Effectiveness of EndoActivator, PATS Vario system, and XP-endo Finisher files on smear layer removal under scanning electron microscope: A comparative study.

CONTEXT: The smear layer may harbor many bacteria; hence, alternative methods are used to disrupt and remove biofilm. AIM: The aim of the study was to compare the effectiveness of EndoActivator, PATS Vario System, and XP-endo Finisher files on smear layer removal using a scanning electron microscope. SUBJECTS AND METHODS: Sixty single-rooted extracted premolars with Vertucci Type 1 configuration were decoronated and divided into four groups. The groups were instrumented with the rotary ProTaper file system. All specimens were flushed with 1 ml of 3% sodium hypochlorite. Group 1 was irrigated with a conventional needle and syringe. In Group 2, the irrigant was activated with an EndoActivator. In Group 3, the irrigant was activated with PATS Vario system, and in Group 4, XP-endo Finisher files were used after biomechanical preparation to remove debris and smear layer. All specimens were finally rinsed with 3 ml of 3% sodium hypochlorite. The teeth underwent longitudinal splitting and grooving in the coronal, middle, and apical thirds, and then, the samples were taken for scanning electron microscopy to evaluate the amount of smear layer removal in each third. RESULTS: The middle and coronal thirds Showed that almost similar efficacy to remove smear layer in both Group II and Group III. At the apical third, Group III showed comparatively better results than Group I, II, and IV, respectively. CONCLUSION: Equal amount of smear layer was seen with EndoActivator and PATS Vario system when used as sonic irrigation devices.

The effect of final irrigation with different solutions on smear layer removal and dentin erosion: A scanning electron microscope study.

AIM: This study aimed to compare the effectiveness of initial irrigation with sodium hypochlorite (NaOCl) and final irrigation with QMix, 40% citric acid, and 17% ethylenediaminetetraacetic acid (EDTA) on smear layer removal and dentin erosion. METHODOLOGY: Forty extracted human mandibular premolar teeth were randomly divided into four groups (n = 10) according to the type of final irrigants used: 17% EDTA, QMix, citric acid, and control (normal saline). Canals were mechanically prepared using ProTaper Next instruments to an apical size of X3. Subsequently, the roots were sectioned in a buccolingual direction. Scanning electron microscopy (SEM) was used to assess the presence of the smear layer and the amount of dentin erosion in the coronal, middle, and apical thirds of the root canals. RESULTS: In regards to smear layer removal, there was a significant difference between the control group and the other tested groups. Moreover, it was significantly higher in the coronal and middle thirds than in the apical third. However, there were no significant differences between the groups of EDTA, QMix, and citric acid. Concerning dentin erosion, citric acid produced significantly more dentin erosion than the other tested groups. CONCLUSION: Final irrigation with solutions had a higher ability to remove the smear layer in the coronal and middle thirds compared to the apical third. Of all the solutions tested, 40% citric acid had the most pronounced impact on dentin erosion, followed by 17% EDTA and QMix.

Assessment of Smear Layer Removal and Penetration Depth of Root Canal Irrigant Using Different Irrigation Activation Systems: A Comparative Study.

AIM: The aim of the current study was to evaluate the penetration depth and smear layer removal of root canal irrigant using various irrigation activation techniques. MATERIALS AND METHODS: In this investigation, sixty single-rooted premolars extracted for orthodontic purposes were chosen. Diamond burs were used to create an access cavity, and #10 K-file was used to determine the patency. About sixty samples were divided into the following three groups (20 samples in each group), group I: Irrigation with conventional needle, group II: Activation of EndoVac system, group III: Passive ultrasonic irrigation (PUI). The efficacy of the smear layer was assessed using a scanning electron microscopy at a ×2000 magnification. One-way ANOVA was used to record and analyze the data. All statistical analyses were performed with a significance level of p < 0.05. RESULTS: At coronal third, the maximum smear layer was removed in group II (1.26 ± 0.02) followed by group III (1.84 ± 0.16) and group I (2.89 ± 0.21). At middle third, smear layer removal was maximum in group I (1.18 ± 0.10) followed by group III (1.72 ± 0.09) and group I (2.66 ± 0.18). At apical third, the more smear layer was removed in group II (1.02 ± 0.01) followed by group III (1.58 ± 0.08) and group I (2.38 ± 0.06). There was a highly significant difference found between the three different irrigation systems at all three levels (p < 0.001). CONCLUSION: In conclusion, every irrigation device that was evaluated was successful in removing the smear layer from the root canal. However, the EndoVac system group removed a greater amount of smear layer compared with PUI and conventional needle group. CLINICAL SIGNIFICANCE: With the goal of promoting cleaning that is beyond the ability of mechanical devices, irrigation is a crucial part of root canal therapy. If an efficient irrigation delivery system is used, the irrigants can reach the working length (WL). This type of distribution system needs to provide a suitable amount of irrigants up to the WL, as well as have enough flow and be effective at debriding the entire canal system. How to cite this article: Pujari MD, Das M, Das A, et al. Assessment of Smear Layer Removal and Penetration Depth of Root Canal Irrigant Using Different Irrigation Activation Systems: A Comparative Study. J Contemp Dent Pract 2024;25(4):331-334.

