Evaluation of Cytotoxicity and Physicochemical Properties of Calcium Silicate-based Endodontic Sealer MTA Fillapex

IntroductionThe aim of the study was to evaluate the cytotoxicity, radiopacity, pH, and flow of a calcium silicate–based and an epoxy resin–based endodontic sealer, MTA Fillapex (Angelus, Londrina, PR, Brazil) and AH Plus (Dentsply, Konstanz, Germany), respectively.MethodsCytotoxicity, radiopacity, and flow evaluation were performed following ISO requirements. The pH level was measured at periods of 3, 24, 72, and 168 hours. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay to check the Balb/c 3T3 cells viability at 1- to 4-week periods. Data were statistically analyzed by analysis of variance and the Tukey test with a significance level of 5%.ResultsIn all tested periods, MTA Fillapex was more cytotoxic than AH Plus (P < .05). Although AH Plus presented higher radiopacity than MTA Fillapex (P < .05), both sealers showed minimum required values. MTA Fillapex presented alkaline pH in all experimental times, whereas AH Plus cement showed a slightly neutral pH and a flow significantly lower than that of MTA Fillapex (P < .05).ConclusionsAlthough MTA Fillapex was more cytotoxic than AH Plus, it showed suitable physicochemical properties for an endodontic sealer.     

Antimicrobial and physicochemical characterization of endodontic sealers after exposure to chlorhexidine digluconate

ObjectivesAssess the antibacterial, physical and chemical properties of AH Plus, BioRoot RCS and Pulp Canal Sealer (PCS) in contact with 2% chlorhexidine digluconate (CHX) used as final irrigant prior to root canal obturation.MethodsThe antimicrobial properties were investigated by direct contact tests for planktonic and biofilm growth of E. faecalis, S. mutans, S.epidermidis and S.aureus in vitro. The setting time, wettability, microhardness and surface roughness were also assessed. The sealers were studied in no contact, 1-minute (short-term) and continuous contact (long-term) with CHX. Chemical characterization of sealers was performed by scanning electron microscopy, X-ray diffraction analysis and Fourier-transform infrared spectroscopy after CHX or saline used as the last irrigant in an ex vivo tooth model and in endo training blocks.ResultsCHX increased the antibacterial activity of all the sealers investigated against planktonic bacteria and biofilms with PCS exerting the highest antimicrobial activity with and without the presence of CHX. The setting of AH Plus and BioRoot RCS was retarded, while for PCS accelerated in the presence of CHX. AH Plus and PCS were more hydrophilic after contact with CHX, whilst BioRoot RCS was hydrophobic in a time-dependent manner. The microhardness of sealers was compromised and the surface roughness increased after CHX exposure for AH Plus and BioRoot RCS, and decreased for PCS. CHX did not affect the sealers’ chemistry, but PCS that exhibited two extra phases.SignificanceCHX improved the antibacterial efficacy of endodontic sealers but further evidence is needed to confirm its suitability as a final irrigant prior to root canal obturation.     

Effect of chlorhexidine digluconate on antimicrobial activity,cell viability and physicochemical properties of three endodontic sealers

ObjectiveAssess the biological and physicochemical properties of AH Plus, BioRoot RCS and Pulp Canal Sealer (PCS) leachates with and without chlorhexidine (CHX).MethodsThe sealers were studied in no contact and 1-minute contact with CHX. For biological properties (antibacterial activity and cytotoxicity), leachates were formed in saline of freshly mixed, 1-, 7- and 28 days set sealers. The antibacterial properties of sealer leachates were investigated for planktonic and biofilm growth of E. faecalis, S. mutans, S.epidermidis and S.aureus. The 3-(4,5 dimethylthiazolyl-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate murine fibroblast cell viability after exposure to the leachates. The physical properties (water uptake, sorption, solubility, porosity, surface characteristics) of sealers and the pH of the immersion liquid (saline or distilled water) were also assessed over a 28-days period.ResultsCHX improved the antibacterial properties of the sealer leachates and reduced cell viability for all sealer leachates, except for freshly mixed PCS. BioRoot RCS leachates presented the highest antibacterial properties and cell viability with and without CHX contact. PCS was the material most affected by CHX in terms of physical properties, whereas for AH Plus, solubility was increased. CHX did not affect the physical properties of BioRoot RCS, except for solubility that was decreased. CHX contact did not change sealers’ alkalinity in distilled water whereas it increased it for AH Plus and BioRoot RCS in saline.SignificanceCHX improved the antibacterial efficacy of sealer leachates and either compromised or did not affect cell viability. CHX affected to various extent sealers’ physicochemical properties.     

