIPS). For the evaluation of irrigant penetration into dentinal tubules, methylene blue was injected and activated as well. Subsequently, teeth were sectioned horizontally, and dye penetration depths were measured. Alternating sections were split in halves and randomly selected for scanning electron microscopic analysis. Root canal dentine was assessed for smear layer removal and surface disintegration according to a defined scoring system. The data were analyzed statistically with nonparametric and chi-squared tests for whole teeth and separately for coronal, middle, and apical thirds. All the tested activation methods removed a thicker smear layer than needle irrigation only. Additional activation of EDTA improved penetration depths of the irrigants, but not the smear layer removal. Surface disintegration of root canal dentine was observed with the additional activation of EDTA and particularly after laser-based techniques. Additional activation of EDTA does not seem to offer any convincing advantages in terms of irrigant penetration or smear layer removal but disrupts the dentine surface. Especially laser-based activation resulted in undesirable destruction of root canal wall dentine.

Smear Layer and Debris Removal from Root Canals Comparing Traditional Syringe Irrigation and 3D Cleaning: An Ex Vivo Study.

Background: Endodontic treatment objectives comprise eliminating or decreasing bacterial load inside the complex endodontic space. Removing the smear layer and debris becomes mandatory to achieve good three-dimensional (3D) cleaning. Aim: This study assesses the difference in smear layer removal using the 3D cleaning technique and traditional syringe needle irrigation. The 3D cleaning technique includes the ultrasonic activation of intracanal-heated NaOCl. Materials and Methods: Our current study used single-rooted human mandibular premolar teeth to test the earlier-mentioned technique (n = 30). Initially, an endodontic access cavity was performed. Consequently, specimens were randomly distributed into three study groups according to irrigation protocol. The groups were Group 1, where the traditional syringe needle irrigation system was applied; Group 2, where the 3D cleaning technique was performed; and Group 3, in which teeth remained uncleaned as it was regarded as the control group. Once the experiment was completed, the teeth were decoronated at the cementoenamel junction (CEJ) and examined using scanning electron microscopy (SEM). Debris and smear layers were viewed in 1000× magnification and scored. Results: Statistical analysis was performed with a standard statistical software package (SPSS, version 28.0; SPSS IBM, Armonk, NY, USA). Data were analyzed with a nonparametric analysis of variance (Kruskal−Wallis ANOVA) among the groups tested and among the thirds of the canals. The level of significance was set at p < 0.05. A statistically significant (p < 0.05) lower mean smear layer and debris score was observed in both study groups compared to the control group. Group 2 showed better results compared to Group 1. Conclusions: The present study concluded that the 3D cleaning technique is an effective irrigation method for removing debris and smear layers. Future research, such as CLSM (Confocal Laser Scanning Microscopy) and Histological study, should be employed to confirm this study’s conclusion.

Investigation of the effectiveness of sonic, ultrasonic and new laser-assisted irrigation activation methods on smear removal and tubular penetration.

The aim of this study was to examine the effectiveness of different irrigation activation methods on smear layer removal and tubular penetration. One hundred-five distal roots of mandibular molar teeth in total; 50 for smear removal efficiency (n = 10) analysis using scanning electron microscopy (SEM), and 55 roots were used to examine tubular penetration using confocal laser scanning microscope (CLSM). Five different irrigation activation methods were used in this study; conventional needle irrigation (CNI), sonic irrigation device of EDDY, passive ultrasonic irrigation (PUI), PIPS and SWEEPS techniques, which are two different laser irrigation activation methods. The obtained data were statistically analyzed and the significance level was determined as p < 0.05. At the apical level, the cleanest canal walls were observed when laser methods PIPS and SWEEPS were used, while in the middle third, there was no difference in smear removal efficiencies between all groups except for the CNI (p > 0.05). Penetration depths and percentages increased from apically to coronally in all groups. The PUI and EDDY generally showed similar penetration depths and percentages to the CNI, except at the coronal root level (p > 0.05). In all groups, when PIPS was used, it showed greater penetration depth and percentage (p < 0.05). PIPS and SWEEPS techniques showed lowest and similar smear scores compared to PUI and EDDY in the apical area where access and effectiveness of the irrigation solution are difficult.

Effect of irrigation protocols on smear layer removal, bond strength and nanoleakage of fiber posts using a self-adhesive resin cement.

