Physical properties and biocompatibility of an injectable calcium-silicate-based root canal sealer: in vitro and in vivo study

Evaluation of dimensional changes in EndoSeal mineral trioxide aggregate and AH Plus sealers using micro-computed tomography imaging

Background

Optimal dimensional stability is required for successful root canal treatment. A sealant called EndoSeal mineral trioxide aggregate (MTA) was recently introduced to the market due to its favorable physical and chemical properties. On the other hand, AH Plus (AHP) is considered the gold-standard seal.

Materials and Methods

In this ex vivo quasi-experimental study, 24 single-canal premolars extracted from humans were cleaned and shaped with a motorized and rotary file, then that is divided into two groups. The teeth of each group were filled with gutta F3 and each type of sealant. The teeth were scanned by a micro-computed tomography device after 24 h. After 7 days of storage in phosphate-buffered saline solution, the samples were re-scanned. Data were analyzed using SPSS software (version 21). Descriptive data were presented as frequency, percentage, mean, and standard deviation. The Shapiro-Wilk and Kolmogorov-Smirnov tests were used to investigate the normality of the data. The Mann-Whitney test was used to compare the two groups, and the differences were ultimately not significant. The level of significance was set at 0.05 (P < 0.05).

Results

The mean differences between sealer volumes before and after the intervention were not significantly different between the two groups indicating that the EndoSeal MTA sealer is not inferior to the gold-standard root canal sealer, AHP.

Conclusion

EndoSeal MTA can be considered a reliable sealer in endodontic treatments and be subjected to further investigation.

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.

Effect of heat application on the physicochemical properties of new endodontic sealers: an in vitro and SEM study

Understanding the properties of endodontic sealers is vital for treatment planning. Calcium silicate-based sealers are important in modern endodontics. This study investigates the effect of heat on the physicochemical properties of new calcium silicate sealers, addressing concerns raised by clinicians seeking to combine their benefits with the gutta-percha obturation technique. Five endodontic sealers (AH Plus Bioceramic®, Total Fill® BC®, One-fil® Bioceramic, K-Biocer, Any-seal®) were evaluated. Each sealer (n = 16/group) was either kept at 37 °C or subjected to heat at 60 or 200 °C for 30 s. ISO 6876-2012 standards were used to measure setting time, flow, film thickness, and dimensional changes over time. SEM and EDS were utilized for surface and chemical analysis. Data analysis employed IBM SPSS Statistics version 26 with a 5% significance level for two-sided tests. The sealers' setting times were shortened by heat, except for Total Fill® BC with extended setting time. All sealers had significantly longer setting times than manufacturer specifications. Film thickness increased with temperature, while flow values decreased. K-Biocer sealer showed the highest flow (16.89 ± 0.57 mm) at 200 °C, while Total Fill® sealer had the lowest (15.32 ± 0.62 mm). Shrinkage was significant at 60 °C and 200 °C, with greater shrinkage at 200 °C. Heat caused surface deformations in all sealers. The 200 °C groups exhibited more voids in AH Plus Bioceramic®, Any-seal®, and One-fil® sealers, and higher void area in Total Fill®, One-fil®, and K-Biocer sealers (p value < 0.001). EDX analysis confirmed heat-induced chemical and elemental changes in all tested sealers. Elevated temperature affects the physicochemical properties and structure of the tested endodontic sealers. The consideration of endodontic sealer compatibility is essential when warm gutta-percha obturation techniques are used.

Effect of different sealer activation techniques on dentinal tubule penetration

The aim of this study was to evaluate the influence of different activation techniques on dentin tubule penetration of root canal sealer. Seventy-five teeth with single canals were chemomechanically prepared. A calcium silicate-based sealer was stained with a fluorescent dye (rhodamine B), placed into the canals and activated according to the following groups: control (no activation), EDDY, EndoActivator, ultrasonic and XP-Endo Finisher. Then, the samples were obturated. The percentages of sealer penetration at various depth levels of root sections were measured with confocal laser scanning microscopy. XP-Endo Finisher presented the highest penetration at 50 μm (p < 0.05). XP-Endo Finisher showed similar penetration with EDDY at 100 and 200 μm (p > 0.05) while presented higher penetration than the other groups (p < 0.05). At 500 μm, XP-Endo Finisher presented higher penetration than EndoActivator (p < 0.05) while similar penetration with the other groups (p > 0.05). XP-Endo Finisher can be recommended for activation during sealer placement for better penetration into dentin tubules.

Cytotoxicity and genotoxicity of various types of endodontic sealers in Chinese hamster ovary (CHO-K1) cells

This study aimed to evaluate the cytotoxicity and genotoxicity of five endodontic sealers (AH Plus, MTA Fillapex, Endoseal MTA, Sealapex, and Zinc oxide eugenol) in Chinese hamster ovary cells. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay to check cell viability at 1, 3, and 7 days. Genotoxicity was assessed by cytokinesis-block micronucleus, single-cell gel electrophoresis, and γH2AX immunofluorescence assays. Cell viability of all endodontic sealers, except Endoseal MTA, on day 1 was less than 100%. Endoseal MTA showed the highest cell viability on day 7. AH Plus and Endoseal MTA showed less DNA damage than other sealers. After complete setting, AH Plus and Endoseal MTA showed low genotoxicity, which could reduce DNA damage in periapical cells, making them suitable as endodontic sealers.

A scientometric, bibliometric, and thematic map analysis of hydraulic calcium silicate root canal sealers

Objectives

This scientometric and bibliometric analysis explored scientific publications related to hydraulic calcium silicate-based (HCSB) sealers used in endodontology, aiming to describe basic bibliometric indicators and analyze current research trends.

Materials and Methods

A comprehensive search was conducted in Web of Science and Scopus using specific HCSB sealer and general endodontic-related terms. Basic research parameters were collected, including publication year, authorship, countries, institutions, journals, level of evidence, study design and topic of interest, title terms, author keywords, citation counts, and density.

Results

In total, 498 articles published in 136 journals were retrieved for the period 2008-2023. Brazil was the leading country, and the universities of Bologna in Italy and Sao Paolo in Brazil were represented equally as leading institutions. The most frequently occurring keywords were "calcium silicate," "root canal sealer MTA-Fillapex," and "biocompatibility," while title terms such as "calcium," "sealers," "root," "canal," "silicate based," and "endodontic" occurred most often. According to the thematic map analysis, "solubility" appeared as a basic theme of concentrated research interest, and "single-cone technique" was identified as an emerging, inadequately developed theme. The co-occurrence analysis revealed 4 major clusters centered on sealers' biological and physicochemical properties, obturation techniques, retreatability, and adhesion.

Conclusions

This analysis presents bibliographic features and outlines changing trends in HCSB sealer research. The research output is dominated by basic science articles scrutinizing the biological and specific physicochemical properties of commonly used HCSB sealers. Future research needs to be guided by studies with a high level of evidence that utilize innovative, sophisticated technologies.

Evaluation of Cytotoxicity of Calcium Silicate-based Mineral Trioxide Aggregate Sealers: A Systematic Review of In Vitro Studies

AIM

This review aimed to evaluate the in vitro studies done with regard to the cytotoxicity associated with mineral trioxide aggregate (MTA)-based root canal sealers.

BACKGROUND

Root canal sealers are used during endodontic treatment as fillers to seal the gaps between the canal gutta-percha cone and canal walls. It is necessary to understand the cytotoxicity of these materials on human-derived cells as these materials interact with human cells periapically.

REVIEW RESULTS

Six in vitro studies were chosen for review. In these selected studies, along with MTA-based root canal sealers, other sealers were tested for cytotoxicity on human periodontal ligament (PDL) stem cells, human PDL fibroblasts, and human osteoblast cells. Regarding cytotoxicity, the studies were diverse, and most were based on 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide) (MTT) assay. In general, the studies suggested that root canal sealers cause mild to severe cytotoxic effects and that several factors influence this effect, such as material setting time, concentration, and duration of exposure.