Evaluation of Physicochemical Properties of a New Calcium Silicate–based Sealer,Bio-C Sealer

IntroductionCalcium silicate–based materials have been proposed as root canal sealers for root canal treatment. The aim of this study was to evaluate the physicochemical properties of a new calcium silicate–based sealer (Bio-C Sealer; Angelus, PR, Brazil) compared with a calcium silicate endodontic sealer (TotalFill BC Sealer; FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) and an epoxy resin sealer (AH Plus; Dentsply DeTrey, Konstanz, Germany).MethodsThe setting time and flow were evaluated based on ISO 6876 standard. The pH value was evaluated after different time intervals of storage in deionized water (1, 7, 14, and 21 days). Radiopacity was evaluated by radiographic analysis in millimeters of aluminum. Solubility and volumetric change were evaluated after 30 days of immersion in distilled water. Solubility was assessed by mass loss (%), and volumetric change was evaluated by micro–computed tomographic imaging. The data were submitted to analysis of variance and Tukey statistical tests (P < .05).ResultsTotalFill BC Sealer and Bio-C Sealer were similar regarding radiopacity, volumetric change, and pH values (P > .05). Bio-C Sealer presented the shortest setting time and the highest flow and solubility (P < .05). AH Plus showed the highest radiopacity and the lowest flow, pH, solubility, and volumetric change (P < .05).ConclusionsBio-C Sealer showed a short setting time, alkalinization ability, and adequate flow and radiopacity as well as low volumetric change. However, this sealer had higher solubility than the rates required by ISO 6876 standard.     

Chemical characterization and bioactivity of epoxy resin and Portland cement-based sealers with niobium and zirconium oxide radiopacifiers

Objective

The purpose of this study was to characterize and to evaluate the bioactivity potential of experimental root canal sealers (ES) based on Portland cement, epoxy resin with nano- and micro-particles of niobium or zirconium oxide used as radiopacifiers in comparison to AH Plus and MTA Fillapex.

Methods

Specimens of the sealers (10 mm in diameter × 1 mm thick) were prepared and the radiopacity was evaluated according to ISO 6876 (2012) specifications. Characterization of the sealers was performed under the scanning electron microscope (SEM) immediately after setting and after immersion for 28 days in Hank's balanced salt solution (HBSS). In addition X-ray energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy were also performed. The pH and calcium ion release were measured after 1, 7, 14, 21 and 28 days after completion of seating using a digital pH meter and an atomic absorption spectrophotometer, respectively.

Results

The experimental sealers exhibited an average radiopacity of 2.5 mm thickness of aluminum, which was similar to MTA Fillapex (P > 0.05) and inferior to AH Plus (P < 0.05). AH Plus did not show bioactivity. Although the experimental sealers did not exhibit the formation of hydration product, they encouraged the deposition of crystalline spherical structures of calcium deficient phosphate. The highest pH and calcium release values were observed with the experimental sealers (P < 0.01). ES-Nb-micro was the only sealer to present hexagonal shaped crystal deposition.

Significance

Novel root canal sealers based on a mixture of Portland cement, epoxy resin and radiopacifier exhibited a degree of bioactivity although no evidence of cement hydration was demonstrated on material characterization. The radiopacifier particle size had limited effect on the sealer microstructure and chemical properties.     

