Calcium Silicate-based Root Canal Sealers Research Articles

Comparative evaluation of physical properties of resin and calcium silicate-based root canal sealers

ABSTRACT Aim: The aim of this study was to evaluate the flow, solubility, and pH of AH Plus sealer, Bio-C Sealer, and Cerafill RCS. Materials and Methods: The selected sealer materials were mixed according to instructions of the manufacturers under aseptic conditions. For flow and solubility, the recommendations of ISO 6876/2012 and ANSI/ADA 2000 standards were followed (n = 10). Additionally, pH changes during the setting of selected sealers (n = 10) were measured at regular intervals of time using a digital pH meter. Data were statistically analyzed using Kruskal–Wallis ANOVA test with post hoc Dunn’s test. Results: The flow of Bio-C Sealer was significantly higher than Cerafill RCS (P < 0.05). Among the sealers, Bio-C Sealer exhibited the highest solubility, whereas AH Plus exhibited the least solubility. Calcium silicate-based sealers showed higher pH than resin-based sealer. Conclusions: The results of the present study indicate that resin-based sealer and calcium silicate-based sealers have acceptable flow, whereas calcium silicate sealers exhibited high solubility and an alkaline pH.

Antimicrobial efficacy of calcium silicate-based bioceramic sealers against Enterococcus faecalis and Staphylococcus aureus - An in vitro study.

The main objective of endodontic therapy is to achieve a sterile environment and three-dimensional filling of the root canals. Endodontic sealers play an important role in the obturation of the root canal system as they may provide a seal, which prevents the penetration of bacteria. Sealers are meant to entomb residual bacteria, prevent leakage of nutrients, and ideally possess antibacterial properties. The aim of the study was to evaluate and compare the antimicrobial effectiveness of calcium silicate-based bioceramic root canal sealers against Enterococcus faecalis and Staphylococcus aureus using the agar diffusion method. The materials were divided into four groups of nine samples each for both E. faecalis and S. aureus. Group I (control group) - MTA-Fillapex (Angelus), Group II - BioRoot RCS (Septodont), Group III - Bio-C Sealer (Angelus), and Group IV - Dia-Root Bio Sealer (Diadent). To evaluate the antibacterial activity of the samples, the agar diffusion method was utilized. To begin, a bacterial suspension was evenly spread onto sterile Petri dishes using sterile swabs. Four wells of 4 mm diameter were then punched, and the sealers were mixed following the manufacturer's instructions and placed onto the prepared wells. The Petri dishes were then incubated at 37°C for 72 h. After incubation, the zones of inhibition around each well were measured at 24 h, 48 h, and 72 h, and the resulting values were statistically analyzed. The data were analyzed using the ANOVA and post hoc Tukey's test. Calcium silicate-based root canal sealers showed significantly better efficacy than the control group. BioRoot RCS (3.44 ± 1.13 mm) showed maximum antibacterial effect against E. faecalis at 24 h, 48 h, and 72 h time intervals. Bio-C Sealer (16.44 ± 1.42 mm) showed maximum antibacterial effect against S. aureus at 24 h, 48 h, and 72 h time intervals. The effectiveness of root canal sealants eventually decreased over a period. Based on analysis using the ANOVA test, a statistically significant difference (P ≤ 0.05) was observed between the mean values of antimicrobial efficacy of sealers against both E. faeca lis and S. aureus. The study's findings lead to the conclusion that BioRoot RCS showed a maximum antibacterial effect against E . faecal is and Bio-C Sealer showed maximum antibacterial effect against S. aureus at 24 h, 48 h, and 72 h.

Premixed calcium silicate-based root canal sealers have better biological properties than AH Plus: A systematic review and meta-analysis of in vivo animal studies and in vitro laboratory studies.