CONCLUSION

All studies in the review indicated that MTA. Fillapex must be used cautiously as it exhibited the highest cytotoxic effect compared to other MTA-based and non-MTA-based sealers.

CLINICAL SIGNIFICANCE

Endodontic sealers do serve the purpose of bridging the gaps between the gutta-percha cone and the canal wall but knowing its biocompatibility becomes important as the material is extruded beyond the apical foramen where it comes in contact with the surrounding tissues. The effect of sealers on the surrounding tissues affects the healing and prognosis of the treatment.

Evaluation of interfacial adaptation and penetration of bioceramic-based sealers in oval root canals: A confocal laser scanning microscope study

To assess the interfacial adaptation and penetration depth of three different bioceramic-based sealers (CeraSeal, EndoSeal MTA, Nishika Canal Sealer BG) compared to an epoxy resin-based sealer (AH Plus) in oval root canals. Fourty extracted single-rooted mandibular premolar with oval canal were prepared and randomly allocated according to the obturation into; CeraSeal, EndoSeal MTA, Nishika Canal Sealer BG and AH Plus. The roots were sectioned at 3, 6 and 9 mm from the apex. The sealer adaptation and the penetration depth were evaluated under confocal laser scanning microscope. One-way ANOVA and Repeated measure ANOVA were used to statistically analyze the data. Nishika Canal Sealer BG showed significantly higher sealer adaptation than EndoSeal MTA (P < .001) at apical and middle thirds. Meanwhile, AH Plus showed significantly higher sealer adaptation than EndoSeal MTA (P = 0.011) at middle third. For sealer penetration, Nishika Canal Sealer BG showed the longest sealer penetration that was significant compared to AH Plus (P < .001) and EndoSeal MTA (P < .001) whereas CeraSeal was significantly higher than EndoSeal MTA (P = 0.029) at coronal third. For AH Plus, there was a significant less sealer penetration at coronal third compared to apical and middle thirds (P < .05). Whereas for EndoSeal MTA, the coronal third has significant less penetration compared to the middle third (P = 0.032). Endoseal has the lowest adaptation and penetration depth. Nishika Canal Sealer BG has better adaptation and penetration depth using single cone obturation technique in oval canal. RESEARCH HIGHLIGHTS: All the tested root canal sealers have some percentage of gaps and vary in their penetration capability into dentinal tubules. Nishika Canal Sealer BG has significantly better sealer adaptation to root dentinal walls than that of EndoSeal MTA at the apical and middle third but not significantly different from other type of sealers used. Nishika Canal Sealer BG has significantly better penetration depth than AH Plus and EndoSeal MTA at the coronal third of radicular dentin.

Clinical applications of calcium silicate-based materials: a narrative review

Calcium silicate-based materials are hydrophilic materials with biocompatibility and bioactivity properties. Despite many advantages, they might present some problems related to discolouration, setting time, manipulation and solubility depending on the composition of the product and the type of clinical application. Calcium silicate-based materials can be evaluated under two types according to their intended use: calcium silicate-based cements (CSCs) and calcium silicate-based sealers (CSSs). CSCs can be used in many endodontic procedures including perforation repair, resorption repair, apical barriers, guided endodontic repair, vital pulp treatment, endodontic surgery, root fractures and root canal filling as a core obturation material. CSSs are available for use with gutta-percha to obturate root canals using cold and warm techniques, including the sealer-based obturation technique. The purpose of this review is to evaluate the available literature on CSCs and CSSs and to provide up-to-date information and recommendations for their clinical applications.

Cytotoxicity and Mineralization Activity of Calcium Silicate-Based Root Canal Sealers Compared to Conventional Resin-Based Sealer in Human Gingival Fibroblast Cells

Background

Root canal obturation is performed by gutta-percha cones and sealer. Therefore, these materials, specially sealers, must be biocompatible. This study investigated the cytotoxicity and mineralization activity of two calcium silicate-based sealers (Endoseal MTA and Ceraseal) and an epoxy resin-based sealer (AH26).

Materials and Methods

In this experiment, the cytotoxicity of Endoseal MTA, Ceraseal, and AH26 on human gingival fibroblast cells was examined using Methyl-Thiazol-Tetrazolium assay at time intervals of 24, 48, 72, and 120 hr. The mineralization activity of sealers was evaluated by Alizarin red staining assay. Prism, ver.3, software was used to perform statistical tests. One-way analysis of variance analysis, followed by Tukey's test, was used to determine the group differences. P-values < 0.05 were considered statistically significant.

Results

Cytotoxicity of sealers decreased gradually (P < 0.0001). AH26 showed the highest level of cytotoxicity (P < 0.001). In terms of cytotoxicity, no considerable differences were observed between the two-calcium silicate-based sealers (P > 0.05). AH26 showed the lowest mineralization activity (P < 0.0001). Among the calcium silicate-based sealers, mineralization and formation of calcium nodules were more frequently observed in the Endoseal MTA group (P < 0.001).

Conclusion

The examined calcium silicate-based sealers had less cytotoxicity and higher mineralization activity than the resin-based sealer (AH26). There was negligible difference between the cytotoxicity of the two-calcium silicate-based, but the cell mineralization caused by Endoseal MTA was higher.

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.

Exploring the Most Effective Apical Seal for Contemporary Bioceramic and Conventional Endodontic Sealers Using Three Obturation Techniques

Background and Objective: Despite a plethora of studies conducted to date, researchers continue to investigate the best sealer and obturation technique combinations. The aim of this study is to compare the apical seal provided by two bioceramic sealers (Endoseal and Endosequence) with that provided by a calcium hydroxide sealer (Sealapex), and to evaluate the effect of different obturation techniques (cold lateral condensation, continuous wave compaction and single cone) on the apical seal under a stereomicroscope. Materials and Methods: A total of 110 single-rooted mandibular premolar teeth were decoronated, cleaned and shaped using the Endosequence filing system to tip size 30/0.04 taper. Canals were irrigated with 5.25% NaOCl and 17% EDTA. The samples were randomly divided into 11 groups (9 experimental and 2 control groups) according to the designated sealer and technique. Samples were stored in an incubator for 7 days at 37 °C under 100% humidity. Samples were coated with nail varnish except for apical 2 mm and vertically placed in 0.2% rhodamine B dye solution for 48 h. Samples were split longitudinally and viewed under a stereomicroscope at 40× magnification. Results: Insignificant results were obtained between obturation techniques (p = 0.499) whereas statistically significant results were attained based on the type of endodontic sealer (p < 0.001). The overall lowest mean apical microleakage and best sealing ability was demonstrated by Sealapex (2.59 ± 1.20 mm) and amongst techniques by continuous wave compaction (3.90 ± 2.51 mm). Conclusions: Endosequence produced the best apical seal with the continuous wave compaction technique, whereas Endoseal did so with the bioceramic-coated single-cone technique. For the Sealapex sealer, the most effective apical seal was observed using cold lateral condensation. The quality and effectiveness of apical seal differed with the type of endodontic sealer and obturation technique used, and vice versa.

Single Cone Obturation versus Cold Lateral Compaction Techniques with Bioceramic and Resin Sealers: Quality of Obturation and Push-Out Bond Strength

Objectives

This study compared the obturation quality and push-out bond strength of single cone obturation (SCO) and cold lateral compaction (CLC) with AH-Plus and Sure Seal Root (SSR).

Materials and Methods

This in vitro experimental study was conducted on 88 single-rootedsingle-canal teeth with straight roots that were randomly divided into four groups (n = 22). All teeth were decoronated and underwent cleaning and shaping. Obturation was performed with AH-Plus and SCO technique in group 1 (SAH), AH-Plus and CLC technique in group 2 (LAH), SSR and SCO technique in group 3 (SS), and SSR and CLC technique in group 4 (LS). The roots were then sectioned into 3-mm thick slices and underwent digital photography at x25 magnification to assess the quality of obturation in the coronal, middle, and apical thirds by Image J software. The PBS was measured by a universal testing machine. The mode of failure was also determined under a stereomicroscope.

