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

Effect of zinc oxide-eugenol endodontic paste on planktonic aggregates and biofilm of Enterococcus faecalis - An atomic force microscopy evaluation

OBJECTIVE

This work aimed to evaluate the in vitro effect of zinc oxide-eugenol paste (ZOE) on planktonic aggregates (EfPA) and biofilm (EfBio) of Enterococcus faecalis, focusing on their morphological aspects observed and analyzed using atomic force microscopy (AFM).

DESIGN

The eugenol and paste were characterized by Gas Chromatography coupled with Mass Spectrometry (GC-MS) and Fourier Transform Infrared Spectroscopy (FTIR), respectively. The effect of ZOE on EfPA and EfBio was evaluated by a direct-contact test through colony counting and crystal violet staining protocol. AFM images of untreated and treated EfPA and EfBio growth on bovine dentin were obtained to analyze the morphological damage caused by the treatments.

RESULTS

The characterization showed high purity in the eugenol composition and chemical interaction between the components of the paste. A bactericidal effect on aggregates was observed after 6 h of exposure, and on biofilm after 24 h of treatment (p < 0.001). A disruptive effect on the biofilm was also evident. AFM images revealed the formation of EfPA, with a notable presence of an exopolysaccharide matrix. After 6 h of ZOE treatment, there was a significant increase in the size and surface roughness profile of treated cells (p < 0.05). Loss of typical cell morphology was observed after 24 h. The effect on the biofilm showed a tendency towards a less condensed biofilm pattern in the treated group, with no differences in surface roughness.

CONCLUSION

ZOE presents bactericidal action on EfPA and EfBio, promoting significant morphological changes after treatment, especially in the aggregates.

Antibacterial and Cytotoxicity characteristics of experimental epoxy -based endodontic sealer loaded with silver gold nanoparticles: in vitro study

BACKGROUND

Enhancing the antibacterial capabilities of dental materials by adding nanoparticles has been the subject of some research. However, the potential toxic effect of this material on the vital tissues should be investigated to avoid additional damage to the tissue.

OBJECTIVE

This study aimed to validate the long-term cytotoxic and antibacterial properties of an epoxy resin-based endodontic sealer (AH Plus) with and without loading with silver gold nanoparticles (Nano Care Plus Silver Gold®).

MATERIAL AND METHODS

The tested groups were Nano Care Gold (group I), modified resin sealer (m AH Plus; group II) and AH Plus served as a control group (group III). Agar diffusion was used to measure the antibacterial activity against Enterococcus faecalis. Using the MTT test, cytotoxicity assessment was carried out in accordance with ISO-10993-5 guidelines to assess the cells' viability as soon as possible and after two and four weeks. The t-test was used to statistically examine the data. The chosen significance threshold was P <0.05.

RESULTS

Antibacterial results revealed that there was no difference in the diameter of the inhibition zones measured in all groups at 24 h. While in 48 and 72 h, the difference was statistically significant (p <0.05). In 48-h Nanogold was significantly higher than AH Plus when tested alone (p <0.05), however their mixture showed insignificant difference. After 72 h, the Nano gold was significantly higher than that of AH Plus & Nano gold mixture (p <0.05). Cytotoxicity result revealed there was a significant difference between tested groups at different intervals (p <0.001). For immediate measurements, values measured with the AH group were significantly higher than those of other groups (p <0.001). For the AH& nanogold group, there was no significant difference between values measured at different intervals (p = 0.578).

CONCLUSIONS

Silver gold nanoparticles have acceptable antibacterial properties and low cytotoxicity to be used as canal pretreatment prior to the application of the sealer or even incorporated with AH Plus sealer.

Effects of radiotherapy dose and application time on the load-to-failure values of teeth filled with different sealers

BACKGROUND

The materials used in root canal filling and radiotherapy (RT) application can affect the load-to-failure of the teeth. This study aimed to compare the load-to-failure of the teeth filled with AH Plus (AHP) or AH Plus bioceramic (AHPB) before or after 60 Gy- and 70 Gy-dose radiotherapy.