Evaluation of the Smear Layer Removal Ability of Various Rotary Files with/without Chemical Agents on Primary Teeth: An In Vitro Study.

AIM: The aim of the current study was to assess the cleaning and smear layer removal efficacy of two different rotary files with or without chemical agents on primary teeth. MATERIALS AND METHODS: For the study, 90 extracted primary maxillary incisors without internal or external resorption and with at least two-thirds of complete roots were chosen. Then, based on the kind of instruments used to clean and shape the canals, they were randomly assigned to three experimental groups, each consisting of 30 teeth. Group-I: The canal was instrumented manually with K-files, Group-II: The canal was instrumented with Kedo-S files, Group-III: The canal was instrumented with Kedo-SG Blue files. After the canals were finally instrumented, 2 mL of QMixTM solution was used to irrigate 15 samples from each group. The samples were subsequently allowed to remain in the canals for 90 seconds in order to eliminate the smear layer. After that a stereomicroscope was used to assess the cleaning effectiveness. RESULTS: With irrigant solution, the highest mean value was found in manual K-files (2.86 ± 0.34), followed by Kedo-S files group (1.34 ± 0.26) and Kedo-SG Blue files (1.28 ± 0.18). Without irrigant solution, the highest mean value was found in manual K-files (2.92 ± 0.22) followed by Kedo-S files group (1.44 ± 0.18) and Kedo-SG Blue files (1.36 ± 0.14). There was a statistically significant difference found at all the three levels. CONCLUSION: On conclusion, the current study's findings demonstrated that irrigation solution was significantly more effective in cleaning and removing smear layers from pediatric rotary files than manual K-files. CLINICAL SIGNIFICANCE: The effectiveness of endodontic therapy depends on a successful chemomechanical preparation. The canals are instrumented using either hand files or rotary instruments; there are several irrigation and instrumentation techniques. In order to completely sterilize the canals, chemical agents are utilized for irrigation during instrumentation. Due to their numerous biological, antibacterial, anti-inflammatory, and antioxidant qualities, many natural compounds are also utilized as irrigants. How to cite this article: Abushanan A. Evaluation of the Smear Layer Removal Ability of Various Rotary Files with/without Chemical Agents on Primary Teeth: An In Vitro Study. J Contemp Dent Pract 2024;25(4):354-357.

Cerium- and samarium-nitrate interaction and accumulation on human dentin.

OBJECTIVE: To investigate the accumulation of cerium-nitrate and samarium-nitrate on dentin without or with smear-layer and to test their antibacterial activity. DESIGN: 24 dentin-enamel slices were cut from 24 extracted molars. 12 slices underwent smear-layer creation (320 grit, 200 g, 5 s), the other 12 smear-layer removal (20 % EDTA, 300 s). Slices were halved to 48 semilunar-shaped specimens. One specimen per tooth was treated with either Ce(NO3)3 (50 wt% aqueous solution; pH = 1.29; n = 6) or Sm(NO3)3 (50 wt% aqueous solution; pH = 1.88; n = 6). The other specimen served as control (A. demin). After water rinsing, elemental composition (Ce, Sm, Ca, P, O, N, Na, Mg, C) was measured (EDX; EDAX Octane-Elect, APEX v2.5, low-vacuum) in dentin. Atomic percent (At%), Ca/P- and Ca/N-ratios were calculated and analyzed non-parametrically (α = 0.05, error rates method). Additionally, antibacterial activity (2 min exposure) of Ce(NO3)3 and Sm(NO3)3 against Streptococcus mutans, Actinomyces naeslundii, Schaalia odontolytica, and Enterococcus faecalis was determined (colony forming units) after anaerobic incubation at 37 °C for 24 h (control: 0.2 % CHX). RESULTS: At% (median) of Ce and Sm were as follows: Ce(NO3)3 3.4 and 0.9 At%Ce with and without smear-layer, respectively; Sm(NO3)3 2.4 and 1.3 At%Sm with and without smear-layer, respectively. Ce(NO3)3 and Sm(NO3)3-application significantly decreased Ca/P-ratios (1.22 - 1.45; p ≤ 0.02) compared to controls (1.47 - 1.63). With smear-layer, significantly higher Ca/N-ratios (5.1 - 29.3) could be detected across all groups (p ≤ 0.004) compared to specimens without smear-layer (0.37 - 0.48). Ce(NO3)3 and Sm(NO3)3 showed reduction rates of up to ≥ 5 log10 steps for S. mutans, A. naeslundii, and S. odontolytica. CONCLUSIONS: Cerium and samarium nitrate showed accumulation on dentin and certain antibacterial activity and could therefore be identified as potential compounds to treat and prevent dentin and root caries and dentin hypersensitivity.