Results

The PBS was significantly higher in the LSS group than LAH and SAH groups, and also in the SSS group than the SAH group in all sections. The PBS in the LSS group was significantly higher than SSS in the coronal and middle thirds. Voids were significantly lower in LAH than in the SAH group in all sections. In LSS, voids in the coronal third were significantly lower than in LAH. In the middle third, voids in SSS were significantly lower than in SAH. The groups had no significant difference in the mode of failure (P > 0.05). The mean percentage of gutta-percha in the use of AH-Plus sealer was significantly higher than SSR (P < 0.05). The mean percentage of gutta-percha in the coronal third was lower than that in the middle and apical thirds (P < 0.05).

Conclusion

SSR showed higher PBS and less voids than AH-Plus. High PBS of the CLC/SSR group showed that CLC should still be preferred to SCO, and in the case of using SCO, SSR should be preferred to AH-Plus.

An Updated Review on Properties and Indications of Calcium Silicate-Based Cements in Endodontic Therapy

Regarding the common use of calcium silicate cements (CSCs) in root canal therapy, their position in the context of past and present dentistry agents can provide a better understanding of these materials for their further improvement. In this context, the present review article addresses a wide range of recent investigations in the field of CSC-based products and describes details of their composition, properties, and clinical applications. The need for maintaining or reconstructing tooth structure has increased in contemporary endodontic treatment approaches. This research thus discusses the attempts to create comprehensive data collection regarding calcium ion release, bond strength, alkalinizing activity and bioactivity, and the ability to stimulate the formation of hydroxyapatite as a bioactive feature of CSCs. Sealing ability is also highlighted as a predictor for apical and coronal microleakage which is crucial for the long-term prognosis of root canal treatment integrity. Other claimed properties such as radiopacity, porosity, and solubility are also investigated. Extended setting time is also mentioned as a well-known drawback of CSCs. Then, clinical applications of CSCs in vital pulp therapies such as pulpotomy, apexification, and direct pulp capping are reviewed. CSCs have shown their benefits in root perforation treatments and also as root canal sealers and end-filling materials. Nowadays, conventional endodontic treatments are replaced by regenerative therapies to save more dynamic and reliable hard and soft tissues. CSCs play a crucial role in this modern approach. This review article is an attempt to summarize the latest studies on the clinical properties of CSCs to shed light on the future generation of treatments.

Efficacy of Bioceramic and Calcium Hydroxide-Based Root Canal Sealers against Pathogenic Endodontic Biofilms: An In vitro Study

Background

Complete eradication of root canal pathogens cannot be predictably achieved by chemomechanical preparation and root canal disinfection. Therefore, an obturation material that has superior antimicrobial activity and sealing ability is required to inactivate residual microbes and prevent them from reentering the root canal system. Recently developed bioceramic root canal sealers are hydraulic cement which form calcium hydroxide during the hydration process. Like calcium hydroxide sealers, they exert an antimicrobial effect by releasing hydroxyl ions and increasing the pH.

Objective

The objective of this study was to evaluate and compare the antimicrobial activity of a calcium hydroxide-based sealer and two bioceramic sealers against Porphyromonas gingivalis, Enterococcus faecalis, and Candida albicans biofilms.

Materials and Methods

The sealers were dissolved in sterile saline to obtain supernatants. Biofilm formation assays, colony counting, and real-time polymerase chain reaction (PCR) were performed to evaluate the antimicrobial activity of each supernatant. The data were analyzed using one-way analysis of variance.

Results

All sealers exerted effects against all three microbial biofilms. The biofilm formation assays showed that the bioceramic sealers were more effective against P. gingivalis and E. faecalis biofilms. In contrast, colony counting and real-time PCR showed that the calcium hydroxide sealer was significantly more effective than the bioceramic sealers. All tests showed that the calcium hydroxide sealer was more effective against C. albicans, with the colony count and real-time PCR results showing statistically significant differences.

Conclusion

The calcium hydroxide-based sealer was more effective than the bioceramic sealers in eradicating pathogenic root canal biofilms.

Pilot Evaluation of Sealer-Based Root Canal Obturation Using Epoxy-Resin-Based and Calcium-Silicate-Based Sealers: A Randomized Clinical Trial

The purpose of this randomized controlled clinical trial was to assess the short-term clinical effectiveness of sealer-based root canal obturation using calcium-silicate-based sealer (CSBS) and epoxy-resin-based sealer (ERBS). A total of eighty patients (eighty teeth) were enrolled and seventy-two patients (seventy-two teeth) were randomly assigned into four different sealer groups: AH Plus (AH, Dentsply Sirona), ADseal (AD, Meta Biomed), CeraSeal (CS, Meta Biomed), or EndoSeal TCS (ES, Maruchi). At the first visit, root canal treatment was performed using ProTaper. Next, the NiTi file system and passive ultrasonic irritation was applied with 2.5% NaOCl. At the second visit, the teeth were obturated with a sealer-based obturation technique using the assigned sealer. The quality of filling obturation was evaluated with postoperative radiographs in terms of the presence of voids and sealer extrusion. The patients were recalled at 1-week, 1-month, and 3-month intervals, and pain levels were measured using visual analog scales (VAS), and clinical examination performed with percussion and palpation. Radiographs were also taken. The results were statistically compared by using the χ2 test or Fisher exact test. Among the 80 teeth included, 72 teeth received allocated intervention and 71 teeth were included in the analysis (98.6% recall). There was no significant difference among the sealers in void and sealer extrusion (p > 0.05). Postoperative pain was not indicated prominently regardless of the type of sealer. For a 3-month follow-up period, all cases were maintained successfully except for one case from AD. According to the findings, there was no significant difference between CSBS and ERBS in terms of postoperative pain or the healing process, and the variation in filling quality appears to be linked to the properties of each product.

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.

Comparison of Dentinal Tubule Penetration between a Calcium Silicate-Based Sealer with Ultrasonic Activation and an Epoxy Resin-Based Sealer: A Study Using Confocal Laser Scanning Microscopy

OBJECTIVE

 The aim of this study was to compare the degree of dentinal penetration between an epoxy resin-based sealer applied by using two different filling methods and an ultrasonically activated calcium silicate-based sealer via confocal laser scanning microscopy (CLSM).

MATERIALS AND METHODS

 Forty-five extracted permanent maxillary premolars with type II canals (Vertucci's classification) were subjected to the experiment. The root canals were instrumented and distributed randomly into the following three groups: AH Plus + continuous wave technique (AHC group); AH Plus + single cone technique (AHS group); and Endoseal MTA + single cone technique with ultrasonic activation (EMS) group. Each sealer was labeled with rhodamine B dye to allow visualization under CLSM. The sealer penetration depth in each sample was observed at 2 mm and 5 mm from the apex by using CLSM. The data were statistically analyzed by using analysis of variance or Kruskal-Wallis H test according to normality of variable (α = 0.05).

RESULTS

 In all groups, the maximum sealer penetration depth, mean fluorescence intensity, and sum fluorescence intensity values were higher at the 5-mm level than at the 2-mm level. At the 5-mm level, the EMS group showed the lowest value (p = 0.02). At the 2-mm level, there were no statistically significant differences among any of the groups. The AHC group showed higher values than the other groups, but there was no statistically significant difference in the apical area where access of instruments was difficult.

CONCLUSION

 The AHC group showed the highest dentinal tubule penetration, but had questionable filing efficacy in the apical area, which is of particular importance for the success of root canal treatment. Therefore, in areas such as the apical 2 mm of premolars with type II canals, which are difficult to access by using instruments such as heat carriers, other appropriate approaches may be required accordingly.

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.