MATERIALS AND METHODS

One hundred and ten maxillary incisors were endodontically prepared up to ProTaper Next X4 instruments. The teeth were randomly divided into 5 main groups as: non-irradiated, root canal treatment (RCT) before 60 Gy radiotherapy, RCT before 70 Gy radiotherapy, RCT after 60 Gy radiotherapy, RCT after 70 Gy radiotherapy. These groups were divided into 2 subgroups for filling material: AHP ve AHPB. After filling and radiotherapy procedures, the teeth were fixed on the thermoplastic mask plane. The plane were placed in the middle of a rectangular prism shaped glass phantom, and irradiated via a linear accelerator device. The teeth were then embedded in cylindrical acrylic blocks and the force (N) that caused the fracture was recorded under the Universal testing device. Student t-test was used for statistical comparisons. Statistical significance level was determined as p < 0.05.

RESULTS

After 70 Gy dose radiotherapy, the group filled with AHPB showed statistically significantly lower fracture strength than the group filled with AHP (p < 0.05). In the control group, before 60 Gy RT group, after 60 Gy RT group, and before 70 Gy RT group, the sealers had statistically significantly similar load-to-failure. (p > 0.05).

CONCLUSION

The group filled with AHPB caused a lower fracture strength than the group filled with AHP following a 70 Gy dose of RT. The sealers in the control group, before 60 Gy RT group, after 60 Gy RT group, and before 70 Gy RT group exhibited comparable load-to-failure values.

Chemical, Antibacterial, and Cytotoxic Properties of Four Different Endodontic Sealer Leachates Over Time

INTRODUCTION

The management of apical periodontitis involves the elimination of bacteria to achieve healing of the periapical tissues. To this end, understanding of the antimicrobial properties and cytotoxicity of root canal sealers over time is important. This study aimed to assess the cytocompatibility and antibacterial activity of leachates obtained from selected endodontic sealers.

METHODS

Four sealers were used in this study; AH Plus, an epoxy resin-based sealer, and three hydraulic calcium silicate-based sealers: AH Plus Bioceramic, BioRoot RCS, and BioRoot Flow. Sealer chemistry was assessed by scanning electron microscopy and energy dispersive spectrum analysis. Leachates of the tested sealers were prepared by immersing sealer discs in Hank's balanced salt solution for 28 and 90 days. Element release was assessed using inductively coupled plasma mass spectroscopy. Enterococcus faecalis and Fusobacterium nucleatum were exposed to the leachates followed by colony-forming unit determination, and the human osteoblast-like cell line Saos-2 was assessed with regard to cell death, caspase expression and activity of alkaline phosphatase (ALP) after stimulation with the leachates.

RESULTS

Calcium leaching was detected in the tricalcium silicate-based sealers, which increased the leachate pH significantly (P < .0001). AH Plus Bioceramic leachate displayed antimicrobial activity at 28 days against E. faecalis (P < .01). ALP levels were reduced in response to AH Plus Bioceramic and BioRoot RCS 1-day leachates (P < .05). High cell viability was observed after exposure to all sealers.

CONCLUSIONS

The leachates of the tested sealers were cytocompatible; however, their antimicrobial activity as well as their potential to induce the bone formation marker ALP was minimal.

The effect of bioactive glass-based, bioceramic based and epoxy amine resin based root canal sealers on post-obturation pain: A double blinded randomized controlled trial

Aim

The aim of this study was to compare the effect of two calcium silicate-based and an epoxy resin-based root canal sealers on postoperative pain and analgesic intake following single-visit root canal treatment.

Materials and Method

Ninety patients with at least one first or second molar tooth diagnosed as symptomatic irreversible pulpitis and symptomatic apical periodontitis were selected and allocated into three groups (n=30) according to the sealer used. Root canals were prepared using Protaper Gold instruments (Dentsply Sirona) in a crown down technique and irrigated with 2.5% NaOCl (Calyx, India) and saline solution. Root canal filling was then accomplished with a single cone obturation technique and treated in a single visit by the same endodontist. Patients were told to use a Visual Analog Scale (VAS) to rate their postoperative pain severity as none, minimal, moderate, or severe after 6 h, 24 h, 48 h, 5 days and 7 days following obturation using the appropriate sealers. The need for analgesic intake was also recorded. The data were statistically analyzed.