The aim was to determine whether premixed calcium silicate-based root canal sealers have better biological properties than AH Plus. Searches of studies published up to January 2023 were performed in the PubMed/MEDLINE and EMBASE and via other methods (databases of the International Endodontic Journal, Journal of Endodontics, and gray literature). The inclusion criteria were in vivo animal and in vitro studies that analyzed the response in the dorsal subcutaneous tissue of rats, cell viability, and genotoxicity. Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias (RoB) tool for in vivo studies and modified CONSORT checklist for in vitro were appraised. Meta-analysis was performed using the Stata. Fifty-two studies were included. In the RoB, in vivo studies fulfilled 20%-50% of the items and in vitro 60%-100%. The studies included in the meta-analysis demonstrated better histocompatibility with the premixed calcium silicate-based sealers at 30 days and greater cell viability with these sealers when used in undiluted extracts in experimental period of 72 h and in extracts with 1:2 and 1:4 dilution in 24 and 72 h. In contrast, no difference between materials was found concerning genotoxicity. Premixed calcium silicate-based root canal sealers have better histocompatibility and are less cytotoxic than the epoxy resin-based sealer AH Plus, demonstrating favorable biological behavior.

Evaluation of stress distributions of calcium silicate-based root canal sealer in bulk or with main core material: A finite element analysis study.

This research aimed to assess the stress distribution in lower premolars that were obturated with BioRoot RCS or AH Plus, with or without gutta percha (GP), and subjected to vertical and oblique forces. One 3D geometric model of a mandibular second premolar was created using SolidWorks software. Eight different scenarios representing different root canal filling techniques, single cone technique with GP and bulk technique with sealer only with occlusal load directions were simulated as follows: Model 1 (BioRoot RCS sealer and GP under vertical load [VL]), Model 2 (BioRoot RCS sealer and GP under oblique load [OL]), Model 3 (AH Plus sealer with GP under VL), Model 4 (AH Plus sealer with GP under OL), Model 5 (BioRoot RCS sealer in bulk under VL), Model 6 (BioRoot RCS in bulk under OL), Model 7 (AH Plus sealer in bulk under VL), and Model 8 (AH Plus sealer in bulk under OL). A static load of 200 N was applied at three occlusal contact points, with a 45° angle from lingual to buccal. The von Mises stresses in root dentin were higher in cases where AH Plus was used compared to BioRoot RCS. Furthermore, shifting the load to an oblique direction resulted in increased stress levels. Replacing GP with sealer material had no effect on the dentin maximum von Mises stress in BioRoot RCS cases. Presence of a core material resulted in lower stress in dentin for AH Plus cases, however, it did not affect the stress levels in dentin for cases filled with BioRoot RCS. Stress distribution in the dentin under oblique direction was higher regardless of sealer or technique used.

Retreatment Strategies for Cases Containing Calcium Silicate-Based Root Canal Sealers: A Comprehensive Review.

This review explores the field of retreatment strategies for cases filled with calcium silicate-based root canal sealers. Since the introduction of calcium silicate-based materials in dentistry, calcium silicate-based root canal sealers have become popular among dentists because of their biocompatibility, bioactivity, and sealing ability. Therefore, effective retreatment strategies are indispensable. This article aims to identify the challenges associated with the removal of calcium silicate-based sealers themselves and removal of gutta-percha with the sealers during retreatment, evaluate current techniques and materials, and provide future directions for research in this field. Regarding the strategies of removal of root canal sealers, calcium silicate-based sealers are still relatively new materials for clinicians compared with traditional sealers such as epoxy- or eugenol-based sealers. First, no clinically established solvents have been reported. Second, calcium silicate-based sealers are currently utilized by clinicians in either the cold sealer-based technique or the warm vertical condensation technique. Third, the setting process of calcium silicate-based sealers generates byproducts, primarily calcium hydroxide and secondarily hydroxyapatite, that could interact with dentine. Lastly, there is a lack of clinical studies evaluating the efficacy of retreatment protocols for teeth filled with calcium silicate-based sealers. Therefore, it is important to investigate the chemo-mechanical properties of calcium silicate-based sealers themselves and their reactions to solvents and/or mechanical instruments and identify the interfacial properties of calcium silicate-based sealers with respect to dentine and gutta-percha. In addition, researchers in the clinical field need to actively gather and report data on retreatments of teeth filled with calcium silicate-based sealers.

