Cytotoxicity, genotoxicity and antibacterial effectiveness of a bioceramic endodontic sealer

Biological Properties of Bioceramic Sealers on Osteoblastic Cells: A Comparative Study

This study aimed to assess the biological properties of two ready-to-use bioceramic sealers (EndoSequence BC Sealer - EBCS; Bio-C Sealer - BCS) on osteoblastic lineage cells. MC3T3 osteoblast-like cells were exposed to extracts of bioceramic materials. Cytotoxicity was evaluated using the MTT method, genotoxicity was assessed by the micronucleus test and the expression of BMP1, BMP2 and ALP was measured by RT-qPCR, after 1, 3 and 7 days. Wound healing was monitored at 1, 2 and 3-day intervals using the scratch test. Statistical analysis involved a two-factor ANOVA, followed by the Tukey Test for multiple comparisons (α=0.05). Cytotoxicity assessment revealed no significant differences between the materials and the control group at any of the time points, indicating that neither material exhibited cytotoxic effects. However, both cements induced greater micronuclei formation compared to the control on days 1 and 7 (p<0.05) when evaluating genotoxicity. No significant differences between the groups were observed in wound healing at any of the time intervals. Both biomaterials upregulated the expression of BMP1, BMP2 and ALP. The two bioceramic sealers exhibited comparable biological properties, including cytocompatibility, promotion of wound healing, and upregulation of bone formation-related genes in osteoblast-like cells. While these results suggest the potential for safe clinical application, the observed genotoxicity warrants caution. Therefore, while the null hypothesis-that the two bioceramic sealers exhibit analogous properties-was accepted in terms of cytocompatibility and gene expression, further investigation is essential to fully ensure their safety and efficacy in bone-related procedures.

Comparison of biocompatibility of epoxy resin and bioceramic-based root canal sealers

OBJECTIVES

The purpose of this study is to compare the cytotoxicity of 2 bioceramic-based (Bioserra and AH Plus Bioceramic (Bio)) and 2 epoxy resin-based (Sealart and AH Plus) root canal sealers on the Saos-2 cell line.

METHODS

The cytotoxicity of the root canal sealers was determined using the MTT metabolic activity assay. The mRNA expression levels of Bcl-2, Beclin1, Cas-3, IL-6, LC3, MMP-9 and TNF-α genes were assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and the expression of Beclin1 and LC3 proteins were assessed using western blot (WB) method. The canal sealers' total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were measured using photometric kits.

RESULTS

AH Plus Bio significantly increased metabolic activity compared to the 2 resin-containing sealers, but there was no difference with Bioserra. Sealart was clearly the most cytotoxic group. QRT-PCR analysis revealed that the mRNA expressions of Bcl-2, Beclin1, Cas-3, IL-6, LC3, and MMP-9 in the Bioserra group, Bcl-2, Cas-3, and IL-6 in the Sealart group, Beclin1, Cas-3, IL-6, and MMP-9 in the AH Plus group, and Bcl2 in the AH Plus Bio group were stimulated. The OSI results showed no significant difference between the root canal sealer groups.

CONCLUSIONS

In the study, the best biocompatibility results in MTT, qRT-PCR, WB and OSI were in the AH Plus Bio group. Although Bioserra, the study's other bioceramic paste, was found to be biocompatible according to MTT and OSI measurements, it increased the expression of all genes in qRT-PCR except for TNF-α, and also increased LC3 protein levels in WB.

CLINICAL RELEVANCE

Since periradicular tissues can be directly affected by the materials used in root canal treatment, the sealers with high biocompatibility are being developed. In vitro studies examining the biocompatibility of newly produced root canal sealers are guiding for clinical success.

Antibacterial and Cytotoxicity characteristics of experimental epoxy -based endodontic sealer loaded with silver gold nanoparticles: in vitro study

BACKGROUND

Enhancing the antibacterial capabilities of dental materials by adding nanoparticles has been the subject of some research. However, the potential toxic effect of this material on the vital tissues should be investigated to avoid additional damage to the tissue.

OBJECTIVE

This study aimed to validate the long-term cytotoxic and antibacterial properties of an epoxy resin-based endodontic sealer (AH Plus) with and without loading with silver gold nanoparticles (Nano Care Plus Silver Gold®).

MATERIAL AND METHODS

The tested groups were Nano Care Gold (group I), modified resin sealer (m AH Plus; group II) and AH Plus served as a control group (group III). Agar diffusion was used to measure the antibacterial activity against Enterococcus faecalis. Using the MTT test, cytotoxicity assessment was carried out in accordance with ISO-10993-5 guidelines to assess the cells' viability as soon as possible and after two and four weeks. The t-test was used to statistically examine the data. The chosen significance threshold was P <0.05.

RESULTS

Antibacterial results revealed that there was no difference in the diameter of the inhibition zones measured in all groups at 24 h. While in 48 and 72 h, the difference was statistically significant (p <0.05). In 48-h Nanogold was significantly higher than AH Plus when tested alone (p <0.05), however their mixture showed insignificant difference. After 72 h, the Nano gold was significantly higher than that of AH Plus & Nano gold mixture (p <0.05). Cytotoxicity result revealed there was a significant difference between tested groups at different intervals (p <0.001). For immediate measurements, values measured with the AH group were significantly higher than those of other groups (p <0.001). For the AH& nanogold group, there was no significant difference between values measured at different intervals (p = 0.578).

CONCLUSIONS

Silver gold nanoparticles have acceptable antibacterial properties and low cytotoxicity to be used as canal pretreatment prior to the application of the sealer or even incorporated with AH Plus sealer.

The Influence of Bioceramic Cements on the Activity of Macrophages of Different Lineages: A Laboratory Study

INTRODUCTION

The repair process of periradicular tissues depends, among other factors, on the properties of endodontic cements. Macrophages are among the main cells involved in this process.

MATERIALS AND METHODS

Murine peritoneal macrophages obtained from C57BL/6 (MBL6) and BALB/c (MBalb) mice, respectively, were cultured with capillaries containing or not Endosequence BC Sealer (BC), Sealer Plus BC (MK), Bio-C Sealer (Ang), and mineral trioxide aggregate (MTA). Cell viability was measured by Trypan blue and MTT methods at 24, 48, and 72 hours. Cell adhesion, phagocytosis of Saccharomyces boulardii, production of reactive oxygen species (ROS), nitric oxide (NO), and the cytokines tumor necrosis factor-α and transforming growth factor (TGF)-β were also evaluated. The data were analyzed using the analysis of variance test (P < .05).

RESULTS

Cell viability was similar between bioceramic sealers and MTA (P > .05). There was no statistical difference between both macrophages when adherence and phagocytose were assayed. The presence of inflammation stimulus significantly altered the production of ROS by MBL6 macrophages in contact with the cements. The production of TGF-β was similar for both lineages of macrophages.

CONCLUSIONS

This study shows that the evaluated bioceramic cements do not interfere with MBL6 and MBalb macrophage adhesion, phagocytic capacity, or TGF-β production. The cements stimulated the production of ROS by MBL6 macrophages in response to induced inflammation, potentially favoring the elimination of residual pathogens.

Oxidative damage analysis and cell viability of Drosophila melanogaster exposed to three different endodontic sealers: an in vivo and ex vivo study

The aim of this work was to evaluate the toxicological action of AH Plus (AHP), Bio-C Sealer (BCS), and EndoSequence BC Sealer (ESB), using Drosophila melanogaster as the model organism performing in vivo and ex vivo analysis. D. melanogaster were exposed for 10 days to three concentrations (5 mg/ml, 10 mg/ml, and 20 mg/ml) of AHP, BCS, and ESB sealers mixed with 10 ml of standard diet. During this period, the mortality of flies was evaluated. On the 11th day, the locomotor activity test was performed and the flies were euthanized for oxidative damage analysis (reactive species and lipid peroxidation) and cell viability (resazurin reduction). For the mortality curves evaluation, the log-rank test (Mantel-Cox) was used. For the analysis of other data, a one-way analysis of variance (ANOVA) was applied, followed by Tukey's post hoc test (α  =  0.05). Regarding mortality, there were no significant differences. The locomotor activity was reduced, mainly in the two highest concentrations of AHP and BCS. Besides, reactive species generation was bigger in the AHP 20 mg/ml group. AHP induced a lipid peroxidation increase in all three concentrations tested, when compared to other sealers. Considering cell viability, the two highest concentrations of AHP reduced this parameter; while in other sealers, viability was reduced only in the highest concentration. AHP showed changes in oxidative markers that led to greater damage to the flies.

