Dentin moisture conditions strongly influence its interactions with bioactive root canal sealers

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

Objectives

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

Materials and Methods

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

Results

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

Conclusions

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

The flow behavior and sealing ability of calcium silicate root canal cement containing dimethyl sulfoxide: An in vitro study

INTRODUCTION

To develop a calcium silicate (CaSi)-based cement containing dimethyl sulfoxide (DMSO) and cement deliver device for new root canal filling technique, and to assess the flow behavior, leakage, and root canal filling quality of CaSi containing DMSO.

METHODS

CaSi containing DMSO (CSC-DMSO) and CaSi containing PEG (CSC-PEG) were prepared, and the flow characteristics of both cements were compared in gypsum and resin channels using a high-speed camera. Eight root canals were obturated by CSC-DMSO or CSC-PEG using a cement delivery device, and root canal filling quality was assessed in terms of filling length using periapical radiographs. The filling length was evaluated by 'apico-coronal extension,' measuring length in reference to apical constriction. Microleakage was measured for thirty human molars that were randomly filled with CSC-DMSO, CSC-PEG, or gutta-percha and AH plus. Preliminary obturation of CSC-DMSO with cement delivery device in human teeth was analyzed in terms of filling length and void, using periapical radiographs. Statistical analysis was performed with the Kruskal Wallis test for simulated root canal fillings and one-way ANOVA for leakage test.

RESULTS

The flow speed of CSC-DMSO reduced in gypsum channels compared to resin channels, but CSC-PEG did not exhibit significant differences in the channels. The median absolute value of apico-coronal extension was significantly lower in CSC-DMSO compared to CSC-PEG (p < 0.05). Microleakage did not statistically differ between the groups (p > 0.05). In the preliminary obturation, the mean apico-coronal extension of CSC-DMSO was -0.297 ± 0.724 mm, while CSC-PEG was not feasible due to excess apical extrusions.

CONCLUSIONS

CSC-DMSO could be considered as an alternative filling material for root canal obturation.

Designing Calcium Silicate Cements with On-Demand Properties for Precision Endodontics

Calcium silicate (C3S) cements are available in kits that do not account for patients' specific needs or clinicians' preferences regarding setting time, radiopacity, mechanical, and handling properties. Moreover, slight variations in powder components and liquid content affect cement's properties and bioactivity. Unfortunately, it is virtually impossible to optimize several cement properties simultaneously via the traditional "one variable at a time" strategy, as inputs often induce trade-offs in properties (e.g., a higher water-to-powder ratio [W/P] increases flowability but decreases mechanical properties). Herein, we used Taguchi's methods and genetic algorithms (GAs) to simultaneously analyze the effect of multiple inputs (e.g., powder composition, radiopacifier concentration, and W/P) on setting time, pH, flowability, diametral tensile strength, and radiopacity, as well as prescribe recipes to produce cements with predicted properties. The properties of cements designed with GAs were experimentally tested, and the results matched the predictions. Finally, we show that the cements increased the genetic expression of odonto/osteogenic genes, alkaline phosphatase activity, and mineralization potential of dental pulp stem cells. Hence, GAs can produce cements with tailor-made properties and differentiation potential for personalized endodontic treatment.

Physical-chemical properties and acellular bioactivity of newly prepared nano-tricalcium silicate-58s bioactive glass-based endodontic sealer

OBJECTIVES

To evaluate the physiochemical properties and apatite-forming ability of a newly prepared nano-tricalcium silicate-58s bioactive glass-based endodontic sealer (C3S-BG-P) and compare its results with the Nishika BG canal sealer and BioRoot™ RCS.

METHODS

The physicochemical properties (setting time, flow, solubility, film thickness, and radiopacity) of C3S-BG-P, Nishika BG canal sealer, and BioRoot™ RCS were evaluated in accordance with ANSI/ADA 57/2000 (reaffirmed 2012) and ISO 6876:2012 for root canal sealing materials. The in vitro apatite-forming ability was evaluated after 28 days of immersion of disc-shaped specimens in phosphate-buffered saline (PBS) using field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy.

RESULTS

The results of physiochemical tests indicated that all the tested sealers complied with the ADA and ISO standards; however, the solubility of the BioRoot did not meet the two standards. C3S-BG-P revealed significantly superior properties in all physicochemical tests compared to Nishika and BioRoot; however, the solubility of Nishika was significantly lower than that of C3S-BG-P. Furthermore, all tested sealers exhibited apatite precipitation on their surfaces after 28 days of immersion in PBS.

