The Antimicrobial Effect of Bioceramic Sealer on an 8-week Matured Enterococcus faecalis Biofilm Attached to Root Canal Dentinal Surface

IntroductionThe aim of this study was to test the antibacterial activity of bioceramic sealer in comparison with AH Plus (Dentsply International Inc, York, PA) on 8-week-old Enterococcus faecalis biofilms attached to root canal surfaces using a dentin infection model.MethodsThe canal surfaces of single-rooted intact extracted teeth were infected by growing E. faecalis biofilms for 8 weeks. AH Plus sealer and EndoSequence BC Sealer (Brasseler USA, Savannah, GA) were placed on the root canal wall of the dentin specimens for 24 hours and 2 weeks in humid conditions at 37°C. Infected samples incubated with no sealers for similar periods were used as the negative controls. Specimens were labeled with fluorescent viability staining, and confocal laser scanning microscopy was used as an assessment tool of the proportions of dead and live bacteria on canal walls after exposure to root canal sealers for the determined times.ResultsEndoSequence BC Sealer killed significantly more E. faecalis in biofilm attached to the canal surfaces when compared with AH plus sealer and control at both time points (P < .05–.0005).ConclusionsEndoSequence BC Sealer exhibited significant antimicrobial capacity in the presence of dentin for up to 2 weeks on an 8-week-old E. faecalis biofilm in comparison with AH Plus sealer.     

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.     

Dentinal tubule penetration of AH Plus,BC Sealer and a novel tricalcium silicate sealer: a confocal laser scanning microscopy study

Objectives

The aim of this in vitro study was to assess the dentinal tubule penetration of three different sealers, AH Plus, BC Sealer and a novel tricalcium silicate sealer (NTS).

Materials and methods

Ninety-six human maxillary central incisors were divided into three experimental groups (n = 32) and were filled with gutta-percha using a single-cone technique in conjunction with one of the three sealers: AH Plus, BC Sealer or NTS. The roots in each group were cross-sectioned at 1 and 5 mm from the root apex, and the surfaces were examined under confocal laser scanning microscopy (CLSM). The sealer penetration depths were measured at their maximum depths and at four circumferential depths (12, 3, 6 and 9 o’clock) and were evaluated using ImageJ software (ImageJ, NIH).

Results

The maximum and mean penetration depths were significantly higher at 5 mm compared to 1 mm from the apex in the AH Plus (p < 0.001), BC Sealer (p < 0.001) and NTS groups (p < 0.001). No significant difference was observed between the groups at 1 mm for both parameters. The maximum and mean penetration depths were significantly lower at 5 mm for AH Plus compared with the other two groups (p = 0.012).

Conclusions

Within the study limitations, the BC Sealer and NTS demonstrated better tubule penetration results than the AH Plus sealer.

Clinical relevance

Although no study has confirmed a relationship between the penetration depth of root canal sealers and the prevention of apical periodontitis, dentinal tubule sealer penetration may improve obturation quality.

     

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.     

Reciproc and Reciproc Blue in the removal of bioceramic and resin-based sealers in retreatment procedures

Objectives

To compare the remaining root canal filling material, dentin removal, apical transportation, and apical extrusion of debris after the retreatment of canals filled with bioceramic or resin-based sealers using the Reciproc or Reciproc Blue instruments.

Materials and methods

Sixty mandibular molars with severely curved mesial roots were selected. The samples were initially instrumented with Reciproc (R25) and then divided into four experimental groups according to the endodontic sealer and retreatment instrument (n = 15): BC Sealer/Reciproc (BCRC), BC Sealer/Reciproc Blue (BCRB), AH Plus/Reciproc (AHRC), and AH Plus/Reciproc Blue (AHRB). The procedure time was measured, and an Eppendorf tube was used in each root canal to store the debris extrusion. The samples were scanned by micro-CT before and after retreatment. The apical transportation, volume of dentin, and filling material were evaluated.

