Release of formaldehyde by 4 endodontic sealers

Cytocompatibility and cell migration evaluation of calcium silicate-based root canal sealer compared to epoxide-amine resin sealer in stem cells from human apical papilla: An in-vitro study

The purpose of this study was to assess the effect of a calcium silicate-based sealers (CeraSeal) and an epoxy resin-based sealer (AH Plus) on cytotoxicity and cell migration of stem cell from the human apical papilla (hSCAPs) by using the Alamar Blue, Annexin V-FICT and wound healing assays. In Alamar Blue assay, hSCAPs exposed to undiluted CeraSeal extract had significantly higher cell viability compared with that observed when cells were treated with AH Plus in all experimental period (p < 0.001). The flow cytometry analysis confirmed the comparison on viable cells and indicated that AH Plus increased apoptosis compared to CeraSeal and the control groups (p < 0.001). Additionally, AH Plus exhibited significantly lower level of cell migration than CeraSeal and the control for up to 48 h observation (p < 0.01). In summary, calcium silicate-based sealer (CeraSeal) is less cytotoxic and more biocompatible than epoxy resin-based sealer (AH Plus).

Evaluation of Antibacterial Effect of New Sealer "Neoseal" and Two Commercially Used Endodontic Sealers against Enterococcus faecalis: An In Vitro Study

AIM

To evaluate the antibacterial activity of three endodontic sealing materials, Neoseal, CeraSeal, and AH Plus against Enterococcus faecalis bacteria in vitro.

MATERIALS AND METHODS

The antibacterial activity of three endodontic sealing materials including two bioceramic sealers; NeoSEALER Flo (group I), CeraSeal (group II), and one epoxy resin sealer; AH Plus (group III) was investigated against E. faecalis bacteria American Type Cell Culture Collection (ATCC) 29212 (ATCC, Rockville, Maryland, USA). Using modified direct contact test (MDCT). The endodontic sealers were tested in contact with bacterial suspension when unset (20 minutes after mixing) and after setting, assessing the antibacterial activity of aged sealers after 1, 3, 7, and 14 days. Analyzing the collected data has been done with version 25.0 of the statistical package for the social sciences (SPSS) IBM software (SPSS, Chicago, Illinois, USA). Descriptive analyses were calculated using standard deviation (SD) and mean. Shapiro-Wilk test was done to detect the normality of the result values. Kruskal-Wallis test was then performed to test the level of significance between groups.

RESULTS

After 20 minutes - Group I showed higher bacterial count mean values (5,500 ± 500) and 0 values for groups II and III groups. After 1 day, the highest bacterial count mean values were in group III (54,333.3 ± 4,041.5) and 0 values for groups I and II. After 3 days - group III again recorded the highest bacterial count mean values (45,000 ± 5,000) and 0 values for I and II groups. After 7 days - Group III still recorded the highest bacterial count mean values (53,333.3 ± 1,527.5) and 0 values for groups I and II. After 14 days - Group III recorded the highest bacterial count mean values (56,000 ± 1,000) followed by group II (6,333.3 ± 577.4), and the least was group I (2,000 ± 500). Kruskal-Wallis test showed significant values between groups in all tested durations, p > 0.05.

CONCLUSION

The sealing material AH Plus showed a strong bactericidal effect at the beginning but lost its ability after 24 hours. CeraSeal showed strong bactericidal activity from the beginning till the end of the first week but showed bacterial count at 14 days. Neoseal took 24 hours to show bactericidal effect and similar to CeraSeal showed bacterial count at 14 days; CeraSeal recorded the best results within the study.

CLINICAL SIGNIFICANCE

Silicate-based (bioceramic) endodontic sealers can be the best available endodontic sealing material that is clinically beneficial in removing residual microbes which had survived irrigation protocols and chemomechanical preparation. How to cite this article: Basta DG, Reslan MR, Rayyan M, et al. Evaluation of Antibacterial Effect of New Sealer "Neoseal" and Two Commercially Used Endodontic Sealers against Enterococcus faecalis: An In Vitro Study. J Contemp Dent Pract 2023;24(11):871-876.

Evaluation of interfacial adaptation and penetration of bioceramic-based sealers in oval root canals: A confocal laser scanning microscope study

To assess the interfacial adaptation and penetration depth of three different bioceramic-based sealers (CeraSeal, EndoSeal MTA, Nishika Canal Sealer BG) compared to an epoxy resin-based sealer (AH Plus) in oval root canals. Fourty extracted single-rooted mandibular premolar with oval canal were prepared and randomly allocated according to the obturation into; CeraSeal, EndoSeal MTA, Nishika Canal Sealer BG and AH Plus. The roots were sectioned at 3, 6 and 9 mm from the apex. The sealer adaptation and the penetration depth were evaluated under confocal laser scanning microscope. One-way ANOVA and Repeated measure ANOVA were used to statistically analyze the data. Nishika Canal Sealer BG showed significantly higher sealer adaptation than EndoSeal MTA (P < .001) at apical and middle thirds. Meanwhile, AH Plus showed significantly higher sealer adaptation than EndoSeal MTA (P = 0.011) at middle third. For sealer penetration, Nishika Canal Sealer BG showed the longest sealer penetration that was significant compared to AH Plus (P < .001) and EndoSeal MTA (P < .001) whereas CeraSeal was significantly higher than EndoSeal MTA (P = 0.029) at coronal third. For AH Plus, there was a significant less sealer penetration at coronal third compared to apical and middle thirds (P < .05). Whereas for EndoSeal MTA, the coronal third has significant less penetration compared to the middle third (P = 0.032). Endoseal has the lowest adaptation and penetration depth. Nishika Canal Sealer BG has better adaptation and penetration depth using single cone obturation technique in oval canal. RESEARCH HIGHLIGHTS: All the tested root canal sealers have some percentage of gaps and vary in their penetration capability into dentinal tubules. Nishika Canal Sealer BG has significantly better sealer adaptation to root dentinal walls than that of EndoSeal MTA at the apical and middle third but not significantly different from other type of sealers used. Nishika Canal Sealer BG has significantly better penetration depth than AH Plus and EndoSeal MTA at the coronal third of radicular dentin.