Physicochemical properties of AH plus bioceramic sealer, Bio-C Sealer, and ADseal root canal sealer

BackgroundThe aim of this study was to evaluate the physicochemical properties of two newly introduced premixed calcium silicate-based root canal sealers (AH Plus Bioceramic Sealer and Bio-C Sealer) compared to a resin-based root canal sealer (ADseal root canal sealer).MethodsSolubility, pH analysis, calcium ion release, and film thickness of each sealer were evaluated following ISO guidelines. The data were examined using the two-way ANOVA test. Furthermore, X-ray diffraction (XRD) examination was performed to investigate the crystalline phase of each type of sealer. X-ray fluorescence (XRF) analysis was done for the chemical elemental analysis of each sealer.ResultsThe least film thickness, highest alkalinity, and highest calcium ion release were all displayed by AH Plus Bioceramic Sealer. High solubility, high alkalinity, intermediate calcium ion release, and intermediate film thickness were all displayed by Bio-C Sealer. While ADseal root canal sealer displayed the greatest film thickness, least solubility, alkalinity, and calcium ion release.ConclusionsBoth AH Plus Bioceramic Sealer and Bio-C Sealer represented adequate properties to be considered a good sealer that could be used as a potential alternative to resin-based root canal sealers.

Preparation and characterization of novel nano-tricalcium silicate-58s bioactive glass-based root canal sealer

Introduction: Calcium silicate-based root canal sealers are gain significant interest in the recent endodontic treatment, but the high solubility and long setting time are the most shortcoming. Therefore, this study aimed to develop new nano-tricalcium silicate-58s bioactive glass (BG)-based root canal sealer with phosphate-buffered saline (PBS) as a liquid precursor, as well as to evaluate the hydration reaction of the newly prepared sealer. Materials and Methods: Different formulae were prepared by adding nano-zirconium dioxide (ZrO2) and 58s BG to the tricalcium silicate (C3S) at different concentrations. Furthermore, two types of liquid were used as precursors (PBS and distilled water). Then after, the setting time and solubility were evaluated for each prepared formula. Statistical analysis was performed using analysis of variance and Tukey tests. The formula that had the best properties was characterized by X-ray diffraction and Fourier transform infrared spectroscopy. Results: It was found that the ZrO2 at 25%, BG at 30%, and the use of PBS as a liquid improved the physical properties of the prepared sealer. Results indicated that the main hydration reactions by products for the best formula were noncrystalline calcium silicate hydrate, crystalline Ca(OH)2, CaCO3, Ca(H2PO4)2, Ca3(PO4)2, and hydroxyapatite. Conclusions: The experimental formula that composed mainly of 45% C3S, 25% ZrO2, and 30% BG as a powder and PBS as a liquid precursor had superior properties, which is in line with the American Dental Association specification.

Performance of two different electronic apex locators during the removal of calcium silicate-based sealers