Influence of bioceramic sealers on dentinal tubule penetration and antimicrobial effectiveness: a systematic review and meta-analysis of in vitro studies

The aim of this systematic review and meta-analysis (SRM) was to evaluate whether bioceramic sealers have better penetration capacity in dentinal tubules and antimicrobial activity when compared to AH Plus® sealer. This SRM was recorded in the Open Science Framework database and followed the guidelines of the PRISMA 2020. Five databases were searched by two independent reviewers. Only in vitro studies that evaluated the effects of bioceramic sealers on dentinal tubule penetration and antimicrobial activity outcomes compared to AH Plus® sealer were included. Meta-analysis was conducted using R software, using the effect measure of the standardized mean difference (SMD) and inverse variance method. A modified Joanna Briggs Institute's Checklist was used for the risk of bias assessment. A total of 1486 studies were identified, and only 54 studies that fulfilled our eligibility criteria were included in this review. There was no statistical difference between the sealers evaluated for dentinal tubule penetration, in the thirds evaluated: coronal SMD 0.58 [0.14; 1.31], p = 0.12; middle SMD 0.07 [0.54; 0.39], p = 0.75; and apical SMD 0.08 [0.73; 0.56], p = 0.80. Both sealers demonstrated similar antimicrobial action (SMD [3.42; 5.32], p = 0.67 and SMD 0.67 [1.89; 0.55], p = 0.28). The studies presented a low risk of bias. Based on the in vitro studies included and according to the limitations of the present review, the data suggest that bioceramic and AH Plus® sealers present similar penetration capacity in dentinal tubules and antimicrobial effect, making them suitable materials to be considered in clinical practice.

Nanoleakage of apical sealing using a calcium silicate-based sealer according to canal drying methods

Objectives

This study investigated the nanoleakage of root canal obturations using calcium silicate-based sealer according to different drying methods.

Materials and Methods

Fifty-two extracted mandibular premolars with a single root canal and straight root were selected for this study. After canal preparation with a nickel-titanium rotary file system, the specimens were randomly divided into 4 groups according to canal drying methods (1: complete drying, 2: blot drying/distilled water, 3: blot drying/NaOCl, 4: aspiration only). The root canals were obturated using a single-cone filling technique with a calcium silicate-based sealer. Nanoleakage was evaluated using a nanoflow device after 24 hours, 1 week, and 1 month. Data were collected twice per second at the nanoscale and measured in nanoliters per second. Data were statistically analyzed using the Kruskal-Wallis and Mann-Whitney U-tests (p < 0.05).

Results

The mean flow rate measured after 24 hours showed the highest value among the time periods in all groups. However, the difference in the flow rate between 1 week and 1 month was not significant. The mean flow rate of the complete drying group was the highest at all time points. After 1 month, the mean flow rate in the blot drying group and the aspiration group was not significantly different.

Conclusions

Within the limitations of this study, the canal drying method had a significant effect on leakage and sealing ability in root canal obturations using a calcium silicate-based sealer. Thus, a proper drying procedure is critical in endodontic treatment.

Evaluation of the antibacterial and cytotoxic properties of TotalFill and NeoSEALER flo bioceramic sealers

Aim

Evaluation of the antibacterial and cytotoxic properties of TotalFill and NeoSEALER Flo bioceramic sealers compared to AH Plus resin sealer.

Materials and Methods

Modified direct contact test was used on three sets of sealers: Freshly mixed sealers, sealers that were 1-day old, and sealers that were 7-day old. After 24 h of incubation, the colony-forming units were digitally counted using Promega Colony Counter after 30 and 60 min of exposure to Enterococcus faecalis. For cytotoxic effect evaluation, 3-(4,5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assay was performed at three different time points: 24 h, 48 h, and 120 h after adding the sealer eluates to human gingival fibroblasts, to assess cell viability. Data were analyzed using mixed model analysis of variance followed by post hoc test.

Results

TotalFill bioceramic sealer showed the highest bacterial reduction against E. faecalis throughout all intervals. AH Plus showed great antibacterial activity initially which reduced drastically after 7 days. All the sealers showed a reduction in their antibacterial activity with time. TotalFill and NeoSEALER Flo showed very high cell viability in contrast to AH Plus.

Conclusion

TotalFill and NeoSEALER Flo demonstrate superior antimicrobial properties against E. faecalis which reduces with time. TotalFill and NeoSEALER Flo demonstrate acceptable biocompatibility against human gingival fibroblasts, which decreased over time.

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

Objectives

The aim was to determine whether premixed calcium silicate-based root canal sealers have better biological properties than AH Plus.

Materials and Methods

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.

Results

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.

Conclusion

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.

Cytotoxicity and genotoxicity of bioceramic root canal sealers compared to conventional resin-based sealer

The aim of this study was to evaluate cytotoxicity and genotoxicity of calcium-silicate based sealers and comparing them with a gold standard-an epoxy-based sealant. Two experimental cell lines were used, gingival fibroblasts (hGF) and monocyte/macrophage peripheral blood cell line (SC). The cytotoxicity (XTT assay) and genotoxicity (comet assay) were evaluated both after 24-h and 48-h incubation. Additionally, after 48-h incubation, the cell apoptosis and cell cycle progression was detected. BioRoot Flow induced a significant decrease in hGF cells viability compared to the negative control groups both after 24-h (p < 0.001) and 48-h incubation (p < 0.01). In group with SC cells, after 24-h incubation significant increase in cells viability was detected for AH Plus Bioceramic Sealer in comparison to negative control (p < 0.05). BioRoot Flow and BioRoot RCS can be considered potentially genotoxic for the hGF cells after 48-h incubation (> 20% DNA damage). BioRoot Flow and BioRoot RCS, may have potential genotoxic effects and induce apoptosis in hGF cells which may irritate periapical tissues, resulting in a delayed healing. The findings of the study would be useful in selection of an appropriate sealant for root canal filling without causing cytotoxicity and genotoxicity.

In silico toxicity and immunological interactions of components of calcium silicate-based and epoxy resin-based endodontic sealers

OBJECTIVES

The present study aimed to determine in silico toxicity predictions of test compounds from hydraulic calcium silicate-based sealers (HCSBS) and AH Plus and computationally simulate the interaction between these substances and mediators of periapical inflammation via molecular docking.

MATERIALS AND METHODS

All chemical information of the test compounds was obtained from the PubChem site. Predictions for bioavailability and toxicity analyses were determined by the Molinspiration Cheminformatics, pkCSM, ProTox-II and OSIRIS Property Explorer platforms. Molecular docking was performed using the Autodock4 AMDock v.1.5.2 program to analyse interactions between proteins (IL-1β, IL-6, IL-8, IL-10 and TNF-α) and ligands (calcium silicate hydrate, zirconium oxide, bisphenol-A epoxy resin, dibenzylamine, iron oxide and calcium tungstate) to establish the affinity and bonding mode between systems.

RESULTS

Bisphenol-A epoxy resin had the lowest maximum dose tolerated in humans and was the test compound with the largest number of toxicological properties (hepatotoxicity, carcinogenicity and irritant). All systems had favourable molecular docking. However, the ligands bisphenol-A epoxy resin and dibenzylamine had the greatest affinity with the cytokines tested.

CONCLUSION

In silico predictions and molecular docking pointed the higher toxicity and greater interaction with mediators of periapical inflammation of the main test compounds from AH Plus compared to those from HCSBS.

CLINICAL RELEVANCE

This is the first in silico study involving endodontic materials and may serve as the basis for further research that can generate more data, producing knowledge on the interference of each chemical compound in the composition of different root canal sealers.

Genotoxicity induced by endodontic sealers: A systematic review

Introduction

This systematic review aimed to help further elucidate the following question: are endodontics sealers able to induce DNA damage in vitro or in vivo?

Methods

This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement 2020 criteria. A total of 23 studies were carefully selected by the authors.

Results

Regarding the general characteristics, most studies evaluated, on average, 3-5 types of sealers (resin epoxy, salicylate, salicylate + MTA, zinc oxide-eugenol, bioceramic products, calcium hydroxide), performing comparisons between them. Our results demonstrate that endodontic sealers may be a genotoxic agent since most studies demonstrated positive findings, with the resin-based ones being the most potentially genotoxic.

Conclusion

The type of genotoxicity assay, material evaluated, and dilution concentration levels influenced the outcome. This study clarifies whether and to what extent endodontic sealers are capable of inducing DNA injury in oral tissues.

Evaluation of Antibacterial Effect of New Sealer "Neoseal" and Two Commercially Used Endodontic Sealers against Enterococcus faecalis: An In Vitro Study

AIM

To evaluate the antibacterial activity of three endodontic sealing materials, Neoseal, CeraSeal, and AH Plus against Enterococcus faecalis bacteria in vitro.