In Vitro Cytotoxicity and Mineralization Potential of an Endodontic Bioceramic Material

OBJECTIVE

 The interest in bioceramic materials has been steadily growing for different applications in endodontics. With the continued introduction of new bioceramic-based materials into the market, it is of great importance to assess the biocompatibility before providing recommendations on their clinical use. This study evaluated the in vitro cytotoxicity and mineralization potential of two consistencies of unset premixed bioceramic material (TotalFill BC RRM putty and TotalFill BC sealer) compared with an epoxy resin-based sealer (AH Plus) on osteoblast cells.

MATERIALS AND METHODS

 Overall, 100% extracts were obtained by weighing 0.1 g of each material in 1 mL of cell culture media. Primary human osteoblast (HOB) cells (n = 4) were treated with different concentrations (100, 50, 25, 12.50, and 6.25%) of each extract. XTT assay and Alizarin Red S staining were used to evaluate the cytotoxic effect and the biomineralization potential, respectively.

STATISTICAL ANALYSIS

 Data were analyzed by one-way analysis of variance followed by Tukey's post hoc tests.

RESULTS

 The cytotoxicity assay after 24 h treatment showed that all materials at high concentrations of the extract (100 and 50%) were toxic to HOB (p < 0.001). On the contrary to TotalFill BC RRM Putty, AH Plus and TotalFill BC sealer were toxic at 25% concentration. However, at 12.5% concentration and lower, all materials were nontoxic. The mineralization potential analyzed after 7 and 14 days showed that TotalFill BC material-treated cells could deposit mineralized nodules in the normal and osteogenic medium unlike AH plus-treated cells.

CONCLUSION

 At low concentrations, TotalFill BC materials showed higher biocompatibility to HOB cells than AH Plus, enhanced the viability of the cells, maintained their typical morphology, and induced the formation of mineralized nodules. Despite the encouraging data, clinical trials are needed to identify the effect of this material on the long-term outcome of endodontic treatment.

Medium- and Long-Term Re-Treatment of Root Canals Filled with a Calcium Silicate-Based Sealer: An Experimental Ex Vivo Study

This study investigated the possibility of re-treating a calcium silicate-based sealer (CSBS), compared to an epoxy-resin sealer (RBS), using rotary instrumentation at different times from obturation (1 month/1 year). Thirty-six human mandibular premolars, extracted as a result of orthodontic or periodontal problems, were instrumented and randomly divided into three groups of 12: BR and BR*, which were filled with CSBS and re-treated after one month and one year of storage, respectively, and AH, which was filled with RBS and re-treated after one month. The same re-treatment protocol was used for all teeth, and the times required for the procedure was recorded. The re-treated specimens were longitudinally sectioned and examined at the stereomicroscope (SM) at 20× magnification. Image J Software was used to process the microphotographs. The percentage of residual filling materials in the root canal and the apical third, the ability to reach working length WL and patency, and the time taken to complete the re-treatment were recorded and analyzed by ANOVA and post hoc Bonferroni test (p = 0.05). Scanning electron microscopy (SEM) and coupled energy-dispersive spectroscopy (EDS) were applied to representative samples to evaluate canal cleanliness and chemical elements. Patency and WL were re-established in all of the teeth. Residual filling materials were retained in all specimens of the three groups. The mean percentage of residual materials was significantly different between BR and BR* (p-value = 0.048), with BR* showing the highest values. The mean time to complete re-treatment was significantly lower for AH, followed by BR (p = 0.0001) and BR* (p = 0.0078). Conclusions: After both medium and long storage periods, the CSBS can be concluded to have been successfully removed from canals with simple anatomy.

In Vitro Evaluation of the Antibacterial Activity of EndoSeal MTA, iRoot SP, and AH Plus against Planktonic Bacteria

This study aimed to investigate the antibacterial activity of three endodontic sealers, AH Plus, iRoot SP, and EndoSeal MTA, against four planktonic bacteria species. The antibacterial activity of the three endodontic sealers was assessed using a modified direct contact test. Bacteria suspension of Actinomycoses viscosus, Enterococcus faecalis, Staphylococcus aureus, and Streptococcus mutans were left in contact with the sealers that were pre-set or set for 1, 3, 7, and l4 days for an hour. Freshly mixed AH Plus and EndoSeal MTA were highly effective against all four tested bacteria as no surviving bacteria were recovered after treatment. Meanwhile, freshly mixed iRoot SP was not able to kill all bacteria, regardless of the species, demonstrating a weak antibacterial effect. After 24 h, AH Plus lost its antibacterial activity. EndoSeal MTA showed a strong and extended bactericidal effect against S. aureus and S. mutans for 3 days and A. viscosus for 7 days. In conclusion, fresh AH Plus and EndoSeal MTA exhibited a potent effect against all four bacteria species. EndoSeal MTA remained effective after setting when tested against A. viscosus, S. aureus, and S. mutans. Among all tested sealers, iRoot SP demonstrates the weakest antibacterial activity.

The Short-Term Antibacterial Activity of Three Selected Endodontic Sealers against Enterococcus faecalis Bacterial Culture

(1) Background: Microorganisms originating from the microflora of the oral cavity are the main cause of the inflammatory diseases of the dental pulp and periapical periodontium, as well as the failure of endodontic treatment. The subsequent root canal treatment is not able to remove all the pathogens, and a small number of viable bacteria remain in the dentine tubules, which must be sealed by endodontic sealers. These sealers should have at least a bacteriostatic effect to prevent the remaining bacteria from reproducing. The aim of this study is to compare the short-term antibacterial activity of three endodontic sealers based on poly-epoxy resin, zinc oxide-eugenol and calcium silicate with a calcium hydroxide-based sealer. Calcium hydroxide is used as temporary intracanal medicament and, thus, should show significant antibacterial activity. (2) Methods: A total of 25 bovine dentine samples infected with Enterococcus faecalis were used in this study. After the sealer placement and a 24 h incubation period, the root canal walls were scraped, and the suspension of dentine fillings was used for a semi-quantitative evaluation of microbial growth. (3) Results: The poly-epoxide resin-based sealer ADSeal™ showed significant antibacterial properties. (4) Conclusions: The highest antibacterial activity was shown in poly-epoxide resin-based sealer group, followed by the zinc oxide-eugenol-based sealer and calcium silicate-based sealer.