Dual- or single rinse? The tubular sealer penetration of endodontic chelating agents.

INTRODUCTION: In this study, we aimed to compare the effectiveness of various chelating agents, ethilenediaminetetraacetic acid (EDTA), citric acid (CA), and etidronic acid (HEDP) mixed in two different forms, in removing the smear layer and promoting the penetration of an endodontic sealer into the dentinal tubules of extracted single-rooted teeth. METHODS: The study used 75 teeth divided into five groups: 17% EDTA, 10% CA, 9% HEDP + NaOCl, 9% HEDP + distilled water (DW), and a control (DW) group. Scanning electron microscopy was used to assess smear layer removal and confocal laser microscopy was used to evaluate tubular sealer penetration at different depths from the apical tip. RESULTS: Sealer penetration was highest with 17% EDTA and 10% CA as compared with the other agents (p<0.001). At the cervical third, the sealer penetration for EDTA, HEDP + NaOCl, and HEDP + DW groups were significantly different than those in DW (p = 0.020). For the middle third, EDTA, CA, and HEDP + NaOCl groups were significantly higher than those of the DW group (p<0.001). Cervical-level values were significantly higher than apical-level values for HEDP + NaOCl, HEDP + DW, and DW (p<0.001). Smear layer removal was lower with 9% HEDP + DW than with 17% EDTA and 10% CA at all depths (p<0.001). A significancy in smear layer removal was observed between 10% CA and control (p = 0.015) in middle depth. CONCLUSION: Within the limitations of this study, highest values were seen in EDTA and CA in terms of sealer penetration and smear layer removal. In the light of these findings, the use of strong chelating agents highlights better clinical efficiency than dual-rinse or single HEDP irrigation.

Antimicrobial efficacy of DJK-5 peptide in combination with EDTA against biofilms in dentinal tubules: Primary irrigation, recovery and re-irrigation.

AIM: To investigate the dynamic recovery of biofilms within dentinal tubules after primary irrigation with different protocols, and to evaluate the efficacy of various re-irrigation protocols on recovered biofilm, considering factors such as smear layer, nutrient conditions, and primary irrigants. METHODOLOGY: A total of 416 mono or multi-species biofilms samples were prepared from human teeth and incubated for 3 weeks. After inducing a smear layer on half of the samples, all specimens were irrigated with one of the following irrigant sequences: (1) 6% NaOCl +17% EDTA, (2) 6% NaOCl +8.5% EDTA, (3) 6% NaOCl and (8.5% EDTA +10 µg/mL DJK-5 antimicrobial peptide), or (4) sterile water. Thirty-two samples were used to assess immediate effect, whilst the rest were re-incubated to assess biofilms recovery. Nutrient conditions were defined based on whether culture media were changed (nutrient-rich) or not (nutrient-poor) during re-incubation. After 16 weeks, recovered biofilms underwent re-irrigation using four additional protocols, with or without DJK-5 peptide, based on primary irrigants. Confocal laser scanning microscopy was employed to evaluate immediate irrigant effects, biofilms recovery intervals (1, 3, 5, 8, 12, and 16 weeks after primary irrigation), and re-irrigation effects at the 16-week. Statistical analysis included one-way anova and two-way mixed anova tests. RESULTS: The DJK-5 peptide irrigation protocols demonstrated the highest killing rates during primary irrigation and resulted in a longer biofilms recovery time of 16 weeks compared to non-peptide protocols (p < .001). Both primary irrigation type and smear layer presence significantly influenced biofilms recovery (p < .001). In the absence of smear layer, re-irrigation efficacy didn't significantly differ from primary irrigation, regardless of primary irrigation type or nutrient conditions. However, with a smear layer present, re-irrigation led to significantly higher proportion of dead bacteria compared to primary irrigation (p < .05). Inclusion of the DJK-5 peptide into the re-irrigation protocol displayed superior killing rate compared to other protocols (p < .001). CONCLUSIONS: Biofilms exhibited susceptibility to both peptide and non-peptide protocols during re-irrigation, irrespective of nutrient conditions or primary irrigation protocols. The DJK-5 peptide irrigation protocols consistently displayed superior effectiveness compared to non-peptide protocols.