Ability of Calcium Silicate and Epoxy Resin-based Sealers to Fill the Artificial Lateral Canals in the Presence or Absence of Smear Layer

Background:The lateral canals are pathways for bacteria and their products to pass between the root canal and the periradicular tissue. Objectives: The present study aims to compare the filling ability of the lateral canals with three calcium silicate based sealers, including MTA Fillapex, Endoseal MTA and Sure-Seal Root, and AH26 epoxy resin sealer in the presence and absence of the smear layer. Materials and methods:Six lateral canals were prepared using an engine reamer in 80 single-rooted human teeth. The root canals were cleaned, then the teeth were randomly divided into two groups. In group A, the smearlayer was removed using 17% EDTA and 5.25% NaOCl, and in group B, the canals were irrigated with normal saline. Groups A and B were divided into four subgroups each, according to the sealer used: A1, B1 (MTA Fillapex sealer), A2, B2 (Endoseal MTA sealer), A3, B3 (Sure-Seal Root sealer), and A4, B4 (AH26 sealer). Obturation of canals was conducted by the warm vertical technique and then teeth were incubated for 72 hours. Teeth were made clear and the filling of lateral canals were evaluated under stereomicroscope. Results:In group A, the highest lateral canals filling rate was in subgroup A2 and the lowest in subgroup A1, and the difference was statistically significant. However, in both groups, the highest lateral canals filling rate was in subgroups B2 and B3 and the lowest in subgroup B1. However, the difference was not statistically significant. In addition, no significant difference was observed in the lateral canals filling rate considering their position in the root. Conclusion:Providing the removal of the smear layer, calcium silicate-based sealers, Endoseal MTA and Sure-Seal Root had a higher ability to fill the lateral canals than AH26 and MTA fillapex sealers.

Comparison of bacterial microleakage of three bioactive endodontic sealers in simulated underwater diving and aviation conditions

BACKGROUND

Bacterial microleakage is an important cause of apical periodontitis and endodontic treatment failure. This study aimed to assess the bacterial microleakage of nano-mineral trioxide aggregate (nano-MTA) as a sealer, Endoseal MTA, and GuttaFlow Bioseal sealers in atmospheric pressure, and simulated underwater diving and aviation conditions.

METHODS

In this in vitro, experimental study, 180 extracted single-rooted teeth were cleaned and shaped, and were then randomly divided into three groups for single-cone obturation using Endoseal MTA, GuttaFlow Bioseal, or nano-MTA as a sealer. Each group was then randomly divided into three subgroups, and subjected to ambient atmospheric pressure, 2 atm pressure (to simulate underwater diving), and 0.5 atm pressure (to simulate aviation) using a custom-made pressure chamber. The teeth then underwent microbial leakage test using Streptococcus mutans (S. mutans), and the percentage of samples showing microleakage was recorded for up to 1 month, and analyzed using the Chi-square test.

RESULTS

The three sealer groups were significantly different regarding bacterial microleakage (P < 0.05). The nano-MTA group showed significantly higher microleakage after 15 days than the other two groups (P = 0.006). The effect of pressure on bacterial microleakage was not significant in any sealer group (P > 0.05).

CONCLUSION

Within the limitations of this in vitro study, it may be concluded that single-cone obturation technique using nano-MTA as a sealer results in lower resistance to bacterial microleakage compared with the use of GuttaFlow Bioseal, and Endoseal MTA. Pressure changes in simulated underwater diving and aviation conditions had no significant effect on bacterial microleakage. Trial Registration Number This is not a human subject research.

Characterization, Antimicrobial Effects, and Cytocompatibility of a Root Canal Sealer Produced by Pozzolan Reaction between Calcium Hydroxide and Silica

This study aimed to evaluate a newly developed pozzolan-based bioceramic sealer (PZBS) regarding setting time, radiopacity, antibacterial effect, and cytocompatibility. The PZBS was manufactured by mixing calcium hydroxide and silica. The pozzolan reaction was verified by identification of calcium silicate hydrate (C-S-H) using X-ray diffraction analysis. The initial setting time and radiopacity were measured using the ISO 6876/2012 protocol in comparison with other commercially available calcium silicate (CS) sealers. The antibacterial effect of PZBS on biofilms cultured in the bovine root canal was evaluated by measurement of colony-forming units and volume of biofilms in comparison with other calcium hydroxide pastes. The morphological features of the biofilms were observed by scanning electron microscopy (SEM). The cytocompatibility of PZBS was assessed by the viability of bone marrow–derived mesenchymal stem cells and scratch wound healing rate in comparison with other CS sealers. The morphology of the cells cultured on the tested sealers was observed by SEM. The detection of the CS peak confirmed the formation of C-S-H. The initial setting time of PZBS was around 11 h, which was twice as long as the other tested sealers. The radiopacity of PZBS was 4.3 mm/Al, which satisfied the ISO criteria. The antibacterial effect and cytocompatibility of PZBS were comparable to those of the commercially available intracanal medicaments and CS endodontic sealers, respectively. The PZBS has the potential to be used for root canal obturation, and is expected to exert a favorable antibacterial effect.

Comparison of the Effects of a Bioceramic and Conventional Resin-Based Sealers on Postoperative Pain after Nonsurgical Root Canal Treatment: A Randomized Controlled Clinical Study

Background: This clinical trial aimed to compare the effects of bioceramic sealer and resin-based sealer on the incidence and intensity of postoperative pain. Methods: Patients with anterior teeth or premolars requiring root canal treatment were assigned to group 1 (n = 51). Those with molars requiring treatment were assigned to group 2 (n = 57). In groups 1En and 2En, root canals were obturated with Endoseal MTA using the single-cone technique. In groups 1AH and 2AH, the sealer used was AH Plus with the continuous wave technique. On the day of canal filling, each patient was instructed to indicate their pain intensity over the 7 day postoperative period, at rest and, while biting, using a visual analog scale. Results: There was no significant difference in the incidence or intensity of postoperative pain between the Endoseal MTA and AH Plus groups during the 7 day postoperative period (p > 0.05). Less time was needed to seal the root canals with Endoseal MTA, especially in group 2 (p < 0.05). Conclusions: Endoseal MTA and AH Plus had similar effects on the incidence and intensity of postoperative pain. The obturation time was shorter when using Endoseal MTA compared to AH Plus.

Investigation of characteristics as endodontic sealer of novel experimental elastin-like polypeptide-based mineral trioxide aggregate

Although mineral trioxide aggregates (MTA) have been adopted as an endodontic sealer because of excellent sealing effect and bioactive property and been modified with improvement of its characteristics, the developed MTA sealers have not yet satisfied all the ideal requirements of endodontic sealers. The aim of this study was to assess the characteristics of elastin-like polypeptide (ELP)-incorporated MTA for use as an endodontic sealer and compare them with those of commercial MTA sealers. Two commercial MTA sealers and three experimental ELP-incorporated MTA sealers with 0.3, 0.4, and 0.5 liquid/powder (L/P) ratio for 10 wt% ELP liquid were evaluated. The push-out bond strength, flow rate, sealer penetrability and wash-out resistance were tested and the sealer-dentin interface was observed using a scanning electron microscope (SEM). Our study revealed the ELP-incorporated MTA sealer, especially in 0.4 L/P ratio, exhibited the higher push-out bond strength and flow rate (P < 0.05), and equal or superior sealer penetration and remarkable wash-out resistance compared to commercial MTA sealers. The groups of ELP-based experimental sealers also exhibited more intimate contact with dentin compared to the commercial MTA sealers. Our research will suggest the possible adoption of the ELP-incorporated MTA as endodontic sealer for clinical use.

Physicochemical properties and cytocompatibility of newly developed calcium silicate-based sealers

The purpose of this study was to compare the physical properties and cytocompatibility of contemporary calcium silicate-based sealers. Four calcium silicate-based sealers (BrightEndo MTA sealer, CeraSeal, EndoSeal TCS and One-Fil) were compared to an epoxy resin-based sealer (AH Plus). Flow, setting time, radiopacity and dimensional change were evaluated according to ISO 6876 standards. Cytotoxicity on human periodontal ligament fibroblast (hPDLF) cells was compared for biological properties using MTT assay. The surface of the sealer was analysed using scanning electron microscopy to evaluate cell attachment. Flow and radiopacity of all sealers met ISO standards, while setting time and dimensional stability did not meet the ISO standards. Calcium silicate-based sealers showed favourable cytocompatibility, and hPDLF cells were well attached to the calcium silicate-based sealers. Calcium silicate-based sealers have clinically acceptable flow and radiopacity, and cytocompatibility. However, these sealers had longer setting time and higher dimensional change than those required by ISO 6876.