Aim: The aim of this in vitro study is to evaluate the accuracy of Root ZX and Propex Pixi during the retreatment of root canals obturated with different calcium silicate-based root canal sealers. Methodology: Root canals of ninety human premolar teeth were shaped with ProTaper universal rotary files up to size F2 under 5.25% NaOCl irrigation for the present study. Root canal filling was carried out by lateral condensation technique using with gutta-percha and sealers; MTA Fillapex, CeraSeal or AH Plus. After seven days, the obturating materials were removed using D-Race files. While actual working length was recorded by direct observation, electronic working lengths were determined by Propex Pixi or Root ZX for tolerance limits of 0.5 mm and 1.0 mm. Data were analyzed using Shapiro Wilk, Mann-Whitney U, and Kruskal-Wallis tests (p < 0.05). Results: The performance of Propex Pixi and Root ZX was found to be statistically similar and did not differ on the root canals filled with different root canal sealers (p < 0.05). Propex Pixi and Root ZX demonstrated more accurate measurements in the range of ±1 mm compared to ±0.5 mm in all groups, regardless of the type of root canal sealer used when filling the root canals before retreatment (p < 0.05). Conclusion: Root ZX and Propex Pixi can be used confidently in the retreatment of the root canals in which CeraSeal, MTA Fillapex, and AH Plus are used as sealers. How to cite this article: Göçer PA, Durmazpınar PM, Baştürk FB. Performance of two different electronic apex locators during the removal of calcium silicate-based sealers. Int Dent Res 2023;13(S1):20-25. https://doi.org/10.5577/idr.2023.vol13.s1.3 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Cytocompatibility and cell migration evaluation of calcium silicate-based root canal sealer compared to epoxide-amine resin sealer in stem cells from human apical papilla: An in-vitro study.

The purpose of this study was to assess the effect of a calcium silicate-based sealers (CeraSeal) and an epoxy resin-based sealer (AH Plus) on cytotoxicity and cell migration of stem cell from the human apical papilla (hSCAPs) by using the Alamar Blue, Annexin V-FICT and wound healing assays. In Alamar Blue assay, hSCAPs exposed to undiluted CeraSeal extract had significantly higher cell viability compared with that observed when cells were treated with AH Plus in all experimental period (p < 0.001). The flow cytometry analysis confirmed the comparison on viable cells and indicated that AH Plus increased apoptosis compared to CeraSeal and the control groups (p < 0.001). Additionally, AH Plus exhibited significantly lower level of cell migration than CeraSeal and the control for up to 48 h observation (p < 0.01). In summary, calcium silicate-based sealer (CeraSeal) is less cytotoxic and more biocompatible than epoxy resin-based sealer (AH Plus).

Effect of cleaning materials on microtensile bond strength of resin composite to primary dentin contaminated with root canal sealers

BackgroundThere have been no studies on the bond strength of adhesives with dentin surfaces contaminated with root canal sealers in primary teeth without underlying permanent teeth germs. This study investigated the cleaning materials used for primary tooth dentin contaminated with root canal sealers. The aim was to increase the success rate of root canal treatment in pedodontics clinics and retain the teeth for longer.MethodsThe occlusal enamel layer was removed, followed by the application of root canal sealers (AH Plus or MTA Fillapex) to the dentin and cleaning using different irrigation solutions (saline, NaOCl, and ethanol). The specimens were restored using a self-etch adhesive and composite. Sticks with a thickness of approximately 1 mm were obtained from each sample, and the bond strengths were measured using a microtensile testing device. The interfacial morphology of the bonded space was evaluated using scanning electron microscopy.ResultsThe control and AH Plus saline groups had the highest bond strengths. The groups cleaned using ethanol had the lowest bond strengths (p < 0.01).ConclusionCleaning the dentin with saline-soaked cotton pellets provided the best bond strengths. Therefore, saline is the most effective material for removing both epoxy resin- and calcium silicate-based root canal sealers from the access cavity.

Effect of continuous chelation on the dentinal tubule penetration of a calcium silicate–based root canal sealer: a confocal laser microscopy study