Synthesis and characterization of experimental endodontic sealers containing bioactive glasses particles of NbG or 45S5

OBJECTIVE

This study evaluated the influence of adding bioactive glasses particles [Niobophosphate (NbG) or bioglass (45S5)] into endodontic cements in relation to physical, chemical and biological properties.

METHODS

The following commercial cements were used as comparison: AH Plus (Dentsply), Endofill (Dentsply), MTA Fillapex (Angelus) and EndoSequence (BC Sealer, Brasseler). Setting time, radiopacity, flow rate, weight loss/variation, alkaline capacity (pH) at different time-intervals (24h/48h/7d/14d/28d), bioactivity (assessed under SEM/EDS, FTIR/ATR and XDR) and cell viability were measured. Data were analyzed by One-way ANOVA/Holm-Sidak post-test (α = 5%) (normal distribution) and Kruskal-Wallis/Students-Newman-Keuls post-test (α = 5%) (non-normal distribution).

RESULTS

Bioactive endodontic experimental cements (containing NbG or 45S5) had high alkalinization capacity. The experimental cements presented high weight loss/variation (p < 0.001). 45S5 experimental cement did not present radiopacity (p < 0.001). AH Plus had the lowest cell cytotoxicity when compared to the other tested cements (p < 0.001). Regarding bioactivity, SEM/EDS analyses showed precipitates with high concentrations of Ca/P for 45S5 and NbG, as well as for MTA Fillapex and BC Sealer. AH plus and Endofill did not present bioactive precipitates. FTIR/ATR and XDR analyses found hydroxyapatite precursors for NbG, 45S5, MTA Fillapex and BC Sealer.

SIGNIFICANCE

The incorporation of bioactive particles (NbG or 45S5) into endodontic cements had potential to neutralize acidic environments and induced formation of hydroxyapatite precursors. Clinically, these would produce a cement that is bactericidal and have the potential to improve tissue healing. The improved radiopacity and flowability would facilitate the visualization of the material in the radiograph and the filling of anatomical complexities during root canal obturation. As drawbacks, the excessive weight loss and post-setting cytotoxicity could result in clinical degradation of the cement and adjacent tissue irritation for the patient.

Carbon Nanotubes for Improved Performances of Endodontic Sealer

In order to overcome the limitations of current endodontic sealers, especially against resistant bacteria, recent developments in the field of nanotechnology have proved the necessity to reconsider the composition and physico-chemical properties of classical sealers. Nanoparticles with their unique features in terms of small size and high specific surface area, are the best choice for incorporation of antiseptic agents and effective delivery. The aim of our study is to prepare a novel platform for antibacterial drug delivery in dental adhesive systems used in endodontics. For this purpose, multi-walled carbon nanotubes (MWCNTs) encapsulating chlorhexidine (CHX) and colloidal silver nanoparticles (AgNPs) were prepared and incorporated into commercial sealer and investigated in terms of bonding performance to dentin and effectiveness against E. faecalis, S. aureus and Candida albicans, which are responsible for the majority of the failures in endodontic treatments. In this context, the challenges related to the long-term biological effects of CHX/AgNPs loaded MWCNTs are discussed.

In vitro comparative evaluation of antifungal efficacy of three endodontic sealers with and without incorporation of chitosan nanoparticles against Candida albicans

Aim:

The aim of this study was to compare the antifungal efficacy of three endodontic sealers (AH Plus, Apexit Plus, and MTA Fillapex) with and without the incorporation of chitosan nanoparticles against Candida albicans.

Materials and Methods:

The present study was carried out by the Kirby–Bauer method. C. albicans were cultured in Sabouraud Dextrose Agar plates. Filter papers (n = 10) were placed in the cultured Petri dishes and the sealers were mixed according to the manufacturer's instructions and placed on the top of the filter papers. Group division of sealers is as follows: Group I – AH Plus, Group II – Apexit Plus, and Group III – MTA Fillapex. Group IC, Group IIC, and Group IIIC were the addition of 2% chitosan nanoparticles with respective sealers. Plates were incubated for 18 h, and the zone of inhibition was measured with a measuring scale and values (in millimeter) were recorded. Statistical analysis was done by one-way analysis of variance followed by post hoc multiple pair-wise comparisons.

Results:

All the tested groups showed statistically significant difference (P < 0.05) from each other. Two percent chitosan-incorporated groups showed superior zone of inhibition compared to sealers used alone. Group IC (16.35 ± 0.71 mm) had the highest zone of inhibition followed by Group I (13.8 ± 0.86 mm). For the remaining groups, the zone of inhibition was in the following order: Group IIC > Group II > Group IIIC > Group III.

Conclusion:

AH Plus sealer mixed with 2% chitosan showed significantly higher antifungal property. Mixing of 2% chitosan with endodontic sealer provides an added advantage so that endodontic re-infections can be minimized and will be helpful in retreatment cases.

Comparison of the antibacterial activity of calcium silicate- and epoxy resin-based endodontic sealers against Enterococcus faecalis biofilms: a confocal laser-scanning microscopy analysis

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 30 days. 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.

A comparison of the characteristics of polyurethane-based sealers including various antimicrobial agents

A novel polyurethane sealer has been fabricated and demonstrates good physicochemical and antibacterial properties and cytocompatibility.

Intradentinal antimicrobial action and filling quality promoted by ultrasonic agitation of epoxy resin-based sealer in endodontic obturation

The aim of this study was evaluate the influence of ultrasonic activation (UA) of AH Plus to improve canal and isthmus filing, and analyse the antimicrobial effect against Enterococcus faecalis within dentinal tubules.

Comparison of antimicrobial activity of traditional and new developed root sealers against pathogens related root canal

Background/purpose

Bacterial infection is closely associated with the failure of endodontic treatment, and use of endodontic sealer with antimicrobial activity and biological compatibility is necessary for the success of root canal treatment. The purpose of this study was to investigate and to compare the antibacterial effect of two calcium silicate-based root canal sealers (Endoseal and EndoSequence BC sealer) as recent development sealers and with three conventional root canal sealers (AH Plus, Sealapex, and Tubli-Seal), before or after setting, on Porphyromonas endodontalis, Porphyromonas gingivalis, and Enterococcus faecalis.