The Influence of New Silicate Cement Mineral Trioxide Aggregate (MTA Repair HP) on Metalloproteinase MMP-2 and MMP-9 Expression in Cultured THP-1 Macrophages

The aim of the present study was to investigate the new silicate cement mineral trioxide aggregate (MTA Repair HP) with respect to its effect on the inflammation process involving the tooth and periodontal tissues. The composition of MTA Repair HP was supplemented with plasticizer agents which can have a negative effect on the modulation of tooth inflammation. The silicate-based material in question is widely used in regeneration of the pulp-dentin complex, treatment of perforations of various locations in the tooth, as well as in surgical treatment of the complications of periapical tissue. The improved bioceramic restorative cement can affect the expression of metalloproteinases MMP-2 and MMP-9 in monocytes/macrophages involved in modulation of inflammation and regenerative processes of the tooth and periodontal tissues. The novel aspect of the present study lies in the application of the model of THP-1 monocyte/macrophage and applying the biomaterial in direct contact with the cells. Hence, it provides a representation of clinical conditions with respect to regenerative pulp and periodontal treatment with the use of MTA Repair HP. A lack of macrophage activation (as measured with flow cytometry) was found. Moreover, the study identified a lack of expression stimulation of the studied metalloproteinases (with the use of Western blotting and fluorescent microscopy). Similarly, no increase in MMP-2 and MMP-9 concentration was found (measured by ELISA method) in vitro when incubated with MTA Repair HP. Based on the results it can be concluded that new MTA Repair HP does not increase the inflammatory response in monocytes/macrophages associated with the activity of the described enzymes. It can also be speculated that they do not affect the process of dentin regeneration in which MMP-2 and MMP-9 play significant roles.

Real-time nanoleakage and the flow characteristics of calcium silicate root canal filling materials

This study aimed to investigate the real-time nanoleakage and flow characteristics of calcium silicate-based (Ca-Si) root canal filling materials. Extracted human teeth (n = 30) were decoronated and standardized in their inner and outer dimensions. After root canal enlargement, the roots were filled with gutta-percha (GP) and AH26 sealer, GP and EndoSeal MTA sealer, or Biodentine. The roots were connected to a Nanoflow device (IB Systems) under hydrostatic pressure (40 cm∙H₂O) and fluid flow was traced through the filled roots. Data were detected at the nanoscale twice per second and automatically recorded in units of nL/s. Leakage was quantified as the mean slope until the curve plateaued over time, and all static flow intervals lasting longer than 1 s were analyzed to identify any increase in flow and duration. Data were statistically analyzed using the Kruskal-Wallis test. The calculated leakage values were 0.0670 ± 0.0516 nL/s for GP/AH26, 0.1397 ± 0.1579 nL/s for GP/EndoSeal MTA, and 0.0358 ± 0.0538 nL/s for Biodentine, with no statistically significant differences among the root filling materials (P > 0.05). An analysis of real-time flow data for 1000 s to identify spot trends and the overall tendency of flow until a plateau was reached revealed a stepwise increase in the roots filled with Ca-Si material, whereas the GP/AH26-filled roots showed a linear increase. Real-time measurements under hydrostatic pressure with the Nanoflow device enabled precise fluid flow tracing through the root canal filling material. In terms of nanoleakage, the tested root canal filling materials showed no significant differences, while the real-time flow patterns of roots filled with Ca-Si material showed different characteristics from those of GP/AH26-filled roots.

Main and Accessory Canal Filling Quality of a Premixed Calcium Silicate Endodontic Sealer According to Different Obturation Techniques

The present study aimed to investigate the effects of different obturation techniques on the main and accessory canal filling quality of a premixed calcium silicate endodontic sealer (Endoseal TCS). We also highlighted the validity of the methods used for evaluating the canal filling quality. Thirty single-rooted premolars were used for the main canal filling and 75 were used for accessory canal filling. The canals were instrumented and randomly divided into three groups according to the filling techniques: (1) single-cone technique (SC), (2) single-cone with ultrasonic activation (SU), and (3) warm vertical compaction (WV). Voids in relation to the root canal fillings were assessed using cross-section images from microcomputed tomography (μCT) scans or transversely sectioned tooth specimens (n = 10). After demineralization and clearing of the teeth, the incidence, number, and completeness of the accessory canal fillings were evaluated (n = 25). One-way analysis of variance (ANOVA) and Tukey's post hoc test was used for the evaluation of the voids in the main root canal and the incidence and number of filled accessory canals. Pearson's chi-squared (χ²) test was used for the evaluation of the filling completeness (α = 0.05). In the stereomicroscopic evaluation of the sectioned specimen, the SC group had significantly higher void occurrence than the other groups (p < 0.05), although there was no difference between groups in the μCT evaluation. However, there was no difference between the SU and WV. There was no difference between all the groups regarding the incidence, number, and completeness of the accessory canal fillings. When the premixed calcium silicate sealer is used with SC, the ultrasonic activation is recommended to obtain a better main canal filling quality. In contrast, the obturation techniques did not affect the accessory canal filling. We also recommend using the sectioning method when the void formation in the root canal filling materials is evaluated.

Flow characteristics and alkalinity of novel bioceramic root canal sealers

Objective

This study aimed to examine the physical properties (pH and flow) of 2 novel bioceramic sealers.

Materials and Methods

The tested sealers were a calcium hydroxide sealer (Sealapex) and 2 bioceramic sealers (BioRoot RCS and TotalFill BC Sealer). Flow measurements were conducted according to ISO 6876/2012, with a press method of 0.05 mL of sealer. The pH of fresh samples was tested immediately after manipulation, while set samples were stored for 3 times the recommended setting time. The predetermined time intervals ranged from 3 minutes to 24 hours for fresh samples and from 10 minutes to 7 days and 4 weeks for the set samples. Analysis of variance was performed, with p = 0.05 considered indicating significance.

Results

The mean flow values were 26.99 mm for BioRoot, 28.19 for Sealapex, and 30.8 mm for TotalFill BC Sealer, satisfying the ISO standard. In the set samples, BioRoot RCS had higher pH values at 24 hours to 1 week after immersion in distilled water. At 2 weeks, both bioceramic sealers had similar pH values, greater than that of Sealapex. In the fresh samples, the bioceramic sealers had significantly higher initial pH values than Sealapex (p < 0.05). At 24 hours post-immersion, all sealers showed an alkaline pH, with the highest pH observed for TotalFill.

Conclusions

The TotalFill BC Sealer demonstrated the highest flow. The bioceramic sealers initially presented higher alkaline activity than the polymeric calcium hydroxide sealer. However, at 3 and 4 weeks post-immersion, all sealers had similar pH values.

Antimicrobial activity and biocompatibility of the mixture of mineral trioxide aggregate and nitric oxide-releasing compound

Background/purpose

Antimicrobial activity and biocompatibility of root canal sealer are related to the success of endodontic treatments. This study investigated the efficacy of mixture of mineral trioxide aggregate (MTA) and a NO-releasing compound for the antimicrobial activity, biocompatibility, and physical properties.

Materials and methods

MTA was mixed with diethylenetriamine-NO (MTA-NO), and the extracts from MTA and the MTA-NO mixture before and after setting was obtained were investigated the antimicrobial activity against Enterococcus faecalis and Porphyromonas endodontalis. After setting MTA and MTA-NO, pulp cell was incubated in the presence of MTA and MTA-NO disk using Transwell® cell culture insert, and the proliferation assay and mineralization-stimulated factors of the cells were analyzed by MTT assay and real-time RT-PCR, respectively. The physical properties of MTA and the MTA-NO mixture, such as surface hardness and flowability was also analyzed.

