Composition and physicochemical properties of calcium silicate based sealers: A review article

Reducing apical voids for intra-canal sealer injection using a modified passive deflation needle

The aim of the study was to evaluate the ability of a modified passive deflation needle to reduce the apical voids during the intra-canal iRoot SP sealer injection. A modified passive deflation injection needle was designed. Forty 20°-curved and twenty S-shaped single-canal resin block models were allocated into six groups. Each group was mechanically prepared to #25/04 or #25/06 file; then the root canals were injected with iRoot SP sealer using a modified needle or a normal plastic needle. Radiographs were taken to measure the length of apical void in each specimen. Similarly, twenty single-canal extracted premolars were collected and randomly divided into four groups. Each group was prepared to #25/04 or #25/06 file; then the root canals were injected with iRoot SP sealer using a modified needle or a normal plastic needle. Roots were then scanned using micro-computed tomography (micro-CT), and the volume of voids in root canals was analyzed and compared among groups. Statistical analysis demonstrated that the length and the volumetric percentage of voids were much lower in the modified needle group in both resin block root canal models and extract teeth than the normal plastic needle group (P < 0.05). The modified passive deflation needle can efficiently reduce apical voids during the intra-canal iRoot SP sealer injection.

Biological properties versus solubility of endodontic sealers and cements

Endodontic sealers and cements used in root canal treatment have different compositions and properties. Common to all materials is that their primary goal is to fill gaps and voids, making a permanent seal of the root canal system. Furthermore, aspects such as antibacterial properties, cytotoxicity, setting time, solubility and biocompatibility are also crucial and ought to be considered. Over the years, a shift in the view on the importance of these aspects has ocurred. Whereas the antibacterial properties were considered important when the technical factors in endodontics were less developed, the sealing ability and biocompatibility have later been considered the most critical factors. The introduction of tricalcium silicate cements and sealers has led to a renewed interest in material properties, as these cements seem to have good sealing ability and at the same time combine favourable antimicrobial effects with excellent biocompatibility. This review discusses how the various properties of root canal sealers and cements may conflict with the primary aim of providing a permanent seal of the root canal system.

Micro-computed tomographic evaluation on the quality of single-cone obturation using a modified passive-deflation sealer injection needle: an in vitro study

OBJECTIVES

This study aimed to design a modified passive-deflation sealer injection needle and investigate its ability to improve obturation quality of single-cone technique through assessing the distribution of voids in root canals using micro-computed tomography (micro-CT).

MATERIALS AND METHODS

Forty-eight mandibular incisors were divided into eight groups (n = 6), according to the taper of root canal preparation (0.06 or 0.04), the needle used for sealer injection (modified or commercial iRoot SP injection needle), and the obturation method (iRoot SP sealer-only or single-cone obturation). After obturation, each specimen was scanned by micro-CT. The volumetric percentage and distribution of all voids were first analyzed and compared among groups, then the open and closed voids were separately analyzed and compared among single-cone obturation groups.

RESULTS

Compared to commercial needle groups, modified needle groups showed much less voids, especially in the apical root canal part (P < 0.05). Besides, the modified needle groups produced much less open voids than commercial needle groups despite the root canal taper (P < 0.05).

CONCLUSIONS

The modified passive deflation sealer injection needle could effectively improve the quality of single-cone obturation through reducing intra-canal voids, especially open voids throughout the root canal, thus might possibly be developed as an effective intra-canal sealer delivering instrument.

Effect of heat application on the physicochemical properties of new endodontic sealers: an in vitro and SEM study

Understanding the properties of endodontic sealers is vital for treatment planning. Calcium silicate-based sealers are important in modern endodontics. This study investigates the effect of heat on the physicochemical properties of new calcium silicate sealers, addressing concerns raised by clinicians seeking to combine their benefits with the gutta-percha obturation technique. Five endodontic sealers (AH Plus Bioceramic®, Total Fill® BC®, One-fil® Bioceramic, K-Biocer, Any-seal®) were evaluated. Each sealer (n = 16/group) was either kept at 37 °C or subjected to heat at 60 or 200 °C for 30 s. ISO 6876-2012 standards were used to measure setting time, flow, film thickness, and dimensional changes over time. SEM and EDS were utilized for surface and chemical analysis. Data analysis employed IBM SPSS Statistics version 26 with a 5% significance level for two-sided tests. The sealers' setting times were shortened by heat, except for Total Fill® BC with extended setting time. All sealers had significantly longer setting times than manufacturer specifications. Film thickness increased with temperature, while flow values decreased. K-Biocer sealer showed the highest flow (16.89 ± 0.57 mm) at 200 °C, while Total Fill® sealer had the lowest (15.32 ± 0.62 mm). Shrinkage was significant at 60 °C and 200 °C, with greater shrinkage at 200 °C. Heat caused surface deformations in all sealers. The 200 °C groups exhibited more voids in AH Plus Bioceramic®, Any-seal®, and One-fil® sealers, and higher void area in Total Fill®, One-fil®, and K-Biocer sealers (p value < 0.001). EDX analysis confirmed heat-induced chemical and elemental changes in all tested sealers. Elevated temperature affects the physicochemical properties and structure of the tested endodontic sealers. The consideration of endodontic sealer compatibility is essential when warm gutta-percha obturation techniques are used.

The outcome of combined use of iRoot BP Plus and iRoot SP for root-end filling in endodontic microsurgery: a randomized controlled trial

OBJECTIVES

Root-end filling is important for the clinical outcome of endodontic microsurgery. Our previous study showed that combined application of iRoot BP Plus Root Repair Material (BP-RRM) and iRoot SP Injectable Root Canal Sealer (SP-RCS) in root-end filling exhibited better apical sealing as compared to the application of BP-RRM alone. The aim of this randomized controlled clinical trial was to evaluate the effect of the combined use of BP-RRM and SP-RCS on the prognosis of teeth with refractory periapical diseases after endodontic microsurgery.

MATERIALS AND METHODS

240 teeth with refractory periapical diseases scheduled for endodontic microsurgery were randomly divided into BP-RRM/SP-RCS group (n = 120) and BP-RRM group (n = 120). The patients were followed up at 3 months, 6 months, and 12 months after endodontic microsurgery. Pre- and post-operative clinical and radiographic examinations were performed to evaluate the treatment outcome. The 1-year success rate of endodontic microsurgery in BP-RRM/SP-RCS and BP-RRM groups was compared by Chi-square test. Factors that might impact the prognosis were further analyzed using Chi-square test or Fisher's exact test.

RESULTS

A total of 221 teeth completed the 12-month follow-up. The 1-year success rates of the BP-RRM/SP-RCS and BP-RRM groups were 94.5% (104/110) and 92.8% (103/111), respectively. The combined use of BP-RRM and SP-RCS achieved a clinical outcome comparable to BP-RRM alone (P = 0.784). Tooth type (P = 0.002), through-and-through/apico-marginal lesion (P = 0.049), periodontal status (P < 0.0001), and Kim's lesion classification (P < 0.0001) were critical factors associated with the 1-year success of endodontic microsurgery.