Results

There were no significant differences in the reduction of the volume of obturator material or dentin removal between groups (p > .05). There were also no differences in the amount of extruded material or apical transportation (p > .05). The retreatment time for the AHRC group was significantly lower than that for the other groups (p = .004).

Conclusions

All tested instruments obtained similar efficacy in filling material removal procedures, although no system completely removed the filling material. Retreatment of canals filled with bioceramic BC Sealer may be more time consuming.

Clinical relevance

This study reported that Reciproc and Reciproc Blue can be indicated in retreatment of severely curved root canals filled either with bioceramic or resin-based sealers.

     

Dentin Extends the Antibacterial Effect of Endodontic Sealers against Enterococcus faecalis Biofilms

Introduction

The purpose of this study was to evaluate the antimicrobial effects of root canal sealers on Enterococcus faecalis biofilms in dentinal tubules by using a novel dentin infection model.

Methods

Cells of E. faecalis were introduced into the dentinal tubules by centrifugation and incubated in brain-heart infusion broth for 3 weeks. An equal thickness of AH Plus, Endosequence BC sealer (BC sealer), and pulp canal sealer EWT (PCEWT) was placed on the root canal wall of the dentin specimens for 1, 7, and 30 days in humid conditions at 37°C. Gutta-percha and water were used in a similar manner as the tested sealers. The proportions of dead and live bacteria inside the dentinal tubules after exposure to root canal sealers were assessed by confocal laser scanning microscopy.

Results

Significantly more bacteria were killed in the 3 sealer groups than in the 2 control groups (P < .05). BC sealer and AH Plus resulted in significantly more dead cells than PCEWT did. There was no statistically significant difference between BC sealer and AH Plus at any time point (P > .05). Thirty days of exposure to BC sealer and AH Plus resulted in significantly more dead bacteria in dentin than 7-day and 1-day exposures in the biofilms, whereas no statistically significant increase of the proportion of dead bacteria was detected between 7-day and 30-day PCEWT (P > .05).

Conclusions

The 3 endodontic root canal sealers had antibacterial effects against E. faecalis in the dentinal tubules. BC sealer and AH Plus had superior antibacterial effects compared with PCEWT. The antibacterial effects of sealers in dentinal tubules continued after setting.     

Immediate and Long-Term Porosity of Calcium Silicate–Based Sealers

IntroductionOpen pores between endodontic sealer and root canal walls present potential niches for bacterial growth and migration pathways. The aim was to assess the internal and external porosity of calcium silicate–based sealers and to ascertain the long-term effect of storage in simulated body fluid on sealer porosity.MethodsSixteen single-rooted teeth were filled with gutta-percha and 1 of 4 root canal sealers: BioRoot RCS, EndoSequence BC, MTA Fillapex, or AH Plus. Obturated roots, stored in Hank's balanced salt solution, were scanned after 7 days and after 6 months by using micro–computed tomography at an isotropic resolution of 9.9 μm. Total, open, and closed porosity were calculated in the coronal, middle, and apical thirds. Data were statistically analyzed by using general linear model and paired t test (α = 0.05).ResultsSignificantly higher percentage of open than closed porosity was found in all groups. Initially, significantly greater open and total porosity were found for MTA Fillapex than for AH Plus. After 6 months, the percentage of open and total porosity increased in BioRoot RCS and MTA Fillapex and decreased in AH Plus and EndoSequence BC. Both initially and after storage, coronal region of all sealers had significantly greater total porosity than middle and apical regions, which were comparable.ConclusionsNone of the root fillings were void-free, with predominant open porosity persisting after long-term storage.     

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.     

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.     

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.     