Results

Results showed a significant difference among the studied groups. Bio-C Sealer Ion+ reported the least pain score followed by Nishika Canal Sealer BG and AH plus sealer at all the time intervals recorded. The intergroup analysis, revealed was a significant difference in postoperative pain at 6 h (p=0.000) and 24 h (p = 0.028), but not at 48 h, 5 day or 7 days (P > 0.05). VAS ratings for all the three groups decreased over time. Also, there were significant differences between the means of analgesic intake among 3 groups (p=0.022). Analgesic intake in group BIO-C Sealer Ion+ is significantly lesser than AH Plus and Nishika Canal Sealer BG group.

Conclusion

Calcium silicate-based sealer (Nishika Canal Sealer BG and Bio-C Sealer Ion+) resulted in significantly lower levels of pain as compared to epoxy resin-based sealer (AH Plus) at 6h and 24-h interval, there was no significant difference in postoperative pain occurrence at 48-h, 5 day and 7-day period. The analgesic intake in Bio-C Sealer Ion+ group is significantly lesser than Nishika Canal Sealer BG and AH Plus group.

To check the antibacterial efficacy against Enterococcus faecalis by various ayurvedic oils used as a solvent in endodontic sealers - An in vitro study

Aim

The aim of the study is to check the antibacterial efficacy of various ayurvedic oils used as a solvent with zinc oxide for preparing endodontic sealers.

Materials and Methods

Forty-five extracted premolars were taken and were cut coronally and apically such that 7 mm of tooth specimen was prepared. Teeth were sterilized by autoclaving inoculated with Enterococcus faecalis and incubated for 24 h. The specimens were divided into three groups of 15 each. Group 1 - ZnO powder + Eugenol, Group 2 - ZnO powder + Aremidadi Oil, and Group 3 - ZnO powder + Dashmool oil. Bacterial growth in each specimen was calculated before and after sealer application and noted as the initial and final colony count. The antimicrobial effect of each sealer was measured by calculating the percentage reduction in colony count (%). One-way analysis of variance and post hoc tests will be used for statistical analysis.

Results

The Zn + Arimedadi oil group showed the maximum antibacterial effect among the sealers tested and the Zn + eugenol sealer showed the least antimicrobial effect In comparison, there was a statistically significant difference between all the groups.

Conclusion

Ayurvedic oil-based root canal sealers showed better antibacterial efficacy than eugenol-based sealers. Arimedadi oil showed the highest antibacterial activity against E. faecalis and Eugenol showed the least when used as a solvent.

Evaluation of Microleakage of Nanoparticle-incorporated Cyanoacrylate Root Canal Sealer Using the Radioisotopic Method: An In Vitro Study

AIM OF THE STUDY

The study aimed to assess the microleakage of nanoparticle-based (NPB) cyanoacrylate sealer and epoxy resin-based (ERB) sealer using radioisotope method and confocal laser scanning microscopy (CLSM).

MATERIALS AND METHODS

A total of 100 single-rooted teeth were collected; specimens were accessed, instrumented, and irrigated, and randomly distributed into 4 groups of 25 samples each: Group I: Positive control, group II: Negative control, group III: Obturated with NPB sealer, and group IV: Obturated with ERB sealer. All samples were immersed in 99mTc pertechnetate solution, for 3 hours after which radioactivity was estimated under a Gamma camera. The radioactivity released by specimens before and after nail varnish removal was statistically analyzed. After 2 weeks, the same samples were used for CLSM analysis. The sealer tubular penetration depth was measured at the deepest level for each group using ZEN lite 2012. Data collected was statistically evaluated.

RESULTS

The amount of radioactivity observed at first in group III and group IV was 194.76 and 599.12 units, respectively, with p-value < 0.001, indicating significant interaction, and after nail varnish removal, it was 89.68 and 468.44 units, respectively, with a p-value < 0.001; again, indicating statistical significance. Hence, the radioactivity of NPB sealer was found to be lower than ERB sealer in both cases, indicating better sealing of the former. The photomicrographs show that mean value of dye penetration in NPB sealer in first, second, and third segment from apex was 85.06, 75.73, and 66.09, respectively; while in the case of ERB sealer, those were 597.28, 461.17, and 195.68, respectively; with p-value < 0.001; signifying that NPB sealer exhibited higher resistance to microleakage than ERB sealer.

CONCLUSION

The NPB sealer can become a potential root canal sealer in future endodontics due to superior physiochemical properties attributed to the cyanoacrylate and incorporated nanoparticles.