MATERIALS AND METHODS

The antibacterial activity of three endodontic sealing materials including two bioceramic sealers; NeoSEALER Flo (group I), CeraSeal (group II), and one epoxy resin sealer; AH Plus (group III) was investigated against E. faecalis bacteria American Type Cell Culture Collection (ATCC) 29212 (ATCC, Rockville, Maryland, USA). Using modified direct contact test (MDCT). The endodontic sealers were tested in contact with bacterial suspension when unset (20 minutes after mixing) and after setting, assessing the antibacterial activity of aged sealers after 1, 3, 7, and 14 days. Analyzing the collected data has been done with version 25.0 of the statistical package for the social sciences (SPSS) IBM software (SPSS, Chicago, Illinois, USA). Descriptive analyses were calculated using standard deviation (SD) and mean. Shapiro-Wilk test was done to detect the normality of the result values. Kruskal-Wallis test was then performed to test the level of significance between groups.

RESULTS

After 20 minutes - Group I showed higher bacterial count mean values (5,500 ± 500) and 0 values for groups II and III groups. After 1 day, the highest bacterial count mean values were in group III (54,333.3 ± 4,041.5) and 0 values for groups I and II. After 3 days - group III again recorded the highest bacterial count mean values (45,000 ± 5,000) and 0 values for I and II groups. After 7 days - Group III still recorded the highest bacterial count mean values (53,333.3 ± 1,527.5) and 0 values for groups I and II. After 14 days - Group III recorded the highest bacterial count mean values (56,000 ± 1,000) followed by group II (6,333.3 ± 577.4), and the least was group I (2,000 ± 500). Kruskal-Wallis test showed significant values between groups in all tested durations, p > 0.05.

CONCLUSION

The sealing material AH Plus showed a strong bactericidal effect at the beginning but lost its ability after 24 hours. CeraSeal showed strong bactericidal activity from the beginning till the end of the first week but showed bacterial count at 14 days. Neoseal took 24 hours to show bactericidal effect and similar to CeraSeal showed bacterial count at 14 days; CeraSeal recorded the best results within the study.

CLINICAL SIGNIFICANCE

Silicate-based (bioceramic) endodontic sealers can be the best available endodontic sealing material that is clinically beneficial in removing residual microbes which had survived irrigation protocols and chemomechanical preparation. How to cite this article: Basta DG, Reslan MR, Rayyan M, et al. Evaluation of Antibacterial Effect of New Sealer "Neoseal" and Two Commercially Used Endodontic Sealers against Enterococcus faecalis: An In Vitro Study. J Contemp Dent Pract 2023;24(11):871-876.

The solubility, pH value, chemical structure, radiopacity, and cytotoxicity of four different root canal sealers: an in vitro study

OBJECTIVE

The aim of this study was to investigate solubility, pH value, chemical structure, radiopacity, and cytotoxicity of AH Plus BC, TotalFill BC, AH Plus, and AH Plus Jet sealers.

MATERIALS AND METHODS

Cytotoxicity analysis with direct and extraction tests at 3 different concentrations (1:1, 1:2, 1:4 v/v%) and time (24 h, 48 h, and 72 h) on Saos-2, PdLF, and THP-1 cell lines, chemical structure with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analysis, solubility, pH, and radiopacity values of AH Plus BC, TotalFill BC, AH Plus, and AH Plus Jet were evaluated. For statistical analyses of the groups, repeated measures, factorial, and one-way ANOVA tests were used. The statistical significance level was set at p < .05.

RESULTS

Resin-based sealers showed higher cytotoxicity values than the bioceramic-based sealers (p < 0.05). Time and concentrations were effective on the cell viabilities for cell lines. Higher peaks of calcium were detected bioceramic-based sealers and higher amount of zirconium was detected in AH Plus BC (p < 0.05). AH Plus BC showed similar radiopacity value with AH Plus, AH Plus Jet, whereas TotalFill BC showed the lowest radiopacity (p < 0.05). Bioceramic-based sealers had higher pH values in all experiment periods, and the difference between resin- and bioceramic-based sealer groups was significant (p < 0.05). However, the solubility values of the tested root canal sealers revealed no differences (p > 0.05).

CONCLUSIONS

The newly produced AH Plus BC Sealer showed similar properties with TotalFill BC, and their biological properties were better than AH Plus and AH Plus Jet.

CLINICAL RELEVANCE

AH Plus BC could be a possible alternative to other bioceramic- or resin-based sealers.

Comparative antimicrobial activity of four different endodontic sealers

Dental cements are widely used in the clinical routine, specifically for root canal sealing. Within this context, it is expected that these materials present antimicrobial activity, since it would help in the prevention of apical and periapical infections. The present study aimed to comparatively verify the antimicrobial activity of four dental cements against microorganisms that are routinely isolated from endodontic infections. Reference strains of Enterococcus faecalis, Candida albicans and Escherichia coli were submitted to the agar diffusion test and to modified direct contact test using four different sealers: an eugenol zinc oxide compound, an epoxy resin associated to calcium hydroxide and bismuth, a mineral trioxide aggregate (MTA) and a bioceramics. Different E. coli, C. albicans and E. faecalis growth inhibition profiles were observed in the agar diffusion assay. In the direct contact test, the bioceramics presented a higher microbicide activity on all microorganisms tested herein. Dental cements have different antimicrobial activities, being that the bioceramics present the most consistent antimicrobial activity, and that the direct contact test presented more uniform results than the agar diffusion test. This study reveals the antimicrobial activities of different cements and allow dentists to decide which material to employ in their daily practice.

Canal Drying Protocols to Use with Calcium Silicate-based Sealer: Effect on Bond Strength and Adhesive Interface

INTRODUCTION

The aim of this study was to evaluate the influence on bond strength and interface quality of different canal drying protocols in roots filled with Bio-C Sealer (BCS; Angelus, Londrina, Paraná, Brazil).

METHODS

Ninety-six roots of upper canines were prepared with an R50 file (Reciproc; VDW GmbH, Munich, Germany) and irrigated with 2.5% sodium hypochlorite and 17% EDTA under ultrasonic agitation. Roots were divided according to the drying protocol as follows: dry, the White Mac tip (Ultradent, Indaiatuba, SP, Brazil) for 5 seconds followed by aspiration with a capillary tip for 5 seconds and paper points; slightly moist, the White Mac tip followed by capillary aspiration without paper points; wet, the White Mac tip followed by a single paper point. The roots were filled with BCS or AH Plus (AHP; Dentsply Maillefer, Ballaigues, Switzerland) (n = 16) and sectioned for the push-out test after 3 months. Failure modes were assessed, and the interface morphology was analyzed under scanning electron microscopy. After 6 months, the other half of the roots were evaluated. Data were analyzed by analysis of variance/Tukey test at 5%. The chi-square test was used in the failure analysis and the Kruskal-Wallis/Dwass-Steel-Critchlow-Fligner for interface analysis.

RESULTS

The AHP-filled roots had the highest bond strength when the canal was dried (P < .05). No difference was found for periods (P > .05). For BCS, the highest bond strength was found in the slightly moist canals (P < .05). A predominance of adhesive failures was observed. The dried canals filled with AHP had the highest percentage of good adaptation, whereas BCS had no difference.

CONCLUSIONS

The best drying protocol for AHP is using the White Mac tip followed by capillary tip aspiration and paper points until complete dryness, and for BCS, it is using the White Mac tip followed by capillary aspiration without paper points.

Calcium Silicate-based Sealer Extrusion into the Mandibular Canal: Three Different Recovery Outcomes: A Report of Three Cases

The use of calcium silicate-based sealers (CSS) is increasing in dentistry as result of their favorable properties. The inadvertent extrusion of these sealers into the mandibular canal (MC) can result in temporary or permanent neurosensory alterations. Three different recovery outcomes of CSS extrusion into the MC after endodontic treatment of mandibular molars, confirmed by cone beam computed tomography (CBCT) imaging, are described. In Case 1, CSS from the mesiolingual canal of #31 was extruded into the MC during obturation. The patient reported paresthesia. The symptoms of paresthesia were completely resolved by nine months. In Case 2, CSS from the mesial canals of #30 was extruded into the MC during obturation. "Plasma-like spreading pattern" of the extruded sealer was observed on the radiographs. The patient reported paresthesia and dysesthesia. In addition, the patient complained of hyperalgesia with heat and mechanical allodynia. The symptoms continued to persist during follow up. At 22 months, the patient still reported persistent paresthesia, hyperalgesia and mechanical allodynia, affecting the ability to eat. In Case 3, CSS from the distal canal of #31 was extruded into the MC during obturation. The patient did not report any paresthesia or dysesthesia. All three patients elected a follow up approach and monitoring rather than surgical intervention. These cases illustrate the need for the development of guidelines for the management of iatrogenic CSS extrusion into the MC because such an occurrence may not necessarily result in permanent, temporary or no neurosensory alterations.