In vitro evaluation of the antimicrobial activity of a new resin-based endodontic sealer against endodontic pathogens

The purpose of this study was to compare the antimicrobial activities of a new resin-based SuperBond (SB) Sealer and five other sealers/cements against endodontic pathogens. The antimicrobial activities of SB Sealer, Sealapex, AH plus, Roeko Seal Automix, Canals N, and ProRoot mineral trioxide aggregate (MTA) were examined using a double-layered method. The microorganisms Staphylococcus aureus, Enterococcus faecalis, Candida albicans, Streptococcus mutans, and Streptococcus sanguinis were used. Live microorganisms were stained using triphenyltetrazolium chloride, and the zones of inhibition of microorganism growth were measured. The antimicrobial activity of SB Sealer was significantly lower than that of the other sealers, except for Pro Root MTA, against S. aureus, C. albicans, S. mutans, and S. sanguinis, but no activity against E. faecalis was detected. On the other hand, AH plus exhibited the highest antimicrobial activity. Pro Root MTA showed no antimicrobial activity against any of the microorganisms tested. SB Sealer offered no antimicrobial advantage over the other sealers tested except for Pro Root MTA. (J. Oral Sci. 50, 309-313, 2008).     

Comparison of physical properties of polycarboxylate-based and conventional root canal sealers.

Several physical properties of nine commercial root canal sealers were evaluated in vitro and were compared with those of two experimental endodontic materials based on polycarboxylate formulations. Flow, setting time, compressive strength, radiopacity, adhesion to root dentin, and solubility were evaluated. The zinc oxideeugenol root canal sealers were typically of low strength and high solubility. These sealers and the Diaket polyvinyl resin sealer showed no adhesion to dentin. The epoxy resin AH26 showed superior properties with respect to strength, flow, radiopacity, and adhesion; solubility of this material was high. The polycarboxylate formulation showed significantly higher values over the commercial sealers in properties of strength, adhesion, and reduced solubility. The tensile adhesive bond strength of the polycarboxylate to root dentin was twice that of AH26. A wide variation in properties of the commercial materials tested showed the empirical nature of these "sealers." Further testing of polycarboxylate endodontic sealers is indicated.     

四种根管封闭剂抗微生物作用的体外评价

目的观察四种根管封闭剂的抗微生物作用:纳米氧化锌糊剂(N-ZO),纳米羟磷灰石糊剂(NHA),AH Plus,mineral trioxide aggregate(MTA)。方法采用琼脂扩散法,选择金黄色葡萄球菌、白色念珠菌、粪肠球菌、大肠杆菌作为实验菌种。观察37℃培养24小时的抑菌环直径。结果 MTA和NHA均没有显示出抑菌作用,只有AH Plus与N-ZO组对金黄色葡萄球菌、白色念珠菌、大肠杆菌有抑菌作用。其中N-ZO产生了最大的抑菌范围从8mm至18mm,粪肠球菌对所有的实验材料都抵抗。结论纳米氧化锌糊剂和AH Plus具有较强的抗微生物作用,而MTA和纳米羟磷灰石糊剂无抑菌作用。所有实验材料对粪肠球菌都没有抑菌作用。     

Physicochemical Properties and Biocompatibility of Various Bioceramic Root Canal Sealers: In Vitro Study

