Calcium Silicate-based Root Canal Sealers Research Articles

The effects of final irrigants on the push-out bond strength of two calcium silicate-based root canal sealers: an in vitro study.

The purpose of the present study was to investigate the effect of the different irrigant combinations used in final irrigation on the push-out bond strength of root canal sealers that have different compositions. In total 60 dentinal slices in 1 mm thickness were collected from 15 extracted mandibular premolar teeth; 4 slices from each tooth. 3 canal-like artificial cavities were opened on each dentinal slice. Samples were divided into 4 experimental groups, each of which consisted of 15 samples. In group 1, samples were immersed in 5.25% NaOCl and 17% EDTA solutions respectively; in group 2, immersed in 5.25% NaOCl and 2% CHX solutions respectively; in group 3, immersed in 5.25% NaOCl, 17% EDTA and 2% CHX solutions respectively; and in group 4 immersed in distilled water. After drying with absorbent papers, each cavity in dentinal slice sample was filled with different sealer (Endoseal MTA, Tech Biosealer Endo or AH Plus). Two days later, the push-out bond examination was performed. AH Plus showed higher push-out bond strength value in two combinations (group 2 and 3) in which final irrigants contained CHX (p<0.001). Dentinal push-out bond strengths of root canal sealers from Endoseal MTA and Tech BioSealer Endo were not affected by final irrigant (p=0.965). Using CHX after NaOCl in final irrigant increases push-out strength of epoxy resinbased sealer but, did not create any difference in dentinal push-out bond strength of calcium silicate-based sealers.

Influence of variations in the environmental pH on the solubility and water sorption of a calcium silicate-based root canal sealer.

To evaluate the influence of pH variation on the solubility and water sorption of a premixed calcium silicate-based root canal sealer (EndoSequence BC Sealer) compared to the gold standard based on epoxy resin (AH Plus Jet) after immersion in distilled water and phosphate-buffered saline (PBS). Solubility and water sorption were evaluated after immersion in distilled water or PBS at several pHs (5, 7 and 12) and the values were calculated as percentages of the original mass after 24h, 7 and 30days of immersion. The crystalline structures present in the sealers and surface precipitates were assessed by X-ray diffraction. The Shapiro-Wilk's test revealed that data were normally distributed; thus, statistical analysis was performed using one-way anova and Tukey's tests or independent t-test, assuming a 5% α-error. EndoSequence BC Sealer was associated with significantly greater water sorption and solubility compared to AH Plus Jet in all tested conditions (P<0.05). The acid environment increased the 24h solubility of EndoSequence BC Sealer immersed in PBS (P<0.05) and did not induce significative changes in the water sorption (P>0.05). Alkaline pH reduced the solubility of EndoSequence BC Sealer and increased that of AH Plus Jet at all experimental times and soaking media (P<0.05). Alkaline environment also significantly increased the water sorption of AH Plus Jet immersed in PBS (P<0.05). Immersion in PBS significantly reduced the solubility of EndoSequence BC Sealer and significantly increased that of AH Plus Jet (P<0.05). Precipitates on the surface of EndoSequence BC Sealer corresponding to hydroxyapatite and calcium carbonate were detected after immersion in PBS at pH 5 and 7 for 30days. EndoSequence BC Sealer had significantly greater solubility and water sorption than AH Plus Jet. Although the alkaline pH and soaking media directly influenced the solubility and water sorption of the sealers, the solubility of AH Plus Jet remained within the limits recommended by ISO 6876, whilst the solubility of the EndoSequence BC Sealer did not comply with ISO recommendations in all the conditions tested.