Canal disinfection using Nd: YAG Laser, synchronized microbubble-photodynamic activation, and carbon quantum dots on microhardness, smear layer removal, and extrusion bond strength of zirconia post to canal dentin. An invitro scanning electron microscopic analysis.

Evaluation of the impact of the latest root canal disinfectant, that is carbon quantum dots (CQDs), synchronized microbubble-photodynamic activation (SYMPA), and Nd: YAG laser along with ethylenediaminetetraacetic acid (EDTA) as a final irrigant on the Marten hardness (MH), smear layer (SL) removal, and extrusion bond strength (EBS) of zirconia post to the canal dentin. Eighty intact single-rooted premolars were obtained and disinfected using 0.5% chloramine-T solution. Root canal preparation was performed using ProTaper files followed by obturation. The post space was prepared for prefabricated zirconia post and all the teeth were randomly divided into four groups based on the disinfection used (n = 20 each) Group 1: 5.25% NaOCl + 17% EDTA (Control), Group 2: Nd: YAG laser + 17% EDTA, Group 3: SYMPA + 17% EDTA, and Group 4: CQDs + 17% EDTA. MH, SL removal, and EBS of zirconia post-bonded to root dentin were performed using a microhardness tester, scanning electron microscope (SEM), and universal testing machine, respectively. Both intragroup and intergroup comparisons were performed using one-way analysis of variance (ANOVA) and posthoc-Tukey test for significant difference (p < .05). Group 2 samples (Nd: YAG laser + 17% EDTA) (0.24 ± 0.06 GPa) exhibited highest values of MH. Samples in group 3 (SYMPA + 17% EDTA) treated teeth unveiled the lowest MH scores (0.13 ± 0.02 GPa). Moreover, the coronal third of Group 3 specimens (SYMPA and 17% EDTA) (1.54 ± 0.31) eliminated SL from the canal with the greatest efficacy as well as presented the highest EBS (10.13 ± 0.69 MPa). However, the apical third of Group 1 samples (5.25% NaOCl + 17% EDTA) (2.95 ± 0.33) exhibited the least efficient elimination of SL from the radicular dentin as well as the lowest bond strength (5.11 ± 0.19 MPa) of zirconia post to the dentin. The SYMPA technique with 17% EDTA proved highly effective in removing the SL from canal dentin and enhancing the EBS of zirconia posts. The least preferable method for SL removal and MH improvement was found to be 5.25% NaOCl + 17% EDTA. CQDs and Nd: YAG laser demonstrated satisfactory smear layer removal properties from the canal, along with achieving appropriate bond strength of zirconia posts. RESEARCH HIGHLIGHTS: Nd: YAG laser and 17% EDTA as canal disinfectant exhibited the highest values of MH. Specimens irrigated with SYMPA and 17% EDTA eliminated SL from the canal with the greatest efficacy. The coronal third of Group 3 (SYMPA + 17% EDTA) samples unveiled the highest zirconia post-bond integrity score to the canal dentin. Cohesive failure was a dominant failure type among different experimental groups.

Assessment of the Smear Layer Removal Efficacy of Three Different Agents on Periodontally Compromised Tooth: An In Vitro Study.

AIM: The purpose of the present study was to evaluate the smear layer removal efficacy of three various agents on periodontally compromised tooth. MATERIALS AND METHODS: The current study included 75 molar teeth that were extracted due to periodontal disease. After that, 25 samples were randomly assigned using a simple random technique to the three different agent groups, group A: Scaling and root planing (SRP) and application of SofScale agent, group B: SRP and application of QMix agent, group C: SRP and application of MTAD agent. Using a diamond circular saw, the treated portions were divided into horizontal and vertical halves. All samples were viewed under Scanning Electron Microscope. Every tooth was focused at the coronal third, middle third, and apical third portion with a magnification of 1000×. Data were recorded and statistically analyzed. RESULTS: The smear layer removal efficacy was more in the QMix agent (3.06 ± 0.04) group followed by MTAD agent (3.28 ± 0.09) and SofScale agent (4.14 ± 0.10) group on the root surface. On intra group comparison, there was a statistically significant difference found in all the intra group agents with all the three levels. On inter group evaluation, at coronal third, there was no significant difference found between the different agents. There was a significant difference found between the different agents at middle and coronal third. CONCLUSION: On conclusion, the current investigation found that, the root surfaces treated with QMix shown a greater ability to remove smear layers compared to tooth surfaces treated with MTAD and SofScale agent. CLINICAL SIGNIFICANCE: Conventional therapies such as SRP effectively eliminate calculus, plaque, and necrosed cementum; nevertheless, they leave behind a smear layer that could impede normal healing. In an effort to overcome this, root conditioning agents were applied on the root surface to remove the smear layer. The traditional root conditioning agents such as citric acid have certain disadvantages, though, such as an acidic pH that could harm the root surface. As a result, researchers have been looking for biocompatible root conditioning treatments that are more effective. How to cite this article: Singh DK, BS Raj H, Soans CR, et al. Assessment of the Smear Layer Removal Efficacy of Three Different Agents on Periodontally Compromised Tooth: An In Vitro Study. J Contemp Dent Pract 2024;25(2):156-159.