Purification, Characterization, and Assessment of Antimicrobial Activity and Toxicity of Portulaca elatior Leaf Lectin (PeLL)

Lectins are carbohydrate-binding proteins with several bioactivities, including antimicrobial properties. Portulaca elatior is a species found at Brazilian Caatinga and data on the biochemical composition of this plant are scarce. The present work describes the purification of P. elatior leaf lectin (PeLL) as well as the assessment of its antimicrobial activity and toxicity. PeLL, isolated by chromatography on a chitin column, had native liquid charge and subunit composition evaluated by electrophoresis. Hemagglutinating activity (HA) of PeLL was determined in the presence of carbohydrates or divalent cations, as well as after heating and incubation at different pH values. Changes in the lectin conformation were monitored by evaluating intrinsic tryptophan fluorescence and using the extrinsic probe bis-ANS. Antimicrobial activity was evaluated against Pectobacterium strains and Candida species. The minimal inhibitory (MIC), bactericidal (MBC), and fungicidal (MFC) concentrations were determined. Finally, PeLL was evaluated for in vitro hemolytic activity in human erythrocytes and in vivo acute toxicity in mice (5 and 10 mg/kg b.w. per os). PeLL (pI 5.4; 20 kDa) had its HA was inhibited by mannose, galactose, Ca²⁺, Mg²⁺, and Mn²⁺. PeLL HA was resistant to heating at 100 °C, although conformational changes were detected. PeLL was more active in the acidic pH range, in which no conformational changes were observed. The lectin presented MIC and MBC of 0.185 and 0.74 μg/mL for all Pectobacterium strains, respectively; MIC of 1.48 μg/mL for C. albicans, C. tropicalis, and C. krusei; MIC and MFC of 0.74 and 2.96 μg/mL for C. parapsilosis. No hemolytic activity or signs of acute toxicity were observed in the mice. In conclusion, a new, low-toxic, and thermostable lectin was isolated from P. elatior leaves, being the first plant compound to show antibacterial activity against Pectobacterium.

Effect of Different Sealers on the Cytocompatibility and Osteogenic Potential of Human Periodontal Ligament Stem Cells: An In Vitro Study

Background: There is tendency for unavoidable sealer extrusion in some clinical cases. This might adversely affect host stem cells and affect healing. This study aimed to investigate the effect of different sealers on the cytocompatibility and osteogenic potential of human periodontal ligament stem cells (hPDLSCs). Methods: The cytotoxic effect of the extracted elutes of VDW.1Seal (VDW.1), Endosequence BC Sealer HiFlow (ES), GuttaFlow-2 (GF), and ADSeal (AD-S) on the hPDLSCs was determined using the MTT assay. Cell proliferation and migration were assessed by the scratch wound healing assay. Osteogenic differentiation potential was assessed. Measurement of pH values and calcium ions release was performed. Results: GF had a significantly higher percentage of viable cells. The cell migration assay showed that GF demonstrated the lowest open wound area percentage. GF and AD-S showed the highest calcium nodule deposition. GF demonstrated higher ALP activity than ES. Expression of RUNX2 and OC genes was similar for all sealers, while OPG gene expression was significantly higher for VDW.1 and GF. ES and AD-S displayed the highest pH values on day 1. Calcium ion release of ES and VDW.1 was significantly the highest. Conclusions: GuttaFlow-2 and VDW.1Seal sealers have favorable behavior toward host stem cells.

In vitro inflammatory modulation of bioceramic endodontic sealer in macrophages stimulated by bacterial lipopolysaccharide

AIM

To evaluate the effects of AH Plus (Dentsply), Sealer 26 (Dentsply), and Sealer Plus BC (Produtos Médicos e Odontológicos) on cytotoxicity and inflammation in macrophage cultures exposed to bacterial lipopolysaccharide (LPS).

METHODOLOGY

After initial setting, the sealers were conditioned with serum-free culture medium for 24 h (1 ml/cm² ). Macrophages from the RAW 264.7 strain were exposed to sealer extracts in a 1:16 ratio in a culture medium with or without LPS. Cell morphology, viability, mitochondrial activity, oxidative stress and gene expression of interleukin 1β (IL-1β) and tumour necrosis factor-alpha (TNF-α) were evaluated. Data on mitochondrial activity, oxidative stress and TNF-α were analysed using a two-way analysis of variance (anova) test, followed by the Student-Newman-Keuls post-test. IL-1β data were analysed using one-way anova, followed by SNK, and the t-test was used for intragroup comparison. The significance level was set at 5%.

RESULTS

In the absence of LPS, only AH Plus and Sealer 26 showed a reduction in cell density, while in the presence of LPS, Sealer 26 had the lowest density compared to the other groups. In terms of mitochondrial activity, at 24 and 48 h, Sealer Plus BC had significantly higher mean values than Sealer 26 and AH Plus (p < .05). Sealer 26 exhibited the lowest levels of oxidative stress and IL-1β and TNF-α expression, regardless of the presence of LPS (p < .05).

CONCLUSIONS

Although all sealers interfere with the response of macrophages to LPS, contact with epoxy resin-based sealers can impair cell activity in vitro, while bioceramic sealer seems to favour the inflammatory functions of these cells.

Mechanism of action of Bioactive Endodontic Materials

A continuous search for bioactive materials capable of supporting the replacement of damaged pulp tissue, with effective sealing potential and biocompatibility, has represented the attention of studies over the last decades. This study involves a narrative review of the literature developed by searching representative research in PUBMED/MEDLINE and searches in textbooks associated with the mechanism of action of bioactive materials (calcium hydroxide, mineral trioxide aggregate (MTA), and calcium silicate cements). The reflective analysis of the particularities of the chemical elements of these materials, considering the tissue and antibacterial mechanism of action, allows a better understanding of the characteristics and similarities in their tissue responses. Calcium hydroxide paste remains the antibacterial substance of choice as intracanal dressing for the treatment of root canal system infections. Calcium silicate cements, including MTA, show a favorable biological response with the stimulation of mineralized tissue deposition in sealed areas when in contact with connective tissue. This is due to the similarity between the chemical elements, especially ionic dissociation, the potential stimulation of enzymes in tissues, and the contribution towards an alkaline environment due to the pH of these materials. The behavior of bioactive materials, especially MTA and the new calcium silicate cements in the biological sealing activity, has been shown to be effective. Contemporary endodontics has access to bioactive materials with similar properties, which can stimulate a biological seal in lateral and furcation root perforations, root-end fillings and root fillings, pulp capping, pulpotomy, apexification, and regenerative endodontic procedures, in addition to other clinical conditions.

In vitro antibacterial activity of endodontic bioceramic materials against dual and multispecies aerobic-anaerobic biofilm models

The aim of this in vitro study was to evaluate the antibacterial activity of calcium silicate repair cements and sealers against a dual-species planktonic aerobic model with different aging times and the ability to inhibit the formation of a mature 21-day-old multispecies anaerobic biofilm. The antibacterial activity of ProRoot MTA, MTA Angelus, Biodentine, BioRoot RCS and TotalFill BC sealer against a dual-species aerobic planktonic model, as well as measuring how materials were affected by aging, was evaluated using the Modified Direct Contact Test. Subsequently, the ability to inhibit the formation of a mature multispecies anaerobic biofilm was evaluated using scanning electron microscopy complemented with confocal laser scanning microscopy. Biodentine and BioRoot RCS had higher antibacterial action, and Biodentine was able to maintain its antibacterial action after a prolonged aging period in vitro. Calcium silicate repair cement MTA ProRoot and Biodentine had higher antibiofilm action.

Effect of the Modified Methacrylate-Based Root Canal Sealer in Single-Cone Technique

This study aimed to modify EndoREZ with 2.5% dimethylaminododecyl methacrylate (DMADDM) and 1% magnetic nanoparticles (MNP) to study its sealing property, penetration and long-term antibacterial and therapeutic effect in the single-cone technique (SCT) compared with EndoREZ and iRoot SP. Thirty single-root human maxillary premolars were assigned into three groups and obturated with three different root canal sealers by SCT. Every specimen was then scanned using micro-CT to analyze void fraction, and void volumes and confocal laser scanning microscope (CLSM) was used to study the dentin penetration. The long-term antimicrobial effects were tested in vitro before and after aging 1 and 4 weeks by the single-strain Enterococcus faecalis biofilm model. In addition, the beagle canine model of apical periodontitis (AP) was utilized to judge and compare the therapeutic effect of three sealers in SCT. The void fraction and void volumes of the modified root canal sealer were not significantly different from iRoot SP (p > 0.05) but were lower than EndoREZ (p < 0.05). The modified root canal sealant displayed a greater penetration, long-term antibacterial property, and treatment effect than the other groups (p < 0.05). This indicated that after being modified with DMADDM and MNP, it showed better performance in SCT.