What’s new for the clinician? - Excerpts from and summaries of recently published papers

Choosing an endodontic sealer clinical use is a decision that contributes to the long-term success of non-surgical root canal treatment. Sealers are used as a thin tacky paste which function as a lubricant and luting agent during obturation, allowing the core obturation material, such as gutta-percha points or other rigid materials, to slide in and become fixed in the canal. Sealers can fill voids, lateral canals, and accessory canals where core obturation materials cannot infiltrate. If the sealer does not perform its function, microleakage may cause root canal failure via clinically undetectable passage of bacteria, fluids, molecules or ions between the tooth and restorative material. It has been reported that extrusion of the sealer during root canal filling has cytotoxic effects on periapical tissues, causing periapical inflammation, necrosis and pain. Endodontic sealers are categorized by composition based on setting reaction and composition: zinc oxide eugenol, salicylate, fatty acid, glass ionomer, silicone, epoxy resin, tricalcium silicate, and methacrylate resin sealer systems. Aslan &amp; Özkan (2021) reported on a trial that sought to evaluate the effect of two calcium silicate-based root canal sealers, Endoseal MTA and EndoSequence BC Sealer, on postoperative pain following single-visit root canal treatment on molar teeth compared to their epoxy/ amine resin-based counterpart AH Plus. The null hypotheses tested in this study were as follows:1. The type of sealer used would not change the incidence and the intensity of post-treatment endodontic pain2. The analgesic intake of patients following single-visit root canal treatment

Heating stability, physical and chemical analysis of calcium silicate-based endodontic sealers.

To evaluate possible modifications in root canal sealers subjected to a variety of heating conditions using vibrational spectroscopy and analysis of physical and chemical properties. EndoSequence BC Sealer HiFlow, Bio-C Sealer, BioRoot RCS and AH Plus were analysed chemically using Raman spectroscopy (25-220°C) and Fourier-transform infrared spectroscopy (FT-IR) (37-100°C ). For FT-IR, the materials were tested individually and mixed with root dentine powder. Scanning electron microscopy (SEM) and coupled energy dispersive spectroscopy (EDS) were used to evaluate surface and chemical elements. ISO 6876-2012 and ASTM-C266-07 specifications were followed to evaluate flow, setting time (moist and dry), solubility and radiopacity. Also, pH analysis at 37 and 100°C was performed. Shapiro-Wilk and Mixed ANOVA (within and between the effects of the subjects), Levene, and a post hoc analyses with Bonferroni correction were performed (P<0.05). Vibrational spectroscopy revealed peaks of tricalcium silicate, dicalcium silicate and zirconium dioxide. Chemical changes in the Raman spectra during heating were discrete, as the inorganic content predominated the signalling for all root canal sealers. FT-IR analysis exhibited spectral changes in water absorption for EndoSequence BC Sealer HiFlow and Bio-C Sealer, probably related to dehydration. For BioRoot RCS and AH Plus, no significant chemical changes were observed. Bio-C Sealer exhibited a band of polyethylene glycol only after heating to 100°C, probably related to its thermal decomposition. SEM/EDS analysis corroborated the composition results observed in vibrational spectroscopy for all materials. Heating to 100°C significantly changed the flowability of all calcium silicate-based sealers with a wide variation in setting times at both temperatures, along with solubility levels above ISO standards. For all tested sealers, radiopacity fulfilled the requirements, and pH exhibited alkaline values. The tested calcium silicate-based sealers were affected by heating. Calcium silicate-based root canal sealers had high solubility which is a concern for their clinical use. AH Plus was the only root canal sealer that was stable after heating.

Solubility of bioceramic- and epoxy resin-based root canal sealers: A systematic review and meta-analysis.

This systematic review and meta-analysis evaluated whether epoxy resin-based root canal sealers present an increased solubility than calcium silicate-based root canal sealers. A systematic search was performed in the following databases: PubMed, Science Direct, Scopus, Web of Science and Open Grey. The inclusion criteria consisted of invitro studies that compared the solubility of epoxy resin-based and calcium silicate-based sealers. The quality assessment and data extraction of the selected articles were performed. The meta-analysis of the pooled data and the subgroups according to the root thirds were carried out using the RevMan software (P < 0.05). After the duplicate removal and eligibility criteria assessment, a total of 22 studies were included all of them were considered as having a low risk of bias. The meta-analysis demonstrated overall lower solubility of AH Plus. AH Plus presented lower solubility than Bio-C Sealer, BioRoot RCS, MTA Fillapex, Sealer Plus and Total Fill BC Sealer.