Glycolic acid on push-out bond strength of fiber post and smear removal: an in vitro study.

This study aims to investigate glycolic acid (GA) as a final irrigant on push-out bond strength of fiber post and smear removal. Ninety mandibular premolars were stabilized with a silicone key and photographed, and canal cross-section was calculated by image processing software. Round canal morphology was selected. The specimens were divided into five groups (n = 18); 10%GA, 17%EDTA, NaOCl + 10%GA, NaOCl + 17%EDTA, and the control. Fifteen specimens were used for the push-out. Three specimens were evaluated using a scanning electron microscope after post space preparation. Two-way ANOVA and Chi-square were used for statistics. GA presented higher strength than EDTA (p < 0.05). The NaOCl + GA showed higher strength than the NaOCl + EDTA (p < 0.05). The highest values were observed in cervical and lowest in apical thirds (p < 0.05). The most failure type was between dentin and resin (p < 0.05). GA removed the smear in the post space including the apical third. The NaOCl + GA has superiority to NaOCl + EDTA on push-out strength. Glycolic acid improved the bond strength of fiber post when used as a final post space irrigant. The combination of NaOCl and glycolic acid did not negatively affect the bond strength and was more effective compared to the combination with EDTA. Glycolic acid improved the bond strength of fiber post when used as a final post space irrigant. The combination of NaOCl and glycolic acid did not negatively affect the bond strength and was more effective compared to the combination with EDTA.

Computational fluid dynamics investigation on the irrigation of a real root canal with a side-vented needle.

BACKGROUND: Root canal therapy is one of the main treatments for root canal diseases, and effective irrigation is the key to successful treatment. Side-vented needle is one of the commonly used needle types in clinic. In the real root canal, due to the influence of the curvature of the root canal, the irrigation flow field in different needle directions shows obvious differences. At the same time, changes in root canal curvature and working depth will lead to changes in irrigation efficiency and the flow field. Both the mainstream of the irrigation flow and the shear stress near the wall changes significant. Consequently, either the replacement in the root canal or the removal efficiency of the smear layers is apparently modified. MATERIALS AND METHODS: In this paper, the permanent root canal of the maxillary first molar prepared until 15/04 were scanned by micro-CT, and then imported into the software for 3D reconstruction. The key parameters of flushing efficiency of 30G side needle at different working depths of 4.75 mm, 5 mm, 5.25 mm and 5.5 mm were compared. Meanwhile, the simulated models with different curvatures of 0°, 5°, 10°, 20° and 30° based on the real root canal were reconstructed to investigate the curvature effect on the irrigation efficiency. RESULTS: The results show that moderate working depth (such as 4.75 mm and 5.25 mm in present paper) helps to improve the replacement capacity of irrigation flow. At the same time, the apical pressure decreased as the working depth increased. The curvature of the root canal seriously affects the removal depth of the smear layers of the root canal. A root canal with a large curvature (especially 20° and 30°) can significantly improve the difficulty of irrigation. CONCLUSIONS: (1) Moderate working depth helps to improve the displacement capacity, the ERD of the irrigation flow is generally improved at the working depths of 4.75 mm and 5.25 mm, and the apical pressure will decrease with the increase of working depth. (2) The large curvature of the root canal can significantly improve the difficulty of irrigation. The curvature of the root canal can severely influence the removal depth of the smear layer on the wall. It can be found both the span and the depth of the ESS for little curvatures (5° and 10°) root canals are higher than those for large curvatures (20° and 30°).

Comparison of Easydo Activator, ultrasonic and needle irrigation techniques on sealer penetration and smear layer removal in vitro.