Clinical outcome of bioceramic sealer iRoot SP extrusion in root canal treatment: a retrospective analysis

Background

During the obturation procedure, sealer extrusion occurs in some cases. iRoot SP is a kind of bioceramic sealer with superior physicochemical and biological properties. This article reports the outcome of iRoot SP extrusion in root canal treatment and the potential factors associated with the outcome.

Methods

Ninety-nine patients and one hundred and eighty-five teeth treated between 2014 and 2020 were included in this retrospective study. All of the cases were filled with a single-cone technique and the iRoot SP sealer. The minimum follow-up visit period was 1 year. The outcome was evaluated by clinical examination and radiographic examination at recall and was classified as healed, healing (success), or not healed (failure).

Results

The overall success rate of all teeth was 96.8%. The success rate of adequately filled teeth was 97.3%, while that of iRoot SP extrusion was 95.8%; the difference was not statistically significant. Factors such as gender, age, tooth position, follow-up visit period, size of periapical lesion, treatment type and extruding sealer amount had no influence on the outcome of iRoot SP extruded teeth.

Conclusions

The results suggested that iRoot SP extrusion has no adverse effect on the outcome of root canal treatment, which may contribute to the endodontic treatment.

Cytotoxicity and Genotoxicity of Epoxy Resin-Based Root Canal Sealers before and after Setting Procedures

Epoxy resin-based sealers are commonly used for successful endodontic treatment. This study aimed to evaluate the cytotoxicity and genotoxicity of epoxy resin-based sealers under unset and set conditions. Three epoxy resin-based sealers were used: Adseal, AH Plus, and Dia-Proseal. To test cytotoxicity, an agar overlay test and a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay were performed using unset and set sealers on L929 mouse fibroblasts. The genotoxicity test of the comet assay was performed using the same cell line. Extract dilutions in the culture media were used as test materials for the MTT and comet assays. The comet tail produced by the damaged DNA was calculated by image analyses. Statistical analyses were performed using one-way analysis of variance and Tukey’s post hoc test. Unset sealers did not show defined decolorized areas. Hardened specimens of resin-based sealers showed circular discolored zones in the agar overlay test. Dia-Proseal was the least cytotoxic after hardening. These results were confirmed in the MTT assay. Cell viability was significantly higher in cells treated with hardened sealers in both groups than that in cells treated with freshly mixed sealers in the MTT assay. Unset AH Plus^® and Dia-Proseal™ significantly increased cell viability with decreasing dilution. Adseal™ was the least cytotoxic. Freshly mixed Adseal™ was more genotoxic when freshly mixed than when set. Unset epoxy resin-based sealers were generally more cytotoxic and genotoxic than set materials. Cytotoxicity does not always match the genotoxicity results; therefore, various test tools are required to test toxicity. It is necessary to properly evaluate the toxic effects to establish a biocompatibility test that mimics clinical conditions.

Influence of acidic pH on antimicrobial activity of different calcium silicate based-endodontic sealers

OBJECTIVE

To investigate the antibacterial activity of calcium silicate-based sealers (CSBSs) against Enterococcus faecalis biofilm in a neutral or acidic condition.

MATERIALS AND METHODS

Dentin cylinders (4 mm length) were prepared and infected with 3-week-old E. faecalis. The samples were filled with BioRoot RCS (BR), EndoSequence BC (ES), and NeoMTA Plus (NMTA) and incubated in either neutral or acidic conditions for 7 days (n=10/group). Sterile or infected samples alone were used as the positive and negative control. The root canal sealers were removed after 7 days, and the remaining bacteria on dentinal walls were determined by colony-forming units (CFUs/ml), and three samples from each group were visualized under a confocal laser scanning microscope (CLSM). The pH was also measured (n=3/group) after 4 h and 7 days of incubation at 37°C in both conditions.

RESULTS

In the neutral condition, all sealers significantly decreased the log-CFU values (p<0.05), while in the acidic condition, the log-CFU reduction was less for ES and NMTA, but a higher reduction was observed in BR (p<0.05). The antibacterial activity of CSBSs was similar in neutral conditions (p>0.05), and BR showed a greater antibacterial effect than ES and NMTA in the acidic condition (p<0.05). The pH of BR, ES, and NMTA ranged from 8.2 to 8.8 in the neutral condition in the presence of dentin after 7 days. However, acidic conditions reduced the pH values to 7.8 for BR, 6.0 for ES, and 5.8 for NMTA.

CONCLUSIONS

All CSBSs showed similar antibacterial activity in neutral conditions, while acidic pH had a reducing antibacterial effect on CSBSs.

CLINICAL RELEVANCE

Inflammatory pH decreased the antibacterial properties of CSBSs depending on the sealer type.

Impact of Immersion Media on Physical Properties and Bioactivity of Epoxy Resin-Based and Bioceramic Endodontic Sealers

This study assessed the effects of immersion media [distilled water (dw), phosphate buffered saline (pbs) and simulated body fluid (sbf)] in the physical properties [fluid uptake/sorption/solubility and alkalinization activity (pH)] and bioactivity of a bioceramic sealer: the BioRoot RCS (BioRoot) (Septodont). The epoxy-resin sealer AH Plus (Dentsply) was used as comparison. Sealers were immersed in dw, pbs and sbf to evaluate the fluid uptake/sorption/solubility and pH’s media. Bioactivity was assessed with SEM/EDS, FTIR-ATR and XRD. BioRoot solubility was as follows: sbf > pbs = dw. BioRoot had alkaline pH, and AH Plus had neutral pH, regardless of the medium. BioRoot presented mineral precipitates and peaks indicating hydroxyapatite-precursors in pbs and sbf. AH Plus physical properties were not affected by immersion media and it had no bioactivity. pbs and sbf should be preferred to investigate bioceramic sealers over distilled water, because they were able to highlight the sealer properties. BioRoot maintained the alkaline environment and favored hard tissue deposition.

Comparison of Obturation Quality between Calcium Silicate-Based Sealers and Resin-Based Sealers for Endodontic Re-treatment

BACKGROUND

The objective of this micro-computed tomography (micro-CT)-based study was to compare the filling quality of endodontic treatment and endodontic Re-treatment between two sealers with matched obturation techniques: calcium silicate-based sealer (Endoseal TCS) with a single-cone technique (SCT) and resin-based sealer (AH Plus) with a continuous wave technique (CWT).

METHODS

Forty maxillary premolars were selected and assigned into four groups, according to the obturation methods of the first endodontic treatment and Re-treatment (n = 10). The AP/AP group was first treated with AH Plus/CWT, then re-treated with AH Plus/CWT. The AP/ET group was first treated with AH Plus/CWT, then re-treated with Endoseal TCS/SCT. The ET/AP group was first treated with Endoseal TCS/SCT, then re-treated with AH Plus/CWT, and the ET/ET group was first treated with Endoseal TCS/SCT, then re-treated with Endoseal TCS/SCT. The specimens were scanned using micro-CT at three time points: after the first endodontic treatment, after gutta-percha (GP) cone removal, and after Re-treatment. The void volume of root canal obturation and the volume of the remaining filling materials were calculated. Data were analyzed using Student's t-tests and ANOVA.

RESULTS

The Endoseal TCS groups (ET/AP and ET/ET) showed a lower percentage of voids than the AH plus groups (AP/AP and AP/ET) on the whole canal and the apical third, after first obturation (p < 0.05). The AH plus group showed significantly fewer remnants than the Endoseal TCS group after GP removal (p < 0.05). Re-treated canals and initially treated canals had similar void volumes (p > 0.05). There was no significant difference in void volume after Re-treatment, regardless of whether the same or different sealers were used for the first treatment and Re-treatment (p < 0.05).

CONCLUSIONS

Endoseal TCS sealer and AH Plus sealer had a similar Re-treatment efficacy, regardless of which sealer was used in the previous treatment.

An in vitro study on the effects of serum proteins on Enterococcus faecalis adhesion to three types of root sealers and gutta-percha

BACKGROUND

The extrusion of overfilled materials that extend beyond the apical foramina into the periradicular tissue may serve as a reservoir for bacterial adhesion and further affect recovery from periapical diseases. The aim of this study was to evaluate the effects of serum proteins on Enterococcus faecalis adhesion and survival on the surface of a calcium hydroxide-based root canal sealer (Apexit Plus), an epoxy resin sealer (AH-Plus) and a bioceramic sealer (iRoot SP).