CLINICAL SIGNIFICANCE

The study clinically signifies that we can equally use the radioisotopic method along with confocal method while conducting the microleakage studies. In addition, NPB sealer can be an emerging replacement with better properties than gold standard root canal sealers for clinical use. How to cite this article: Shetty C, Qaiser S, Shetty A, et al. Evaluation of Microleakage of Nanoparticle-incorporated Cyanoacrylate Root Canal Sealer Using the Radioisotopic Method: An In Vitro Study. J Contemp Dent Pract 2024;25(4):335-341.

Genotoxicity induced by endodontic sealers: A systematic review

Introduction

This systematic review aimed to help further elucidate the following question: are endodontics sealers able to induce DNA damage in vitro or in vivo?

Methods

This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement 2020 criteria. A total of 23 studies were carefully selected by the authors.

Results

Regarding the general characteristics, most studies evaluated, on average, 3-5 types of sealers (resin epoxy, salicylate, salicylate + MTA, zinc oxide-eugenol, bioceramic products, calcium hydroxide), performing comparisons between them. Our results demonstrate that endodontic sealers may be a genotoxic agent since most studies demonstrated positive findings, with the resin-based ones being the most potentially genotoxic.

Conclusion

The type of genotoxicity assay, material evaluated, and dilution concentration levels influenced the outcome. This study clarifies whether and to what extent endodontic sealers are capable of inducing DNA injury in oral tissues.

Postoperative pain of single-visit endodontic treatment with gutta-percha versus MTA filling: a randomized superiority trial

BACKGROUND

Postoperative pain has remained a challenge for clinicians. This randomized superiority trial compared the levels of postoperative pain following the use of gutta-percha (GP) and sealer or mineral trioxide aggregate (MTA) as root canal filling materials in teeth with asymptomatic apical periodontitis.

METHODS

A total of 119 patients were initially evaluated in this two-arm, parallel-group, single-blind, superiority randomized trial. The inclusion criteria were participants aged 18-65 years with single-canal premolars diagnosed with asymptomatic apical periodontitis. The participants were finally divided into two groups using the permuted block randomization method. In the GP group (N = 46), the cleaned and shaped root canals were filled with gutta-percha and AH Plus sealer, while in the MTA group (N = 48), the cleaned and shaped root canals were filled with an MTA apical filling and a coronal gutta-percha and sealer. Patient pain level was measured 6, 12, 24, 48, and 72 h postoperatively using a 10-point visual analog scale (VAS). The data were analyzed by the chi-square, independent t, Friedman, and Mann-Whitney U tests.

RESULTS

The mean of VAS scores decreased significantly over time in both groups (P < 0.001). The mean VAS scores were significantly lower in the MTA filling group than in the other group (P < 0.05). Female patients reported higher VAS scores at 6- and 12-hour periods in both groups (P < 0.05).

CONCLUSION

MTA as a root canal filling material might be a valuable option for clinicians due to its low postoperative pain.

TRIAL REGISTRATION

The trial protocol was registered at the Registry of Clinical Trials (IRCT20191104045331N1).

Nanoparticles and Their Antibacterial Application in Endodontics

Root canal treatment represents a significant challenge as current cleaning and disinfection methodologies fail to remove persistent bacterial biofilms within the intricate anatomical structures. Recently, the field of nanotechnology has emerged as a promising frontier with numerous biomedical applications. Among the most notable contributions of nanotechnology are nanoparticles, which possess antimicrobial, antifungal, and antiviral properties. Nanoparticles cause the destructuring of bacterial walls, increasing the permeability of the cell membrane, stimulating the generation of reactive oxygen species, and interrupting the replication of deoxyribonucleic acid through the controlled release of ions. Thus, they could revolutionize endodontics, obtaining superior results and guaranteeing a promising short- and long-term prognosis. Therefore, chitosan, silver, graphene, poly(lactic) co-glycolic acid, bioactive glass, mesoporous calcium silicate, hydroxyapatite, zirconia, glucose oxidase magnetic, copper, and zinc oxide nanoparticles in endodontic therapy have been investigated in the present review. The diversified antimicrobial mechanisms of action, the numerous applications, and the high degree of clinical safety could encourage the scientific community to adopt nanoparticles as potential drugs for the treatment of endodontic diseases, overcoming the limitations related to antibiotic resistance and eradication of the biofilm.