CONCLUSIONS

C3S-BG-P had superior physicochemical properties, which mitigated the disadvantages of calcium silicate-based sealers. Moreover, it exhibited apatite precipitation after immersion in PBS. Further in vivo studies utilizing animal models or clinical studies are necessary to support the rationale of the newly developed sealer for clinical application.

Outcome of root canal treatment using warm vertical compaction with bioceramic and resin-based sealers: A randomised clinical trial

This study aimed to compare the effect of a bioceramic sealer (iRoot SP) and a resin-based sealer (AH Plus) on the outcome of root canal treatment in a 2-year follow-up. Seventy-six teeth with irreversibly or necrotic pulp were recruited. After instrumentation and disinfection, the root canals were obturated using warm vertical compaction with iRoot SP (n = 43) or AH Plus (n = 33). Patients were followed up by clinical and radiographic examination at 6 12 and 24 months with recall rates of 84.2%, 65.8% and 48.7%, respectively. During each recall session, the success rates were 80%, 85.2% and 85% in the iRoot SP group and 82.8%, 91.3% and 88.2% in the AH Plus group. The success rates of the two groups did not differ significantly (p > 0.05). The bioceramic sealer resulted in a similar clinical performance and success rate to the resin-based sealer in endodontic treatment during a 2-year follow-up.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of push-out bond strength of endodontic sealers after root canal drying with different techniques

OBJECTIVES

An ideal endodontic sealer should bond to both dentin and root-filling material. This study aimed to assess the push-out bond strength (PBS) of mineral trioxide aggregate (MTA)-Fillapex, Endoseal MTA, AH26, and Sure-Seal Root to root dentin after root canal drying with different techniques.

MATERIALS AND METHODS

This in vitro study was conducted on 160 extracted mandibular premolars. After root canal preparation, the teeth were randomly divided into four groups (n = 40) of drying with ethanol, paper point, air vacuum, and control (wet canal). Each group was divided into four subgroups (n = 10) for use of AH26, Sure-Seal Root, MTA-Fillapex, and Endoseal MTA sealers. The mean PBS was measured by a universal testing machine. The mode of failure was determined under a stereomicroscope. Data were analyzed by the Kruskal-Wallis and Games-Howell tests.

RESULTS

The maximum mean PBS was equally recorded in ethanol and paper point groups, and was significantly higher than that of control and air vacuum groups (p < .001). In the use of AH26 sealer, the mean PBS in drying with ethanol was significantly higher than all other methods (p < .05). The mean PBS in drying with a paper point was also significantly higher compared with control and air vacuum methods (p < .05). In the use of Sure-Seal, the mean PBS in drying with a paper point was significantly higher than other methods (p < .05). The mean PBS in drying with ethanol was significantly higher than that in control and air vacuum methods (p < .001). In the use of MTA-Fillapex and Endoseal-MTA, the technique of drying had no significant effect on PBS. Adhesive and mixed failures were the most common in all drying groups.

CONCLUSIONS

Drying with ethanol and paper point enhanced the PBS of sealers to root dentin.

Biocompatibility analysis in subcutaneous tissue and physico-chemical analysis of pre-mixed calcium silicate–based sealers

OBJECTIVES

To evaluate the biocompatibility, physical and chemical properties of three pre-mixed calcium silicate-based sealers and an epoxy resin-based material were assessed. Pre-mixed sealers supposedly obtain water from the root canal moist to hydrate and set.

MATERIALS AND METHODS

Polyethylene tubes were filled with the materials Bio-C Sealer Ion+, Bio-C Sealer, EndoSequence BC Sealer and AH Plus Jet, or left empty and surgically implanted in the subcutaneous tissue of Wistar rats. The animals were euthanised and the tubes and tissue were removed for histological analysis and scanning electron microscopy (SEM) coupled with energy-dispersive spectrometry (EDS). Materials' surface chemical characterisation was assessed using Raman spectroscopy and SEM/EDS. Flow, setting time (in two conditions), solubility, radiopacity and pH were also analysed. ANOVA and Bonferroni correction were performed for comparisons (P < 0.05).