METHODS

Apexit Plus, AH-Plus and iRoot SP were evenly coated on gutta-percha, using gutta-percha alone as the control. After root canal sealer setting, the number of E. faecalis adhering to the root canal sealers and gutta-percha was counted in fetal bovine serum (FBS) or tryptic soy broth supplemented with 1% glucose (TSBG) by viable cell plate counts. The morphology of 7-day-old E. faecalis biofilms in FSB and TSBG was observed by scanning electron microscopy (SEM). Furthermore, E. faecalis biofilms on the three root canal sealers were labeled with a LIVE/DEAD BacLight™ Bacterial Viability Kit, and the ratios of viable to dead cells were analyzed using laser scanning microscopy operative software (Zen software).

RESULTS

In the assays, after 1 and 7 days, the number of E. faecalis adhering to the root canal sealers or gutta-percha in FBS were significantly lower than those in TSBG (P < 0.05). In FBS, E. faecalis adhesion to iRoot SP and gutta-percha was reduced to a greater extent than that adhered to Apexit Plus and AH-Plus. Few E. faecalis accumulated on iRoot SP in FBS, whereas many bacteria assembled on iRoot SP and formed biofilms in TSBG. The ratio of viable cells in the E. faecalis biofilm on iRoot SP was the lowest.

CONCLUSIONS

Calcium hydroxide-based root canal sealers, epoxy resin sealers and bioceramic sealers may provide a substrate for E. faecalis adhesion, and the bioceramic sealer in this study showed the least E. faecalis adhesion in the presence of serum proteins compared to the other two sealers.

Evaluation of the Physicochemical and Biological Properties of EndoSequence BC Sealer HiFlow

INTRODUCTION

Understanding the physicochemical and biological properties of endodontic sealers is important for endodontic treatment planning. This study evaluated the properties of EndoSequence BC Sealer HiFlow (BCH; Brasseler USA, Savannah, GA), EndoSequence BC Sealer (BC, Brasseler USA), and AH Plus (AHP; Dentsply DeTrey, Konstanz, Germany). The effect of temperature on the setting time and flow of these sealers was also evaluated.

METHODS

The setting time, flow, radiopacity, pH, solubility, and calcium release were investigated following ISO guidelines. The morphology and chemical composition of the sealers were evaluated by scanning electron microscopy and energy-dispersive spectroscopy. The antibacterial activity of sealers was tested against 2 strains of Enterococcus faecalis. Sealer cytotoxicity and the effects on messenger RNA expression of proinflammatory and mineralization genes were also investigated. Data analysis was performed using analysis of variance, Tukey, Kruskal-Wallis, and Dunn multiple comparison tests. P ≤ .05 was considered statistically significant.

RESULTS

The setting time and flow rate of all sealers were affected by heat (P ≤ .05). The setting times and solubility of BCH and BC were significantly higher than AHP (P ≤ .0001). The radiopacity of AHP was higher than BCH and BC (P ≤ .0001). All sealers were alkaline and had antibacterial effects. Cell viability was higher for BCH and BC than AHP (P ≤ .0001). No significant differences in messenger RNA expression of proinflammatory and mineralization genes were observed.

CONCLUSIONS

Overall, BCH and BC had similar physicochemical and biological properties. The observed high solubility of BCH and BC as well as the high cytotoxicity of AHP might negatively impact the clinical performance of these materials. The application of heat affected the setting time and flow of all sealers.

Adding Two Antimicrobial Glasses to an Endodontic Sealer to Prevent Bacterial Root Canal Reinfection: An In Vivo Pilot Study in Dogs

Current endodontic procedures continue to be unsuccessful for completely removing pathogens present inside the root canal system, which can lead to recurrent infections. In this study, we aimed to assess the antimicrobial capacity and tissue response of two inorganic bactericidal additives incorporated into a paste root canal sealer on contaminated root dentin in vivo. An experimental study was performed in 30 teeth of five Beagle dogs. After inducing microbiological contamination, root canal systems were treated by randomly incorporating one of two antimicrobial additives into a commercial epoxy-amine resin sealer (AH Plus), i.e., G3T glass-ceramic (n = 10) and ZnO-enriched glass (n = 10); 10 samples were randomized as a control group. After having sacrificed the animals, microbiological, radiological, and histological analyses were performed, which were complemented with an in vitro bactericidal test and characterization by field emission scanning electron microscopy. The tested groups demonstrated a non-significant microbiological reduction in the postmortem periapical index values between the control group and the bactericidal glass-ceramic group (p = 0.885), and between the control group and the ZnO-enriched glass group (p = 0.169). The histological results showed low values of inflammatory infiltrate, and a healing pattern characterized by fibrosis in 44.4% of the G3T glass-ceramic and 60.0% of ZnO-enriched glass. Bactericidal glassy additives incorporated in this root canal sealer are safe and effective in bacterial reduction.

Antimicrobial Activity of Calcium Silicate-Based Dental Materials: A Literature Review

Endodontic biomaterials have significantly improved dental treatment techniques in several aspects now that they can be used for vital pulp treatments, as temporary intracanal medication, in definitive fillings, in apical surgeries, and for regenerative procedures. Calcium silicate-based cement is a class of dental material that is used in endodontics in direct contact with the dental structures, connective tissue, and bone. Because the material interacts with biological tissues and stimulates biomineralization processes, its properties are of major importance. The main challenge in endodontic treatments is the elimination of biofilms that are present in the root canal system anatomical complexities, as it remains even after chemical-mechanical preparation and disinfection procedures. Thus, an additional challenge for these biomaterials is to exert antimicrobial activity while maintaining their biological properties in parallel. This article reviews the literature for studies considering the antimicrobial properties of calcium silicate-based dental biomaterials used in endodontic practice. Considering the reviewed studies, it can be affirmed that the reduced antimicrobial effect exhibited by calcium silicate-based endodontic materials clearly emphasizes that all clinical procedures prior to their use must be carefully performed. Future studies for the evaluation of these materials, and especially newly proposed materials, under poly-microbial biofilms associated with endodontic diseases will be necessary.

Calcium Silicate-Based Root Canal Sealers: A Narrative Review and Clinical Perspectives

Over the last two decades, calcium silicate-based materials have grown in popularity. As root canal sealers, these formulations have been extensively investigated and compared with conventional sealers, such as zinc oxide-eugenol and epoxy resin-based sealers, in in vitro studies that showed their promising properties, especially their biocompatibility, antimicrobial properties, and certain bioactivity. However, the consequence of their higher solubility is a matter of debate and still needs to be clarified, because it may affect their long-term sealing ability. Unlike conventional sealers, those sealers are hydraulic, and their setting is conditioned by the presence of humidity. Current evidence reveals that the properties of calcium silicate-based sealers vary depending on their formulation. To date, only a few short-term investigations addressed the clinical outcome of calcium silicate-based root canal sealers. Their use has been showed to be mainly based on practitioners' clinical habits rather than manufacturers' recommendations or available evidence. However, their particular behavior implies modifications of the clinical protocol used for conventional sealers. This narrative review aimed to discuss the properties of calcium silicate-based sealers and their clinical implications, and to propose rational indications for these sealers based on the current knowledge.

The presence of smear layer affects the antimicrobial action of root canal sealers

AIM

To assess the chemical and microstructural characteristics of dentine after the use of two irrigation protocols and correlate this with the antimicrobial properties of hydraulic calcium silicate cement (HCSC) sealers and changes to the dentine structure/chemistry after sealer placement.

METHODOLOGY

Two irrigation protocols - Protocol A using 2% NaOCl used 5 mL/5 min and Protocol B with 2% NaOCl (5 mL/5 min) followed by 17% EDTA (5 mL/3 min) - were used to prepare dentine. The chemical and microstructural changes following irrigation were assessed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy (n = 5) on dentine obtained from the mid-root and coronal parts of extracted human teeth. Four sealers (AH Plus, BioRoot, MTA Fillapex, TotalFill) were characterized by SEM/EDS (n = 3). The ability of the sealers to eradicate intratubular Enterococcus faecalis biofilms was assessed by live/dead dye and confocal laser scanning microscopy to measure the percentage of living cells. The effect of combined irrigation and root filling on dentine was assessed by SEM and EDS analysis (n = 5). Statistical analysis was undertaken using one-way anova and a number of post hoc tests to detect intergroup differences. The F-test was used for comparison of variances in the microbiology testing.

RESULTS

The use of NaOCl alone left the smear layer intact, with traces of chlorine remaining on dentine. The use of BioRoot sealer restored the calcium levels of dentine which had been depleted by the irrigation with EDTA. BioRoot exhibited antimicrobial properties against intratubular bacteria even in the presence of smear layer (Protocol A). Smear layer removal improved the bactericidal effect of all sealers and Ca²⁺ leaching. The use of a chelating agent was important for the intratubular sealer penetration for AH Plus but not the other sealers.