IntroductionThe aim of this study was to compare the physicochemical properties and biocompatibility of various calcium silicate–based bioceramic sealers (CSBSs).MethodsFour recently developed CSBSs, including AH Plus Bioceramic Sealer (AHB), EndoSequence BC Sealer (ESB), TotalFill BC Sealer (TTB), and Bio-C Sealer (BIC), were compared with the epoxy resin–based sealer AH Plus (AHP). Their physical properties, including flow, setting time, radiopacity, dimensional stability, and pH, were evaluated according to the International Organization for Standardization (ISO) 6876. Their cytotoxicity in human periodontal ligament fibroblast (hPDLF) was assessed through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and compared. Additionally, cell attachment to the sealer surface was analyzed using green fluorescent protein and confocal laser scanning microscopy to evaluate cell viability. Data were analyzed using a one-way analysis of variance to determine the difference between groups for categorical variables, followed by Tukey's post hoc test at the significance level of 95%.ResultsThe flow, setting time, and radiopacity of all tested CSBSs satisfied the ISO 6876/2012 standards. Further, these CSBSs showed shrinkage after immersion in distilled water for 30 days and complied with the ISO 6876/2001 requirements. The pH values of AHB, ESB, TTB, and BIC were greater than 11, whereas AHP had a pH of 6.69 after 4 weeks. CSBS showed excellent biocompatibility compared with that of AHP (P < .05). Confocal laser scanning microscopy showed that alive hPDLFs were attached well to all the tested CSBSs but not to AHP.ConclusionsCSBSs have similar physical characteristics within the ISO standards and higher biocompatibility than epoxy resin–based sealers.     

In vitro evaluation of the antimicrobial activity of endodontic sealers

The purpose of this study is to evaluate the antimicrobial activity of the endodontic sealers: N-Rickert, Sealapex, AH Plus, Mineral Trioxide Aggregate (MTA) and portland cement. The Agar diffusion method was used in plates previously inoculated with the following microorganisms: C. albicans, S. aureus, E. faecalis, E. coli. The diameters of microbial inhibition zones were measured after 24 hours of incubation in kiln at 37 degrees C. According to the methodology used, it was possible to conclude that only the sealers AH Plus and N-Rickert presented antimicrobial activity against C. albicans, S. aureus, and E. coli; no antimicrobial activity in MTA, Sealapex and portland cement was observed. N-Rickert presented the largest inhibition zones varying from 8 to 18 mm, and the microorganism E. faecalis was resistant against all sealers tested.     

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

IntroductionUnderstanding the physicochemical and biological properties of endodontic sealers is important for endodontic treatment planning. This study evaluated the properties of EndoSequence BC Sealer HiFlow (BCH; Brasseler USA, Savannah, GA), EndoSequence BC Sealer (BC, Brasseler USA), and AH Plus (AHP; Dentsply DeTrey, Konstanz, Germany). The effect of temperature on the setting time and flow of these sealers was also evaluated.MethodsThe setting time, flow, radiopacity, pH, solubility, and calcium release were investigated following ISO guidelines. The morphology and chemical composition of the sealers were evaluated by scanning electron microscopy and energy-dispersive spectroscopy. The antibacterial activity of sealers was tested against 2 strains of Enterococcus faecalis. Sealer cytotoxicity and the effects on messenger RNA expression of proinflammatory and mineralization genes were also investigated. Data analysis was performed using analysis of variance, Tukey, Kruskal-Wallis, and Dunn multiple comparison tests. P ≤ .05 was considered statistically significant.ResultsThe setting time and flow rate of all sealers were affected by heat (P ≤ .05). The setting times and solubility of BCH and BC were significantly higher than AHP (P ≤ .0001). The radiopacity of AHP was higher than BCH and BC (P ≤ .0001). All sealers were alkaline and had antibacterial effects. Cell viability was higher for BCH and BC than AHP (P ≤ .0001). No significant differences in messenger RNA expression of proinflammatory and mineralization genes were observed.ConclusionsOverall, BCH and BC had similar physicochemical and biological properties. The observed high solubility of BCH and BC as well as the high cytotoxicity of AHP might negatively impact the clinical performance of these materials. The application of heat affected the setting time and flow of all sealers.     