CONCLUSIONS

The combined use of BP-RRM and SP-RCS is a practicable method for root-end filling in endodontic microsurgery with a satisfactory 1-year clinical outcome.

CLINICAL RELEVANCE

The combined application of BP-RRM and SP-RCS in EMS is an effective root-end filling method with a satisfactory 1-year clinical outcome.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Registry (ChiCTR2100052174).

Evaluation of push-out bond strength, dentinal tubule penetration and adhesive pattern of bio-ceramic and epoxy resin-based root canal sealers

INTRODUCTION

Root canal sealing materials play a crucial role in an endodontic procedure by forming a bond between the dentinal walls and the gutta-percha. The current study aims to analyse the dentinal tubule penetration and adhesive pattern, including the push-out bond strength of six commercially available root canal sealers.

METHODOLOGY

Eighty-four mandibular first premolars were split into seven groups (and n = 12), Group 1: Dia-Root, Group 2: One-Fil, Group 3: BioRoot RCS, Group 4: AH Plus, Group 5: CeraSeal, Group 6: iRoot SP, Group 7: GP without sealer (control). Two groups were made, one for dentinal tubule penetration and the other for push-out bond strength; the total sample size was one hundred sixty-eight. Root canal treatment was performed using a method called the crown down technique, and for obturation, the single cone technique was used. A confocal laser scanning microscope (Leica, Microsystem Heidel GmbH, Version 2.00 build 0585, Germany) was used to evaluate dentinal tubule penetration, and Universal Testing Machine was utilised to measure the push-out bond strength (Shimadzu, Japan) using a plunger size of 0.4 mm and speed of 1mm/min. Finally, the adhesive pattern of the sealers was analysed by HIROX digital microscope (KH-7700). Statistical analysis was carried out by a one-way Anova test, Dunnet's T3 test, and Chi-square test.

RESULTS

Highest dentinal tubule penetration was noticed with One-Fil (p<0.05), followed by iRoot SP, CeraSeal, AH Plus, Dia-Root also, the most negligible value was recorded for BioRoot RCS. Meanwhile, BioRoot RCS (p<0.05) demonstrated the greater value of mean push-out bond strength, followed by One-fil, iRoot SP, CeraSeal, AH Plus and Dia-Root. Regarding adhesive pattern, most of the samples were classified as type 3 and type 4 which implies greater sealing ability and better adherence to the dentinal wall. However, BioRoot RCS revealed the most type 4 (p<0.05), followed by AH Plus, One-Fil, CeraSeal and Dia-Root.

CONCLUSION

The highest dentinal tubule penetration was shown by One-Fil compared to other groups. Meanwhile, BioRoot RCS had greater push-out bond strength and more adhesive pattern than other tested materials.

Evaluation of Cytotoxicity, Cell Attachment, and Elemental Characterization of Three Calcium Silicate-Based Sealers

We investigated three calcium silicate-based sealers with respect to their chemical characterization, cytotoxicity, and attachment to RAW264.7 cells. BioRoot RCS (BR), Bio-C Sealer (BC), and Sealer Plus BC (SPBC) were assessed using Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence spectroscopy (XRF), and energy-dispersive X-ray spectroscopy (EDX) (n = 4) for elemental characterization, and using scanning electron microscopy (SEM) to evaluate cell morphology and adhesion. Cytotoxicity was determined at different dilutions (1:1, 1:2, and 1:5) using the succinate dehydrogenase activity (MTT assay). Statistical analysis was performed for normal distribution using the Shapiro-Wilk test and for homoscedasticity using Levene's test, and one-way ANOVA, Tukey's/Dunnett's post hoc tests for cell viability and XRF (α = 0.05). Calcium silicate hydrate and calcium hydroxide were detected by FTIR in all groups. EDX detected a higher calcium content for BR and SPBC and aluminum only in the premixed sealers. XRF detected the highest calcium release in BR (p < 0.05). The surface morphology showed irregular precipitates for all the sealers. SPBC at a 1:2 dilution resulted in the lowest cell viability compared to BR (p < 0.05) and BC (p < 0.05). The calcium silicate-based sealers produced a statistically significant reduction in cellular viability at a 1:1 dilution compared to the control group (p < 0.0001). All the sealers maintained viability above 70%.

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.

Effect of full pulpotomy using a calcium silicate-based bioactive ceramic in adult permanent teeth with symptoms indicative of irreversible pulpitis: A retrospective study

BACKGROUND

The authors studied the treatment effect of full pulpotomy using a calcium silicate-based bioactive ceramic in adult permanent teeth with symptoms indicative of irreversible pulpitis.

METHODS

Eighty-one adult permanent teeth with symptoms indicative of irreversible pulpitis in 78 patients aged 18 through 72 years were evaluated for inclusion in the study. After caries excavation, the pulp was amputated to the level of the canal orifices. After hemostasis was achieved, calcium silicate-based bioactive ceramic was placed as the capping agent. The cavity was sealed temporarily with a glass ionomer cement and then restored with flowable resin and composite resin after 2 weeks if no positive symptoms were reported or detected. Postoperative evaluation was performed by means of clinical and radiographic examination at 2 weeks and 3, 6, and 12 months.

RESULTS

Overall success rates of the procedure were 96.3% (78 of 81), 93.8% (76 of 81), 92.6% (75 of 81), and 92.6% (75 of 81) at the 2-week, 3-month, 6-month, and 12-month recall visits, respectively. Six of the 81 teeth failed and required root canal therapy. In these 6 teeth, 3 exhibited severe cold stimuli pain and spontaneous pain at the 2-week follow-up, 2 had no response to electric pulp testing with apical percussion pain and periapical rarefaction at the 3-month follow-up, and 1 tooth exhibited periapical rarefaction and labial mucosal fistula at the 6-month follow-up.

CONCLUSIONS

Under the conditions of this study, full pulpotomy using a calcium silicate-based bioactive ceramic was a successful option for the treatment of adult permanent teeth with carious originated symptoms indicative of irreversible pulpitis.

PRACTICAL IMPLICATIONS

Vital pulp therapy is no longer impossible for adult permanent teeth with carious originated symptoms indicative of irreversible pulpitis.