Cytotoxicity and genotoxicity of various types of endodontic sealers in Chinese hamster ovary (CHO-K1) cells

This study aimed to evaluate the cytotoxicity and genotoxicity of five endodontic sealers (AH Plus, MTA Fillapex, Endoseal MTA, Sealapex, and Zinc oxide eugenol) in Chinese hamster ovary cells. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay to check cell viability at 1, 3, and 7 days. Genotoxicity was assessed by cytokinesis-block micronucleus, single-cell gel electrophoresis, and γH2AX immunofluorescence assays. Cell viability of all endodontic sealers, except Endoseal MTA, on day 1 was less than 100%. Endoseal MTA showed the highest cell viability on day 7. AH Plus and Endoseal MTA showed less DNA damage than other sealers. After complete setting, AH Plus and Endoseal MTA showed low genotoxicity, which could reduce DNA damage in periapical cells, making them suitable as endodontic sealers.

Antimicrobial efficacy of Kerr pulp canal sealer (EWT) in combination with 10% amoxicillin on Enterococcus faecalis: A confocal laser scanning microscopic study

Background: Sealers with antimicrobial properties play an important role in endodontic therapy success especially against Enterococcus faecalis infection found in failed root canal therapy. Addition of antibiotic agents to endodontic sealers may show significant increase in their antibacterial properties both against anaerobic and aerobic microbes. The purpose of the present study was to evaluate antimicrobial efficacy of Kerr pulp canal sealer (EWT) in combination with 10% amoxicillin against E. faecalis and post-root canal treatment viability of Enterococcus faecalis on the first and seventh day. Methods: A total of 60 extracted human mandibular premolar teeth were decoronated after initial decontamination with 1% NaOCl. Root length standardized to 12 mm. Canal instrumentation was done using ProTaper Universal file system till size F2 using 5.25% NaOCl. It was then infected with a pure strain of E. faecalis for a period of four days. Obturation was done using plain sealer, (n=30) and sealer-antibiotic combination, (n=30). Half of the teeth were sectioned at 24 hours (S, SA) and other half were sectioned seven days after obturation (S7, SA7). All samples were stained with SYTO9 and propidium iodide for imaging under Confocal Laser Scanning microscope. Statistical analysis was performed with the statistical software SPSS v. 17.0 (SPSS for Windows; SPSS Inc, Chicago, IL). Data was analysed using One Way ANOVA and post hoc Tukey test to determine statistical significance with p value < 0.01 considered significant. Results: Statistically significant differences were observed in green to red ratio between group S (9.561976) and S7 (0.435418) (p < 0.01). There was no difference found between SA (mean of green to red ratio, (0.70431) and SA7 (mean of green to red ratio, 0.85184). Conclusions: Antibiotics added to the sealer effectively eradicated of E. faecalis 24 hours post-obturation. However, after seven days, plain sealer was as effective as sealer-antibiotic combination.

Antimicrobial efficacy of Kerr pulp canal sealer (EWT) in combination with 10% amoxicillin on Enterococcus faecalis: A confocal laser scanning microscopic study

Background: Sealers with antimicrobial properties play an important role in endodontic therapy success especially against Enterococcus faecalis infection found in failed root canal therapy. Addition of antibiotic agents to endodontic sealers may show significant increase in their antibacterial properties both against anaerobic and aerobic microbes. The purpose of the present study was to evaluate antimicrobial efficacy of Kerr pulp canal sealer (EWT) in combination with 10% amoxicillin against E. faecalis and post-root canal treatment viability of Enterococcus faecalis on the first and seventh day. Methods: A total of 60 extracted human mandibular premolar teeth were decoronated after initial decontamination with 1% NaOCl. Root length standardized to 12 mm. Canal instrumentation was done using ProTaper Universal file system till size F2 using 5.25% NaOCl. It was then infected with a pure strain of E. faecalis for a period of four days. Obturation was done using plain sealer, (n=30) and sealer-antibiotic combination, (n=30). Half of the teeth were sectioned at 24 hours (S, SA) and other half were sectioned seven days after obturation (S7, SA7). All samples were stained with SYTO9 and propidium iodide for imaging under Confocal Laser Scanning microscope. Statistical analysis was performed with the statistical software SPSS v. 17.0 (SPSS for Windows; SPSS Inc, Chicago, IL). Data was analysed using One Way ANOVA and post hoc Tukey test to determine statistical significance with p value < 0.01 considered significant. Results: Statistically significant differences were observed in green to red ratio between group S (9.561976) and S7 (0.435418) (p < 0.01). There was no difference found between SA (mean of green to red ratio, (0.70431) and SA7 (mean of green to red ratio, 0.85184). Conclusions: Antibiotics added to the sealer effectively eradicated of E. faecalis 24 hours post-obturation. However, after seven days, plain sealer was as effective as sealer-antibiotic combination.