Response of Human Osteoblastic and Osteoclastic Cells to AH Plus and Pulp Canal Sealer Containing Quaternary Ammonium Polyethylenimine Nanoparticles

Introduction

The incorporation of quaternary ammonium polyethylenimine (QPEI) nanoparticles into endodontic sealers induces alterations in their structure and surface properties, which may affect the compatibility with the periapical tissues. This work addressed the behavior of human bone cells exposed to extracts from commercial and QPEI containing AH Plus (DeTrey, Konstanz, Germany) and Pulp Canal Sealer EWT (PCS; Kerr Italia Srl, Salerno, Italy).

Methods

Freshly mixed AH Plus and PCS or containing 2% QPEI (0.3 mL spread over the well bottom of a 24-well plate) were extracted with culture medium (1.5 mL for 24 hours at 37°C) and diluted (1:20–1:5000). Osteoblastic or osteoclastic cells were cultured in the presence of QPEI particles (1%–10%) and were exposed to the extracts from unmodified and QPEI containing sealers.

Results

QPEI nanoparticles, at 1% and 2%, did not affect cell behavior. On osteoblastic cells, AH Plus and PCS increased DNA at 1:2500 dilution (levels ≤1:100 were cytotoxic). Alkaline phosphatase activity decreased at dilutions ≤1:500. Comparatively, QPEI containing AH Plus increased DNA at 1:2500 and 1:500 dilutions, and QPEI containing PCS induced ALP activity at 1:2500 and 1:500 dilutions. Regarding osteoclastic cells, DNA increased (AH Plus) or was not affected (PCS) at dilutions up to 1:500 and decreased with more concentrated extracts. Tartrate-resistant acid phosphatase activity decreased with dilutions ≤1:500 for both sealers. QPEI containing sealers presented a similar behavior. The sealers affected some intracellular signaling pathways, and QPEI containing sealers further modulate these mechanisms.

Conclusions

QPEI nanoparticles, at 2%, did not affect cell behavior. However, the incorporation of 2% QPEI particles into AH Plus and PCS modulates the proliferation and differentiation of bone cells, depending on the sealer and the cell type, without increasing the sealers' cytotoxicity.     

The Effect of Primary Root Canal Treatment on Dentinal Tubule Penetration of Calcium Silicate–based Sealers during Endodontic Retreatment

IntroductionThe aim of this study was to evaluate the effect of previous root canal treatment on dentinal tubule penetration of calcium silicate–based sealers during endodontic retreatment and to compare 2 different (commonly used and modified) tubule penetration depth measurement techniques.MethodsThe crowns of mandibular premolar teeth were removed, and root canals were prepared (ProTaper Universal; Dentsply Sirona, York, PA) and obturated using AH Plus (AH; Dentsply DeTrey, Konstanz, Germany), MTA Fillapex (MTAF; Angelus, Londrina, Brazil), and WellRoot ST (WRST; Vericom, Gyeonggi-do, South Korea); 0.1% red Rhod-2 dye (Chemodex, St Gallen, Switzerland) was added to the sealers. After storage for 3 weeks (37°C, 100% humid), the following sealer combination subgroups were created (the sealer used during the primary root canal treatment/the sealer used during the retreatment, n = 8): AH/AH, AH/MTAF, and AH/WRST; MTAF/AH, MTAF/MTAF, and MTAF/WRST; and WRST/AH, WRST/MTAF, and WRST/WRST. Green Fluo-3 dye (0.1%) was added to the sealers during retreatment. Sealer penetration depths were measured at 8 points and averaged, and the ratio of the retreatment sealer to the initial sealer was recorded as the mean tubule penetration depth ratio in the first technique, whereas the percentage of the circumferential penetration area ratios of the retreatment and initial sealers was calculated in the second technique. Statistical analyses were performed using Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests.ResultsThe mean penetration depth of AH and MTFA was found to be higher at the coronal third region in the control groups (P < .05). Both methods showed a significant difference among the groups at the coronal and median regions (P < .05). The AH/WRST, MTAH/AH, MTAF/MTAF, MTAF/WRSTS, and WRST/WRST groups showed deeper tubule penetration (first technique, P = .01). Both techniques showed that the penetration depth of the sealers was the same at the apical region (P > .05), whereas a difference was found among the techniques at the coronal and median regions. The sealers used in the previous root canal treatment limited the penetration depth of the sealers used during the retreatment process (P < .05). When MTAF was used as the initial sealer, the penetration depth of the second sealer did not change, whereas if WRST was the initial sealer, the penetration depth of the sealers at the median and apical regions is negatively affected during the retreatment process (P < .05).ConclusionsPrevious root canal treatment affects the penetration depth of calcium silicate–based sealers. The use of AH Plus and MTA Fillapex during the retreatment process showed an advantage. Both measurement techniques showed similar performances at the apical region, whereas the results varied at the coronal and midcoronal regions; therefore, a more stable sealer penetration measurement technique is still necessary.     