Bioceramics in Endodontics: Updates and Future Perspectives

Bioceramics, with excellent bioactivity and biocompatibility, have been widely used in dentistry, particularly in endodontics. Mineral trioxide aggregate (MTA) is the most widely used bioceramic in endodontics. Recently, many new bioceramics have been developed, showing good potential for the treatment of endodontic diseases. This paper reviews the characteristics of bioceramics and their applications in various clinical endodontic situations, including root-end filling, root canal therapy, vital pulp therapy, apexification/regenerative endodontic treatment, perforation repair, and root defect repair. Relevant literature published from 1993 to 2023 was searched by keywords in PubMed and Web of Science. Current evidence supports the predictable outcome of MTA in the treatment of endodontic diseases. Although novel bioceramics such as Biodentine, EndoSequence, and calcium-enriched mixtures have shown promising clinical outcomes, more well-controlled clinical trials are still needed to provide high-level evidence for their application in endodontics. In addition, to better tackle the clinical challenges in endodontics, efforts are needed to improve the bioactivity of bioceramics, particularly to enhance their antimicrobial activity and mechanical properties and reduce their setting time and solubility.

Comparative Evaluation of Physicomechanical Properties and Antimicrobial Activity of White Portland Micro- and Nanoparticulate Peruvian Cement, Mineral Trioxide Aggregate, and Neomineral Trioxide Aggregate

AIM

To compare the surface microhardness, compressive strength, and antimicrobial activity of white Portland nanoparticle and microparticle Peruvian cement, mineral trioxide aggregate (MTA), and neomineral trioxide aggregate (NeoMTA) at 24 hours and 28 days.

MATERIALS AND METHODS

Twenty specimens were prepared for each group of cement microparticulated powder (PCm), nanoparticulated cement (PCn), MTA, and NeoMTA to be evaluated at two different times, 24 hours and 28 days for the surface microhardness test and compressive strength. For the antimicrobial activity tests, another 20 specimens were prepared for each group of cement where they were subdivided into two subgroups according to the different periods at 24 hours and 48 hours. For the surface microhardness and compressive strength, the specimens, and the cement groups were mixed according to the manufacturer's instructions and transferred to a cylindrical polyethylene mold of 6-mm diameter and 4-mm height. The compressive strength test was conducted using a universal testing machine. Moreover, the agar diffusion technique was to evaluate the antibacterial and antifungal activity of the American Type Culture Collection (ATCC) Enterococcus faecalis and Candida albicans. Finally, the data were statistically analyzed.

RESULTS

The highest microhardness values for the 24-hour subgroup were recorded for NeoMTA cement (16.99 ± 2.02), followed by MTA, PCn, and PCm, respectively. As for the 28-day subgroup, PCn cement (41.64 ± 3.20) presented the highest microhardness, followed by NeoMTA, PCm, and MTA, respectively, with statistically significant differences among them. The compressive strength of both subgroups 24 hours and 28 days exhibited the highest mean for PCn (41.3 ± 4.29, 65.74 ± 3.06), followed by PCm, NeoMTA, and the lowest value for MTA cement. Finally, for the antimicrobial activity, the highest mean for the 24-hours and 48-hours subgroup was recorded for NeoMTA cement (17.6 ± 1.26, 17.8 ± 1.44), followed by PCn, PCm, and the lowest value for MTA, with significant differences between them.

CLINICAL SIGNIFICANCE

It is highly recommended, Portland cement (PC) as a viable substitute since it has very similar components and properties, but at a lower cost.

CONCLUSION

Regardless of the evaluation time, PCn produced higher surface microhardness and compressive strength; however, NeoMTA showed higher antimicrobial activity.

Real-time evaluation of the biocompatibility of calcium silicate-based endodontic cements: An in vitro study

INTRODUCTION

An ideal filling material should hermetically seal the communication pathways between the canal system and surrounding tissues. Therefore, during the last few years, the development of obturation materials and techniques to create optimal conditions for the proper healing of apical tissues has been a focus of interest. The effects of calcium silicate-based cements (CSCs) on periodontal ligament cells have been investigated, and promising results have been obtained. To date, there are no reports in the literature that have evaluated the biocompatibility of CSCs using a real-time live cell system. Therefore, this study aimed to evaluate the real-time biocompatibility of CSCs with human periodontal ligament cells (hPDLCs).

METHODOLOGY

hPDLC were cultured with testing media of endodontic cements for 5 days: TotalFill-BC Sealer, BioRoot RCS, Tubli-Seal, AH Plus, MTA ProRoot, Biodentine, and TotalFill-BC RRM Fast Set Putty. Cell proliferation, viability, and morphology were quantified using real-time live cell microscopy with the IncuCyte S3 system. Data were analyzed using the one-way repeated measures (RM) analysis of variance multiple comparison test (p < .05).

RESULTS

Compared to the control group, cell proliferation in the presence of all cements was significantly affected at 24 h (p < .05). ProRoot MTA and Biodentine lead to an increase in cell proliferation; there were no significant differences with the control group at 120 h. In contrast, Tubli-Seal and TotalFill-BC Sealer inhibited cell growth in real-time and significantly increased cell death compared to all groups. hPDLC co-cultured with sealer and repair cements showed a spindle-shaped morphology except with cements Tubli-Seal and TotalFill-BC Sealer where smaller and rounder cells were obtained.

CONCLUSIONS

The biocompatibility of the endodontic repair cements performed better than the sealer cements, highlighting the cell proliferation of the ProRoot MTA and Biodentine in real-time. However, the calcium silicate-based TotalFill-BC Sealer presented a high percentage of cell death throughout the experiment similar to that obtained.

In vitro evaluation of the sealing ability of combined use of iRoot BP Plus and iRoot SP for root-end filling

OBJECTIVES

The aim of this in vitro study was to evaluate the sealing ability of combined application of iRoot BP Plus Root Repair Material (BP-RRM) and iRoot SP Injectable Root Canal Sealer (SP-RCS) for root-end filling.

MATERIAL AND METHODS

A total of 120 extracted human teeth were used in this study and were randomly divided into four groups. The BP-RRM+SP-RCS group included teeth retro-filled with combined use of BP-RRM and SP-RCS (n=45), and the BP-RRM group included teeth retro-filled by BP-RRM alone (n=45). Teeth without root-end preparation and filling were equally divided into positive control (n=15) and negative control (n=15). The apical sealing ability was evaluated by micro-CT analysis, dye penetrant examination, bacterial leakage test, and glucose leakage test.

RESULTS

Micro-CT analysis showed that the total void fraction of BP-RRM+SP-RCS group was significantly lower than that of BP-RRM group, particularly at the coronal 1/3 segment of the retro-filled roots. Consistently, the maximum linear depth of dye leakage in BP-RRM+SP-RCS group was less than that of BP-RRM group. Bacterial leakage test showed that the microbial leakage in BP-RRM+SP-RCS group was significantly less than that in BP-RRM group. However, no significant difference in glucose leakage between BP-RRM+SP-RCS group and BP-RRM group was observed.

CONCLUSION

Combined use of BP-RRM and SP-RCS for root-end filling promotes apical sealing in vitro.