The effects of Easydo Activator (EA), a new sonic irrigation system, on sealer penetration at the root apex were compared to needle irrigation (NI) and passive ultrasonic irrigation (PUI) in this study. Forty-two single-rooted teeth were prepared and randomly divided into three groups (n = 14): group 1: NI; group 2: PUI; and group 3: EA. A solution of 3% sodium hypochlorite (NaOCl) was used for irrigation. Nine teeth in each group were filled with AH Plus sealer mixed with CY5 fluorescent dye and a single gutta-percha cone. The sealer penetration area, maximum penetration depth and percentage of sealer penetration at 5 mm and 1 mm from the apex were analyzed by confocal laser scanning microscopy (CLSM). The remaining 5 teeth in each group were subjected to test smear layer scores by scanning electron microscopy (SEM). The CLSM evaluation showed that increases in the area, depth and percentage of sealer penetration were detected at 1 and 5 mm from the root apex in the PUI group compared with the NI group, and greater increases were observed in the EA group (P < 0.05). The SEM experiment showed that the lowest scores for the smear layer and debris removal were achieved by the EA group when compared with the PUI and NI groups (P < 0.05). In conclusion, EA was superior to PUI and NI regarding sealer penetration at the root apex during endodontic treatment, and it could provide a new technical idea for clinical root canal therapy.

Effectiveness of Triton Irrigation Solution in Smear Layer Removal: An in-vitro Study.

OBJECTIVE: This in vitro study aimed to compare and evaluate the effectiveness of different irrigation solutions, including Triton, 0.5% Chitosan nanoparticles (CNP), and 17% ethylenediaminetetraacetic acid (EDTA), on the smear layer removal of the root canal walls. METHODS: Forty extracted sound mandibular premolars were examined; the samples were decoronated to obtain a root length of 14 mm. Each sample was instrumented using ProTaper Next rotary file X4 (40/0.06). The samples were longitudinally sectioned and examined under a scanning electron microscope at 3000x magnification in the coronal, middle, and apical thirds using a four-level scoring system. RESULTS: Triton demonstrated the lowest mean smear layer removal (p>0.05) compared to the other irrigation solutions at all the levels of the root canal. No significant differences were observed (p>0.05) at the coronal and middle levels of the root canal between the CNP and EDTA groups. CNP demonstrated significantly more smear layer removal at the apical level compared to EDTA. CONCLUSION: Smear layer removal was least effective with Triton at all the levels of the root canal compared to the other irrigation solutions tested in this study. CNP demonstrated superior smear layer removal at the apical level compared to the other irrigation solutions.

Canal disinfection using photo-chemically activated micro-bubble emulsion, Emblica officinalis, and Nd: YAP laser on smear layer and push-out bond strength of resin-based root canal sealer to the radicular dentin.

AIMS: Evaluation of the effects of the latest root canal disinfectants i.e., Micro-bubble emulsion (MBE), Neodymium-doped yttrium aluminum perovskite (Nd: YAP), Emblica officinalis (E. officinalis) on the removal of smear layer (SL) and push out bond strength (PBS) of resin-based root canal sealer to the radicular dentin. METHODS: The coronal portion of sixty single-rooted human mandibular premolar teeth was precisely sectioned at the cementoenamel junction. The canals were prepared to utilize ProTaper universal rotary files till F3. All the study specimens were divided into four groups based on the disinfection regime (n = 15) Group 1: 5.25% NaOCl, Group 2: MBE, Group 3: Nd: YAP laser and Group 4: E. officinalis extract. All the canals were then finally irrigated using 17% EDTA solution as a final disinfecting agent. SL removal assessment was performed on five samples from each group using a scanning electron microscope (SEM). Ten samples from each group were then filled with root canal filling material and the roots were sectioned. Push-out test and failure mode analysis were performed using the universal testing machine (UTM) and stereomicroscope respectively. The mean scores of PBS and SL removal were compared using a one-way analysis of variance (ANOVA) and Post Hoc Tukey's HSD test p = 0.05. RESULTS: Group-2 (MBE + EDTA) coronal section (1.50 ± 0.23) exhibited the most effective eradication of SL from the canal space. The apical third of Group-1 (NaOCl+EDTA) (2.68 ± 0.82) samples demonstrated the least effective removal of SL from the radicular canal. The maximum score of PBS of AH plus sealer to the canal dentin was exhibited by the coronal section of Group-2 (MBE + EDTA) (9.55 ± 0.45 MPa) samples. However, the apical third of Group-1 (NaOCl+ EDTA) specimens (5.16 ± 0.32 MPa) demonstrated the minimum EBS. CONCLUSION: MBE+ EDTA displayed better smear layer removal and bond integrity of AH plus sealer to the root canal dentin. Nd: YAP+ EDTA laser and E.officinalis displayed comparable outcomes to that of control NaOCl+ EDTA.