Push-out Bond Strength of Resilon/Epiphany and Resilon/Epiphany Self-Etch to Root Dentin

IntroductionThe present study was designed to investigate the bond strength produced by Epiphany and Epiphany SE to root canal dentin.MethodsA sample of 36 human upper canines was prepared and assigned to experimental groups (n = 12), designated as group 1, Resilon/Epiphany; group 2, Resilon/Epiphany SE; and group 3, AH Plus/gutta-percha. After the filling procedures, each tooth was prepared for push-out assessment by using root slices of 1-mm thickness. Loading was performed on a universal testing machine at a speed of 0.5 mm/min. One-way analysis of variance and Tukey test for multiple comparisons were used to compare the results among the experimental groups.ResultsAH Plus/gutta-percha root fillings showed significantly higher push-out bond strength than both Resilon/Epiphany and Resilon/Epiphany SE (P < .05). There was no significant difference between Epiphany/Resilon and Epiphany SE/Resilon (P > .05).ConclusionsUnder the present in vitro conditions, the adhesiveness quality to root dentin promoted by both Epiphany sealers is compromised even when teeth with simple anatomic features were obturated under well-monitored laboratory conditions.     

Characterization of Leachates from 6 Root Canal Sealers

Introduction

The aim of this study was to evaluate 6 different endodontic sealers by characterizing their leachates and comparing their solubility in water over a 4-week period.

Effect of Photoactivated Disinfection on Bond Strength of Root Canal Filling

IntroductionThe aim of this in vitro study was to assess and compare the effect of photoactivated disinfection (PAD) on the bond strength of root canal sealers to human root canal dentin using the push-out test.MethodsFifteen extracted human mandibular premolar teeth with single and straight roots were used. After the clinical crowns were removed from the cementoenamel junction, root canals were prepared with the ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) rotary system to the size of the F3 file. The smear layer of the roots was removed using 17% EDTA followed by 5.25% sodium hypochlorite (NaOCl) and distillate water. The roots were then randomly divided into 3 groups (n = 5) according to the final irrigation regimen. In group 1, PAD (FotoSan; CMS Dental, Copenhagen, Denmark) was applied to the root canals and light cured for 20 seconds. Group 2 was finally irrigated with a 2% solution of chlorhexidine gluconate, and group 3 served as the control group (NaOCl + EDTA). All the canals were then obturated with the lateral condensation technique using gutta-percha and AH Plus sealer (Dentsply Maillefer) sealer. One-millimeter-thick horizontal sections from the coronal and midthirds of each root (n: 5 × 4 = 20) were sliced for the push-out bond strength measurement. The data were converted to megapascals and statistically analyzed using 1-way analysis of variance and the post hoc Tukey test.ResultsThere was no significant difference among the bond strength of PAD, chlorhexidine gluconate, and NaOCl (P > .05).ConclusionsWe conclude that PAD does not adversely affect the bond strength of the AH Plus sealer to root canal dentin and that it can be used for the final disinfection of root canals.     

A Novel Polyurethane Expandable Root Canal Sealer

IntroductionEndodontic sealers play a vital role in the obturation of root canal space. The aim of this study was to evaluate the utility of a recently developed polyurethane expandable sealer (PES), along with its cytotoxicity and dimensional changes.MethodsL929 fibroblasts and an cell viability assay (MTS assay) were used to determine the cytotoxicity of dental sealers (AH Plus [Dentsply Maillefer, Ballaigues, Switzerland], Sure-Seal Root [Sure Dent Corporation, Gyeonggi-do, South Korea], and the PES) at 24, 48, 72, and 96 hours. An advanced choroidal neovascularization model was used to assess the effect of these sealers on angiogenesis. Thirty-six extracted single-rooted human teeth were prepared and randomly divided into 3 groups (n = 12). Obturation was performed with gutta-percha and a sealer using lateral compaction as follows: group 1, AH Plus; group 2, Sure-Seal; and group 3, PES. The average depth of sealer penetration into dentinal tubules was measured with a scanning electron microscope. Data were analyzed using 1-way analysis of variance and post hoc Tukey tests (level of significance, P < .05).ResultsThe values of MTS, choroidal neovascularization, and the penetration depth of PES were significantly higher than in other experimental groups (P < .05). The lowest values were noted in specimens of AH Plus, whereas the highest were detected in the PES group.ConclusionsPES showed promising results in terms of biocompatibility and dentinal tubule adaptation and penetration.     