Drug-Silica Coassembled Particles Improve Antimicrobial Properties of Endodontic Sealers

IntroductionThe purpose of this study was to assess the antimicrobial activity and flow of root canal sealers after incorporating novel highly loaded antimicrobial drug-silica coassembled particles (DSPs).MethodsDSPs were synthesized through coassembly of silica and octenidine dihydrochloride (OCT) antimicrobial surfactant. DSPs were loaded (1% and 2% wt) into epoxy resin sealer (AH Plus [AH]; Dentsply DeTrey GmbH, Konstanz, Germany) or calcium silicate–based sealer (EndoSequence Bioceramic Sealer (BC); Brasseler, Savannah, GA). OCT release from DSP-modified sealers was determined using liquid chromatography. Antimicrobial activity of sealers against planktonic or biofilm form Enterococcus faecalis was assessed using direct contact and membrane restricted tests. Sealer flow was tested according to ISO6876:2012.ResultsOCT release from BC + 1% or 2% DSPs was above the minimum inhibitory concentration following 2 days throughout the 30-day experiment, whereas OCT release from AH + 1% or 2% DSP was significantly below the minimum inhibitory concentration against E. faecalis (4 μg/mL) over the whole 30-day experimental period. All materials (with or without DSPs) killed planktonic bacteria initially. AH ± 1% or 2% DSPs had no antimicrobial activity after 7 days. BC + 1% or 2% DSPs maintained antibacterial activity over the 30-day period. Both modified and unmodified sealers completely inhibited the growth of E. faecalis biofilms after 24 hours of contact. DSPs decreased the flow of AH and BC sealers; for AH, the reduction was proportional to the amount of DSPs added. All modified and unmodified sealers, except for AH + 2% DSPs, were within the acceptable limits of ISO 6876 flow tests.ConclusionsDSPs enhanced the antimicrobial performance of BC but not AH, whereas the material’s flow remained compliant with ISO 6876 standards. Depending on the sealer, DSPs may enhance antimicrobial efficacy in root canal treatment and potentially improve treatment outcome.     

Evaluation of Selected Properties of Mineral Trioxide Aggregate Sealer Cement

IntroductionThe addition of a water-soluble polymer to mineral trioxide aggregate (MTA), which to date has been used primarily to seal lateral root perforations and as a root-end filling material, resulted in material that is suitable for use as an endodontic sealer.MethodsMTA was mixed with water at powder/liquid ratios of 4 and 3.33 and an addition of 2 μL to 20 μL of water-soluble polymer. The materials were tested for flow and film thickness, and the optimal quantity of polymer required to conform to EN ISO 6876 Section 4.3.1, 4.3.4 (2002) was determined. The resultant MTA sealer was tested for radiopacity using methods suggested by ISO 6876 (2002) using pulp canal sealer (PCS) as control. The effect of polymer addition on the hydration characteristics of the MTA and calcium silicate cement was evaluated by assessing paste microstructure under the scanning electron microscope after 30 days and by collecting 50 quantitative analyses of the hydration products and plotting the data as atomic ratios. Plots of Al/Ca versus Si/Ca and S/Ca and Al/Ca were drawn.ResultsHigh additions of polymer were required for the flow and film thickness of MTA to conform to ISO 6876 (2002). The resultant cement sealer had a lower radiopacity than PCS but greater than the 3-mm thickness of Al specified by the international standard. The addition of polymer did not modify the hydration mechanism of MTA.ConclusionsThe addition of a water-soluble polymer to MTA did not alter the hydration characteristics of the material and resulted in a material with improved properties suitable for use as endodontic sealer cement.     