Effect of EDTA Activation on Blood Clot Structure in Regenerative Endodontics: A Scanning Electron Microscopy Study.

INTRODUCTION: EDTA plays a crucial role in regenerative endodontic therapy (RET) because of its significant biological effects. However, EDTA is also recognized as the preferred anticoagulant for hematologic tests. Thus, this study aimed to assess the influence of different EDTA activation techniques on the morphology of blood clots after conditioning the root canal dentin. METHODS: Forty extracted human teeth were prepared to simulate immature teeth and divided into the following 5 groups: (1) saline solution (negative control), (2) EDTA 17% + saline solution (CNI), (3) CNI + ultrasonic activation, (4) CNI + Easy clean activation, and (5) CNI + XP-endo Finisher activation. After irrigation, the roots were cleaved, and the root canals were filled with human blood to clot formation. The morphology and density of erythrocytes, platelets, and the fibrin network were observed using a scanning electron microscope. The fibrin network density was classified using a 4-point scale. Data were analyzed using the Friedman test and the Kruskal-Wallis test with Bonferroni adjustment (α = 5%). RESULTS: All groups exhibited consistent blood clot morphology characterized by a high density of erythrocytes, platelets, and white blood cells throughout the entire length of the root canal. The negative control group showed statistically significant high scores of fibrin density compared with the CNI group in all root thirds (P < .05). However, there was no statistical difference in the scores for the fibrin network density between the groups irrigated with EDTA with and without activation (P > .05). CONCLUSIONS: EDTA may impair the fibrin network formation compared with the saline group. However, EDTA activation did not significantly change the effects on the blood clot in contact with the conditioned intraradicular dentin.

In Vitro Evaluation of Smear Layer and Debris Removal and Antimicrobial Activity of Different Irrigating Solutions.

OBJECTIVE: The aim of this in vitro study was to compare the smear layer and debris removal and antimicrobial activity of two dual-action irrigating solutions for continuous chelation (Triton; Brasseler, Savannah, USA and Dual Rinse HEDP; Medcem GmbH, Weinfelden, Switzerland) with a dual step irrigation protocol with sodium hypochlorite (NaOCl) followed by ethylenediaminetetraacetic acid (EDTA). METHODS: Thirty single-rooted single-canal teeth were divided into three groups (n=10) and irrigated with Triton, Dual Rinse HEDP mixed with 6% NaOCl and 6% NaOCl/17% EDTA. The teeth were observed under a scanning electron microscope (SEM) to assess the canal wall cleanliness. In addition, 80 dentine discs were contaminated with Candida albicans and 80 discs with Enterococcus faecalis and irrigated with Triton, Dual Rinse HEDP mixed with 6% NaOCl and 6% NaOCl/17% EDTA or not treated (n=20). Fifteen discs were used to evaluate colony-forming units, while 5 discs were analysed by SEM. Data were analysed using the Shapiro- Wilk, Kruskal-Wallis and One-Way ANOVA tests. RESULTS: Triton was statistically more effective than Dual Rinse HEDP and NaOCl/EDTA in removing debris (p<0.05), except with NaOCl/EDTA in the coronal third. Triton was more effective than Dual Rinse HEDP in removing the smear layer from the apical and middle thirds (p<0.05). All the irrigation protocols significantly re- duced the number of E. faecalis. The Triton group showed the lowest number of remaining C. albicans (p<0.05). CONCLUSION: Triton was the most effective irrigation solution in removing debris and as effective as NaOCl/ EDTA in removing the smear layer. Triton showed the highest efficacy against C. albicans. New irrigating solutions that provide continuous chelation may provide an alternative to current irrigation protocols.

Micromorphology of Root Canal Walls After Laser Activated Irrigation.

This study aims to investigate the effects of laser-activated irrigation on root canal dentin using different laser wavelengths. Sixty-six roots were prepared and split longitudinally. First, lasers with different power settings were tested on 34 samples, pre-etched with phosphoric acid, or remaining with a smear-layer to determine the test parameters. Selected parameters were then applied on thirty roots (9 groups) covered with smear layer: 1. Smear-layer removed; 2. Smear-layer untouched; 3. Conventional needle irrigation with NaOCl and EDTA; 4. ER:YAG laser; 5. 9.3 µm CO2 laser; 6-9. Diode lasers. All lasers were applied in ultra-pure water as an irrigant. Root halves were examined by scanning electron microscope to analyze the intracanal dentin micromorphology on 9 consequent photos per specimen @ a magnification of 1000X. The results showed that conventional needle irrigation was effective in removing the smear-layer from coronal and middle root parts, while laser-activated irrigation had two main mechanisms: cleaning and opening of the dentinal tubules by removing the smear layer (Er:YAG laser) and melting of dentin (CO2 and diode lasers) in all root parts. The study concluded that laseractivated irrigation with different wavelengths impacted the smear layer and root canal dentin differently through pure physical/mechanical effects.