Materials and methods

The sealers were soaked in phosphate buffered saline to elute its compositions after and before setting, and the elutes were performed the antimicrobial assay. Also, X-ray fluorescence analysis was carried out to compare compositions of two calcium silicate-based sealers.

Results

The conventional root canal sealers have strong antibacterial activity against the Gram-negative bacteria, P. endodontalis and P. gingivalis. Endoseal sealer showed antibacterial activity against not only the Gram-negative bacteria, but also against the Gram-positive bacteria, E. faecalis. However, Endosequence BC sealer exhibited a weak antibacterial effect on all bacteria in this study. X-ray fluorescence analysis exhibited that Endoseal contained more types and more amount of the oxide compound known to have strong antimicrobial activity such as Al₂O₃, Fe₂O₃, MgO, Na₂O, NiO, and SO₂ than Endoseqeunce BC.

Conclusion

Endoseal, which contains various types of oxide compounds, seems to be a suitable sealer for preventing bacterial infection in both treated and untreated root canals.

Cellular Responses in Human Dental Pulp Stem Cells Treated with Three Endodontic Materials

Human dental pulp stem cells (HDPSCs) are of special relevance in future regenerative dental therapies. Characterizing cytotoxicity and genotoxicity produced by endodontic materials is required to evaluate the potential for regeneration of injured tissues in future strategies combining regenerative and root canal therapies. This study explores the cytotoxicity and genotoxicity mediated by oxidative stress of three endodontic materials that are widely used on HDPSCs: a mineral trioxide aggregate (MTA-Angelus white), an epoxy resin sealant (AH-Plus cement), and an MTA-based cement sealer (MTA-Fillapex). Cell viability and cell death rate were assessed by flow cytometry. Oxidative stress was measured by OxyBlot. Levels of antioxidant enzymes were evaluated by Western blot. Genotoxicity was studied by quantifying the expression levels of DNA damage sensors such as ATM and RAD53 genes and DNA damage repair sensors such as RAD51 and PARP-1. Results indicate that AH-Plus increased apoptosis, oxidative stress, and genotoxicity markers in HDPSCs. MTA-Fillapex was the most cytotoxic oxidative stress inductor and genotoxic material for HDPSCs at longer times in preincubated cell culture medium, and MTA-Angelus was less cytotoxic and genotoxic than AH-Plus and MTA-Fillapex at all times assayed.

Cytotoxicity, Biocompatibility, and Biomineralization of the New High-plasticity MTA Material

INTRODUCTION

Mineral trioxide aggregate (MTA) has excellent biological properties, but its handling properties have been criticized for both ProRoot MTA (Tulsa Dental Products, Tulsa, OK) and white MTA-Angelus (MTA-Ang; Angelus Indústria de Produtos Odontológicos S/A, Londrina, PR, Brazil). Angelus MTA HP (high plasticity) (Angelus Indústria de Produtos Odontológicos S/A) has been introduced recently. Considering the importance of biological properties of materials that will be in contact with the tissues, this study evaluated the cytotoxicity, biocompatibility, and biomineralization of MTA HP compared with white MTA-Ang.

METHODS

L929 fibroblast cell lines were cultured, and cell viability was assessed at 6, 24, 48, and 72 hours using the alamar Blue assay (Thermo Fisher Scientific, Waltham, MA). A subcutaneous implant test was performed with polyethylene tubes containing 1 of the materials or empty tubes (control) using 20 Wistar rats. After 7 and 30 days of implantation, the tubes with surrounding tissues were removed for analysis using hematoxylin-eosin or von Kossa stain or they remained unstained for observation under polarized light. The results were statistically analyzed (P < .05).

RESULTS

A significant increase in cell viability for MTA HP was observed after 24, 48, and 72 hours compared with the control (P < .05). At 72 hours, MTA HP exhibited a higher viability compared with white MTA-Ang (P < .05). Histologic analysis performed at 7 days showed moderate inflammation and a thick fibrous capsule in all groups (P > .05). At 30 days, mild inflammation and a thin fibrous capsule were observed in all groups (P > .05). All materials had structures positive for von Kossa and birefringent to polarized light.

CONCLUSIONS

MTA HP showed biocompatibility and biomineralization similar to MTA-Ang. In addition, MTA HP showed increased fibroblast cell viability compared with white MTA-Ang after a longer period.

Extrusion of Root Canal Sealer in Periapical Tissues - Report of Two Cases with Different Treatment Management and Literature Review

Background: Extrusion of root canal sealers may cause damage to the surrounding anatomic structures. Clinical symptoms like pain, swelling and paresthesia or anesthesia may be present. The purpose of this presentation is to describe two cases of root canal sealer penetration into periapical tissues. A different treatment management was followed in each case.

Case reports: A 55 year-old man underwent root canal retreatment of the right mandibular first molar tooth due to a periapical lesion. Postoperative periapical radiographs revealed the presence of root canal sealer (AH26) beyond the apex in the distal root in proximity to the mandibular canal. The patient reported pain for the next 7 days. Radiographic examination after 1 year showed complete healing of the periapical area and a small absorption of the root canal sealer. A 42 year-old woman was referred complained of swelling and pain in the area of the right maxillary first incisor. Radiographic examination showed extrusion of root canal sealer in the periapical area associated with a periapical lesion. Surgical intervention was decided upon, which included removal of the sealer, apicoectomy of the tooth and retrograde filling with MTA. After 1 year, complete healing of the area was observed.

Conclusion: In conclusion, cases of root canal sealer extrusion, surgical treatment should be decided on only in association with clinical symptoms or with radiographic evidence of increasing periapical lesion.

