Fracture Resistance and Biomechanical Behavior of Retreated Teeth Obturated with Different Sealers: Combined Laboratory Testing and Finite Element Analysis.

This research aimed to assess the stress distribution in lower premolars that were obturated with BioRoot RCS or AH Plus, with or without gutta percha (GP), and subjected to vertical and oblique forces. One 3D geometric model of a mandibular second premolar was created using SolidWorks software. Eight different scenarios representing different root canal filling techniques, single cone technique with GP and bulk technique with sealer only with occlusal load directions were simulated as follows: Model 1 (BioRoot RCS sealer and GP under vertical load [VL]), Model 2 (BioRoot RCS sealer and GP under oblique load [OL]), Model 3 (AH Plus sealer with GP under VL), Model 4 (AH Plus sealer with GP under OL), Model 5 (BioRoot RCS sealer in bulk under VL), Model 6 (BioRoot RCS in bulk under OL), Model 7 (AH Plus sealer in bulk under VL), and Model 8 (AH Plus sealer in bulk under OL). A static load of 200 N was applied at three occlusal contact points, with a 45° angle from lingual to buccal. The von Mises stresses in root dentin were higher in cases where AH Plus was used compared to BioRoot RCS. Furthermore, shifting the load to an oblique direction resulted in increased stress levels. Replacing GP with sealer material had no effect on the dentin maximum von Mises stress in BioRoot RCS cases. Presence of a core material resulted in lower stress in dentin for AH Plus cases, however, it did not affect the stress levels in dentin for cases filled with BioRoot RCS. Stress distribution in the dentin under oblique direction was higher regardless of sealer or technique used.

Aims:The present study aimed to evaluate and examine the degree of marginal adaptation of several root canal sealers using a scanning electron microscope (AH Plus, MTA-Fillapex, Total-Fill, and GuttaFlow Bioseal) to root dentine.
 Methods and Material:Forty extracted mandibular premolars with completely formed apices and a single root were selected. The root canals were instrumented after the decoronation of teeth. The samples (n = 10) were divided randomly into four groups. Group (1) was sealed with a resin-based sealer (AH Plus), Group (2) with an MTA-based sealer (MTA-Fillapex), Group (3) with a bioceramic sealer (TotalFill BC), and Group (4) with a silicone-based sealer (GuttaFlow Bioseal). After horizontally slicing samples with a diamond disk, marginal adaptability was evaluated using SEM.
 One-way ANOVA test and the multiple Post hoc test of Tukey was reliant on the statistical analysis of the data.
 Results: TotalFill BC has shown significantly higher marginal adaptation than MTA-Fillapex and GuttaFlow Bioseal (P < 0.05). There is no significant difference between apical and coronal sections in the four tested groups under SEM (P < 0.05).
 Conclusions: Total fill BC outperformed the other tested sealers in terms of marginal adaptability.

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.

Purpose: This study compared the antimicrobial efficacy of calcium silicate sealers (BioRoot RCS and Total Fill BC) and conventional sealers (AH Plus and Tubli-seal) against planktonic bacteria and a nutrient-stressed multispecies biofilm. Methods: Antimicrobial properties of freshly mixed sealers were investigated using the direct contact test (DCT) and a nutrient-stressed multispecies biofilm comprised of five endodontic strains. Antimicrobial activity was determined using quantitative viable counts and confocal laser scanning microscopy (CLSM) analysis with live/dead staining. The pH of the sealers was analysed over a period of 28 days in Hanks Balanced Salt Solution (HBSS). Analysis of variance (ANOVA) with Tukey tests and the Kruskal–Wallis test were used for data analysis with a significance of 5%. Results: All endodontic sealers exhibited significant antimicrobial activity against planktonic bacteria (p < 0.05). BioRoot RCS caused a significant reduction in viable counts of the biofilms compared to AH Plus and the control (p < 0.05), while no significant difference could be observed compared to TotalFill BC and Tubli-seal (p > 0.05). CLSM analysis showed that BioRoot RCS and TotalFill BC exhibited significant biofilm inhibition compared to Tubli-seal, AH Plus and the control (p < 0.05). BioRoot RCS presented with the highest microbial killing, followed by TotalFill BC and Tubli-seal. Alkalizing activity was seen from the onset by BioRoot RCS, TotalFill BC and AH Plus. After 28 days, BioRoot RCS demonstrated the highest pH in HBSS (pH > 12). Conclusions: Calcium silicate sealers exhibited effective antimicrobial properties. This was demonstrated by superior biofilm inhibition capacity and microbial killing, with strong alkalizing activity compared to epoxy-based and zinc oxide-eugenol-based sealers.