CONCLUSION

The removal of smear layer was necessary for penetration of AH Plus into the dentinal tubules. BioRoot was a more effective sealer in reducing the bacterial load in the dentinal tubules than the other materials tested and the presence of smear layer did not affect its activity.

Could the Calcium Silicate-Based Sealer Presentation Form Influence Dentinal Sealing? An In Vitro Confocal Laser Study on Tubular Penetration

Dentinal tubule penetration influences root canal treatment sealing. The aim of this study was to compare dentinal penetration of two clinical presentations of silicate-based sealers using confocal laser. Sixty single-rooted human teeth from 50-70 year-old patients extracted for orthodontic/periodontal reasons were used. Canals were prepared using Mtwo system up to 35/0.04, with 5.25% NaOCl irrigation and final irrigation using 17% EDTA. Teeth were randomly assigned into study groups (n_i = 20): EndoSequence BC sealer (ES, group 1), BioRoot RCS (BR, group 2); and a control group (n_c = 20) with AH Plus (AHP). Root canals were obturated with 35/0.04 gutta-percha (single-cone technique). The samples were obtained from apical, middle, and coronal thirds. Dentinal tubule penetration depth and percentage of penetration around the canal perimeter were measured. The statistical analysis was performed using Mann Whitney U test and Wilcoxon t-test (95% confidence interval). ES exhibited a significantly higher penetration than AHP in apical and middle thirds (p < 0.05), and in middle and coronal thirds relative to BR (p < 0.05). The percentage of penetration around the canal perimeter was significantly higher for ES compared to BR in all thirds, but only in the apical third for AHP (p < 0.05). The pre-mixed silicate-based sealer exhibited better penetration than the powder/liquid one.

Comparison of Biocompatibility of Calcium Silicate-Based Sealers and Epoxy Resin-Based Sealer on Human Periodontal Ligament Stem Cells

The aim of this study was to evaluate the biocompatibility of calcium silicate-based sealers (CeraSeal and EndoSeal TCS) and epoxy resin-based sealer (AH-Plus) in terms of cell viability, inflammatory response, expression of mesenchymal phenotype, osteogenic potential, cell attachment, and morphology, of human periodontal ligament stem cells (hPDLSCs). hPDLSCs were acquired from the premolars (n = 4) of four subjects, whose ages extended from 16 to 24 years of age. Flow cytometry analysis showed stemness of hPDLSCs was maintained in all materials. In cell viability test, AH-Plus showed the lowest cell viability, and CeraSeal showed significantly higher cell viability than others. In ELISA test, AH-Plus showed higher expression of IL-6 and IL-8 than calcium silicate-based sealers. In an osteogenic potential test, AH-Plus showed a lower expression level than other material; however, EndoSeal TCS showed a better expression level than others. All experiments were repeated at least three times per cell line. Scanning electronic microscopy studies showed low degree of cell proliferation on AH-Plus, and high degree of cell proliferation on calcium silicate-based sealers. In this study, calcium silicate-based sealers appear to be more biocompatible and less cytotoxic than epoxy-resin based sealers.

Physicochemical and Antibacterial Properties of Novel, Premixed Calcium Silicate-Based Sealer Compared to Powder-Liquid Bioceramic Sealer

The aim of this study was to compare the physicochemical properties, filling ability, and antibacterial activity of a premixed calcium silicate-based sealer to those of a powder–liquid bioceramic sealer. Ceraseal (CS) and BioRoot (BR) materials were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy at 7 and 14 d of immersion in distilled water. The filling ability of the two sealers as well as the water contact angle, solubility, flow, roughness, crystalline microstructure, pH, and compressive strength were also evaluated. The antibacterial activity was assessed through an agar diffusion as well as through direct tests. All the results were statistically analyzed using one-way or two-way analysis of variance tests. Statistically significant lower void percentages were observed for CS at 2 and 8 mm from the working length (WL) compared to those for the BR group, whilst no significant difference was observed at 5 mm from the WL. BR sealer showed higher alkaline pH, rougher surface, lower water contact angle values, lower flowability, and higher solubility compared to CS. BR showed globular and needle-like crystalline microstructure, whilst CS had globular and flower-like crystalline microstructure up to 72 h. No statistical difference was found for the compressive strength between the two sealers. BR and CS showed no antibacterial effect against Enterococcus faecalis after 3 h, whilst both sealers showed antibacterial capacity after 24 and 72 h. BR demonstrated higher antibacterial activity after 24 h. In conclusion, the use of bioceramic sealers may play an important role in controlling bacterial growth. Moreover, CS may have superior filling ability and lower solubility than the BioRoot sealer due to its specific chemical composition and mixing method.

Endodontic approach in a replanted tooth with an immature root apex and chronic apical periodontitis: a case report

This study describes the clinical steps taken in the treatment of a patient who had an avulsed right upper central incisor that presented with incomplete root development and chronic apical periodontitis. A 7-year-old boy was referred from a private dentist to a dental office specializing in endodontics. The tooth had remained in a dry environment for 20 minutes, and tooth replantation was performed at an emergency appointment. After clinical and radiographic examinations, root canal decontamination was performed, followed by several changes in intracanal calcium hydroxide medication. Blood clot formation was attempted, but bleeding within the root canal was insufficient; therefore, we opted for an intracanal medication change to stimulate mineralized tissue formation in the apical region. Root obturation was performed 45 days after the last change of intracanal medication, and clinical, radiographic, and tomographic follow-up examinations were performed at 3, 6, 18, and 40 months after the endodontic intervention. The increase in thickness and length of the root structure and the absence of root resorption were verified through follow-up examinations. Therefore, it was concluded that the procedures used were successful for tooth replantation.

Antimicrobial Effectiveness of Calcium Silicate Sealers against a Nutrient-Stressed Multispecies Biofilm

Purpose: This study compared the antimicrobial efficacy of calcium silicate sealers (BioRoot RCS and Total Fill BC) and conventional sealers (AH Plus and Tubli-seal) against planktonic bacteria and a nutrient-stressed multispecies biofilm. Methods: Antimicrobial properties of freshly mixed sealers were investigated using the direct contact test (DCT) and a nutrient-stressed multispecies biofilm comprised of five endodontic strains. Antimicrobial activity was determined using quantitative viable counts and confocal laser scanning microscopy (CLSM) analysis with live/dead staining. The pH of the sealers was analysed over a period of 28 days in Hanks Balanced Salt Solution (HBSS). Analysis of variance (ANOVA) with Tukey tests and the Kruskal–Wallis test were used for data analysis with a significance of 5%. Results: All endodontic sealers exhibited significant antimicrobial activity against planktonic bacteria (p < 0.05). BioRoot RCS caused a significant reduction in viable counts of the biofilms compared to AH Plus and the control (p < 0.05), while no significant difference could be observed compared to TotalFill BC and Tubli-seal (p > 0.05). CLSM analysis showed that BioRoot RCS and TotalFill BC exhibited significant biofilm inhibition compared to Tubli-seal, AH Plus and the control (p < 0.05). BioRoot RCS presented with the highest microbial killing, followed by TotalFill BC and Tubli-seal. Alkalizing activity was seen from the onset by BioRoot RCS, TotalFill BC and AH Plus. After 28 days, BioRoot RCS demonstrated the highest pH in HBSS (pH > 12). Conclusions: Calcium silicate sealers exhibited effective antimicrobial properties. This was demonstrated by superior biofilm inhibition capacity and microbial killing, with strong alkalizing activity compared to epoxy-based and zinc oxide-eugenol-based sealers.

Genotoxicity of root canal sealers: a literature review

OBJECTIVES

Root canal sealers are widely used worldwide in endodontics to prevent reinfection and growth of surviving microorganisms. Considering the strong correlation between genetic damage and carcinogenesis, evaluation of genotoxicity induced by endodontic sealers is recommended for elucidating the true health risks to patients and professionals. The purpose of this article was to provide a comprehensive review of studies involving genotoxicity analysis of endodontic sealers and the used methodologies.

MATERIALS AND METHODS

A literature search was made in PubMed using the following combination of words "genotoxicity," "mutagenicity," "endodontic sealers," and "root canal sealers." A total of 39 articles with genotoxicity studies were selected for the present study.

RESULTS

Sealers have been ranked in decreasing order of their genotoxicity as: ZOE sealers > GIC sealers > S sealers > ER sealers > MR sealers > Novel sealers > CH sealers > CS sealers.

CONCLUSIONS

All published data showed some evidence of genotoxicity for most of the commercial root canal sealers; however, contradictory results were found, mainly for AH Plus, the most studied sealer.

CLINICAL RELEVANCE

The information provided would direct the endodontists to use the less genotoxic materials in endodontic treatment in a way to reduce DNA damage promoting oral healthcare.