Results

The MTA-NO mixture showed stronger antimicrobial activity against E. faecalis and P. endodontalis than that by MTA. Both MTA and MTA-NO mixture increase the ratio of cell proliferation and induced the expression of alkaline phosphatase, collagen type I, osteocalcin, and osteopontin. Moreover, the induction of gene expression by MTA-NO mixture was higher than that by MTA alone. No significant difference was observed for surface hardness and flowability between MTA and MTA-NO mixture.

Conclusion

The addition of a NO-releasing compound to the endodontic treatment using MTA root canal sealer might reduce the risk of bacterial infection and help to regenerate the dental pulp tissue.

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.

A micro-computed tomographic evaluation of root canal filling with a single gutta-percha cone and calcium silicate sealer

Objectives

The purpose of this study was to evaluate the void of root canal filling over time when a calcium silicate sealer was used in the single gutta-percha cone technique.

Materials and Methods

Twenty-four J-shaped simulated root canals and twenty-four palatal root canals from extracted human maxillary molars were instrumented with ProFile Ni-Ti rotary instruments up to size 35/0.06 or size 40/0.06, respectively. Half of the canals were filled with Endoseal MTA and the other half were with AH Plus Jet using the single gutta-percha cone technique. Immediately after and 4 weeks after the root canal filling, the samples were scanned using micro-computed tomography at a resolution of 12.8 μm. The scanned images were reconstructed using the NRecon software and the void percentages were calculated using the CTan software, and statistically analyzed by 1-way analysis of variance, paired t-test and Tukey post hoc test.

Results

After 4 weeks, there were no significant changes in the void percentages at all levels in both material groups (p > 0.05), except at the apical level of the AH Plus Jet group (p < 0.05) in the simulated root canal showing more void percentage compared to other groups. Immediately after filling the extracted human root canals, the Endoseal MTA group showed significantly less void percentage compared to the AH Plus Jet group (p < 0.05).

Conclusions

Under the limitations of this study, the Endoseal MTA does not seem to reduce the voids over time.

Comparative Evaluation of Physicochemical Properties and Apical Sealing Ability of a Resin Sealer Modified with Pachymic Acid

Objective:

The addition of pachymic acid (PA) to AH Plus (an epoxy resin sealer) offsets the cytotoxicity of the latter. Prior to the clinical implementation of this formulation, a thorough knowledge of its physicochemical properties and sealing ability becomes mandatory. Hence, this in vitro study aimed to characterize and evaluate the physicochemical properties and apical sealing ability of AH Plus (AHP) with and without the addition of PA.

Methods:

Flow, setting time, film thickness, solubility and radiopacity of AHP (group 1) and AHP modified with PA (AHP/PA, group 2) were evaluated in accordance with the guidelines put forth by ISO 6876:2012. The percentage was determined under each parameter. Apical sealing ability was assessed using fluid filtration device. An independent samples t-test was used for inter- and intra-group comparisons of mean fluid flow (MFF).

Results:

Incorporating PA to AHP decreased its flow, setting time and film thickness by 24.34%, 2.14% and 31.71% respectively. The solubility of group 2 increased on day 1 by 85.71% and decreased on days 3, 7 and 14 by 46.67%, 34.79% and 13.8% respectively. The radiopacity of AHP was not altered by the addition of PA. MFF rates of group 2 was significantly higher than group 1 on day 1, but not significantly different on day 7.

Conclusion:

AHP/PA exhibited physicochemical properties that were within the requirements of ISO and with time, and showed fluid flow similar to AHP.

Different Application Methods for Endoseal MTA Sealer: A Comparative Study

Introduction

The aim of present ex vivo study was to investigate the filling quality and voids, using Endoseal mineral trioxide aggregate (Endoseal MTA) with a single-cone technique with and without ultrasonic application and to compare these methods with lateral compaction technique.

Methods and Materials

Thirty-six extracted human anterior single-root teeth were prepared and assigned to 3 groups: Group 1: EMS group was Endoseal MTA+ single-cone; Group 2: EMSU group was Endoseal MTA+ single-cone with ultrasonic activation; and Group 3: LC group was Endoseal MTA+ lateral condensation technique. Teeth were sectioned transversely in coronal, middle and apical of the teeth and the existence of voids and their areas in the slices were measured and scored under a dental microscope. One-way analysis of variance and Post Hoc test were used for statistical analysis and also to detect any significance (α=0.05).

Results

EMS group showed significantly more void area than lateral compaction group (P<0.05), but the difference between the EMSU group and the other two groups were not significant (P>0.05). Also, EMS group had significantly higher void score than the other two groups (P<0.017).

Conclusion

Endoseal MTA as a premixed calcium silicate sealer has a better performance when used with gutta-percha cone-mediated ultrasonic activation, so we suggest gentle ultrasonic activation for applying Endoseal MTA in the clinical use.

Biocompatibility and Mineralization Activity of Three Calcium Silicate-Based Root Canal Sealers Compared to Conventional Resin-Based Sealer in Human Dental Pulp Stem Cells

The purpose of this study was to compare the cytotoxic effects and mineralization activity of three calcium silicate-based root canal sealers to those of a conventional resin-based sealer. Experiments were performed using human dental pulp stem cells grown in a monolayer culture. The root canal sealers tested in this study were EndoSequence BC Sealer (Brasseler), BioRoot RCS (Septodont), Endoseal MTA (Maruchi), and AH Plus (Dentsply DeTrey). Experimental disks 6 mm in diameter and 3 mm in height were made and stored in a 100% humidity chamber at 37 °C for 72 h to achieve setting. The cytotoxicity of various root canal sealers was evaluated using a methyl-thiazoldiphenyl-tetrazolium (MTT) assay. To evaluate cell migration ability, a scratch wound healing method was used, and images of the scratch area were taken using a phase-contrast microscope. Cell morphology was evaluated by a scanning electron microscope after direct exposure for 72 h to each sealer disk. In the cell viability assay, there were no significant differences between the EndoSequence BC, BioRoot RCS, Endoseal MTA, and control groups in any experimental period (p > 0.05). In the cell migration assay, there were no significant differences between the EndoSequence BC, Endoseal MTA, and control groups in any experimental period (p > 0.05). BioRoot RCS exhibited slower cell migration relative to EndoSequence BC and Endoseal MTA for up to 72 h (p < 0.05). Conversely, it showed a similar wound healing percentage at 96 h (p > 0.05). In an evaluation of cell morphology, cells in direct contact with EndoSequence BC, BioRoot RCS, and Endoseal MTA disks showed superior spreading compared to those in contact with the AH Plus disk. In an Alizarin red staining assay, EndoSequence BC, BioRoot RCS, and Endoseal MTA showed a significant increase in mineralized nodule formation compared to the AH Plus group (p < 0.05). In conclusion, all calcium silicate-based root canal sealers tested in this study showed good biological properties and mineralization activity compared to conventional resin-based sealer.

In Vitro Comparison of Biocompatibility of Calcium Silicate-Based Root Canal Sealers

The aim of this study was to assess the effect of three calcium silicate-based sealers (EndoSeal MTA, Nano-ceramic Sealer, and Wellroot ST) and two epoxy resin-based sealers (AH-Plus, AD Seal) on various aspects, such as cell viability, inflammatory response, and osteogenic potential, of human periodontal ligament stem cells (hPDLSCs). AH-Plus showed the lowest cell viability on hPDLSCs in all time periods in fresh media. In set media, hPDLSCs showed no significant differences in cell viability among all the tested materials. Wellroot ST showed the highest level of cell adhesion and the morphology of attached cells. AH-plus presented a significantly higher expression of IL-6 and IL-8 than the other sealers. AD Seal and three calcium silicate sealers showed high expression of the mesenchymal stem cell markers. ALP mRNA expression showed a significant increase in time-dependent manner on all of three calcium silicate-based sealers, which do not seem to interfere with the differentiation of hPDLSCs into osteoblasts. Based on the results from this study, calcium silicate-based sealers appear to be more biocompatible and less cytotoxic than epoxy resin-based sealers. Meanwhile, further and long-term clinical follow-up studies are required.