Comparative evaluation of retreatability of calcium silicate-based root canal sealers and epoxy resin-based root canal sealers in curved canals-An In-Vitro micro-CT analysis.

To compare and evaluate the retreatability of calcium silicate-based root canal sealers and epoxy resin-based root canal sealers in curved canals using micro-CT scanning. Forty-five maxillary molars with curved roots were selected after confirming with the Schneiders test. Teeth were decoronated near the cemento-enamel junction and moderate to severely curved canals were selected for the study using cone-beam computed tomography. All the samples were subjected to pre-operative micro-CT scanning. Cleaning and shaping were done using step-back preparation, obturation was done using lateral compaction technique, and homogeneous obturation was achieved. All the specimens were kept in 10 mL of phosphate buffered-saline solution at a pH of 8.4 for 48 h and transferred to a plastic container containing moistened foam with 10 mL of phosphate- buffered saline solution, and stored at 37 °C with 100% relative humidity for 4 months. Retreatment was performed for all the samples using Protaper universal retreatment files. Micro-CT scanning was performed to compare and evaluate the remaining sealer volume and resultant cracks formed in the root canal after retreatment. The volume of sealer remaining in the root canal and the length of a crack within the groups were analysed using kruskal-Wallis test and among the groups using post-hoc scheffe test showed that more sealer present in the Diaproseal sealer followed by MTA Fillapex and Bioroot RCS and more crack length was seen in Diaproseal sealer followed by MTA Fillapex and no visible cracks were seen in Bioroot RCS, which had statistically significant results with a P value of < 0.05. Within the limitations of the study it was concluded that in-terms of retrievability, Diaproseal sealer was the best among the tested groups followed by MTA Fillapex and Bioroot RCS.

Antimicrobial effect of different calcium silicate – Based bioceramic endodontic sealers against Enterococcus faecalis: An in vitro study

Introduction: A successful root canal treatment ensures complete sealing of the root canal to abstain from re-infections. The efficiency of antimicrobial activity of the sealers is important for achieving long term success in root canal therapy. Aim: This study compared the antibacterial properties of three calcium silicate-based root canal sealers against Enterococcus faecalis at varying incubation time periods. Materials and Methods: This in vitro cross sectional experimental study was designed with three root canal sealers, namely, Endosequence/BC Sealer, CeraSeal, and BioRoot RCS. Freshly mixed selars were placed in agar plates infused with Enterococcus faecalis. Incubation at 37°C under anaerobic conditions was done for 1 week, during which measurements of the inhibition zones were recorded at 24 h, 48 h, 72 h, and 7 days. Data were compared using ANOVA, and Tukey's tests (P Results and Discussion: Bacterial growth inhibition was demonstrated by all the sealers tested, with antimicrobial activity being highest for BioRoot RCS and least for CeraSeal. An increase in duration of incubation, positively affected the antimicrobial properties. Conclusion: Significant difference (P

Effects of heating on the physical properties of premixed calcium silicate-based root canal sealers.

The purpose of this study was to examine the effect of heating on the physical properties of four types of premixed calcium silicate-based root canal sealers. Endoseal MTA, Well-Root ST, EndoSequence BC Sealer, EndoSequence BC Sealer HiFlow, and AH Plus (epoxy resin root canal sealer) were heated at 100°C for 1 min, and changes in setting time, flow, and film thickness were evaluated in accordance with ISO 6876:2012 standards. In addition, pH measurement and scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses of the set materials were performed. All root canal sealers heated at 100°C showed significant decreases in setting time and flow, particularly Endoseal MTA. In addition, the film thickness of Endoseal MTA increased significantly after heating at 100°C. The pH and SEM/EDS results were not affected by heating. Heating calcium silicate-based root canal sealers accelerated setting time, decreased flow, and increased film thickness. However, the degree of these changes varied among the products. The present findings indicate that heat-induced changes in the physical properties of calcium silicate-based root canal sealers could adversely affect the quality of warm vertical condensation technique.