CLINICAL RELEVANCE

Combined use of BP-RRM and SP-RCS for root-end filling exhibited better apical sealing as compared to BP-RRM alone in vitro, and this may help reducing technical sensitivity and promoting clinical efficiency during endodontic microsurgery.

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.

A Micro-CT Analysis of Initial and Long-Term Pores Volume and Porosity of Bioactive Endodontic Sealers

The evaluation of the porosities within the interface of root canals obturated with endodontics materials is extremely important for the long-term success of endodontic treatments. The aim of this study was to compare initial and long-term volume of pores (total, open, closed) and porosity (total, regional) of three bioactive endodontic sealers: GuttaFlow Bioseal, Total Fill BC Sealer, and BioRoot RCS. Root canals were obturated with three “bioactive” sealers using the single-cone technique. The volume of open and closed pores and porosity were calculated using a micro-computed tomography (MCT) method. The measurements were performed after 7 days (initial) and after 6 months (long-term) of incubation. Statistical significance was considered at p < 0.05. The total volume of pores remained unchanged after the 6-month storage. GuttaFlow Bioseal exhibited significantly higher long-term volume in open pores than Total Fill BC Sealer. The total porosity in all the tested sealers presented no statistically significant change after the 6-month storage, except for BioRoot RCS. The total porosity values of this latter material significantly increased after long-term incubation, especially in the apical region. In conclusion, the use of bioactive sealers with excessive tendency to create porosities both in shorth- and long-term periods of storage may compromise the long-term success of endodontic treatments.

Characterization of fungus ball CT-hyperdensities within maxillary and sphenoid sinuses

OBJECTIVES

CT-scan hyperdensities (HD) are described in more than 60% of all paranasal sinus fungus ball (FB) cases. Two types can be distinguished according to their density: calcium and metal types. We aimed to establish the prevalence and density of the HD observed in sphenoid and maxillary sinus FB and their relation to dental factors.

METHODS

This retrospective study included 64 patients operated in a tertiary referral center for unilateral maxillary or sphenoid FB diagnosed by histology or mycology. Pre-operative CT scans were analyzed by three independent observers (two ENT and one radiologist).

RESULTS

There were 45 maxillary FB and 19 sphenoid FB. 63 FB showed HD. Metal-type HD were observed in 28 maxillary FB but not in sphenoid sinuses. Among maxillary FB, the prevalence of endodontic treatment was significantly more significant on the FB side than on the healthy side (p = 0.02). The prevalence of endodontic treatment on the pathological side was more significant in the metal-type group than in the group without metal-type HD (p = 0.01). Isolated calcium-type HD were evidenced in 17 maxillary FB and 18 sphenoid FB (p = 0.019).

CONCLUSION

This study highlights the existence of two different types of HD in FBs of the paranasal sinuses with an association between metal-type HD and endodontic treatments.

Evaluation of Bond Strength of Four Different Root Canal Sealers

The purposes of the study were to evaluate the influence of the sealer’s chemical composition on the interfacial strength between root canal dentin and root filling material, for two different classes of endodontic sealers, and to assess their failure modes. Methods: Forty extracted single-rooted teeth were randomly divided into four groups using the following endodontic sealers: RealSeal SE and Resilon (RSSE); EndoSequence BC sealer and BC Point (EBCS); Endoseal MTA and gutta-percha (EDS); Bioroot RCS and gutta-percha (BRS). Teeth were embedded in acrylic resin, and the roots were sectioned horizontally into 1 mm slices. For each slice, the perimeter was measured. A push-out test was performed using an Instron universal testing machine. For each sample, bond strength was calculated. Specimens were examined by SEM investigation in order to analyze the dentin−sealer−core interface. Results were assessed using analysis of variance (ANOVA) and Tukey and Bonferroni test. Results: Statistical analysis revealed that EDS and gutta-percha had significantly higher resistance to dislodgement compared to the other three groups (p < 0.05). EBCS and BC Point showed significantly greater push-out bond strength values compared to RSSE and Resilon (p < 0.05). Conclusions: Bioceramic endodontic sealers showed a higher bond strength to root dentin than methacrylate resin-based endodontic sealer.

Physicochemical properties and osteoclastogenesis for three premixed calcium silicate-based sealers post set

Solubility, pH, ion release, cytotoxicity, and osteoclastogenesis inhibition in bone marrow-derived monocyte macrophages (BMMs) were evaluated in EndoSequence BC Sealer (END), Bio-C Sealer (BC), and Sealer Plus BC (SPBC). pH was determined after immersion of the sealers in deionized water (DW) and Minimum Essential Medium Alpha (α-MEM). Solubility was obtained by mass loss. Ion release was measured by using X-ray fluorescence spectroscopy (XRF). Cytotoxicity was evaluated by MTT assay. Inhibition of osteoclastogenesis was evaluated by tartrate-resistant acid phosphatase (TRAP). Data were analyzed using the t-test, ANOVA and Tukey/Dunnett's post-hoc tests (α = 0.05). END had the highest pH in DW (p < 0.05), and BC, in α-MEM (p < 0.05). Solubility in DW was the lowest for SPBC (p < 0.005). The highest calcium release was observed for BC in DW at 12 h (p < 0.05), and in α-MEM at 12 and 24 h (p < 0.05). The lowest toxicity was detected for END (p < 0.05). BC had the highest inhibitory effect on osteoclasts (p < 0.05). Overall, the highest solubility and pH values were found in DW. However, the calcium silicate-based sealer showed higher solubility than the ISO standards. Calcium release was the highest for BC. END showed the highest cell viability, and BC, the highest osteoclast inhibition.

Physicochemical properties of a novel bioceramic silicone-based root canal sealer

Background/purpose

With introduction into endodontics, bioceramic-based sealers have gained considerable popularity for excellent properties. The aim of this study was to investigate the physicochemical properties of a novel bioceramic silicone-based sealer, GuttaFlow Bioseal, and measure heat flow of setting reactions.

Materials and methods

Film thickness, flow, working and setting time of Bioseal were compared with other 4 kinds of sealers: iRoot SP, AH Plus, RoekoSeal and GuttaFlow2. Differential scanning calorimetry test was performed to measure heat flow.

Results

Bioseal demonstrated the highest film thickness of 44 μm, double to triple that of the other 4 sealers (P < 0.05). The highest flow was detected in iRoot SP and RoekoSeal, with values of 27.35 and 27.20 mm, while GuttaFlow2 and Bioseal had the lowest of 22.31 and 21.43 mm (P < 0.05). For each sealer, working time at 37 °C was shorter than that at 23 °C (P < 0.05). At 37 °C, Bioseal had the shortest working and setting time of 4.5 and 16.3 min, while iRoot SP showed the longest of 105.0 and 571.7 min (P < 0.05). Differential scanning calorimetry test revealed that setting process of all the tested sealers was exothermic. Bioseal reached an exothermic peak at 14 min, with almost 1.5 times peak intensity of GuttaFlow2 and RoekoSeal. Whereas iRoot SP and AH Plus reached an exothermic peak 5 h after mixing, with intensity 1/2 to 2/3 that of Bioseal.