This study aimed to investigate the effect of the application method of 2% chlorhexidine (CHX) and its influence on the adhesion of fiberglass posts cemented with a self-adhesive resin cement. Sixty human mandibular premolars were endodontically treated and divided into 5 groups (n = 12), according to the canal irrigant and its application method: 2 groups with conventional syringe irrigation (CSI)-2.5% sodium hypochlorite (NaOCl) (control) and 2% CHX- and 3 groups with 2% CHX irrigation/activation-by passive ultrasonic irrigation (PUI), Easy Clean file, and XP-Endo Finisher file. Two roots per group were evaluated for smear layer (SL) removal by scanning electron microscopy. For other roots, fiber posts were luted using a self-adhesive resin cement. The roots were sectioned into 6 slices for push-out bond strength (BS) (7/group) and nanoleakage (NL) (3/group). Data from SL removal were submitted to Kruskal-Wallis and Student-Newman-Keuls tests (α = 0.05). Data from BS and NL were evaluated by 2-way analysis of variance and Tukey's test (α = 0.05). For SL removal and BS, the CHX irrigation/activation promoted better values than CSI with CHX (p < 0.05), but it was not significantly different from CSI with NaOCl (p > 0.05). For NL, the lowest values were obtained by the chlorhexidine irrigation/activation groups (p < 0.05). Active 2% CHX irrigation can be used to improve the post space cleaning and adhesion before fiber post cementation with self-adhesive resin cements.

Evaluation of Effect of Natural Extract Sodium Gluconate on Smear Layer and Dentine Decalcification Compared with EDTA - An In-vitro Study.

Mechanical instrumentation of the root canal system generates a smear layer on the canal walls which are removed most commonly with the help of chelators such as ethylenediaminetetraacetic acid (EDTA) but can potentially cause severe dentinal erosion. Considerable research has been conducted to find an al- ternative to EDTA which removes the smear layer without causing dentinal erosion. The current study aimed at evaluating the ability of sodium gluconate compared with that of 17% EDTA in smear layer removal along with its effect on dentine decalcification when used as a final irrigant. Twenty single-rooted mandibular premolars were collected and prepared based on the pre-set criteria. Following preparation, the specimens were exposed to the test solutions as a final irrigant. Then the specimens were subjected to (Scanning electron microscope) SEM analysis at 1000x for evaluating the smear layer and 5000x for evaluating the dentinal erosion, and a Vickers microhardness tester was used for evaluat- ing the reduction in dentine microhardness post-treatment. The values obtained were analysed using SPSS software for a statistically significant difference with Mann-Whitney U test for evaluating of smear layer remov- al and dentinal erosion and using one-way (Analysis of variance) ANOVA test for microhardness evaluation. The smear layer removal capability of sodium gluconate was as effective as EDTA on the contrary so- dium gluconate did not cause any dentinal erosion compared to EDTA with a statistically significant difference (p=0.002 in middle third and p=0.001 in apical third of the canal). Microhardness reduction caused by sodium gluconate was less compared to EDTA, however, no statistically significant difference (p=0.113) was noted. Sodium gluconate, therefore, can produce a balance between smear layer removal and dentinal decalcification and can be considered a potential alternative to EDTA. (EEJ-2023-01-017).

Evaluation of Intracanal Smear Layer Removal after Passive Microvolume Irrigation with Sodium Hypochlorite and Rotary NickelTitanium Instruments: An In-vitro Study

Introduction: Passive Microvolume Irrigation (PMI) with Sodium Hypochlorite (NaOCl) has been proposed as a new method for root canal disinfection. It is based on the concept that irregular surface characteristics of endodontic instruments can carry NaOCl into the canal space with controlled fluid volume, without applying any pressure. Aim: To compare and evaluate the efficacy of 3% and 5% NaOCl PMI, Saline PMI, and 3% NaOCl Standard Irrigation (SI) in removing the Smear Layer (SL) from the root canal walls at the cervical, middle, and apical thirds of single-rooted teeth. Materials and Methods: This study was conducted in the Department of Conservative Dentistry and Endodontics at Vishnu Dental College, Andhra Pradesh, India. The study was conducted in February 2018. Forty maxillary central incisors with a single canal, extracted within three months of the study, were collected. The teeth were divided into four groups (n=10) based on the irrigation method: Group-1 (3.0% NaOCl SI), Group-2 (3.0% NaOCl PMI), Group-3 (5.0% NaOCl PMI), and Group-4 (Saline PMI). All samples were instrumented upto F4 size with Protaper rotary files, and a final rinse of 17% Ethylenediaminetetraacetic Acid (EDTA) was used. SL removal was evaluated using Scanning Electron Microscope (SEM). The data were analysed using Statistical Package for Social Sciences (SPSS) 21.0. Statistical tests used were Kruskal Wallis and Mann-Whitney-U tests. A p-value of &lt;0.05 was considered statistically significant for all comparisons. Results: There was no significant difference (p&gt;0.05) in SL removal between 3.0% NaOCl SI, 3.0% NaOCl PMI, and 5.0% NaOCl PMI in the middle and apical thirds of the root canals. However, 5.0% NaOCl PMI showed significantly higher efficiency in SL removal at the cervical third compared to the other groups (p&lt;0.05). Conclusion: Passive microvolume irrigation with 3% and 5% NaOCl showed comparable efficacy to 3% hypochlorite SI in the middle and apical thirds of the root canal.