Evaluation of Cytotoxicity of Calcium Silicate-based Mineral Trioxide Aggregate Sealers: A Systematic Review of In Vitro Studies

AIM

This review aimed to evaluate the in vitro studies done with regard to the cytotoxicity associated with mineral trioxide aggregate (MTA)-based root canal sealers.

BACKGROUND

Root canal sealers are used during endodontic treatment as fillers to seal the gaps between the canal gutta-percha cone and canal walls. It is necessary to understand the cytotoxicity of these materials on human-derived cells as these materials interact with human cells periapically.

REVIEW RESULTS

Six in vitro studies were chosen for review. In these selected studies, along with MTA-based root canal sealers, other sealers were tested for cytotoxicity on human periodontal ligament (PDL) stem cells, human PDL fibroblasts, and human osteoblast cells. Regarding cytotoxicity, the studies were diverse, and most were based on 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide) (MTT) assay. In general, the studies suggested that root canal sealers cause mild to severe cytotoxic effects and that several factors influence this effect, such as material setting time, concentration, and duration of exposure.

CONCLUSION

All studies in the review indicated that MTA. Fillapex must be used cautiously as it exhibited the highest cytotoxic effect compared to other MTA-based and non-MTA-based sealers.

CLINICAL SIGNIFICANCE

Endodontic sealers do serve the purpose of bridging the gaps between the gutta-percha cone and the canal wall but knowing its biocompatibility becomes important as the material is extruded beyond the apical foramen where it comes in contact with the surrounding tissues. The effect of sealers on the surrounding tissues affects the healing and prognosis of the treatment.

The effect of two different root canal sealers on treatment outcome and post-obturation pain in single-visit root canal treatment: A prospective randomized clinical trial

AIM

This randomized clinical trial aimed to evaluate and compare the effect of mineral trioxide aggregate (MTA)-based bioceramic- and resin-based sealers on the incidence and intensity of post-obturation pain and treatment outcome in asymptomatic vital molar teeth in single-visit root canal treatment.

METHODOLOGY

One hundred asymptomatic mandibular molar teeth with vital pulp were randomly assigned into two groups according to the sealer used: MTA Fillapex or AH Plus sealer. WaveOne Gold instruments were used for root canal preparations. Root canals were obturated with WaveOne Gold gutta-percha cones corresponding in size and taper to the last instrument used. MTA Fillapex was used in the first group and AH Plus was used in the second group as the root canal sealer. The effects of age, gender, tooth types and the level of root canal filling on the treatment outcome were evaluated after 1 and 2 years. Postoperative pain at 6, 12, 24, 48, 72 h, 4, 5, 6, 7 and 30 days after root canal treatment was measured with the Numerical Rating Scale. Chi-square test was used for the treatment outcome and Mann-Whitney U, chi-Square and Spearman correlation analyses were used for postoperative pain. α = .05 was the level of significance.

RESULTS

Twelve patients did not complete the 2-year follow-up and the study finished with 88 patients. In the MTA Fillapex group 41 correct, one short, two extruded, and in the AH Plus group 40 correct, one short and three extruded root canal fillings were detected. No significant differences were observed between the first- and second-year treatment outcomes between the groups (p > .05).There was no association between age, gender, tooth number, root canal filling length and the treatment success in all evaluated teeth (p > .05). The differences between the groups in terms of postoperative pain incidence and intensity at all time-points were not significant (p > .05). There was no correlation between the age and postoperative pain (p > .05), but pain was statistically higher in women (p < .05).