Conclusion

The novel bioceramic silicone-based sealer Bioseal showed intense and fast exothermic reactions with characteristic physicochemical properties.

A critical analysis of research methods and experimental models to study root canal fillings

Canal filling materials and techniques have been one of the most studied topics in Endodontics. A simple search using the mesh term "root canal filling" in PubMed revealed more than 11,000 articles, an impressive number that is much higher than "root canal disinfection" (5,544 articles) or even the popular "root canal preparation" (8,527 articles). The overriding importance attributed to root filling procedures is not merely intuitive. It derived from the appealing relevance given by the appearance of the white lines in common radiographs grounded on retrospective clinical data that had identified the quality of a root filling as one of the major causes of treatment failure (lack of healing). Since the publication of the Washington study, impressive efforts have been made for the release of new materials and techniques, as well as, for the development of a plethora of laboratory methods to assess the quality of root filling procedures. This narrative review aims to address and discuss the most relevant laboratory methods to assess the root canal filling. Since filling quality improvements have not translated into higher success rates, as reported in longitudinal clinical studies, more than to deliver a simple methodology-based review, this paper aims to present an in-depth critical view on the assessment of laboratory methods used to study the filling materials and techniques. Recent data indicate that the long-term dimensional stability/degradation over time of endodontic sealers plays a central role in the treatment outcome. In this context, laboratory methods should be developed focusing on predicting, at least to some degree, the long-term clinical behaviour of root canal fillings, rather than simply ranking different materials or techniques.

Bone repair in defects filled with AH Plus sealer and different concentrations of MTA: a study in rat tibiae

Objectives

This study aimed to evaluate the effects on bone repair of different concentrations of mineral trioxide aggregate (MTA) added to AH Plus.

Materials and Methods

Bone tissue reactions were evaluated in 30 rats (Rattus norvegicus) after 7 and 30 days. In the AH + MTA10, AH + MTA20, and AH + MTA30 groups, defects in the tibiae were filled with AH Plus with MTA in proportions of 10%, 20% and 30%, respectively; in the MTA-FILL group, MTA Fillapex was used; and in the control group, no sealer was used. The samples were histologically analyzed to assess bone union and maturation. The Kruskal-Wallis and Mann-Whitney tests were performed for multiple pairwise comparisons (p ≤ 0.05).

Results

At the 7-day time point, AH + MTA10 was superior to MTA-FILL with respect to bone union, and AH + MTA20 was superior to MTA-FILL with respect to bone maturity (p < 0.05). At the 30-day time point, both the AH + MTA10 and AH + MTA20 experimental sealers were superior not only to MTA-FILL, but also to AH + MTA30 with respect to both parameters (p < 0.05). The results of the AH + MTA10 and AH + MTA20 groups were superior to those of the control group for both parameters and experimental time points (p < 0.05).

Conclusions

The results suggest the potential benefit of using a combination of these materials in situations requiring bone repair.

Physicochemical Properties of Two Generations of MTA-Based Root Canal Sealers

This study evaluated the physicochemical properties and the effect of solubility on the surface morphology and composition of the root canal sealers MTA-Bioseal, MTA-Fillapex, and Adseal. Discs (n = 10) of freshly mixed sealer were prepared and then analyzed by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX). The discs were immersed for 1, 7, 14, and 28 days in deionized water. The solubility %; pH change of the solution; and released calcium, phosphate, and silicon were measured for each period. The flowability and film thickness were also evaluated. Changes in the surface morphology and composition after 28 days of immersion were evaluated by SEM/EDX. The data were statistically analyzed by one-way ANOVA at p < 0.05. The FTIR and EDX results revealed similar compositions of MTA-Bioseal and MTA-Fillapex, but with different concentrations. The two MTA-based sealers had higher solution alkalinity (pH > 10) than Adseal (pH ≈ 8.5). MTA-Fillapex exhibited the highest solubility % and the largest calcium and silicon ion release. MTA-Bioseal had the highest phosphate ion release. After 28 days, the sealer surfaces showed large micropores, with larger pores in MTA-Fillapex. Adseal had an intermediate flowability but exhibited the greatest film thickness. Finally, the highest solubility and largest amount of silicon release was exhibited by MTA-Fillapex, which might predispose it to the development of large micropores, compromising the apical seal of obturation.

Effects of dentine surface cleaning on bonding of a self-etch adhesive to root canal sealer-contaminated dentine

OBJECTIVES

To compare the effectiveness of different sealer cleaning methods on bonding of a self-etch adhesive to root canal sealer-contaminated dentine.

METHODS

Forty-nine extracted molars were divided into seven groups. Dentine surfaces were exposed and cotaminated with a thin layer of epoxy resin-based sealer (AH Plus (AHP)) or zinc oxide eugenol-based sealer (Pulp Canal Sealer (PCS)). Three cleaning protocols were examined: dry cotton pellet, 70% ethanol-saturated cotton pellet or a surfactant-based cleaner (Katana^TM Cleaner (KC), Kuraray Noritake Dental Inc.). Uncontaminated dentine served as control. The dentine surfaces were bonded with a two-step self-etch adhesive and restored with resin composite. Bond strength testing was performed using a microtensile approach. Two teeth from each group were used for scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The pulpal floor of the teeth was covered with sealer and cleaned. The percentage of zinc/zirconium on the dentine surface was detected to indicate the amount of remnant sealer.

RESULTS

Tensile bond strength for uncontaminated dentine control was 46.4±7.3 MPa; bond strength decreased significantly for the dry cotton group (29.6±4.2 MPa for AHP, 24.7±4.7 MPa for PCS, p<0.05). Both ethanol and KC restored bonding performance after cleaning, with no significant difference from the control. Significantly lower MTBS was observed for the ZOE/ethanol subgroup (38.9±5.1 MPa). Cleaner surfaces and less zinc/zirconium elements were identified by SEM/EDX after cleaning with ethanol or KC.

CONCLUSIONS

Katana^TM Cleaner decontaminates root canal sealer-smeared dentine surfaces effectively and restores the bonding performance of a self-etch adhesive to dentine.

CLINICAL SIGNIFICANCE

The surfactant-based Katana^TM Cleaner, originally designed for cleaning zirconia surfaces prior to adhesive bonding, may be used as for cleaning dentine that has been contaminated with unset root canal sealers after root canal treatment to restore the bonding strength of a self-etch adhesive to sealer-contaminated dentine.