BackgroundThis study aimed to evaluate the effect of various irrigation protocols on the penetration depth of a calcium silicate–based sealer into dentinal tubules using confocal laser scanning microscopy (CLSM).MethodsTwenty single-rooted mandibular premolars were endodontically prepared and divided into the following two groups according to the irrigation protocol used (n = 10): Group I: NaOCl + EDTA and Group II: continuous chelation (NaOCl/Dual Rinse). Obturation was performed with the warm vertical compaction technique using TotalFill HiFlow bioceramic sealer mixed with a fluorophore dye. Samples were observed using CLSM at 10× to measure the percentage of sealer penetration and its maximum depth into the dentinal tubules. Data were analysed using one-way ANOVA followed by Tukey’s post-hoc test. The significance level was set at p < 0.05 within all tests.ResultsComparing the overall results of all sections tested, no statistically significant differences existed between the groups regarding the percentage of sealer penetration (p = 0.612) and maximum depth of penetration (p > 0.05).ConclusionsWith both types of irrigation used, dentinal tubule penetration was higher in the coronal section than in the apical section. Continuous chelation using NaOCl/Dual Rinse HEDP performed better in the coronal segments, while irrigation using NaOCl + EDTA promoted a higher percentage of sealer penetration in the apical segment.

Physico-chemical properties of calcium silicate-based sealers in powder/liquid and ready-to-use forms.

Calcium silicate-based root canal sealers have been developed in powder/liquid or premixed ready-to-use forms. The evaluation of the physico-chemical properties of a prototype powder/liquid MTApex Sealer (Ultradent) in comparison to a ready-to-use material EndoSequence BC Sealer (Brasseler) was performed. The paste/paste epoxy resin-based AH Plus (Dentsply) served as control for comparisons. The sealers were evaluated (n = 6) regarding setting time (in dry and moist environments), flow and radiopacity, following the ISO-6876/2012 standard. Also, the pH was assessed. Material's surface and chemical characterization was evaluated using scanning-electron-microscopy (SEM) and energy-dispersive-spectrometry (EDS). Mixed ANOVA, Shapiro-Wilk, Levene, and post-hoc analysis with Bonferroni correction were performed at a significance level of 5%. MTApex Sealer exhibited the highest flow and EndoSequence BC Sealer had a significantly longer setting time in dry compared to the moist environment; however, for MTApex Sealer and AH Plus no significant changes occurred when additional moisture was provided. All materials exceeded 7 mm Al of radiopacity and showed a decreasing alkalinity over the 21 day-analysis. SEM/EDS evaluation resulted in peaks of calcium, silicon, and the respective radiopacifier. The prototype powder/liquid MTApex Sealer had the highest flow and similar setting time in both dry and moist environments; opposingly, EndoSequence BC Sealer was crucially influenced by external moisture. This suggests that the powder/liquid materials' setting seems to be more predictable.

Premixed Calcium Silicate-Based Root Canal Sealer Reinforced with Bioactive Glass Nanoparticles to Improve Biological Properties.

Recently, bioactive glass nanoparticles (BGns) have been acknowledged for their ability to promote interactions with the periapical tissue and enhance tissue regeneration by releasing therapeutic ions. However, there have been no studies on calcium silicate sealers with bioactive glass nanoparticle (BGn) additives. In the present study, a premixed calcium silicate root canal sealer reinforced with BGn (pre-mixed-RCS@BGn) was developed and its physicochemical features and biological effects were analyzed. Three specimens were in the trial: 0%, 0.5%, and 1% bioactive glass nanoparticles (BGns) were gradually added to the premixed type of calcium silicate-based sealer (pre-mixed-RCS). To elucidate the surface properties, scanning electron microscopy, X-ray diffraction, and energy-dispersive spectroscopy were used and flowability, setting time, solubility, and radiopacity were analyzed to evaluate the physical properties. Chemical properties were investigated by water contact angle, pH change, and ion release measurements. The antibacterial effects of the bioactive set sealers were tested with Enterococcus faecalis and the viability of human bone marrow-derived mesenchymal stem cells (hMSCs) with this biomaterial was examined. In addition, osteogenic differentiation was highly stimulated, which was confirmed by ALP (Alkaline phosphatase) activity and the ARS (Alizarin red S) staining of hMSCs. The pre-mixed-RCS@BGn satisfied the ISO standards for root canal sealers and maintained antimicrobial activity. Moreover, pre-mixed-RCS@BGn with more BGns turned out to have less cytotoxicity than pre-mixed-RCS without BGns while promoting osteogenic differentiation, mainly due to calcium and silicon ion release. Our results suggest that BGns enhance the biological properties of this calcium silicate-based sealer and that the newly introduced pre-mixed-RCS@BGn has the capability to be applied in dental procedures as a root canal sealer. Further studies focusing more on the biocompatibility of pre-mixed-RCS@BGn should be performed to investigate in vivo systems, including pulp tissue.