A novel antibacterial resin-based root canal sealer modified by Dimethylaminododecyl Methacrylate

Persistent apical periodontitis, mainly caused by microorganisms infections, represents a critical challenge for endodontists. Dimethylaminododecyl methacrylate (DMADDM) is a well-studied and potent antibacterial agent used in various studies described in the literature. The aim of this study is to develop a novel antibacterial root canal sealer by incorporating DMADDM into EndoREZ and investigate the properties of the resulting material. Different mass fractions (0, 1.25%, 2.5%, and 5%) of DMADDM were incorporated into EndoREZ and the cytotoxicity, apical sealing ability and solubility of the resulting material were evaluated. Furthermore, a direct contact test, determination of colony-forming units, a crystal violet assay, scanning electronic microscopy and live/dead bacteria staining were performed to evaluate the antibacterial effect of the sealer to multispecies bacteria (Enterococcus faecalis, Streptococcus gordonii, Actinomyces naeslundii, and Lactobacillus acidophilus), in planktonic cells or biofilms. Fluorescence in situ hybridization and quantitative real-time polymerase chain reaction were carried out to assess the composition of the multispecies biofilms. No difference on the cytotoxicity, apical sealing ability and solubility between sealers containing DMADDM (1.25%, 2.5%) and EndoREZ (0%) could be determined. However, when the mass fraction of DMADDM increased to 5%, significantly different properties were found compared to the 0% (p < 0.05) group. Moreover, incorporating DMADDM into the sealer could greatly improve the antibacterial properties of EndoREZ. In addition, the composition ratio of E. faecalis could be decreased in multispecies microecology in sealers containing DMADDM. Therefore, a EndoREZ sealer material containing DMADDM could be considered useful in clinical applications for preventing and treating persistent apical periodontitis.

Evaluation of the Dislodgement Resistance of a New Pozzolan-Based Cement (EndoSeal MTA) Compared to ProRoot MTA and Biodentine in the Presence and Absence of Blood

INTRODUCTION

This in vitro study investigated the dislodgement resistance of EndoSeal MTA, a new pozzolan-containing calcium silicate-based material, in comparison with ProRoot MTA and Biodentine in the presence and absence of contamination with blood.

METHODS

Standard furcal perforations were created in 180 human mandibular first molars. The teeth were randomly allocated to 12 groups of 15 each. ProRoot MTA, Biodentine, and EndoSeal MTA were used to repair the perforations. In half of the samples, the walls of the perforated areas were contaminated with blood, whereas saline was injected into the other half. A push-out test was performed using a universal testing machine after 24 hours or 7 days. To evaluate failure patterns, the samples were split into half and were examined under a stereomicroscope at a 20x magnification. Data were analyzed using three-way analysis of variance, Tukey test, and Student's t-test.

RESULTS

At both time intervals and in the presence and absence of contamination with blood, ProRoot MTA and Biodentine had significantly higher retention values than EndoSeal MTA (p < 0.001). Contamination with blood had no effect on EndoSeal MTA; however, it negatively affected the dislodgement resistance of Biodentine at 24 hours and ProRoot MTA at both time intervals (p < 0.05). Time significantly affected only the bond strength of the uncontaminated groups (p > 0.001). The most common type of failure was mixed for ProRoot MTA and Biodentine, whereas it was cohesive for EndoSeal MTA.

CONCLUSIONS

ProRoot MTA and Biodentine showed higher values of bond strength than EndoSeal MTA and may thus be better options for the repair of root perforations.

Do in vitro solubility studies on endodontic sealers demonstrate a high level of evidence? A systematic review

OBJECTIVE

To systematically review the quality of evidence of available in vitro solubility studies on endodontic sealers according to prespecified evidence criteria.

MATERIAL AND METHODS

This systematic review was based on the PRISMA guidelines and the AMSTAR measurement tool. A systematic duplicate search of the literature on endodontic sealer solubility studies was conducted in PubMed and Embase databases (until 18 October 2017). Mapping terms to subject headings and free text terms were used and combined with hand searching before exclusion of duplicates. Studies specifically dealing with endodontic sealer solubility were selected. The evidence level was graded (low, medium or high) independently by two investigators following systematic data extraction in pilot forms, which was based on prespecified evidence criteria and the modified CONSORT checklist for in vitro studies on dental materials.

RESULTS

The search retrieved 1053 articles, from which 88 were assessed in full. From the 63 articles retained in the final analysis, 11 were classified as having moderate and 52 as low quality of evidence (0 high). The studies graded as low had low sample size (n < 10) and/or insufficient details to allow replicability. Most of the studies did not conform to the modified CONSORT checklist and did not include parameters considered relevant in the prespecified criteria.

CONCLUSIONS

Existing in vitro studies on the solubility of endodontic sealers do not demonstrate a high quality of evidence. Most of these studies do not present systematic reporting nor employ relevant parameters prespecified in our evidence criteria.

A micro-computed tomographic study of remaining filling materials of two bioceramic sealers and epoxy resin sealer after retreatment

Objective

This study evaluated the presence of residual root canal filling material after retreatment using micro-computed tomography (micro-CT).

Materials and Methods

Extracted human teeth (single- and double-rooted, n = 21/each; C-shaped, n = 15) were prepared with ProFile and randomly assigned to three subgroups for obturation with gutta-percha and three different sealers (EndoSeal MTA, EndoSequence BC sealer, and AH Plus). After 10 days, the filling material was removed and the root canals were instrumented one size up from the previous master apical file size. The teeth were scanned using micro-CT before and after retreatment. The percentage of remaining filling material after retreatment was calculated at the coronal, middle, and apical thirds. Data were analyzed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni post hoc correction.

Results

The tested sealers showed no significant differences in the percentage of remaining filling material in single- and double-rooted teeth, although EndoSeal MTA showed the highest value in C-shaped roots (p < 0.05). The percentage of remaining filling material of AH Plus and EndoSeal MTA was significantly higher in C-shaped roots than in single- or double-roots (p < 0.05), while that of BC sealer was similar across all root types. EndoSeal MTA showed the highest values at the apical thirds of single- and double-roots (p < 0.05); otherwise, no significant differences were observed among the coronal, middle, and apical thirds.

Conclusions

Within the limitations of this study, a large amount of EndoSeal MTA remained after retreatment, especially in C-shaped root canals.

The Penetration Ability of Calcium Silicate Root Canal Sealers into Dentinal Tubules Compared to Conventional Resin-Based Sealer: A Confocal Laser Scanning Microscopy Study

The purpose of this study was to compare the penetration ability of calcium silicate root canal sealers and conventional resin-based sealer using confocal laser scanning microscopy (CLSM). A total of 60 recently extracted single-rooted human premolars were used in this study. The root canals were prepared to a size 40/0.06 taper with ProFile rotary instruments and irrigated with NaOCl and EDTA. After drying all canals, the specimens were randomly divided into three experimental groups (n = 20): Group 1, gutta-percha (GP)/AH Plus with continuous wave compaction; group 2, GP/BioRoot RCS with a single-cone technique; and group 3, GP/Endoseal MTA with a single-cone technique. All experimental samples were sectioned perpendicular to their long axis using a low-speed diamond wheel at the apical, middle, and coronal third levels. The penetration abilities of all samples were evaluated using CLSM. A Kruskal⁻Wallis analysis and a series of Mann⁻Whitney U post hoc tests were performed. A higher intensity level was found in the coronal area and a lower intensity level in the apical area in all the experimental groups. The AH Plus group showed higher sum fluorescence intensity in the apical and coronal thirds compared with the BioRoot RCS and Endoseal MTA groups, whereas the BioRoot RCS group showed a higher intensity level in the middle third, similar to the AH Plus group. The maximum sealer penetration depth was low in the apical area and high in the coronal area in the AH Plus and Endoseal MTA groups. In the BioRoot RCS group, maximum sealer penetration was observed in the middle third. In conclusion, there were significant differences in sealer penetration pattern and distance according to the root level and sealer type.