Antifungal activity of several root canal sealers against Candida albicans

Abstract

Objective. The purpose of this in vitro study was to evaluate the antifungal activity of several root canal sealers (iRoot SP, MTA Fillapex and GuttaFlow) against Candida albicans and compare them to that of AH Plus Jet. Materials and methods. A 10 μL fungi in suspension was allowed to directly contact the sealers, which were freshly mixed or allowed to set for 1 or 7 days. Fresh media was then added and survival of fungi was determined by using 10-fold serial dilution and inoculated onto agar plates. After incubation for 48 h, colony-forming units (CFU) were calculated and their log₁₀ values converted. The data were analyzed using ANOVA and Tukey tests (α = 0.05). Results. Freshly mixed AH Plus Jet totally inhibited the growth of fungi and showed the highest antifungal activity. GuttaFlow did not show any significant antifungal activity at all times. Freshly mixed iRoot SP and MTA Fillapex were found to be antifungal. Statistical differences were found between freshly mixed and set samples (p < 0.05) in favor of the former, except GuttaFlow. No statistically significant differences were found among the tested sealers at the 1 and 7-day samples (p > 0.05). Conclusions. Fresh AH Plus Jet had very potent antifungal activity. All sealers, except GuttaFlow, exhibited antifungal activity when freshly mixed.     

Antibacterial Activity of Endodontic Sealers by Modified Direct Contact Test Against Enterococcus faecalis

IntroductionThe antibacterial effectiveness of 7 different endodontic sealers, AH Plus, Apexit Plus, iRoot SP, Tubli Seal, Sealapex, Epiphany SE, and EndoRez against Enterococcus faecalis was studied in vitro.MethodsA modified direct contact test was used. Bacteria in suspension were exposed to the materials for 2–60 minutes by using sealers that were freshly mixed or set for 1, 3, and 7 days. The pH values and contact angles of sterile water on sealers at different times after setting were also measured.ResultsFresh iRoot SP killed all bacteria in 2 minutes, AH Plus in 5 minutes, EndoRez in 20 minutes, and Sealapex and Epiphany in 60 minutes. Freshly mixed Apexit Plus and Tubli Seal failed to kill all bacteria at 60 minutes. For 1-day and 3-day samples, iRoot SP and EndoRez had the strongest antibacterial activity, followed by Sealapex and Epiphany; Tubli Seal and AH Plus did n'ot show any significant antibacterial activity. Of all the samples, Apexit Plus had the lowest antimicrobial activity. The pH of the sealers could not alone explain their antibacterial effect.ConclusionsFresh iRoot SP, AH Plus, and EndoRez killed E. faecalis effectively. IRoot SP and EndoRez continued to be effective for 3 and 7 days after mixing. Sealapex and EndoRez were the only ones with antimicrobial activity even at 7 days after mixing.     

The Osteogenic Assessment of Mineral Trioxide Aggregate–based Endodontic Sealers in an Organotypic Ex Vivo Bone Development Model