RESULTS

Inflammatory response observed in the tissues subsided from 7 to 30 days. Tungsten migration could be detected in the surrounding tissue following AH Plus Jet implantation. All calcium silicate-based sealers exhibited zirconium oxide (radiopacifier) and tricalcium silicate peaks before and after implantation. All materials exhibited flow values above 17 mm. An approximately tenfold difference was observed between the plaster- and metal-mould setting times of the calcium silicate cements indicating its sensitivity to moist variations and solubility above 8% was also observed for these materials.

CONCLUSIONS

Pre-mixed materials exhibited variable setting time and solubility with a decreasing inflammatory response.

CLINICAL RELEVANCE

The variable moist-dependant setting time with high solubility poses a concern for the clinical use of these pre-mixed sealers.

Effect of operators' proficiency level and patients' related factors on possible complications, using a high frequency polyamide sonic intracanal irrigation device: A prospective clinical cohort study

OBJECTIVES

Sonic/ultrasonic devices are essential tools in today's endodontics. This prospective trial evaluated for the first time the impact of practitioners' proficiency levels and patient-related factors on complications associated with a high frequency polyamide sonic irrigant activation device.

METHODS

In total 334 patients (females:158, males:176; age:18-95 years) received in the course of their endodontic therapy an intracanal irrigation, using a high frequency polyamide sonic irrigant activation device, by practitioners of different proficiency levels (undergraduate students, general practitioners or endodontists). Intracanal bleeding (yes/no), postoperative pain (0-10 scale), emphysema (yes/no) and polyamide tip fractures (yes/no) were recorded and related to proficiency levels, age, gender, tooth type, smoking-status, systemic conditions affecting healing ability, baseline pain, swelling, fistula, sensitivity to percussion and diagnosis.

RESULTS

Intracanal bleeding was associated with patients' age (p<0.05), baseline pain level (OR = 1.14, 95%CI = 0.91-1.22) and baseline swelling (OR = 2.73, 95%CI = 0.14-0.99; p<0.05) but not proficiency level, gender, tooth type, smoking, systemic conditions, baseline fistula or sensitivity to percussion (p>0.05). Postoperative pain development was related to proficiency level (p<0.05) and baseline pain level (p<0.001), with no influence of age, gender, tooth type, smoking, systemic conditions, baseline fistula, swelling or sensitivity to percussion (p>0.05). Emphysema and polyamide tip fractures were not reported.

CONCLUSIONS

Within the current study's limitations, younger patients with higher baseline pain and swelling, were associated with higher intracanal bleeding. Apart from higher postoperative pain observed with less experienced practitioners, proficiency level had no influence on bleeding, polyamide tip fracture or emphysema, endorsing the high frequency polyamide sonic irrigation device as a safe therapeutic device.

Effect of using calcium-silicate and silicone based root canal sealers in bulk or with main core material on bond strength

Background

The purpose of this study was to assess the push-out bond strength of calcium-silicate and silicone based root canal sealers in bulk and with main cone.

Methods

Roots (n=48) randomly divided into 4 groups (n=12) according to the obturation protocol; (1) iRoot SP in bulk; (2) iRoot SP with gutta-percha; (3) GuttaFlow Bioseal in bulk; (4) GuttaFlow Bioseal with gutta-percha. Six horizontal sections were obtained from each root (n=72). Effect of sealers on bond strength was statistically significant (P<0.05).

Results

Highest mean value was obtained in iRoot-Bulk group and lowest in GuttaFlow Bioseal-GP group. Both iRoot SP groups had significantly higher bond strength values than both GuttaFlow Bioseal groups (P<0.05). There was no significant difference between iRoot-GP and iRoot-Bulk groups (P=0.603) also GuttaFlow Bioseal-GP and GuttaFlow Bioseal-Bulk groups (P=0.684).

Conclusion

Based on findings, using calcium silicate-based sealer in bulk can be also suitable in clinical practice.

Evaluation of the Sealing Ability and Bond Strength of Two Endodontic Root Canal Sealers: An In Vitro Study

BACKGROUND

Obturation represents a critical step in endodontic treatment, which relies on a core material and a sealer. This study aims to evaluate the sealing ability and bond strength to the root canal walls of an epoxy resin-based sealer (AH-Plus®, Dentsply Sirona, Johnson City, TN, USA) and a bioceramic sealer (GuttaFlow Bioseal®, Coltène/Whaledent, GmbH + Co. KG, Langenau, Germany).