Calcium silicate-based root canal sealers: a literature review

Epoxy resin-based sealers are currently widely used, and several studies have considered AH Plus to be the gold-standard sealer. However, it still has limitations, including possible mutagenicity, cytotoxicity, inflammatory response, and hydrophobicity. Drawing upon the advantages of mineral trioxide aggregate, calcium silicate-based sealers were introduced with high levels of biocompatibility and hydrophilicity. Because of the hydrophilic environment in root canals, water resorption and solubility of root canal sealers are important factors contributing to their stability. Sealers displaying lower microleakage and stronger push-out bond strength are also needed to endure the dynamic tooth environment. Although the physical properties of calcium silicate-based sealers meet International Organization for Standardization recommendations, and they have consistently reported to be biocompatible, they have not overcome conventional resin-based sealers in actual practice. Therefore, further studies aiming to improve the physical properties of calcium silicate-based sealers are needed.

Cytotoxicity, antibacterial and physicochemical properties of a new epoxy resin-based endodontic sealer containing calcium hydroxide

Background

This study evaluated the cytotoxicity, antibacterial and physicochemical properties of a new epoxy resin-based endodontic sealer containing calcium-hydroxide Sealer Plus. AH Plus was used as a reference for comparison.

Material and Methods

Cytotoxicity evaluation was performed according to ISO-10993-5 specifications using MTT assay to check the 3T3 cells viability at 1- to 4-week periods. Antibacterial activity was evaluated using a direct contact test against Enterococcus faecalis. Radiopacity, solubility and flow evaluations were performed according to ISO-6876/2012 specifications. Setting time was assessed following the ANSI/ADA-standard-n.57. The pH level was measured at 3,24,48,72, and 168 hours. Data were statistically analyzed using t-test. The significance level adopted was P<0.05.

Results

AH Plus and Sealer Plus showed cytotoxic effects after 24 hours and 1 week of manipulation and become noncytotoxic after 2 weeks. No differences were observed in the cytotoxicity of both tested sealers (P>0.05). Direct contact results revealed that both freshly prepared sealers has antibacterial effects against Enterococcus faecalis. However, after 7 days both sealers had lost much of their antibacterial effects. Although AH Plus presented higher radiopacity and flow than Sealer Plus (P<0.05), both sealers showed minimum required values. No differences were observed in the solubility of both sealers (P>0.05). AH Plus showed a higher setting time when compared to Sealer Plus (P<0.05). AH Plus and Sealer Plus showed a neutral pH during all tested periods (P<0.05).

Conclusions

It can be concluded that Sealer Plus showed suitable properties to be used as an endodontic sealer, comparable with those obtained by AH Plus.

Key words:Cytotoxicity, root canal filling materials, root canal obturation.

Calcium hypochlorite on mouse embryonic fibroblast cells (NIH3T3) in vitro cytotoxicity and genotoxicity: MTT and comet assay

Antimicrobial irrigation solutions are widely used under clinical settings. Their effect on dental tissue is a subject of recent research, which aims for a safer irrigant for clinical use. In this regard, here our goal was to evaluate the cytotoxicity and the genotoxicity of calcium hypochlorite (Ca(OCl)₂) solution, along with NaOCl, on Mouse embryonic fibroblast cells (NIH3T3). First, Cells were treated either with NaOCl or Ca(OCl)₂ in a time- and dose-dependent manner for cytotoxicity by 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, then cell viability was calculated according to cell proliferation plots. Secondly, genotoxicity was assessed by Comet assay. Data were statistically analyzed by Tukey's test (P < .05). NaOCl and Ca(OCl)₂ had similar effects on cellular viability at 3 and 6 h treatments. Cell viability of Ca(OCl)₂ at concentrations of 0.0125%, 0.025%, 0.05%, or 0.125% was significantly lower than that of NaOCl at 24 h treatment (P < .05).Comparing Ca(OCl)₂ and NaOCl treatments at all time points and concentrations, the damaged cell number of Ca(OCl)₂ was almost fourfold higher than that of NaOCl. In conclusion, both, NaOCl and Ca(OCl)₂ solutions were cytotoxic and genotoxic to NIH3T3, however, Ca(OCl)₂ had a significantly higher damaged cell percentage than NaOCl at all time points and concentrations investigated.

Short-Term Antibacterial Efficacy of Three Bioceramic Root Canal Sealers Against Enterococcus Faecalis Biofilms

Objectives

The aim of the study was to evaluate the antimicrobial efficacy of three bioceramic root canal sealers against Enterococcus faecalis (E. faecalis) biofilm.

Material and methods

E. faecalis bacterial suspension was grown on filter paper discs on agar plates. After the incubation period, the discs were covered with four different root canal sealers: 1) Premixing bioceramic root canal sealer (TotalFill BC Sealer); 2) Dual component bioceramic sealer (BioRoot RCS); 3) Mineral trioxide agreggate based sealer (MTA Fillapex); 4) Epoxy resin-based selar (AH Plus). After contact time of 60 minutes, the sealers were removed, and the discs were transferred into sterile tubes containing phosphate buffered saline. After serial dilutions, the aliquots of the suspension were cultivated for 24 hours. After the incubation period, the colony forming units (CFUs) were counted.

Results

There were no significant differences in antibacterial efficacy between the Total Fill BC Sealer and the AH Plus sealer (p=0.386). Both sealers showed better antibacterial efficacy compared to the BioRoot RCS and the MTA Fillapex (p<0.001).

Conclusion

The Total Fill BC Sealer and AH Plus had better antibacterial efficacy than the BioRoot RCS and the MTA Fillapex sealers.

Cytotoxicity and release ions of endodontic sealers incorporated with a silver and vanadium base nanomaterial

The modification of endodontic sealers with nanoparticles to confer antimicrobial activity allow greater effect, with interaction at a molecular level. The nanostructured silver vanadate decorated with silver nanoparticles (AgVO₃) is a nanomaterial unprecedented in dentistry for this application. This study incorporated the AgVO₃ into three endodontic sealers of different compositions and evaluate the cytotoxicity and release of compounds. The groups of commercially available AH Plus, Sealer 26, and Endomethasone N and groups of the same sealers with incorporated AgVO₃ (at concentrations 2.5, 5, 10%) were prepared, and extracts of the specimens were obtained for 24 h. The cell viability (cytotoxicity) of human gingival fibroblasts (HGF) was assessed after 24 h, 7 and 14 days. Silver (Ag⁺) and vanadium (V⁴⁺/V⁵⁺) ion release was quantified after 24 h by ICP-MS. Data were analyzed by Kruskal-Wallis and Dunn's post-hoc (α = 0.05). The cell viability was inversely proportional to treatment time. The Sealer 26 and Endomethasone N groups were cytotoxic for HGF cells, regardless of the incorporation of the AgVO₃ (p > 0.05), and the incorporation reduced cell viability of AH Plus (p < 0.05). The release of ions was proportional to the concentration of AgVO₃. AH Plus released more Ag⁺ ions, and Sealer 26 and Endomethasone N releases more V⁴⁺/V⁵⁺ ions. In conclusion, it was not possible to confirm the influence of AgVO₃ on HGF cell viability to Sealer 26 and Endomethasone N, however, nanomaterial influenced cell-viability to AH Plus, so the commercial sealers can be cytotoxic in synergy with the nanomaterial. The release of Ag⁺ and V⁴⁺/V⁵⁺ was proportional to the AgVO₃ incorporated.

Current Trends in Practice of Residents in the Saudi Board of Endodontics Program

Objectives The purpose of the current study was to collect information about some techniques and armamentarium currently used by the Saudi Board of Endodontics residents in relation to the technical steps of root canal therapy.

Materials and Methods A web-based survey was sent to the Saudi Board of Endodontics residents, based in the western area of Saudi Arabia. The survey assessed controversial concepts, and collected information regarding new instruments and materials, used in the technical steps of nonsurgical root canal treatment. A one-sample chi-square test, with a 95% level of significance, was applied to determine whether there were significant differences between respondents’ answers.

Results A total of 45 out of 50 residents (90%) responded to the questionnaire. The majority of Saudi Board residents of Endodontics, who participated in this survey, used the mean of working length (ML) measured by periapical X-Ray and apex locator in the presence of a radiographic lesion (63.3%), and maintained apical patency in all cases (80.0%). ProTaper Universal (40%) and ProTaper Next (41.2%) were the most common NiTi rotary systems used for root canal instrumentation. Thirty percent of respondents used adjunct device with irrigation, and 80% advocated smear layer removal. Zinc oxide–eugenol-based sealers were the most common used sealers (70%), and most residents (86.6%) did not advocate sealer extrusion.

Conclusions This study revealed that residents of the Saudi Board of Endodontics program adopt new endodontic technologies. There is, however, a need for more investigations regarding this objective, including responses from all residents in Saudi Arabia.