Calcium Silicate-Based Root Canal Sealers: A Narrative Review and Clinical Perspectives

Over the last two decades, calcium silicate-based materials have grown in popularity. As root canal sealers, these formulations have been extensively investigated and compared with conventional sealers, such as zinc oxide-eugenol and epoxy resin-based sealers, in in vitro studies that showed their promising properties, especially their biocompatibility, antimicrobial properties, and certain bioactivity. However, the consequence of their higher solubility is a matter of debate and still needs to be clarified, because it may affect their long-term sealing ability. Unlike conventional sealers, those sealers are hydraulic, and their setting is conditioned by the presence of humidity. Current evidence reveals that the properties of calcium silicate-based sealers vary depending on their formulation. To date, only a few short-term investigations addressed the clinical outcome of calcium silicate-based root canal sealers. Their use has been showed to be mainly based on practitioners' clinical habits rather than manufacturers' recommendations or available evidence. However, their particular behavior implies modifications of the clinical protocol used for conventional sealers. This narrative review aimed to discuss the properties of calcium silicate-based sealers and their clinical implications, and to propose rational indications for these sealers based on the current knowledge.

Porosity Distribution in Single Cone Root Canal Fillings Performed by Operators with Different Clinical Experience: A microCT Assessment

The objective of this study was to assess the porosity distribution of BioRoot RCS/single gutta-percha point root-canal fillings performed by a general dental practitioner and endodontist. Fourteen plastic models of maxillary premolars with two roots were selected and shaped with HyFlex EDM instruments to a size 40/0.04 taper and randomly divided into two experimental groups. A total of 14 canals in each group were obturated by two different operators with one HyFlex EDM size 40 gutta-percha point and BioRoot RCS sealer. The specimens were scanned with a high-resolution micro-computed tomography scanner, and the porosity of the fillings at the coronal, middle, and apical thirds of the root canals was qualified and quantified. The differences between groups and root-canal thirds were compared using Mann–Whitney, Friedman, and Wilcoxon tests with the significance level set at p < 0.05. The highest number of pores was observed in the apical third of root-canal fillings in both groups; however, the porosity distribution between the two groups was not significantly different in the apical and middle thirds (p > 0.05). Statistically significant differences were determined only in the coronal third (p < 0.05). The predominance of open pores was detected in all root-canal thirds and groups, with no significant differences in the number of open pores between the coronal and middle thirds (p > 0.05).

Physicochemical properties and cytocompatibility of newly developed calcium silicate-based sealers

The purpose of this study was to compare the physical properties and cytocompatibility of contemporary calcium silicate-based sealers. Four calcium silicate-based sealers (BrightEndo MTA sealer, CeraSeal, EndoSeal TCS and One-Fil) were compared to an epoxy resin-based sealer (AH Plus). Flow, setting time, radiopacity and dimensional change were evaluated according to ISO 6876 standards. Cytotoxicity on human periodontal ligament fibroblast (hPDLF) cells was compared for biological properties using MTT assay. The surface of the sealer was analysed using scanning electron microscopy to evaluate cell attachment. Flow and radiopacity of all sealers met ISO standards, while setting time and dimensional stability did not meet the ISO standards. Calcium silicate-based sealers showed favourable cytocompatibility, and hPDLF cells were well attached to the calcium silicate-based sealers. Calcium silicate-based sealers have clinically acceptable flow and radiopacity, and cytocompatibility. However, these sealers had longer setting time and higher dimensional change than those required by ISO 6876.

Impact of Warm Vertical Compaction on the Sealing Ability of Calcium Silicate-Based Sealers: A Confocal Microscopic Evaluation

The aim of this in vitro study was to evaluate the dentinal tubule penetration of two calcium silicate-based sealers used in warm vertical compaction (WVC) obturation technique in comparison with the single cone (SC) technique by confocal laser scanning microscopy (CLSM). The null hypothesis was that both obturation techniques produced similar sealer penetration depths at 1 and 5 mm from the apex. Forty-four mandibular single-rooted premolars were randomly divided into four equally experimental groups (n = 10) and two control groups (n = 2) according to the type of sealer (Bio-C Angelus, Londrína, PR, Brazil or HiFlow Brasseler, Savannah, GA, USA) with either SC or WVC. The sealers were mixed with a fluorescent dye Rhodamine B (0.1%) to enable the assessment under the CLSM. All the specimens were sectioned horizontally at 1 and 5 mm from the apex. The maximum penetration depth was calculated using the ImageJ Software (ImageJ, NIH). Data were analyzed by Mann-Whitney U and Kruskal-Wallis tests (p < 0.05). A significant difference was shown between the four groups at 1 mm (p = 0.0116), whereas similar results were observed at 5 mm (p = 0.20). WVC allowed better diffusion for both sealers at 1 mm (p = 0.01) and 5 mm (p = 0.034). The maximum penetration of the Bio-C and HiFlow sealers was more important at 5 mm with the two obturation techniques. Within the limitations of this study, WVC enhanced the penetration of calcium silicate-based sealers into the dentinal tubules in comparison with the SC technique at both levels.

Antifungal Effectiveness between Tricalcium Silicate-White Portland Cements Added Bi2O3 and Mineral Trioxide Aggregate Against Candida albicans

Background

Candida albicans is the most dominant fungus found in root canal reinfection cases. This microorganism can withstand extreme pH, low oxygen levels, lack of nutrients, and penetrate the dentinal tubules so that it can resist the intracanal medicament. Root canal cement helps prevent microorganisms and causing root canal reinfection. MTA is one of the root canals cement which is widely used and has an excellent antifungal activity, but it is less beneficial economically. Tricalcium silicate-white Portland cement (WPC) has a similar main composition as MTA, except there is no Bi2O3 content that functions as a radiopacifier.

Objectives:

To fabricate a mixture of tricalcium silicate-WPC with Bi2O3 through a simple solution method and investigate antifungal activity's effectiveness between tricalcium silicate-WPC added Bi2O3 and MTA to C. albicans.

Materials and Methods:

The 80 g of tricalcium silicate-WPC was mixed with 20 g of Bi2O3 through the simple solution method using 99.9% isopropanol as a solution. This sample solution is stirred until homogeneous, then centrifuged. The precipitate was dried until a dry powder was obtained. The powder was analyzed using X-Ray fluorescence spectrometry to identify its chemical composition and concentration. A total of 30 samples were divided into two experimental groups of tricalcium silicate-WPC added Bi2O3 and ProRoot MTA. The vials, which contain cement and C. albicans, respectively, were incubated at 37°C for 24 hours and diluted to obtain a suspension 104, 106 (0.5 in McFarland’s nephelometer) and then inoculated with sterile cotton swabs onto Saboroud Dextrose Agar Plates. The plates were incubated at 37°C for 24 hours. The measurement of colony number of C. albicans was counted by colony counter (CFU/ml).