Rational design of EDTA-incorporated nanoflowers as novel and effective endodontic disinfection against biofilms.

The ethylenediaminetetradiacetic acid (EDTA) is one of the most commonly used irrigation solutions. Although EDTA has a very low antimicrobial property, it is used to remove inorganic part of smear layer in areas of root canal system. Herein, we developed EDTA-incorporated nanoflowers (EDTA NFs), for the first time, as novel and effective irrigation solution with quite high antimicrobial property to provide complete disinfection in root canal system. We both systematically elucidated the formation of the EDTA NFs with various techniques, and their catalytic and antimicrobial activities in the presence of hydrogen peroxide (H2O2) were documented through intrinsic EDTA property and peroxidase-like activities.

Effectiveness of continuous chelation irrigation protocol in endodontics: a scoping review of laboratory studies.

This scoping review aimed to synthesize and explore the current boundaries and limitations of laboratory research on the effectiveness of continuous chelation irrigation protocol in endodontics. This scoping review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. Literature search was conducted on Pubmed and Scopus to identify all laboratory studies evaluating smear layer and hard-tissue debris removal or, antimicrobial efficacy, or dentine erosion induced by continuous chelation. Two independent reviewers performed the all review steps and the relevant items were recorded. Seventy-seven potentially relevant studies were identified. Finally, 23 laboratory studies met the eligibility criteria for qualitative synthesis. Seven studies focused on the smear layer/debris removal outcome, 10 on antimicrobial activity, and 10 on dentine erosion. In general, the continuous chelation protocol was equally or more effective in the cleanliness of root canals and antimicrobial activity compared with traditional sequential protocol. In addition, etidronate solutions seemed to be milder chelating agents compared to those with EDTA, thus resulting in reduced or no dentine erosion and roughness modification. Yet, the methodological differences among the included studies limit the results' generalizability. The continuous chelation seems to be equally or more effective in all investigated outcomes when compared with the traditional sequential protocol. The methodological variability among the studies and shortcomings in the methods employed limit the generalizability and clinical relevance of the results. Standardized laboratory conditions combined with reliable three-dimensional investigation approaches are necessary to obtain clinically informative findings.

The comparative of chitosan and chitosan nanoparticle versus ethylenediaminetetraacetic acid on the smear layer removal: A systematic review and meta-analysis of in vitro study.

The purpose of this systematic review of meta-analysis was to compare the effectiveness of removing the smearing layer using EDTA versus Chitosan (Ch) and Chitosan nanoparticles (Ch-NPs). A search was performed in four electronic databases (Web of Science, PubMed, Scopus, and Cochrane). The included studies were assessed by two reviewers using Joanna Briggs Institute's critical appraisal checklist for the quasi-experimental studies. Outcomes obtained by scanning electron microscopy (SEM) and conventional methods were presented as standardized mean differences alongside 95% confidence intervals. Seven investigations employed 212 single-root teeth. In the apical section (p = .317, 95% CI = -0.820 to 0.266, Tau2 = 0.387), middle segment (p = .914, 95% CI = -1.019 to 0.912, Tau2 = 1.027), and coronal segment (p = .277, 95% CI = -1.008 to 0.289, Tau2 = 0.378). This meta-analysis found no difference between Ch, Ch-NPs, and EDTA in removing the smear layer in the three segments. This systematic review is designed to show evidence related to the PICO question, in which our outcome is smear layer removal and not the clinical success of such a treatment. RESEARCH HIGHLIGHTS: The study aimed to compare the effectiveness of chitosan and chitosan nanoparticles with ethylenediaminetetraacetic acid (EDTA) in removing the smear layer, a layer of debris and organic material on the tooth surface, through a systematic review and meta-analysis. The removal of the smear layer is crucial for successful dental treatments, as it enhances the adhesion of restorative materials and improves the penetration of antimicrobial agents into dentinal tubules. The researchers conducted a systematic review and meta-analysis, searching various databases of electron microscopy results for relevant in vitro studies comparing the effects of chitosan or chitosan nanoparticles with EDTA on smear layer removal. The results encourage further exploration of chitosan and chitosan nanoparticles for clinical use in dentistry, while considering their specific applications and long-term effects.