METHODS

Thirty-eight maxillary anterior teeth with single roots and identical round sections were separated into two experimental groups according to the root canal sealers used, namely, G1 = AH-Plus® and G2 = GuttaFlow Bioseal®, and two control groups, specifically, G3 = the negative control and G4 = the positive control. The sealing capacity was measured by the penetration of the radioactive isotope 99mTc. For the push-out test, the compressive force test was performed in a universal machine and the force was applied by exerting pressure on the surface of the material to be tested in the apical to the coronal direction and using three test points with different diameters.

RESULTS

GuttaFlow Bioseal® exhibited superior sealing ability compared to AH-Plus® (p = 0.003). Regarding the bond strength, AH-Plus® provided higher adhesion values than GuttaFlow Bioseal® in the three sections of the tooth root (p = 0.001).

CONCLUSIONS

GuttaFlow Bioseal® had significantly better sealing ability than AH-Plus® but lower adhesion values in the three zones of the root canal, with statistically significant differences between the groups. However, it is important to note that for the action of endodontic sealers to be maximized, the root-filling technique must be most appropriate.

Physico-chemical properties of calcium silicate-based sealers in powder/liquid and ready-to-use forms

Calcium silicate-based root canal sealers have been developed in powder/liquid or premixed ready-to-use forms. The evaluation of the physico-chemical properties of a prototype powder/liquid MTApex Sealer (Ultradent) in comparison to a ready-to-use material EndoSequence BC Sealer (Brasseler) was performed. The paste/paste epoxy resin-based AH Plus (Dentsply) served as control for comparisons. The sealers were evaluated (n = 6) regarding setting time (in dry and moist environments), flow and radiopacity, following the ISO-6876/2012 standard. Also, the pH was assessed. Material's surface and chemical characterization was evaluated using scanning-electron-microscopy (SEM) and energy-dispersive-spectrometry (EDS). Mixed ANOVA, Shapiro-Wilk, Levene, and post-hoc analysis with Bonferroni correction were performed at a significance level of 5%. MTApex Sealer exhibited the highest flow and EndoSequence BC Sealer had a significantly longer setting time in dry compared to the moist environment; however, for MTApex Sealer and AH Plus no significant changes occurred when additional moisture was provided. All materials exceeded 7 mm Al of radiopacity and showed a decreasing alkalinity over the 21 day-analysis. SEM/EDS evaluation resulted in peaks of calcium, silicon, and the respective radiopacifier. The prototype powder/liquid MTApex Sealer had the highest flow and similar setting time in both dry and moist environments; opposingly, EndoSequence BC Sealer was crucially influenced by external moisture. This suggests that the powder/liquid materials' setting seems to be more predictable.

How do imaging protocols affect the assessment of root-end fillings?

Objectives

This study investigated the impact of micro-computed tomography (micro-CT)-based voxel size on the analysis of material/dentin interface voids and thickness of different endodontic cements.

Materials and Methods

Following root-end resection and apical preparation, maxillary premolars were filled with mineral trioxide aggregate (MTA), Biodentine, and intermediate restorative material (IRM) (n = 24). The samples were scanned using micro-CT (SkyScan 1272; Bruker) and the cement/dentin interface and thickness of materials were evaluated at voxel sizes of 5, 10, and 20 µm. Analysis of variance and the Tukey test were conducted, and the degree of agreement between different voxel sizes was evaluated using the Bland and Altman method (p < 0.05).

Results

All materials showed an increase in thickness from 5 to 10 and 20 µm (p < 0.05). When evaluating the interface voids, materials were similar at 5 µm (p > 0.05), while at 10 and 20 µm Biodentine showed the lowest percentage of voids (p < 0.05). A decrease in the interface voids was observed for MTA and IRM at 20 µm, while Biodentine showed differences among all voxel sizes (p < 0.05). The Bland-Altman plots for comparisons among voxel sizes showed the largest deviations when comparing images between 5 and 20 µm.

Conclusions

Voxel size had an impact on the micro-CT evaluation of thickness and interface voids of endodontic materials. All cements exhibited an increase in thickness and a decrease in the void percentage as the voxel size increased, especially when evaluating images at 20 µm.

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

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

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

AIM

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.

METHODOLOGY

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).

RESULTS

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.

CONCLUSIONS

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.

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

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