Biocompatibility of a New Calcium Silicate-Based Root Canal Sealer Mediated via the Modulation of Macrophage Polarization in a Rat Model

(1) Background: The EndoSequence BC Sealer HiFlow (Brasseler, Savannah, GA, USA) has recently been introduced in clinical applications. Thus, the aims of the present study are to determine its biocompatibility in vivo and to examine its ability to drive macrophage polarization in vitro and in vivo. (2) Methods: HiFlow was implanted into rat connective tissue for 7, 30 and 150 days. The microstructures and elemental compositions were determined by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX). Hematoxylin–eosin, immunofluorescence, RT–qPCR and flow cytometry were used to elucidate the effects on inflammatory responses and macrophage polarization. (3) Results: SEM-EDX revealed the formation of surface hydroxyapatite crystal layers. Histological evaluation showed that HiFlow exhibited long-term biocompatibility because it decreased inflammatory responses and reduced the number of macrophages over time; however, tissue necrosis was observed in all the groups. RT–qPCR verified that HiFlow regulated the expression of inflammatory factors to inhibit the inflammatory response. Immunofluorescence analysis performed on in vivo samples revealed that HiFlow promoted M2-like macrophage polarization, and these results were confirmed by flow cytometry in vitro. (4) Conclusion: After 150 days of investigation, HiFlow was considered biologically acceptable, and the formation of apatite crystal layers and the promotion of M2-like macrophage polarization may contribute to its favorable biocompatibility.

Retrievability of Calcium Silicate–based Root Canal Sealers During Retreatment: An Ex Vivo Study

IntroductionThe retrievability of calcium silicate–based sealers (CSSs) during nonsurgical retreatment has been equivocal. This study compared the retrievability of 3 different CSSs using 1 of 3 different solutions or no solution. MethodsA total of 130 extracted teeth with a straight canal were decoronated to a standardized root length. The canals were instrumented to 35/.04 and divided into 3 groups (BC: EndoSequence BC sealer; EBC: EdgeBioceramic; NEO: NeoSEALERFlo), and each group was further divided into 4 subgroups (6% sodium hypochlorite; 5% acetic acid; carbonated water; no solution). After sealer placement, each master gutta-percha cone was placed intentionally 2 mm short of the working length (WL) to ensure the apical 2 mm was filled only with sealer. After storage for 21 days at 37°C and 100% humidity, retreatment was performed until apical patency was obtained. The operator was blinded to the CSS and solution used. Data were analyzed using analysis of variance to compare apical patency rates and the mock chair-times. ResultsOverall success rates for apical patency in BC, EBC, and NEO were 63.64%, 69.77%, and 100%, respectively. There was significantly higher apical patency rate in NEO than BC and EBC. The chair-time for NEO was significantly shorter than BC (P < .05) and EBC sealer (P < .001). There was no significant difference in the chair-time between BC and EBC sealer groups. ConclusionBC, EBC, and NEO sealers in a straight canal were consistently retrievable when no solution was used. Compared with no solution, the retrievability of BC, EBC, and NEO decreased when solutions were used.