Bioactive mono-dispersed nanospheres with long-term antibacterial effects for endodontic sealing

Endodontic sealers with antibacterial capability play an important role in preventing reinfection of an endodontically treated root canal and improving the long-term success of root canal treatment. However, current endodontic sealers rapidly lose their antibacterial properties after fixation. In this work, we designed and synthesized quaternized mono-dispersed bioactive nanospheres as a potential substrate for the development of a long-term antibacterial endodontic sealer with excellent cytocompatibility and biocompatibility. First, mono-dispersed silica-based bioactive glass nanospheres (SBG-NS) were prepared via a modified sol-gel process. Next, a series of quaternary ammonium methacrylate salts (QAMs) with broad antibacterial spectra were synthesized and grafted onto the surfaces of the SBG-NS via a two-step coupling approach. The antibacterial effect of the quaternary ammonium polymethacrylate (QAPM)-containing SBG-NS (SBG-QAPM) against persistent microorganisms associated with infected root canals was evaluated using a direct contact test. Evaluations of the SBG-QAPM cytocompatibility and biocompatibility were performed using LIVE/DEAD staining, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2, 5-tetrazoliumbromide (MTT) assay, and a calvarial implantation model. The results showed that the SBG-QAPMs had the strongest long-term antibacterial effect against the Enterococcus faecalis, Streptococcus mutans, and Streptococcus sanguis during the study period, the best cytocompatibility, and the lowest systemic inflammation compared to three commercial products: ProRoot MTA, Endomethasone C, and AH Plus. In addition, the SBG-QAPMs showed excellent stability in aqueous solution. This work indicates that the SBG-QAPMs are promising substrates for the development of long-term antibacterial endodontic sealers.

In vitro evaluation of the antibacterial activity of five sealers used in root canal therapy

BACKGROUND

Antibacterial activity is one of the important characteristics of an ideal root canal sealer. The aim of this study was to investigate the antibacterial activity of five different sealers against Enterococcus faecalis using two different methods.

MATERIALS AND METHODS

The mineral trioxide aggregate (MTA) Fillapex, Tg-sealer, Endomethasone, AH-26, and RoekoSeal sealers were placed into the brain heart infusion (BHI) culture medium containing E. faecalis (PTCC1393). The diameter of the bacterial zone of inhibition was measured. In the direct contact test, a suspension containing grinded set sealers and E. faecalis bacteria was cultured in BHI after 6, 15, and 60 min. The number of colonies in milliliter was calculated. Data were subjected to one-way ANOVA and Tukey's multiple comparisons test (P < 0.05).

RESULTS

In the agar diffusion test, Endomethasone had the highest antibacterial activity against E. faecalis compared to other sealers (P < 0.001). In the direct test, the antibacterial effect of MTA Fillapex was significantly higher than that of all other sealers (P < 0.001).

CONCLUSION

The technique and components of the tested sealers affect the antibacterial activity results. This study showed that all of sealers had antimicrobial effect.

Biological Tissue Response to a New Formulation of a Silicone Based Endodontic Sealer

Abstract Satisfactory biological behavior is a necessary requirement for clinical application of endodontic materials. In this study, the connective tissue responses to silicone (GuttaFlow 2), epoxy resin (AH Plus) and zinc oxide and eugenol (Endofill) based sealers were compared. Twelve Wistar rats had polyethylene tubes (four per animal) containing one of the tested sealers and empty tubes (negative control) implanted in their subcutaneous tissue. The tubes were randomly placed 2 cm from the spine and at least 2 cm apart from one another. Tissue samples with implants were processed for histological analysis after 7 or 60 days (n=6 animals per period). Inflammatory cells, fibrous condensation and abscess were scored according to their intensity. Friedman, followed by Dunn's post hoc, was used to compare sealers. Differences between the two experimental periods were verified using Mann-Witney U test (p<0.05). At 7 days, most of the histological parameters showed no significant differences amongst groups. Endofill group scored higher than the others for giant cells (o<0.05) and promoted a greater number of samples presenting abscess formation. GuttaFlow 2 tended to show a less intense inflammatory infiltrate compared to the other materials. At 60 days, there were no significant differences between groups in most of the histological parameters evaluated. However, it was observed that Endofill scored higher for macrophages (p<0.05) compared to the control group, and GuttaFlow 2 tended to present lower scores than the others for neutrophils and abscess. GuttaFlow 2 showed proper biological behavior and should be considered adequate for clinical practice.

In Vitro Antimicrobial Effectiveness of Root Canal Sealers against Enterococcus faecalis: A Systematic Review

INTRODUCTION

The purpose of this systematic review was to summarize the outcomes of in vitro studies of root canal sealers for their antimicrobial effectiveness against Enterococcus faecalis on the basis of direct contact test.

METHODS

An exhaustive literature search was performed by using MEDLINE, Scopus, TRIP, and OpenThesis databases, followed by an extensive hand search of references of identified articles. Two independent reviewers evaluated the studies for eligibility against inclusion and exclusion criteria and performed data abstraction and risk of bias evaluations.

RESULTS

A total of 31 articles were assessed for eligibility. Of these, 24 met the inclusion criteria and were included in the systematic review. A considerable heterogeneity was found in the methodologies of included studies. Therefore, it was not feasible to perform meta-analysis. Majority of the studies reported that different categories of freshly prepared sealers possessed some form of positive antimicrobial activity against E. faecalis for up to 24 hours. Antimicrobial efficacy was lost as the material set. Moderate evidence was found for no antimicrobial activity of aged (2-day to 7-day set) sealer samples across all categories.

CONCLUSIONS

The evidence indicated positive antimicrobial activity of freshly mixed sealers against E. faecalis. Antimicrobial efficacy was lost as the material set, with no bacterial growth inhibition by 2-day to 7-day set sealer samples. However, the studies included in this review presented medium to high risk of bias. This review identified the need for the development of standardized methods to evaluate antimicrobial activity of root canal sealers in in vitro studies.

In vitro comparison of antibacterial properties of bioceramic-based sealer, resin-based sealer and zinc oxide eugenol based sealer and two mineral trioxide aggregates

Objective:

Our goal of the study was to evaluate the antibacterial properties of endodontic sealers against the E. faecalis.

Materials and Methods:

Six millimeters wells were made for each material in all the preinoculated petri plates. Then, the petri plates were incubated for 24 h. The zones of inhibition appeared were measured, and the measurements were put to statistical analysis.