Physicochemical, cytotoxicity, and biological properties of calcium silicate-based root canal sealers: A literature review

The aim of this study was to evaluate the main calcium silicate-based root canal sealers (bioceramic-based root canal sealers) currently used in endodontic field as well as their specific characteristics and to compare with other conventional sealers. A review of the literature was made to evaluate numerous investigations covering different properties of these materials. The properties of interest were physical properties, bond strength, pH, radiopacity, solubility, setting and working time, dimensional changes, flow, calcium ion release, biocompatibility, antimicrobial activity, sealing ability, adhesion, and cytotoxicity. The outcome of these studies of bioceramic-based sealers revealed favorable biological and physicochemical properties along with comparative investigations of other agents. It was concluded that bioceramic-based sealers, in spite of drawbacks of some, were found to be attractive due to their bioactivity, dimensional stability, and acceptable physicochemical properties in comparison with other conventional sealers.

Cytotoxicity and the Effect of Temperature on Physical Properties and Chemical Composition of a New Calcium Silicate–based Root Canal Sealer

IntroductionThe suitability of EndoSequence BC Sealer (BC Sealer; Brasseler USA, Savannah, GA) for warm vertical compaction has been questioned. The aim was to evaluate the cytotoxicity and the effect of heating on the physicochemical properties of a new calcium-based root canal sealer (EndoSequence BC Sealer HiFlow [HiFlow]) in comparison with EndoSequence BC Sealer. MethodsHuman periodontal ligament fibroblasts were incubated for 1, 2, or 3 days with material extracts of different concentrations, and cell viability was evaluated by Cell Counting Kit-8 (Enzo Life Sciences Inc, Burlington, Ontario, Canada). The setting time, flow, film thickness, microhardness, radiopacity, and radiopacity of the 2 sealers were measured according to ISO 6786/2012. The continuous changes in viscosity were tested by a stress-controlled rheometer at shear rates ranging from 0.01–10 s−1 and different temperatures, and chemical composition was assessed by Fourier-transform infrared spectroscopy. ResultsCell viability was significantly decreased on day 3 for the 1:4 diluted extract from both materials. The setting time, microhardness, and solubility of HiFlow were similar to BC Sealer at 37°C and 100°C. HiFlow had significantly higher flow and radiopacity than BC Sealer at room temperature (P < .05), and when heated, HiFlow retained its higher flow and lower film thickness (P < .05). Both sealers showed decreasing viscosity with increasing shear rate, and at a shear rate of 0.01 and 0.1 s−1, HiFlow exhibited lower viscosity than BC Sealer at all temperatures measured. The chemical composition of the 2 sealers was not changed by heating. ConclusionsHiFlow showed better performance on flow/viscosity and film thickness, especially under high temperatures, which are generated by the commonly used warm vertical compaction technique.

Micro-computed tomographic evaluation of a new system for root canal filling using calcium silicate-based root canal sealers.

ObjectivesThis study evaluated by using micro-computed tomography (micro-CT) the filling ability and sealer apical extrusion promoted by a new Sealer Injection System (SIS; Angelus) with side openings needle, in comparison with the conventional injection system, associated with a new ready-to-use calcium silicate-based sealer (Bio-C Sealer).Materials and MethodsAcrylic resin models containing a main curved artificial canal and 3 simulated lateral canals in apical, middle and cervical thirds were used. The main root canals were prepared using a rotary system up to size 35.05. The canals were filled with Bio-C sealer by using a single cone technique and the conventional delivery system or SIS. Samples were scanned in micro-CT. The percentage of voids throughout the entire extension of the main root canal and in each third of the lateral canals, besides the apical extrusion of the sealer was calculated. Data were submitted to t-test (p < 0.05).ResultsThere was no difference between both systems in the main root canals filling. Although the volume percentage of voids was similar in the apical and middle thirds of lateral canals, SIS had the greatest filling ability of the cervical third lateral canal. Moreover, the conventional system showed the highest apical extrusion of the sealer.ConclusionsThe conventional and SIS obturation systems had an appropriate filling ability of the main root canal. SIS had the best filling of the cervical third of the lateral canals, besides lower sealer apical extrusion, suggesting its clinical indication.