Results:

The Bi2O3 was revealed in tricalcium silicate-WPC based on XRF characterization, and the antifungal test showed that both materials were effective against C. albicans. There was no statistically significant difference in the number of C. albicans colonies between tricalcium-WPC added Bi2O3 and MTA (p>0.05).

Conclusion:

The mixture of Bi2O3 in tricalcium silicate-WPC was successfully fabricated through a simple solution method, and both samples were effective against the C. albicans.

Real-time nanoleakage and the flow characteristics of calcium silicate root canal filling materials

This study aimed to investigate the real-time nanoleakage and flow characteristics of calcium silicate-based (Ca-Si) root canal filling materials. Extracted human teeth (n = 30) were decoronated and standardized in their inner and outer dimensions. After root canal enlargement, the roots were filled with gutta-percha (GP) and AH26 sealer, GP and EndoSeal MTA sealer, or Biodentine. The roots were connected to a Nanoflow device (IB Systems) under hydrostatic pressure (40 cm∙H₂O) and fluid flow was traced through the filled roots. Data were detected at the nanoscale twice per second and automatically recorded in units of nL/s. Leakage was quantified as the mean slope until the curve plateaued over time, and all static flow intervals lasting longer than 1 s were analyzed to identify any increase in flow and duration. Data were statistically analyzed using the Kruskal-Wallis test. The calculated leakage values were 0.0670 ± 0.0516 nL/s for GP/AH26, 0.1397 ± 0.1579 nL/s for GP/EndoSeal MTA, and 0.0358 ± 0.0538 nL/s for Biodentine, with no statistically significant differences among the root filling materials (P > 0.05). An analysis of real-time flow data for 1000 s to identify spot trends and the overall tendency of flow until a plateau was reached revealed a stepwise increase in the roots filled with Ca-Si material, whereas the GP/AH26-filled roots showed a linear increase. Real-time measurements under hydrostatic pressure with the Nanoflow device enabled precise fluid flow tracing through the root canal filling material. In terms of nanoleakage, the tested root canal filling materials showed no significant differences, while the real-time flow patterns of roots filled with Ca-Si material showed different characteristics from those of GP/AH26-filled roots.

Calcium silicate-based root canal sealers: a literature review

Epoxy resin-based sealers are currently widely used, and several studies have considered AH Plus to be the gold-standard sealer. However, it still has limitations, including possible mutagenicity, cytotoxicity, inflammatory response, and hydrophobicity. Drawing upon the advantages of mineral trioxide aggregate, calcium silicate-based sealers were introduced with high levels of biocompatibility and hydrophilicity. Because of the hydrophilic environment in root canals, water resorption and solubility of root canal sealers are important factors contributing to their stability. Sealers displaying lower microleakage and stronger push-out bond strength are also needed to endure the dynamic tooth environment. Although the physical properties of calcium silicate-based sealers meet International Organization for Standardization recommendations, and they have consistently reported to be biocompatible, they have not overcome conventional resin-based sealers in actual practice. Therefore, further studies aiming to improve the physical properties of calcium silicate-based sealers are needed.

Calcium Silicate-Based Cements as Root Canal Medicament

Purpose

This study aims to retard the setting reaction of CSC by mixing it with 2% chlorhexidine gel (CHX) which will be used as an intracanal medicament, and to evaluate the removal of the experimental medicaments from the root canal.

Materials and Methods

White Portland cement, white ProRoot MTA and Biodentine were mixed with 2% CHX. The setting time, flowability and film thickness of the CSC/CHX mixture (experimental medicaments) were assessed and measured following the standards of ISO specification. Calcium ion release was measured using ICP-OES, while pH was tested using a pH meter. Moreover, twenty single-rooted teeth were filled with the experimental medicaments for seven days, then the medicaments were removed and the samples analyzed using SEM. Calcium hydroxide paste was used as a control.

Results

The setting time of the experimental medicaments was inhibited until 84 days. The calcium ion release of the experimental medicaments was significantly higher compared to the control over the period of 14 days (P<0.001). The mean pH value was above 11.45 for all tested materials over a period of 14 days, with no significant difference between them (P<0.05). There was no significant difference in film thickness of the experimental medicaments compared to the control (P> 0.05). However, the flowability of the experimental medicaments was significantly higher than the control (P<0.05). SEM showed no significant differences in the removal of the intracanal medicaments between all the tested groups.

Conclusion

The addition of 2% CHX to CSCs retarded or inhibited its setting reaction over a period of 84 days. The calcium ion release and flowability of these experimental medicaments was found to be better than calcium hydroxide. Removal of the intracanal medicaments from the root canal was successfully achieved in all groups. Therefore, these experimental medicaments have the potential to be used as an enhanced root canal medicament.

Experimental Resin-Based Monoblock Endodontic Obturation System

Objective. The aim of the present study was to characterize a novel resin-based monoblock endodontic obturation system consisting of a polymeric cone and a resin-based endodontic sealer. Methods. The preliminary tests performed for the experimental cone were as follows: cohesive strength, dimensional stability, standardization of the diameter and taper, calcium ion release, and radiopacity, for the characterization of the experimental sealer, film thickness and flow tests were performed. Tests were performed according to the American National Standards Institute/American Dental Association (ANSI/ADA) Standards Nos. 57 and 78. The experimental cone was compared to gutta-percha, whereas the experimental sealer was compared to AH Plus. Data were analyzed by Student’s t-test (α = 0.05). Results. The experimental cone had superior values for cohesive strength and dimensional stability compared to gutta-percha. Regarding calcium ion release, the experimental system continued to release calcium ions after 30 days. Film thickness was similar for both endodontic sealers; conversely, the experimental resin-based sealer achieved higher values for flow compared to AH Plus. Conclusion. The experimental resin-based monoblock obturation system fully met the requirements of the ANSI/ADA Standard No. 78 and the ANSI/ADA Standard No. 57, except for radiopacity. Considering this, further studies are still needed to evaluate other radiopacifiers and the effect of their incorporation on the physicochemical properties of this novel resin-based monoblock endodontic obturation system.

Antimicrobial efficacy of commercially available endodontic bioceramic root canal sealers: A systematic review

Background

Recently, a new generation of bioceramic root canal sealers has been introduced onto the market. Many in vitro studies have investigated the antimicrobial properties of these sealers, but their comparative efficacy in antimicrobial activity is still unknown.

Methodology

Three electronic databases were searched: MEDLINE and Embase via the OvidSP platform, and Web of Science, up to June 25, 2019. Studies were included irrespective of study design, type of publication and language. Reporting quality was assessed by two authors independently. Meta-analysis was not performed due to studies being highly heterogeneous.

Results

We included 37 studies that analysed the antimicrobial effects of bioceramic sealers. Most of them used a planktonic cell model, with the exception of nine studies which used biofilms. It was not possible to make direct comparison of results from studies and to give a clear conclusion about the comparative antimicrobial activity of these materials because the studies used heterogeneous sources and ages of microorganisms, setting and contact times of sealers, and antimicrobial tests. Furthermore, some materials showed completely different results when tested with different methods.