BackgroundThe objective of this study was to examine the impact of varying taper dimensions and different forms of bioceramic sealers on the fracture resistance of mandibular premolar teeth prepared using single-file Ni-Ti instrumentation systems in vitro.MethodsForty single-rooted mandibular premolars were randomly allocated into four groups (n = 10) according to the taper value and type of sealer used: Group T4-AHBC – 25/0.04 taper with AH Plus BCS (premixed syringe form), Group T6-AHBC – 25/0.06 taper with AH Plus BCS, Group T4-BRCS – 25/0.04 taper with BioRoot RCS (powder-liquid form), and Group T6-BRCS – 25/0.06 taper with BioRoot RCS. Root canals were prepared and then obturated with the designated sealers. Using a universal testing machine at a crosshead speed of 1 mm/min, fracture resistance was measured, and the resulting data were analyzed statistically.ResultsStatistical analysis revealed that there were no significant differences in fracture resistance between the groups (p = 0.188). Neither the taper value nor the bioceramic sealer form had a significant effect on fracture resistance.ConclusionsWithin the limitations of this in vitro study, variation in taper values and sealer forms did not affect fracture resistance. Both powder-liquid and premixed syringe forms demonstrated similar performance, suggesting that clinicians may choose between them based on handling preference and clinical practicality.

The aim of this study was to evaluate the aging effect of thermomechanical cyclic load on fracture resistance of lower premolars obturated with AH Plus and BioRoot RCS root canal sealers. Forty-eight single-rooted premolars teeth were instrumented with REVO-S files up to SU/0.06 taper. The teeth were randomly assigned into 2 main groups (n = 24) according to the selected two root canal sealers (AH Plus or BioRoot RCS). All teeth were obturated using matching gutta-percha. Each main group were further divided into 3 subgroups (A, B and C) (n = 8). Group A acted as the negative control group (non-Thermomechanical aging). Whereas Group B and C were subjected first to thermal variations in a thermal cycling machine (7500 and 15,000 thermal cycles), then two different dynamic loading periods namely 3 × 105 and 6 × 105 in a masticatory simulator with a nominal load of 5 kg at 1.2 Hz which simulate approximately 1 ½ and 3 years of clinical function respectively. The roots were decoronated and fracture resistance were measured using a universal testing machine. After thermal-mechanical aging, BioRoot RCS showed significantly higher fracture resistance (p &lt; 0.05) than AH Plus. As the thermal-mechanical cycles increased both AH Plus and BioRoot RCS exhibited a significant decrease in fracture resistance (p &lt; 0.05). It could be concluded that thermomechanical aging had a significant impact on the outcome of the fracture resistance of AH Plus and BioRoot RCS.

Objectiveexamination of the influence of chemical composition changes on the ability of sealers to withstand a pull-out test.Materials and methodsFifty distal or palatal canals of extracted teeth were prepared by Dc Taper files. The teeth were divided into five groups: AH Plus, BJM RCS, Total Fill BC,AH Plus Bioceramic and a group with Gutta Percha with no sealer added. Ten days after obturation, each cone was subjected to the “pull-out test” with the Shimadzo Universal Testing Machine until it was torn or removed from the canal. A force to Stroke graph was generated and the maximum vertex of this graph was recorded. The number of times the cone was torn or removed was recorded.ResultsThe amount of force needed to remove or rupture the cone was significantly higher in all sealer groups compared to the AH Plus Bioceramic group. The force needed for the AH Plus group was double that needed for the AH Plus Bioceramic group 4 (1.87 ± 0.53 N vs 0.93 ± 0.48 N, respectively, P < 0.001). All of the cones (n = 10) in the AH Plus Bio Ceramic Sealer group were removed in their entirety (P = 0.01 compared to each of the other groups).ConclusionsThe addition of macromolecules to epoxy sealer does not change the material’s ability to withstand the pull-out test. Decreasing the amount of tri- and di-calcium silicate compounds combined with increasing amounts of zirconium oxide in a Bioceramic sealer significantly decreased the material’s ability to withstand the pull-out test.