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.

Effect of immersion in distilled water or phosphate-buffered saline on the solubility, volumetric change and presence of voids within new calcium silicate-based root canal sealers.

To assess the effect of immersion in distilled water or phosphate-buffered saline (PBS) on the solubility, volumetric change and presence of voids of calcium silicate-based root canal sealers (TotalFill BC, Sealer Plus BC and Bio-C), in comparison with the gold standard epoxy resin-based sealer (AH Plus). All properties were evaluated after immersion in distilled water or PBS. Solubility was determined by the percentage of mass loss, whereas volumetric change and presence of voids were evaluated by micro-computed tomography, after 7days of immersion. The volumetric change and percentage of voids between the baseline (after setting) and the experimental period were calculated. Statistical analysis was performed using one-way anova and Tukey's or Student's t-tests (α=0.05). The calcium silicate-based sealers had significantly greater solubility and volumetric loss than AH Plus, after immersion in distilled water or PBS (P<0.05). Bio-C had the greatest solubility (P<0.05), followed by TotalFill BC and Sealer Plus BC, which were similar (P>0.05). Regarding the volumetric change, AH Plus had a volume increase, with similar values in distilled water and PBS (P>0.05). TotalFill BC, Sealer Plus BC and Bio-C had a similar volumetric change (P>0.05). The calcium silicate-based materials had the greatest solubility and volume loss after immersion in distilled water (P<0.05). There was no difference in the percentage of voids amongst the sealers, before and after immersion in distilled water or PBS (P>0.05). TotalFill BC, Sealer Plus BC and Bio-C had significantly greater solubility and volumetric loss than AH Plus. Although storage in PBS significantly reduced the solubility and volumetric change of calcium silicate-based sealers, their solubility remained above that recommend by ISO 6876. All the sealers evaluated had low and similar voids, even after immersion in distilled water or PBS.

Antibacterial effectiveness of calcium silicate-based root canal sealer against Enterococcus faecalis biofilms in infected dentinal tubules in vitro

Objective: To evaluate the antiseptic effect of combined using of 5% sodium hypochlorite and calcium silicate-based root canal sealer against Enterococcus faecalis (Ef) biofilms in infected dentinal tubules in vitro. Methods: Cells of Ef were inoculated into the dentinal tubules of single-rooted teeth (without caries, periapical lesions and malformations extracted due to periodontal disease or orthodontic reasons; collected from Department of Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University) with centrifugation and incubated in brain-heart infusion (BHI) to form 3-week-old biofilms. The infected samples were subjected to sodium hypochlorite or sterile water bathing for 10 minutes followed by calcium silicate-based root canal sealer (iRoot SP) (calcium silicate-based group), Gutta-percha group and sterile water group placed on the root canal wall for 1, 4 and 12 weeks. There were two samples in each treatment at each point. The antiseptic effectiveness of combined use of sodium hypochlorite and calcium silicate-based root canal sealer was analyzed by laser scanning confocal microscope (LSCM), ANOVA and LSD-t test. Results: After treatment with 5% sodium hypochlorite, in calcium silicate-based group for 4 and 12 weeks more Ef biofilm cells [(75.3±3.5)% and (74.8±3.8)%] were killed than in Gutta-percha group [(65.9±4.1)% and (63.0±3.7)%] and sterile water group [(63.9±4.0)% and (64.2±3.5)%] (P<0.05). After being treated with sterile water, the proportion of dead bacterial cells in calcium silicate-based group for 1, 4 and 12 weeks [(27.5±4.6)%, (43.0±4.4)% and (40.3±6.1)%] were more than those in Gutta-percha group and sterile water group (P<0.05). After being treated with 5% sodium hypochlorite or sterile water, more biofilm bacteria were killed in calcium silicate-based group for 4 and 12 weeks than in calcium silicate-based group for 1 week (P<0.05). Conclusions: The combined use of sodium hypochlorite and calcium silicate-based root canal sealer kills more biofilm cells in infected dentinal tubules.