IntroductionMineral trioxide aggregate (MTA)-based sealers are endodontic materials with widespread success in distinct clinical applications, potentially embracing direct contact with the bone tissue. Bone response to these materials has been traditionally addressed in vitro. Nonetheless, translational data are limited by the absence of native cell-to-cell and cell-to-matrix interactions that hinder the representativeness of the analysis. Ex vivo organotypic systems, relying on the culture of explanted biological tissues, preserve the cell/tissue composition, reproducing the spatial and organizational in situ complexity. This study was grounded on an innovative research approach, relying on the assessment of an ex vivo organotypic bone tissue culture system to address the osteogenic response to 3 distinct MTA-based sealers.MethodsEmbryonic chick femurs were isolated and grown ex vivo for 11 days in the presence of MTA Plus (Avalon Biomed Inc, Bradenton, FL), ProRoot MTA (Dentsply Tulsa Dental, Hohnson City, Germany), Biodentine (Septodont, Saint Maurdes Fosses, France), or AH Plus (Dentsply Sirona, Konstanz, Germany); the latter was used as a control material. Femurs were characterized by histologic, histochemical, and histomorphometric analysis. Gene expression assessment of relevant osteogenic markers was conducted by quantitative polymerase chain reaction.ResultsAll MTA-based sealers presented an enhanced osteogenic performance compared with AH Plus. Histochemical and histomorphometric analyses support the increased activation of the osteogenic program by MTA-based sealers, with enhanced collagenous matrix deposition and tissue mineralization. Gene expression analysis supported the enhanced activation of the osteogenic program. Comparatively, ProRoot MTA induced the highest osteogenic functionality on the characterized femurs.ConclusionsMTA-based sealers enhanced the osteogenic activity within the assayed organotypic bone model, which was found to be a sensitive system for the assessment of osteogenic modulation mediated by endodontic sealers.     

Physical Properties of 5 Root Canal Sealers

Introduction

The aim of this study was to evaluate the pH change, viscosity and other physical properties of 2 novel root canal sealers (MTA Fillapex and Endosequence BC) in comparison with 2 epoxy resin-based sealers (AH Plus and ThermaSeal), a silicone-based sealer (GuttaFlow), and a zinc oxide-eugenol–based sealer (Pulp Canal Sealer).

Methods

ISO 6876/2001 specifications were followed. The pH change of freshly mixed and set sealers was evaluated during periods of 1 day and 5 weeks, respectively. The viscosity was investigated at different injection rates (72, 10, and 5 mm/min) at room temperature by using a syringe-based system that was based on the Instron 3360 series universal testing system.

Results

The flow, dimensional change, solubility, and film thickness of all the tested sealers were in agreement with ISO 6876/2001 recommendations. The MTA Fillapex sealer exhibited a higher flow than the Endosequence BC sealer (P < .05). The MTA Fillapex and Endosequence BC sealers showed the highest film thicknesses among the tested samples. The Endosequence BC sealer exhibited the highest value of solubility, which was in accordance with 3% mass fraction recommended by the ISO 6876/2001, and showed an acceptable dimensional change. The MTA Fillapex and Endosequence BC sealers presented an alkaline pH at all times. The pH of fresh samples of the AH Plus and ThermaSeal sealers was alkaline at first but decreased significantly after 24 hours. The viscosity of the tested sealers increased with the decreased injection rates.

Conclusions

The tested sealers were pseudoplastic according to their viscosities as determined in this study. The MTA Fillapex and Endosequence BC sealers each possessed comparable flow and dimensional stability but higher film thickness and solubility than the other sealers tested.     

Evaluation of the radiopacity of root canal sealers by digitization of radiographic images

The aim of this study was to evaluate the radiopacity of a zinc oxide and eugenol-based (Endofill), a calcium hydroxide-based (Sealapex), two resin-based (Sealer 26 and AH Plus), and a silicone-based root canal sealer (Roeko Seal). Specimens, measuring 10mm in diameter and 1mm in thickness, were radiographed simultaneously with an aluminum step wedge using occlusal films, according to ISO 6876/2001 standards. Radiographs were digitized, and the radiopacity of sealers was compared to the different thicknesses of the aluminum step wedge, using the VIXWIN 2000 software. Results demonstrated that AH Plus was the most radiopaque sealer, while Sealapex was the least radiopaque (p<0.05). Roeko Seal, Endofill and Sealer 26 presented intermediate radiopacity values. Sealapex presented less radiopacity than the other types of root canal sealers.