ABSTRACTIntroduction: The aim of this in vitro study was to assess the pH values of selected calcium-silicate root canal sealers in comparison with AH Plus resin-based root canal sealer.Materials and methods: Six root canal sealers were included in this study: BioRoot RCS (Septodont, France), GuttaFlow bioseal (Coltėne/Whaledent, Switzerland), MTA Fillapex (Angelus, Brazil), Total Fill BC Sealer (FKG, Switzerland), Well-Root ST (Vericom, Korea) and AH Plus (Dentsply, DeTrey, Germany). Materials samples (n = 6) were placed in dishes and immersed in 10 mL of distilled water (pH = 6.8). After 1, 3, 24, 48, 72, 168, 336 and 504 hrs, water pH was determined with a pH meter calibrated with a solution of known pH. Data were statistically analyzed using Student-t test (p &lt; 0.05).Results: There were differences in the water pH between the materials tested. The highest water pHs were exhibited by Total Fill BC Sealer, Well-Root ST and BioRoot RCS (pH ~12), followed by GuttaFlow bioseal (pH ~10.5) and MTA Fillapex (pH ~9). The lowest pH was shown by AH Plus (pH ~8).Conclusions: All calcium-silicate root canal sealers studied are able to elevate the pH level, which could have biological and antimicrobial effects. The AH Plus root canal sealer has poor alkalizing properties.

The adhesion of endodontic sealers to dentin may be influenced both by the chemical composition of the sealer and the final irrigation protocol. The aim of this study was to examine the push-out bond strength of three differently formulated bioceramic sealers to root canal dentin, after different irrigation protocols. Four cavities were prepared in dentine discs obtained from middle thirds of third molars with fused roots. Discs were randomly divided into three groups (n = 8). Group 1: specimens were immersed in 2.5% NaOCl; group 2: in 2.5% NaOCl followed by 17% EDTA; and group 3: in a solution of 2.5% NaOCl with 9% etidronic acid (HEDP). The cavities on each disk were filled with four tested sealers: AH Plus Bioceramic, Bio C Angelus, BioRoot RCS, and AH Plus (n = 8 per sealer). The push-out bond strength test was performed after 7 days. The data were statistically analyzed using two-way analysis of variance with the Bonferroni post hoc test (α = 0.05). Irrigation with NaOCl resulted in significantly lower bond strength values of the sealers in comparison to NaOCl/EDTA and NaOCl/HEDP groups. In the NaOCl and NaOCl/HEDP groups, BioRoot RCS showed similar push-out bond strength compared to AH Plus and significantly higher compared to Bio-C and AH Plus Bioceramic. In the NaOCl/EDTA group, bioceramic sealers achieved a significantly weaker bond strength compared to AH Plus. The bond strength of BioRoot RCS was significantly higher compared to Bio-C and AH Plus Bioceramic. The irrigation protocols and the chemical composition of the sealers significantly influenced their bond strength to dentin. Epoxy resin-based sealer achieved the strongest bond strength, while within bioceramic sealers, the highest values were obtained for BioRoot RCS and the lowest for AH Plus Bioceramic.

We compared the effects of heat on the physicochemical properties of recently developed calcium silicate-based sealers (CSBSs), including BioRoot Flow, BioRoot RCS, and AH Plus Bioceramic sealer, with those of the epoxy-resin-based sealer (ERBS) AH Plus. The flow, film thickness, setting time, and solubility of sealers were evaluated at 37 °C and 100 °C using ISO 6876/2012. Furthermore, pH and calcium ion release were evaluated at these temperatures. In addition, the mass change in sealers at a high temperature was assessed via thermogravimetric analysis. Then, the chemical composition and components of the sealers were analyzed using a scanning electron microscope and Fourier-transform infrared spectroscopy (FTIR). BioRoot Flow, AH Plus Bioceramic, and AH Plus complied with ISO standards in terms of flow and film thickness, both before and after heat application. However, BioRoot RCS exhibited significantly increased film thickness at 100 °C. The setting times of all sealers were significantly reduced at 100 °C. The solubility of CSBS was >3%, exceeding the ISO 6876/2012 standard, both before and after heat exposure. Conversely, the solubility of AH Plus complied with the standard, regardless of the thermal condition. For 4 weeks, CSBS showed a significantly higher pH than AH Plus at both 37 °C and 100 °C. After heat treatment, calcium release decreased in Bioroot RCS and BioRoot Flow, while AH Plus showed no significant differences before and after treatment. However, CSBS consistently exhibited significantly higher calcium release than AH Plus at both temperatures. An FTIR analysis revealed that the chemical composition of the sealers did not change at the high temperature, whereas a thermogravimetric analysis demonstrated a >5% weight reduction in CSBS and a 0.005% weight reduction in AH Plus at 100 °C. BioRoot Flow, AH Plus Bioceramic, and AH Plus possess favorable physicochemical properties, which make them suitable for application under thermal conditions. At a high temperature, BioRoot RCS did not exhibit changes in its chemical composition. However, its film thickness was increased, and pH and solubility were reduced. Therefore, caution is needed when it is applied at high temperatures, such as during the warm obturation technique.