Radiopacity of premixed and two-component Calcium silicate-based Root Canal sealers

Background/Aim: Radiopacity enables radiographic visualization, which is significant in diagnostic procedures and assessment of the quality of endodontic filling. It is important to compare newly developed endodontic sealers with materials that are already in clinical use in order to promote evidence-based dentistry. The aim of our study was to evaluate radiopacity of different calcium silicate-based sealers in comparison with control, epoxy resin-based sealer. The null hypothesis was that there were no statistically significant differences in radiopacity of the tested sealers. Material and Methods: Premixed (TotalFill BC Sealer, EndoSequence BC Sealer, Ceraseal, Bio-C Sealer), two-component (BioRoot RCS, MTA Fillapex, Bioceramic Root Canal Sealer, GuttaFlow Bioseal) calcium silicate-based sealers and AH Plus, as a control, were used. Specimens were radiographed using a Radiovisiography (RVG-4) CCD (charge-coupled devices)-based digital sensor. Results: Ceraseal had the highest, while Bioceramic Root Canal Sealer had the lowest radiopacity. Bioceramic Root Canal Sealer and MTA Fillapex had radiopacity significantly lower than all other sealers. Radiopacity level of AH Plus, was similar to premixed and significantly higher than radiopacities of all two-component endodontic sealers. Conclusions: Calcium silicate-based sealers radiopacity ranged from slightly above minimal required value (3mm), to a value higher than control sealer. Premixed endodontic sealers showed similar radiopacity as AH Plus which suggests that their clinical performance, in terms of visibility on dental radiograms, should be similar

Toxicity of bioceramic and resinous endodontic sealers using an alternative animal model: Artemia salina.

Aims:The present study assessed the toxicity of a novel calcium silicate-based root canal sealer (Bio-C Sealer) in comparison to Endosequence BC Sealer and AH Plus through a lethality assay involving brine shrimp (Artemia salina).Methods:Brine shrimp cysts were incubated for 24 h for the hatching of the larvae, which were then exposed to different concentrations (2.5, 5, 10, 20, 40, 80, and 100 μg/mL) of the test endodontic sealers for 24 h, followed by the determination of the survival rate.Statistical Analysis Used:One-way repeated-measures ANOVA and the Newman–Keuls post hoc test were used to compare the different materials as well as different concentrations of the same material. Dunnett's test was used to compare the different concentrations and different sealers to the control. The lethal concentration of each endodontic sealer necessary to kill 50% of the brine shrimp larvae (LC50) was also determined.Results:The toxicity of Bio-C (10, 20, 40, 80, and 100 μg/mL) and Endosequence BC Sealer (20, 80, and 100 μg/mL) was lower than that of AH Plus. No significant difference was found between Bio-C and Endosequence BC Sealer or among the different intragroup concentrations of these sealers. In the AH Plus group, concentrations ≥5.0 μg/mL exhibited greater toxicity compared to the concentration of 2.5 μg/mL and the control. AH Plus had the lowest LC50 (59.95 μg/mL), whereas Bio-C and Endosequence BC Sealer had LC50 values >200 μg/mL.Conclusions:Bio-C Sealer proved to be less toxic than AH Plus and exhibited similar toxicity to that of Endosequence BC Sealer.

Retreatability of calcium silicate-based root canal sealer using reciprocating instrumentation with different irrigation activation techniques in single-rooted canals.

This study analysed the bioceramic sealer cleaning ability of two chemo-mechanical systems in intact and restored teeth. Thirty-two single-rooted teeth were used, and half of them restored with a pre-endodontic composite restoration (PCR). All samples were instrumented with a size 40 Reciproc Blue file and filled with BioRoot RCS. Canals were retreated using the R40 and then R50 Reciproc Blue. The samples were divided into four experimental groups (n = 8): intact teeth/passive ultrasonic irrigation (PUI) (G1), intact teeth/shock wave-enhanced emission photoacoustic streaming (SWEEPS) (G2), PCR/PUI (G3) and PCR/SWEEPS (G4). The samples were scanned by micro-CT before and after retreatment, and the volume of remaining filling material was evaluated. The minor percentage of residues were observed in G2, with a volume of 0.447 ± 0.356% of the endodontic space (P < 0.001). The Reciproc/SWEEPS technique showed the better performance in intact teeth compared with PUI technique. Pre-endodontic restoration did not significantly affect the effectiveness of sealer removal.