Results:

EndoSequence BC Sealer, MM-mineral trioxide aggregate (MTA), and ProRoot MTA showed maximum means of diameter of zones of inhibition, whereas MM-seal and Endoseal did not show any zones of inhibition.

Conclusion:

EndoSequence BC Sealer was found to be a better endodontic sealer as compared to resin-based and zinc oxide-eugenol-based sealer.

An in vitro Comparison of Antimicrobial Activity of Three Endodontic Sealers with Different Composition

AIMS

The aim of the study was to compare the antimicrobial property of newly introduced EndoSequence BC sealer with commonly used zinc oxide-eugenol-based sealer (Zical) and epoxy resin-based sealer (MM-Seal) against Candida albicans, Lactobacillus, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.

MATERIALS AND METHODS

The agar diffusion test was done to measure the antimicrobial activity of sealers. The sealers were put in the 4 mm wells prepared in the inoculated agar plates. The agar plates were incubated at 37°C for 24 hours and the zones of inhibition that appeared was measured. Chi-square test was done to evaluate intraobserver bias for all study samples. Intergroup comparison was done for all five parameters using Pearson correlation statistical analysis.

RESULTS

EndoSequence BC sealer showed maximum mean of diameter of zones of inhibition against all the microorganisms but with no statistically significant difference with other sealers. Zical did not show any zone of inhibition against the P. aeruginosa. MM-Seal did not show any inhibitory activity against the P. aeruginosa and C. albicans.

CONCLUSION

EndoSequence BC sealer showed antimicrobial activity against all the microorganisms and proved to be a better choice when compared with other two sealers.

CLINICAL SIGNIFICANCE

Antimicrobial properties of endodontic sealers are important to prevent the persistent infection of the complex root canals. EndoSequence BC sealer has been proved to be a better sealer in this aspect.

Comparison of the Apical Sealing Ability of Calcium Silicate-Based Sealer and Resin-Based Sealer Using the Fluid-Filtration Technique

OBJECTIVE

The aim was to evaluate the apical sealing ability of tricalcium silicate-based (MTA Fillapex®) and resin-based (AH Plus®) sealers at 24 h, 7 days and 4 weeks.

MATERIALS AND METHODS

Thirty-four extracted human upper anterior teeth were used. All the teeth were sectioned to leave the root 15 mm long, and then all the roots were instrumented using a set of ProTaper® rotary instruments. Four roots were selected randomly as controls, and the remaining 30 were randomly divided into 2 groups of 15 each: MTA Fillapex and gutta-percha (group 1) and AH Plus and gutta-percha (group 2) using a warm vertical compaction technique. The apical sealing ability of the filled root canal was measured using the fluid-filtration method with 200 mm Hg (26.67 KPa) above atmospheric pressure at 24 h, 7 days and 4 weeks. The apical microleakage of the 2 groups was compared using Student's t test. p < 0.05 was considered statistically significant.

RESULTS

The mean apical microleakage in group 1 at 24 h, 7 days and 4 weeks was 1.01 ± 0.24, 0.43 ± 0.07 and 0.24 ± 0.08 nl/s. The corresponding values in group 2 were 1.15 ± 0.40, 0.32 ± 0.09, and 0.38 ± 0.10 nl/s. MTA Fillapex had significantly more leakage than AH Plus at 7 days, but at 4 weeks, MTA Fillapex showed a significantly better sealing ability than AH Plus (p < 0.05).

CONCLUSIONS

In this study, the tricalcium silicate-based sealer promoted proper sealing when used for filling the root canals.

Biotoxicity of commonly used root canal sealers: A meta-analysis

INTRODUCTION

The main objective of a root canal sealer is to provide a fluid tight seal. The purpose of this systematic meta-analysis was to determine the relative toxicity of commonly used root canal sealers like zinc oxide eugenol, calcium hydroxide, and resin-based sealers.

MATERIALS AND METHODS

An online search was conducted in peer-reviewed journals listed in PubMed, Cochrane, EBSCO, and IndMed databases between 2000 and 2012). Statistical analysis was carried out by using analysis of variance (ANOVA) followed by post-hoc comparison by Bonferroni method. The comparison between toxicity at 24 h and between 3 and 7 days was done by using paired t-test for each sealer.

RESULTS

At 24 h, the relative biotoxicity of the three sealers reported was insignificant (P- value 0.29), but the difference in toxicity was found significant (P < 0.001) after 3 days.

CONCLUSION

Calcium hydroxide sealer and zinc oxide eugenol were found to be significantly biotoxic as compared to resin-based sealers after 3 days.

Physicochemical and biological properties of a novel injectable polyurethane system for root canal filling

A root canal sealer with antibacterial activity can be efficacious in preventing reinfection that results from residual microorganisms and/or the leakage of microorganisms. In the present study, a series of injectable, self-curing polyurethane (PU)-based antibacterial sealers with different concentrations of silver phosphate (Ag₃PO₄) were fabricated. Subsequently, their physicochemical properties, antibacterial abilities, and preliminary cytocompatibilities were evaluated. The results indicated that the fabricated PU-based sealers can achieve a high conversion rate in a short amount of time. More than 95% of the isocyanate group of PU sealers with 3 wt% (PU3) and 5 wt% (PU5) concentrations of Ag₃PO₄ were included in the curing reaction after 7 hours. With the exception of those for film thickness for PU5, the results of setting time, film thickness, and solubility were able to meet the requirements of the International Organization for Standardization. The antibacterial tests showed that PU3 and PU5 exhibit stronger antimicrobial effects than that achieved with 1 wt% Ag₃PO₄ (PU1) and AH Plus (positive control) against Streptococcus mutans. The cytocompatibility evaluation revealed that the PU1 and PU3 sealers possess good cytocompatibility and low cytotoxicity. These results demonstrate that the PU3 sealer offers good physicochemical and antimicrobial properties along with cytocompatibility, which may hold great application potential in the field of root canal fillings.