Introduction: International standards require adequate radi-opacity of root canal filling materials to distinguish them from natural structures, such as tooth tissues, and to allow evaluation of the quality of the root canal filling. The aim of this in vitro study was to assess the radiopacity of selected calcium-silicate root canal sealers compared with the resin-based AH Plus root canal sealer. Materials and methods: The study included 6 root canal sealers: BioRoot RCS, GuttaFlow bioseal, MTA Fillapex, Total Fill BC Sealer, Well-Root ST and AH Plus. Six disc-shaped samples were prepared from all analysed materials (4 mm in diameter and 1 mm thick) and analysed using a digital radiography technique and aluminium step wedges (1.5–15 mm thick) as a standard reference. The radiopacity was determined using computer image analysis. The data was statistically analysed using a Tukey’s range test. Results: All root canal sealers showed radiopacity at least corresponding to the 3 mm aluminium step wedge. AH Plus (13.23 mm Al) showed the highest radiopacity, followed by Total Fill BC Sealer (7.93 mm Al), Well-Root ST (7.12 mm Al), BioRoot RCS (5.93 mm Al) and GuttaFlow bioseal (5.08 mm Al). MTA Fillapex (3.02 mm Al) showed the lowest radiopacity. Conclusions: Although the evaluated root canal sealers show different radiopacities, all the materials met the criteria laid down by the International Organization of Standardization.

BackgroundThe selection of an appropriate filling material in root canal treatments of primary molars is crucial for long-term success. However, evaluating the biomechanical behavior of these materials under in vivo conditions remains challenging. This study aimed to investigate the effect of different root canal filling materials on the fracture resistance of the mandibular second primary molar by analyzing stress distributions and failure risk using finite element analysis (FEA) models.MethodsA mandibular second primary molar extracted for orthodontic reasons was used in the study. The tooth was scanned using micro-computed tomography (micro-CT) to obtain original DICOM data, which were imported into Geomagic + SpaceClaim 2023R2 to create a solid model. A total force of 330 N was applied to three points on the occlusal surface of each model. The analysis was conducted using Ansys mesh and evaluated with Hyperview 2024. Maximum von Mises (vM) stress values were used to assess stress distribution.ResultsThe highest vM stress in the remaining dentin was observed in the gutta-percha (GP) + AH Plus model (148.5 MPa), followed by mineral trioxide aggregate (MTA) (127.24 MPa), Biodentine (125.65 MPa), and GP + BioRoot RCS (118.37 MPa). Stress concentrations were primarily located in the pericervical region. The GP + AH Plus group showed the highest stress, while the GP + BioRoot RCS group showed the lowest. Among contemporary filling materials, GP + BioRoot RCS demonstrated the lowest dentin stress, suggesting it may offer better root fracture resistance. However, generalizing these findings is difficult due to limited data on primary teeth in the literature.ConclusionThe study suggests that GP + BioRoot RCS may be a more promising filling material for enhancing root fracture resistance in primary molars. Further research is needed to validate these findings in clinical settings.