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.

Shear bond strengths of calcium silicate-based sealer to dentin and calcium silicate-impregnated gutta-percha.

To compare the shear bond strengths of a calcium silicate-based root canal sealer (CSS), to dentin or calcium silicate-impregnated gutta-percha (CSGP), with the shear bond strengths of an epoxy resin-based sealer. For sealer/dentin testing, 40 hemisectioned roots were divided into 2 groups. Coronal root dentin discs were bonded with CSS or epoxy resin-based sealer. For sealer/core material testing, CSGP and conventional gutta-percha discs were bonded with a matching sealer (N=20 per group). The shear bond strengths were tested using a universal testing machine. The failed modes were analyzed using stereomicroscopy and scanning electron microscopy. The CSS sealer had significantly higher shear bond strength to dentin than did epoxy resin-based sealer (P<.01). However, shear bond strengths of the 2 sealers to core materials did not significantly differ (P=.74). The remnants of the CSS sealer adhering to dentin or calcium silicate gutta-percha disc were observed. The CSS sealer had better adhesion to dentin than did epoxy resin-based sealer. However, the bond of the CSS sealer to impregnated gutta-percha was not superior to the epoxy resin-based sealer bonded to conventional gutta-percha.

Comparative Evaluation of the Adaptation of Two Calcium Silicate-Based Endodontic Sealers with a Conventional Resin-Based Sealer to Dentinal Walls: An In vitro Scanning Electron Microscopic Study

Aim of the study: The aim of this study was to compare the adaptation of two calcium silicate-based root canal sealers with a resin-based sealer to root canal walls at the middle and apical levels using scanning electron microscope.Material and methods: Twenty-six single-canalled lower premolars were instrumented and randomly divided into three groups according to the sealer used with gutta-percha (n=8); AH plus, Bioroot RCS, and Endoseal MTA. Two random specimens served as the blank control group to assess the smear layer removal from the dentinal walls. Teeth were sectioned at middle and apical levels and gap width was evaluated using scanning electron microscope. Data were statistically analyzed with significance level set at p ≤ 0.05. Results: At the apical and mid-root levels, the highest mean values were found in Endoseal MTA group followed by Bioroot RCS group while the lowest mean value was found in AH Plus group with statistically significant difference between all groups. Statistically significant differences were found between Endoseal MTA and each of Bioroot RCS and AH Plus groups. No statistically significant difference was found between Bioroot RCS and AH Plus groups. Conclusions: AH Plus and Bioroot RCS showed statistically better results than Endoseal MTA regarding adaptation to the root canal walls.

SEM and EDS study of TotalFill BC Sealer and GuttaFlow Bioseal root canal sealers.