In Vivo Molecular Toxicity Profile of Dental Bioceramics in Embryonic Zebrafish ( Danio rerio)

The investigation of the biocompatibility of potential and commercially available dental material is a major challenge in dental science. This study demonstrates that the zebrafish model is a novel in vivo model for investigating the biocompatibility of dental materials. Two commercially available dental materials, mineral trioxide aggregate (MTA) and Biodentine, were assessed for their biocompatibility. The biocompatibility analysis was performed in embryonic zebrafish with the help of standard toxicity assays measuring essential parameters such as survivability and hatching. The mechanistic and comparative analysis of toxicity was performed by oxidative stress analysis by measuring ROS induction and apoptosis in zebrafish exposed to dental materials at different concentrations. The molecular investigation at the protein level was done by a computational approach using in silico molecular docking and pathway analysis. The toxicity analysis showed a significant reduction in hatching and survivability rates along with morphological malformations with an increase in the concentration of exposed materials. ROS and apoptosis assay results revealed a greater biocompatibility of Biodentine as compared to that of MTA which was concentration-dependent. In silico analysis showed the significant role of the tricalcium silicate-protein ( Sod1, tp53, RUNX2B) interaction in an exhibition of toxicity. The study provides a new vision and standard in dental material sciences for assessing the biocompatibility of potential novel and commercially available dental materials.

Interfacial Characteristics and Cytocompatibility of Hydraulic Sealer Cements

INTRODUCTION

The stability and long-term success of root canal obturation depends on the choice of sealer because the sealer bonds to the dentin and stabilizes the solid cone. Furthermore, the sealer needs to be nontoxic because sealer toxicity will certainly lead to treatment failure. The aim of this study was to assess the sealer-dentin interface of 3 hydraulic root canal sealers and to evaluate their cytocompatibility compared with AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany).

METHODS

Four dental root canal sealers were assessed. AH Plus, MTA Fillapex (Angelus, Londrina, Brazil), BioRoot RCS (Septodont, Saint-Maur-des-Fossés, France), and Endoseal (Maruchi, Wonju-si, Gangwon-do, South Korea) were characterized using scanning electron microscopy and energy-dispersive spectroscopy. The sealer-tooth interface was assessed by confocal microscopy and scanning electron microscopy, and biocompatibility was measured by assessing the cell metabolic function using direct contact assays and alkaline phosphatase activity.

RESULTS

The tricalcium silicate-based sealers presented a different microstructure and elemental composition despite their similar chemistry and classification. BioRoot RCS was free of aluminum, and all sealers presented different radiopacifying elements. The sealer penetration in the dentinal tubules and interfacial characteristics were different. The migration of silicon was evident from sealer to tooth for all sealers containing tricalcium silicate. MTA Fillapex and BioRoot RCS exhibited the best cytocompatibility in both the direct contact test and alkaline phosphatase activity.

CONCLUSIONS

The use of hydraulic calcium silicate-based sealers has introduced a different material type to endodontics. These materials are different than other sealers mostly because of their hydraulic nature and their interaction with the environment. Although the sealers tested had a similar chemistry, their cytocompatibility and bonding mechanisms were diverse.

Comparison of antimicrobial activity of traditional and new developed root sealers against pathogens related root canal

Background/purpose

Bacterial infection is closely associated with the failure of endodontic treatment, and use of endodontic sealer with antimicrobial activity and biological compatibility is necessary for the success of root canal treatment. The purpose of this study was to investigate and to compare the antibacterial effect of two calcium silicate-based root canal sealers (Endoseal and EndoSequence BC sealer) as recent development sealers and with three conventional root canal sealers (AH Plus, Sealapex, and Tubli-Seal), before or after setting, on Porphyromonas endodontalis, Porphyromonas gingivalis, and Enterococcus faecalis.

Materials and methods

The sealers were soaked in phosphate buffered saline to elute its compositions after and before setting, and the elutes were performed the antimicrobial assay. Also, X-ray fluorescence analysis was carried out to compare compositions of two calcium silicate-based sealers.

Results

The conventional root canal sealers have strong antibacterial activity against the Gram-negative bacteria, P. endodontalis and P. gingivalis. Endoseal sealer showed antibacterial activity against not only the Gram-negative bacteria, but also against the Gram-positive bacteria, E. faecalis. However, Endosequence BC sealer exhibited a weak antibacterial effect on all bacteria in this study. X-ray fluorescence analysis exhibited that Endoseal contained more types and more amount of the oxide compound known to have strong antimicrobial activity such as Al₂O₃, Fe₂O₃, MgO, Na₂O, NiO, and SO₂ than Endoseqeunce BC.

Conclusion

Endoseal, which contains various types of oxide compounds, seems to be a suitable sealer for preventing bacterial infection in both treated and untreated root canals.

Different Setting Conditions Affect Surface Characteristics and Microhardness of Calcium Silicate-Based Sealers

OBJECTIVE

To investigate the effect of different setting conditions on surface microhardness and setting properties of calcium silicate-based sealers.

METHODS

Three sealers, EndoSequence Bioceramic (BC; Brasseler USA, Savannah, GA, USA), Endoseal MTA (ES; Maruchi, Wonju, Korea), and Well-Root ST (WR; Vericom, Chuncheon, Korea), were compared. Specimens were exposed to either butyric acid (pH 5.4) or phosphate-buffered saline (PBS [pH 7.4]) for 48 h and stored at 100% humidity for 12 days. The control specimens were stored at 100% humidity for 14 days. Surface microhardness was measured, topographic changes were observed, and phase analysis was performed using X-ray diffraction. Microhardness according to storage conditions was compared using one-way analysis of variance and Tukey's multiple comparison tests (P < .05).

RESULTS

The BC and ES sealers exhibited decreased microhardness when stored in acid or PBS compared with control (P < .05). In the WR group, acid exposure lowered microhardness of the specimens compared with control (P < .05). Scanning electron microscopy revealed different topographies in specimens from all tested sealers exposed to acid or PBS.

CONCLUSION

The surface microhardness of calcium silicate-based sealers was reduced by exposure to either acid or PBS. Acid solutions, however, had a more detrimental effect than PBS.

Influence of environment on testing of hydraulic sealers

In vitro material testing is undertaken by conducting a series of tests following procedures outlined in international standards. All material properties are measured in water; however biological behavior is undertaken in alternative media such as Dulbecco’s modified eagle medium (DMEM) or simulated body fluid. The aim of this study was to characterize four dental root canal sealers and study their properties in different media. Four dental root canal sealers were assessed. They were characterized by a combination of techniques and the sealer properties were tested as specified by ISO 6876 (2012) and also in alternative media. The sealer biocompatibility was measured by cell function and proliferation assays of elutions. All sealers complied with ISO specifications. The material properties were effected by the type of soaking medium used and the surface micromorphology and elemental composition were dependent on the soaking solution type. Both BioRoot and MTA Fillapex showed cytotoxicity which reduced at higher dilutions. The material chemistry, presentation, environmental conditions and testing methodology used affected the sealer properties. Standards specific to sealer type are thus indicated. Furthermore the methodology used in the standard testing should be more relevant to clinical situations.

Composition and physicochemical properties of calcium silicate based sealers: A review article

Background

Recently a new generation of endodontic sealers has been developed based on calcium silicate as MTA Fillapex, Endoseal MTA, Total Fill BC Sealer, EndoSequence BC Sealer, iRoot SP, Endo CPM sealer, MTA-Angelus and ProRoot Endo Sealer. A review of literature was conducted to discuss the composition, physicochemical properties, and clinical perspectives of calcium silicate based sealers.

Material and Methods

A literature search was conducted in PubMed and web of knowledge databases with appropriate MeSh terms and keywords. A total of 71 studies were reviewed for data extraction.

Results and Conclusions

Calcium silicate based sealers showed suitable physical properties to be used as an endodontic sealer. However, its high solubility remains an important issue. They show good performance regarding calcium ion release, film thickness, and fowability. More researches are required about features of calcium silicate based sealers before recommending them for clinical applications.

Key words:Calcium silicate, root canal filling materials, composition, physical properties.