ObjectiveThe objective of this investigation was to assess and compare the fracture resistance of roots filled with AH Plus (AHP), Total Fill bioceramic (TFBC), and AH Plus bioceramic (AHBC) sealers using a single cone, warm vertical compaction (WVC), and Soft-Core techniques.MethodsThis study used the palatal root canals of eighty extracted human maxillary first molars. All roots were sectioned to maintain a uniform root length of 11 mm. The samples were mechanically prepared using EdgeFile X7 rotary files to size 40/0.04. Eight teeth were left unfilled as a control group, while the remaining teeth were classified into three primary categories according to the sealer used for obturation: AHP, TFBC, and AHBC. Each group was divided into three subgroups (n=8) based on the obturation technique: single cone, WVC, and Soft-Core. Every tooth was set into blocks of acrylic resin, and universal testing equipment (Instron Corp) with a metal-like spreader tip was used to measure the fracture force at a speed of 0.5 mm/min. The collected data were examined using ANOVA, which was succeeded by Tukey’s test.ResultsThe control group's fracture resistance values were significantly less than the obturated groups in the study. Overall, the fracture resistance of AHP and AHBC was significantly higher than that of TFBC sealers. The WVC and Soft-Core were significantly higher than single cone techniques. The obturation technique did not significantly influence the fracture resistance of AHP and TFBC. While the fracture resistance of AHBC was significantly impacted., WVC was significantly higher than the single cone group. When roots were obturated with the WVC technique, AHBC exhibited statistically significant higher values of fracture resistance than AHP and TFBC. There was no significant difference between the three sealers when a single cone and Soft-Core were used.ConclusionAccording to this in vitro investigation, Obturation with AHP and AHBC sealers enhanced the fracture resistance of the roots more significantly than TFBC sealer, while obturation with WVC and Soft-Core yielded greater fracture resistance compared to the single cone approach.

Effective root canal treatment relies on the ability of sealers to wet and penetrate the root canal system, ensuring a tight seal and preventing bacterial leakage. The current study investigates the wetting ability of newer root canal sealers by evaluating their contact angle. The objective of the present study was to evaluate and compare the wetting behavior of Guttaflow bioseal, Ceraseal, and AH plus root canal sealers. Decoronation and apical third resections of thirty extracted singlerooted human mandibular premolars were done. The roots were then split longitudinally into two halves buccolingually. The root dentin surfaces were treated using 10 mL 3% sodium hypochlorite for 5 min, 10 mL of 17% ethylenediaminetetraacetic acid for 5 min, and 2% chlorhexidine for 10 min. Then, these sixty dentin bars were randomly divided into three groups (n = 20): Group 1 - AH Plus, Group 2 - Ceraseal, and Group 3 - Guttaflow bioseal. The controlled volume of 0.1 mL sealer has been dispensed onto the dentin specimen using a micropipette. The contact angle of a drop of sealer was measured after 5 min using Ossila goniometer. The data were analyzed using one-way analysis of variance and Tukey post hoc tests. The statistical significance was at P < 0.05. The mean contact angle values for AH Plus sealer were lower when compared to the other two sealer groups which is statistically highly significant. AH Plus showed lesser contact angle thereby better wettability than Ceraseal and Guttaflow bioseal on the root canal dentin surface.

BackgroundBioceramic sealers are increasingly used due to their favorable properties, but their strong bonding to dentin complicates retreatment procedure. In addition, canal irregularities such as isthmuses make the complete removal of filling materials more challenging.AimThis study aimed to evaluate the retreatability of five bioceramic sealers (BioRoot RCS, Bio-C Sealer, CeraSeal, Endoseal MTA, and AH Plus Bioceramic Sealer) using passive ultrasonic irrigation.Materials and MethodsSixty human mandibular premolars with straight canals were prepared to size 40/0.04 taper. After longitudinal splitting, standardized grooves were created. The root canals were subsequently obturated using the single cone technique and stored at 37 °C with 100% humidity for 21 days. Passive ultrasonic irrigation was used to assess sealer removal. Statistical analysis was performed with Kruskal–Wallis and Mann–Whitney U tests.ResultsThe amount of residual sealer in the apical region was statistically higher compared with the coronal region. In the coronal region, the highest amount of residual material was observed in the Bio-C Sealer group, and this difference was statistically significant compared to the other groups. There was no significant difference among the other groups. In the apical region, there were no statistically significant difference between Bio-C Sealer and Endoseal MTA; however Bio-C Sealer showed a statistically significantly higher amount of residual material compared to BioRoot RCS, Ceraseal, and Ah Plus Bioceramic Sealer.ConclusionAmong the evaluated bioceramic sealers, Bio-C Sealer exhibited the highest amount of residual material, particularly in the apical region, indicating its lower retreatability. Passive ultrasonic irrigation improved the removal of BioRoot RCS, CeraSeal, and AH Plus Bioceramic Sealer, but was less effective for Bio-C Sealer and EndoSeal MTA. These findings highlight the variability in retreatability among different bioceramic sealers and emphasize the importance of material selection in cases with potential need for retreatment.