Recently, a new generation of calcium silicate-based root canal sealers has been developed. These new types of sealers have the ability to set in wet environment, have high alkalinity and present potential antimicrobial activity. The aim of this study was to determine the chemical composition and microstructure of 2 novel calcium silicate-containing root canal sealers - TotalFill® BC Sealer and GuttaFlow® Bioseal. The tested sealers were prepared according to the manufacturers' instructions. Sixteen cylindrical dishes (inner diameter: 4 mm; height: 3 mm) were placed on a glass Petri dish and packed with the materials. The Petri dish was transferred to an incubator. After the sealers set, excess material was removed with diamond discs and polishing paste. The materials were assessed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) X‑ray microanalysis. Both TotalFill BC Sealer and GuttaFlow Bioseal contained calcium, zirconium, oxygen, carbon, silicon, and a trace of sodium. In the case of TotalFill BC Sealer, trace amounts of copper and technetium were also present, and for GuttaFlow Bioseal, iron, zinc, and a trace of magnesium and hafnium were noted. No bismuth was found. Both of the assessed sealers contained fine particles embedded in the matrix; however, GuttaFlow Bioseal also had larger particles with a diameter of 2-10 μm. TotalFill BC Sealer represents a higher degree of purity in comparison with GuttaFlow Bioseal. The clinical implications of heavy metals present in GuttaFlow Bioseal need to be investigated. Both materials have a fine particle structure, which is desirable for root canal sealers.

Comparison of the antibacterial activity of calcium silicate- and epoxy resin-based endodontic sealers against Enterococcus faecalis biofilms: a confocal laser-scanning microscopy analysis.

This study assessed the antibacterial activity of BioRoot RCS in comparison with that of the Totalfill BC and AH Plus sealers against Enterococcus faecalis biofilms in dentinal tubules using confocal laser-scanning microscopy. Sixty-six root dentin halves were prepared and sterilized. Three sections were used to ensure sterilization. The remaining were inoculated with E. faecalis. Three specimens were examined to verify the viability of biofilms. The sixty specimens were randomly divided into four groups: AH Plus, BioRoot RCS, Totalfill BC sealer, and no sealer. The specimens were incubated for 1, 7, and 30days. The specimens were stained and four corners of each disc were scanned. Statistical analysis was performed using two-way ANOVA and Tukey's post hoc test. Almost half of the bacteria were dead in BioRoot RCS group on day 1 and in Totalfill BC group on day 7. All sealers killed significantly more bacteria than the control after 30 days (P < .05). On day 7, Totalfill BC showed a significantly higher percentage of dead bacteria than BioRoot RCS (P < .05). On day 30, the BioRoot RCS group registered the highest percentage of dead cells (61.75%), which was significantly higher than the percentages of the AH Plus and Totalfill BC groups (P < .05). Calcium silicate-based root canal sealers exerted antimicrobial effects against E. faecalis biofilms. The antibacterial activity of BioRoot RCS was significantly higher than that of the Totalfill BC and AH Plus sealers after 30 days of exposure.

Comparative pH and calcium ion release in newer calcium silicate-based root canal sealers

Aims: The aim of this study is to compare and evaluate pH and calcium ion release in newer calcium silicate-based root canal sealers. Methodology: Polyethylene tubes were cut into 35 tubes of equal sizes; with each tube measuring 10 mm length × 1 mm diameter. The tubes were pre-weighted using digital weighing balance machine to allow a similar weight of each tube. The polyethylene tubes were divided into four groups according to the materials with which they were filled. Group 1 (n = 5) control group, Group 2 (n = 10) sealapex, Group 3 (n = 10) mineral trioxide aggregate (MTA) fillapex, and Group 4 (n = 10) White MTA. The tubes after being packed with the respective sealers were placed inside polypropylene flasks containing 10 ml of deionized water. The flask was closed and stored at a constant temperature of 37°C during all the evaluation period. At 24 h, 7 days and 1 month, pH and calcium ion released was measured using pH meter and atomic absorption spectrophotometer, respectively. Results: At 24 h, White MTA showed the highest pH (8.52) and highest calcium (Ca++) release (14.7). At 7 days and 28 days, MTA fillapex showed significantly higher pH (8.64; 8.7) and Ca++ release (10.30; 18.60) than the other two groups. Conclusion: Although at 24 h, the new calcium silicate-based root canal sealer, MTA fillapex showed the least Ca++ release but over longer time intervals, i.e., at 7 days and 28 days, MTA fillapex showed significantly higher pH and Ca++ release than both White MTA and sealapex.