Comparison of Root Filling Quality of Two Types of Single Cone-Based Canal Filling Methods in Complex Root Canal Anatomies: The Ultrasonic Vibration and Thermo-Hydrodynamic Obturation versus Single-Cone Technique.

This study aimed to assess the effectiveness of ultrasonic vibration and thermo-hydrodynamic obturation (VibraTHO) using two types of root canal sealers, in comparison to the single-cone (SC) technique and a calcium silicate-based root canal sealer in complex root canal anatomies. Thirty single-rooted human maxillary premolars with two canals that had a complex root canal anatomy of transverse anastomoses or ramifications were prepared and assigned to the following three experimental groups, according to the filling method: SE group, SC technique with Endoseal TCS; VE group, VibraTHO with Endoseal TCS; and VG group, VibraTHO with GuttaFlow 2. Each tooth was scanned using micro-computed tomography, and the volume percentages of the filling material were calculated. The analysis of variance was used to analyze the statistical differences between the three groups (p < 0.05). The mean volume of the filling material was higher in the VG and VE groups than that in the SE group (p < 0.05) along the apical to middle-to-coronal thirds, and significant differences were observed between each root canal area (p < 0.05), with the only exception being at the apical thirds between the VE and SE groups. The VibraTHO technique using GuttaFlow 2 can be a more effective root canal filling method for anatomically complex root canal systems than the SC technique with Endoseal TCS. On the other hand, the VibraTHO technique using Endoseal TCS has a limited effect on improving the quality of the root filling at the apical portion of anatomically complex root canal systems, compared to the SC technique with Endoseal TCS.

A Comparative Analysis of Cytotoxicity of Three Different Root Canal Sealers

Aim: This study aims to evaluate Well-Root ST in comparison with CeraSeal and AH Plus regarding cytotoxicity using (MTT) assay on human epithelial type 2 (HEp-2) cells. Materials and Methods: Teflon mold was used to fabricate disc samples of each root canal sealer. Samples were divided into 3 groups: group (A) (Well-Root ST), group (B) (Ceraseal) and group (C) (AH Plus) in two evaluation periods (24h and 72h). All samples of root canal sealers were mixed according to the manufacturer’s instructions and the discs were allowed to set in a at 37°C for 24 hours before extraction. Extract collected at each time point was diluted to various concentrations of 12.5%, 25%, 50% and 100% with DMEM to create a total of four different concentrations of each extract. DMEM incubated for 24 hours served as the control. (HEp-2) cell line was seeded in 96 well micro-titer plates and cultures were then subjected to 100 μL of the (12.5%, 25%, 50% and 100%) extracts medium while cell cultures with supplemented DMEM were used as controls. The plates were left in the incubator for 24 or 72 h before the cytotoxicity evaluation was carried out by (MTT) assay. Viability percentage was calculated and cytotoxicity was evaluated by rating according to cell viability relative to control group, non-cytotoxic (more than 90%), slightly cytotoxic (from 60 to 90%), moderately cytotoxic (from 30 to 59%) and severely cytotoxic (less than 30%) cell viability. Statistics: Data were collected, tabulated and statistically analyzed using one way ANOVA test and Bonferroni's post-hoc test. Results: According to evaluation time, Well-Root ST showed the highest viability values in all concentration percentages at both intervals (24 and 72 hours) while AH plus showed the least viability values. According to concentration percentage, The viability increased with decreasing the concentration in all tested groups. Conclusion: The evaluated root canal sealers showed varying degrees of cytotoxicity. However, Well-Root ST was associated with significantly highest cell viability percentages. 1- AH plus significantly showed less cell viability in comparison to calcium silicate-based root canal sealers.