Conclusions

In conclusion, multiple in vitro studies have shown that bioceramic sealers may have various degrees of antimicrobial activity. However, it is still impossible to make conclusions about their comparative efficacy and to recommend the use of one over another in clinical practice because the studies available were conducted in different ways, which makes meta-analysis futile. A uniform methodological approach, consistent definitions and studies on humans are urgently needed in this field of research so that recommendations for practice can be made.

An international survey on the use of calcium silicate-based sealers in non-surgical endodontic treatment

OBJECTIVES

To gain insight on the current clinical usage of bioceramic root canal sealers (BRCS) by general dental practitioners (GDPs) and endodontic practitioners (EPs) and to determine if BRCS clinical application is in accordance with the best available evidence.

MATERIAL AND METHODS

An online questionnaire of 18 questions addressing BRCS was proposed to 2335 dentists via a web-based educational forum. Participants were asked about socio-demographic data, clinical practice with BRCS, and their motivation for using BRCS. Statistical analysis (chi-squared test or Fisher's exact test) was applied, as appropriate, to assess the association between the variable categories (p value < 0.05).

RESULTS

The response rate was 28.91%. Among respondents, 94.8% knew BRCS (EPs more than GDPs, p < 0.05) and 51.70% were using BRCS. The primary reason for using BRCS was their belief of its improved properties (87.7%). Among BRCS users, single-cone technique (SCT) was the most employed obturation method (63.3%) which was more applied by GDPs (p < 0.05); EPs utilized more of the thermoplasticized obturation techniques (p < 0.05). A proportion of 38.4% of BRCS users indicated the usage of SCT with BRCS regardless of the root canal anatomy (GDPs more than EPs p < 0.05) and 55.6% considered that BRCS may influence their ability to re-establish apical patency during retreatment (GDPs more than EPs p < 0.05).

CONCLUSIONS

This study highlights wide variation in the clinical use of BRCS which is not in accordance with the current literature.

CLINICAL RELEVANCE

This inconsistency among EPs and GDPs on BRCS clinical application requires further clarifications to better standardize their use and improve their future evaluation.

The Penetration Ability of Calcium Silicate Root Canal Sealers into Dentinal Tubules Compared to Conventional Resin-Based Sealer: A Confocal Laser Scanning Microscopy Study

The purpose of this study was to compare the penetration ability of calcium silicate root canal sealers and conventional resin-based sealer using confocal laser scanning microscopy (CLSM). A total of 60 recently extracted single-rooted human premolars were used in this study. The root canals were prepared to a size 40/0.06 taper with ProFile rotary instruments and irrigated with NaOCl and EDTA. After drying all canals, the specimens were randomly divided into three experimental groups (n = 20): Group 1, gutta-percha (GP)/AH Plus with continuous wave compaction; group 2, GP/BioRoot RCS with a single-cone technique; and group 3, GP/Endoseal MTA with a single-cone technique. All experimental samples were sectioned perpendicular to their long axis using a low-speed diamond wheel at the apical, middle, and coronal third levels. The penetration abilities of all samples were evaluated using CLSM. A Kruskal⁻Wallis analysis and a series of Mann⁻Whitney U post hoc tests were performed. A higher intensity level was found in the coronal area and a lower intensity level in the apical area in all the experimental groups. The AH Plus group showed higher sum fluorescence intensity in the apical and coronal thirds compared with the BioRoot RCS and Endoseal MTA groups, whereas the BioRoot RCS group showed a higher intensity level in the middle third, similar to the AH Plus group. The maximum sealer penetration depth was low in the apical area and high in the coronal area in the AH Plus and Endoseal MTA groups. In the BioRoot RCS group, maximum sealer penetration was observed in the middle third. In conclusion, there were significant differences in sealer penetration pattern and distance according to the root level and sealer type.

Antimicrobial Efficacy of Different Endodontic Sealers against Enterococcus faecalis: An In vitro Study

Objective

The aim of this in vitro study is to compare the antimicrobial efficacy of four different endodontic sealers against Enterococcus faecalis.

Material and Method:

Four different endodontic sealers, namely, resin based (AH Plus), zinc oxide-eugenol based (Tubliseal), calcium hydroxide based (Sealapex), and mineral trioxide aggregate (MTA Fillapex) based were tested for their antimicrobial efficacy against E. faecalis using agar diffusion method. Four wells were made by the removal of agar at equidistant points and filled with freshly mixed respective root canal sealers and were inoculated with E. faecalis. All the three plates were incubated for a period of 72 h at 37°C under aerobic conditions. The diameter of inhibition zones was measured at 24, 48, and 72 h time intervals. Data obtained were statistically analyzed using one-way analysis of variance and unpaired t-test.

Results:

All the tested sealers showed some bacterial growth inhibition of E. faecalis. Their efficacy in descending order of antibacterial activity was as follows: Sealapex > AH Plus > Tubliseal > MTA Fillapex. The efficacy of the root canal sealers decreased marginally with increase in their duration of action.

Conclusion:

Antimicrobial efficacy of calcium hydroxide-based sealer was highest followed by resin-based sealer and was the least with MTA based sealer.

Novel Calcium Zirconate Silicate Cement Biomineralize and Seal Root Canals

This study evaluated the sealing ability of gutta-percha (GP) with a calcium silicate-based sealer and a novel calcium zirconate containing calcium silicate cement (ZC). The root canals of the extracted premolars were prepared, which were then randomly allocated to three experimental groups (12 root canals per group) for obturation by continuous wave of condensation with the GP and AH 26 sealer (CW); obturation using a single GP with a calcium silicate-based EndoSequence BC sealer (SC); or obturation with ZC. The roots were inserted into sterile Eppendorf tubes, which were inoculated coronally with Porphyromonas gingivalis. The amount of endotoxin leakage into the apical reservoirs were measured using the Limulus Amebocyte Lysate (LAL) assay over 21 days, with comparisons made using one-way ANOVA and Scheffe’s tests (α = 0.05). After 21 days, 75% of the canals that had been obturated by SC, 50% of those obturated by CW and 42% of those obturated by ZC showed endotoxin leakage. The amount of leakage was higher in the SC canals than in the CW (p = 0.031) or ZC (p = 0.03) canals, although there was no significant difference in the amount of leakage for CW and ZC (p > 0.05). X-ray diffraction revealed the presence of tricalcium silicate (Ca₃SiO₅) and calcium zirconate (CaZrO₃) in the synthesized ZC. Scanning electron microscopy revealed mineralized precipitates on the dentin of canals obturated by ZC. The novel calcium zirconate silicate cement appears to promote biomineralization and seal root canals at least as effectively as the conventional sealer.