Evaluation of Physicochemical Properties of a New Root Canal Sealer

Introduction

The aim of this study was to evaluate some of the physicochemical properties of a new root canal sealer.

Assessment of Root Canal Sealers Loaded with Drug-Silica Coassembled Particles Using an In Vitro Tooth Model

IntroductionThe purpose of this study was to assess the antimicrobial activity of root canal sealers modified with novel highly loaded antimicrobial drug-silica coassembled particles (DSPs) on Enterococcus faecalis–infected root canal dentin.MethodsDSPs were synthesized through coassembly of silica and octenidine dihydrochloride (OCT) surfactant drug (35% w/w OCT). DSPs (1% wt of the total mass of the sealer) were mixed homogenously with either epoxy resin sealer (AH Plus [AH]; Dentsply Sirona, Tulsa, OK) or calcium silicate–based sealer (EndoSequence BC Sealer [BC]; Brasseler, Savannah, GA). To assess the antimicrobial activity of DSP-loaded sealers, the apical third of single-rooted teeth was obtained and infected with E. faecalis for 3 weeks followed by the application of experimental (DSP-loaded) sealers or corresponding controls for up to 28 days. Microbiological analysis and laser scanning confocal and scanning electron microscopy were used to determine the colony-forming unit (CFU)/mL, the percentage of live bacteria, and the intratubular bacterial and sealer penetrations. Factorial analysis of variance and Tukey post hoc tests were used to assess the antimicrobial effect of DSPs on different sealers.ResultsAll experimental groups showed significant reductions in CFUs at all-time points compared with positive controls (P < .05). The addition of DSPs to BC significantly reduced the CFUs (2.11 ± 0.13, 2.22 ± 0.19, and 2.25 ± 0.17 at 1, 7, and 28 days, respectively) compared with the unmodified sealer (3.21 ± 0.11, 4.3 ± 0.15, and 4.2 ± 0.2 at 0, 7, and 28 days). DSPs enhanced the antimicrobial performance of AH only at 1 day (4.21 ± 0.17 vs 5.19 ± 0.12, P < .05). AH and AH + DSPs showed higher bacterial viability compared with BC and BC + DSPs at all incubation periods (P < .05).ConclusionsLoading endodontic sealers with DSPs had a material-dependent effect on the antimicrobial properties and could reduce the incidence of secondary infections.     

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.     

Push‐out bond strength of gutta‐percha with a new bioceramic sealer in the presence or absence of smear layer

The purpose of this study was to compare the bond strength of a new bioceramic sealer (EndoSequence BC Sealer) and AH Plus in the presence or absence of smear layer. Extracted single‐rooted human teeth were prepared and randomly divided into four groups. In groups 1 and 3, the root canals were finally irrigated with 5.25% NaOCl and smear layer was not removed, but in groups 2 and 4, the root canals were finally irrigated with 17% EDTA followed by 5.25% NaOCl in order to remove the smear layer. In groups 1 and 2, the root canals were obturated with gutta‐percha/AH Plus, but in groups 3 and 4, obturation was performed with gutta‐percha/EndoSequence BC Sealer. Push‐out bond strength and failure modes were evaluated. The bond strength of gutta‐percha/AH Plus and gutta‐percha/EndoSequence BC Sealer was not significantly different (P = 0.89). The presence or absence of smear layer did not significantly affect the bond strength of filling materials (P = 0.69). The mode of bond failure was mainly cohesive for all groups. In conclusion, the bond strength of the new bioceramic sealer was equal to that of AH Plus with or without the smear layer.