A review of the effects of formaldehyde release from endodontic materials

Formaldehyde is present in most living cells and the environment. In dentistry, patients may be exposed to formaldehyde through the use of several endodontic materials (e.g. AH 26) and during formocresol pulpotomies. This review outlines how the human body reacts to formaldehyde exposure, how recent data has relooked at the issue of carcinogenicity and leukaemia associated with formaldehyde, and whether it is possible to quantify the amount of formaldehyde produced by endodontic cements. The review analyses the way formaldehyde is produced from epoxy resins and addresses the question of whether the amount of formaldehyde from endodontic cements is large enough to override the body's ability to deal with its own endogenous levels of formaldehyde and should the amount of formaldehyde produced be a concern.

In Vitro Evaluation of the Antimicrobial Efficacy of Four Endodontic Biomaterials against Enterococcus faecalis, Candida albicans, and Staphylococcus aureus

Root canal sealers that possess good antimicrobial property can prevent residual and recurrent infection and contribute to successful endodontic therapy. This study evaluated the antimicrobial activity of four endodontic sealers, AH Plus, Tubliseal EWT, EndoRez, and iRoot SP, against three different microorganisms, E. faecalis, C. albicans, and S. aureus, by direct contact test. 10 μL microbial suspensions were allowed to directly contact the four endodontic sealers for 1 hr at 37°C. Subsequently microbial growth was measured spectrophotometrically every 30 min for 18 hours. The microbial suspensions were simultaneously tested to determine the antimicrobial effect of components which are capable of diffusing into the medium. The results revealed that AH Plus and iRootSP had significantly higher antimicrobial activity against E. faecalis. AH Plus and Tubliseal EWT showed significantly higher antimicrobial activity against C. albicans and S. aureus compared to iRoot SP and EndoRez. EndoRez showed the least antimicrobial activity against all the three microorganisms. Inhibition of microbial growth is related to the direct contact of microorganisms with the sealers. In conclusion AH Plus had significantly higher antimicrobial activity against E. faecalis, C. albicans, and S. aureus.

Evaluation physical characteristics and comparison antimicrobial and anti-inflammation potentials of dental root canal sealers containing hinokitiol in vitro

Hinokitiol displays potent antimicrobial activity. It has been used in toothpaste and oral-care gel to improve the oral lichen planus and reduce halitosis. The aim of this study was to evaluate the antimicrobial activity of 3 different dental root canal sealers with hinokitiol (sealers+H) and their physical and biological effects. AH Plus (epoxy amine resin-based, AH), Apexit Plus (calcium-hydroxide-based, AP), and Canals (zinc-oxide-eugenol-based, CA), were used in this study. The original AH and CA exhibited strong anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity, but AP did not. The setting time, working time, flowability, film thickness, and solubility of each sealer+0.2%H complied with ISO 6876:2001. CA+0.2%H exhibited high cytotoxicity, but the others sealers+0.2%H did not. Because hinokitiol combined with Zn²⁺ in CA creates a synergistic effect. The physical tests of AP+0.5%–1%H complied with ISO 6876:2001, improved antimicrobial activity, inhibited inflammation genes cyclooxygenase-2 (COX-2) and hypoxia-inducible factor-1α (HIF-1α) mRNA in MG-63 cells and human gingival fibroblasts (HGF), and down-regulated lysyl oxidase (LOX) mRNA of HGF. In summary, AH and CA demonstrated strong antimicrobial activity, but AP did not. Application of hinokitiol increases AH anti-MRSA activity should less than 0.2% for keep well flowability. AP+0.5%–1% hinokitiol exhibited strong physical, antibacterial, and anti-inflammation potentials, and inhibited S. aureus abscess formation. Applying an appreciable proportion of hinokitiol to epoxy-amine-resin-based and calcium-hydroxide-based root canal sealers is warranted, but the enhanced cytotoxicity and synergistic effect must be considered.

Evaluation of the biocompatibility of resin-based root canal sealers in rat periapical tissue

We evaluated the biocompatibility of resin-based root canal sealers (RCSs) in the periapical tissues of rats. Wistar rats underwent tooth replantation for reproducing the response of periapical tissue with RCSs. The resin-based Epipany SE, AH Plus Jet, the eugenol-based sealer (Canals) and a control group were employed. The upper right first molar was extracted and applied with RCSs on apices, and then the tooth was repositioned. Histological evaluation demonstrated that mild inflammation occurred in the periapical tissue with Epiphany and AH Plus Jet sealers on day 7, whereas Canals induced severe-to-moderate inflammation. The statistical analyses demonstrated that the significant differences were observed between Canals and the other groups on day 7 regarding inflammatory response. On day 14, the lesions induced by all sealers were healed and replaced predominantly by fibrous connective tissue. Our results suggest that Epiphany SE and AH Plus Jet are good biocompatible materials.

Connective tissue reaction of rats to a new zinc-oxide-eugenol endodontic sealer

The aim of this study was to evaluate the biocompatibility in rat subcutaneous connective tissue of a new zinc oxide endodontic sealer (Endomethasone N) compared to those provided by Endofill and Sealer 26. Polyethylene tubes containing the test materials were implanted into dorsal subcutaneous connective tissue of Wistar albino rats. After 7 and 42 days, the implants with the surrounding tissue were collected, fixed, and processed for histologic evaluation. Sections were evaluated for the presence of inflammatory cells (poly or monomorfonuclear), blood vessels, necrosis area, and thickness of fibrous capsule. Comparisons between groups and time-periods were performed with Kruskal-Wallis and Mann-Whitney U non-parametric tests for 5% significance level. No differences in the biocompatibility patterns among the materials for the 2 experimental periods were observed. Independently of the sealer, the tissue behavior showed a tendency to decrease the irritation effect over time. It can be concluded that all sealers are irritant, but its toxicity decreased with time. Endomethásone N showed biocompatible characteristics comparable with those provided by Endofill and Sealer 26.

Evaluation of the responses of MHC class II molecule-expressing cells and macrophages to epoxy resin-based and 4-META-containing, methacrylate resin-based root canal sealers in rat subcutaneous tissue

Major histocompatibility complex (MHC) class II molecule-expressing cells and macrophages play a pivotal role in mediating the host tissue response to biomaterials. This study investigated the responses of these cells to epoxy resin-based and 4-META-containing, methacrylate resin-based endodontic sealers (AH Plus and MetaSEAL respectively) in rat connective tissue. Silicone tubes loaded with one of the sealers or solid silicone rods (control) were subcutaneously implanted in male Wistar rats for three time periods of 7, 14, or 28 days. Tissue specimens were immunoperoxidase-stained for MHC class II molecules and CD68 (a general macrophage marker). Results showed that AH Plus-implanted tissue displayed significantly more MHC class II-positive cells than the control at 14 and 28 days, whereas MetaSEAL-implanted tissue showed significantly more CD68-positive cells than both AH Plus-implanted tissue and the control at all time periods. It was concluded that the epoxy resin-based sealer induced the infiltration of MHC class II molecule-expressing cells, whereas 4-META-containing, methacrylate resin-based sealer elicited macrophage infiltration.

Evaluation of the pH, calcium release and antibacterial activity of MTA Fillapex

OBJECTIVE: This study evaluated, in several analysis periods, pH and calcium release and antibacterial activity provided by MTA Fillapex sealer compared to Sealapex and AH Plus sealers. MATERIAL AND METHOD: Polyethylene tubes were filled with a sealer and immersed in distilled water. After 24 hours, 14 and 28 days, pH and calcium release by endodontic sealers were evaluated directly in water which the tubes were stored. Sealers antibacterial activity was evaluated against Enterococcus faecalis and Staphylococcus aureus by means of agar diffusion test. All data were submitted to ANOVA and Tukey tests (α=0.05). RESULT: In all periods evaluated, Sealapex had the highest pH value (p<0.05) in comparison to other sealers and MTA Fillapex provided higher pH values than AH Plus (p<0.05). In 14-days period, MTA Fillapex had greater calcium release value than Sealapex (p<0.05). In 28-days period, Sealapex provided higher calcium release than MTA Fillapex (p<0.05). In all periods, AH Plus provided lower calcium release than other sealers (p<0.05). In relation to E. faecalis, there were no differences among the sealers, in relation to antibacterial activity (p>0.05). In relation to S. aureus, Sealapex presented better antibacterial effectiveness than the MTA Fillapex and AH Plus (p<0.05), which were similar each other (p>0.05). CONCLUSION: In final evaluation period, pH values and calcium release provided by MTA Fillapex were lower than provided by Sealapex and higher than provided by AH Plus. The MTA Fillapex antimicrobial action was similar to other endodontic sealers.

Antibacterial Effects of Six Endodontic Sealers

Purpose

The objective of this study was to perform an in vitro evaluation of the antibacterial properties of 6 endodontic sealers (Endomethasone C, Argoseal, Bioseal Normal, Acroseal, AH Plus, Sicura Seal).

Methods

The agar diffusion test (well and paper disc methods) with Enterococcus faecalis, Staphylococcus aureus and Streptococcus mutans was used. For the well method, Petri dishes were inoculated with bacterial suspensions. Each well was completely filled with freshly mixed endodontic sealer. For the paper disc method, sterile paper discs were immersed in freshly mixed sealers and put on agar plates. Diameters of halos formed around the sealers were measured after 24 h and 48 h. Statistical analysis: The effects of well method and of paper disc method were analyzed by 1-way ANOVA.

Results

Endomethasone C, Argoseal and Bioseal showed the largest inhibition halos for all the tested microorganisms, while Sicura Seal and AH Plus showed low antibacterial effects. Moreover, the comparison of well method and paper disc methods showed significant statistical differences (P<0,01) for all sealers and indicated a dose-dependent antimicrobial effect.

Cytotoxicity evaluation of Gutta Flow and Endo Sequence BC sealers

OBJECTIVE

This study evaluated the cytotoxicity of GuttaFlow and EndoSequence BC sealers and compared them with AH Plus and Tubli-Seal sealers.

STUDY DESIGN

Samples (0.5 mg) of freshly mixed or set BC, GuttaFlow, AH Plus, and Tubli-Seal sealers were eluted with 300, 600, and 1,000 μL cell culture medium for 24 and 72 hours. L929 cells were seeded into 96-well plates at 3 × 10(4) cells/well and cultured with 100 μL eluate from each eluate group. Cells cultured only with culture medium served as control. After 24 hours' incubation, the cytotoxicity was evaluated by MTT assay. Cell viability was calculated as the percentage of the control group, and the results were analyzed with a one-way analysis of variance.

RESULTS

For the freshly mixed sealer, cell viability in the AH Plus group was less than in all of the other 3 sealer groups. The Tubli-Seal sealer group had less cell viability than the EndoSequence BC and GuttaFlow sealer groups. For the set sealer, the Tubli-Seal and AH Plus groups had less cell viability than the EndoSequence BC and GuttaFlow sealer groups. There was no cell viability difference between the EndoSequence BC and GuttaFlow sealer groups in the either freshly mixed or set sealer group.

CONCLUSIONS

The GuttaFlow and EndoSequence BC sealers have lower cytotoxicity than the AH Plus and Tubli-Seal sealers.

Preliminary study of the inflammatory response to subcutaneous implantation of three root canal sealers

AIM

To evaluate the kinetics of the inflammatory tissue response to three root canal sealers using a physicochemical method for quantification of the enhanced vascular permeability and histopathological analysis.

METHODOLOGY

Twenty-eight male Wistar rats randomly assigned to four groups according to the evaluation periods (1, 3, 7 and 14 days) were used to assess the vascular permeability and histopathological reaction to RoekoSeal, AH Plus and Sealapex (new formulation) sealers, using saline and Chloropercha as negative and positive controls, respectively. Seven rats were sacrificed per period. The biocompatibility of the sealers was evaluated spectrophotometrically and histopathologically.

RESULTS

At day 14, Sealapex produced significantly more inflammatory exudate than AH Plus and RoekoSeal (P < 0.05); however, there was no significant difference between AH Plus and RoekoSeal (P > 0.05). Sealapex (new formulation) was the most irritating sealer, producing severe inflammation with the presence of multinucleated giant cells. RoekoSeal was the most biocompatible sealer, producing the least amount of inflammatory exudate.

CONCLUSIONS

RoekoSeal root canal sealer was biocompatible when implanted in connective tissue.