CONCLUSIONS

Mineral trioxide aggregate Fillapex showed similar success rate and post-obturation pain incidence and intensity as AH Plus sealer and can be used as a root canal sealer in asymptomatic mandibular molars with irreversible pulpitis.

Comparative evaluation of the effect of calcium silicate and epoxy resinbased root canal sealers on postoperative pain in patients with primary endodontic lesion: A randomized clinical study

Introduction

This study's objective was to assess and compare postoperative pain response between bioceramic sealer (Nishika BG) and epoxy resin based (AH Plus) in patients with primary endodontic lesion at time interval of 24 h, 48 h, and 7 days using the Visual Analog Scale (VAS).

Materials and Methods

The study included 40 individuals with necrotic pulp and apical periodontitis. Calcium hydroxide was administered as the intracanal medication during the two-visit endodontic therapy. They were subsequently allocated randomly to either the AH Plus root canal sealer or the Nishika Canal Sealer BG, with a total of 20 participants in each group. Patients were told to use a VAS to rate their postoperative pain severity as none, minimal, moderate, or severe after 24 h, 48 h, and 7 days following obturation using the appropriate sealers.

Results

Nishika Canal Sealer BG (CS-BG) has a lower pain score as compared to the AH Plus group at 24-h time point. VAS ratings for both the groups decreased over time. According to the intergroup analysis, there was a significant difference in postoperative pain at the 24 h (P = 0.022), but not at the 48 h or 7 days (P > 0.05).

Conclusion

Although bioceramic sealer (Nishika Canal Sealer BG) resulted in significantly lower levels of pain as compared to epoxy resin-based sealer (AH Plus) at 24-h interval, there was no significant difference of postoperative pain at 48-h interval and 7-day period.

Immunomodulatory Effects of Endodontic Sealers: A Systematic Review

Inflammation is a crucial step prior to healing, and the regulatory effects of endodontic materials on the immune response can influence tissue repair. This review aimed to answer whether endodontic sealers can modulate the immune cells and inflammation. An electronic search in Scopus, Web of Science, PubMed, and Google Scholar databases were performed. This systematic review was mainly based on PRISMA guidelines, and the risk of bias was evaluated by SYRCLEs and the Modified CONSORT checklist for in vivo and in vitro studies, respectively. In total, 28 articles: 22 in vitro studies, and six in vivo studies were included in this systematic review. AH Plus and AH 26 can down-regulate iNOS mRNA, while S-PRG sealers can down-regulate p65 of NF-κB pathways to inhibit the production of TNF-α, IL-1, and IL-6. In vitro and in vivo studies suggested that various endodontic sealers exhibited immunomodulatory impact in macrophages polarization and inflammatory cytokine production, which could promote healing, tissue repair, and inhibit inflammation. Since the paradigm change from immune inert biomaterials to bioactive materials, endodontic materials, particularly sealers, are required to have modulatory effects in clinical conditions. New generations of endodontic sealers could hamper detrimental inflammatory responses and maintain periodontal tissue, which represent a breakthrough in biocompatibility and functionality of endodontic biomaterials.

Silver Nanoparticles Alone or in Combination with Calcium Hydroxide Modulate the Viability, Attachment, Migration, and Osteogenic Differentiation of Human Mesenchymal Stem Cells

This study aimed to evaluate the effect of silver nanoparticles (AgNPs) alone or in combination with calcium hydroxide (Ca(OH)2) on the proliferation, viability, attachment, migration, and osteogenic differentiation of human mesenchymal stem cells (hMSCs). Different concentrations of AgNPs alone or mixed with Ca(OH)2 were prepared. Cell proliferation was measured using AlamarBlue, and hMSCs attachment to dentin disks was evaluated using scanning electron microscopy. Live-dead imaging was performed to assess apoptosis. Wound healing ability was determined using the scratch-migration assay. To evaluate osteogenic differentiation, the expression of Runt-related transcription factor (RUNX2), Transforming growth factor beta-1 (TGF-β1), Alkaline Phosphatase (ALP), and Osteocalcin (OCN) were measured using real-time reverse transcriptase polymerase chain reaction. ALP staining and activity were also performed as indicators of osteogenic differentiation. AgNPs alone seemed to favor cell attachment. Lower concentrations of AgNPs enhanced cell proliferation. AgNP groups showed markedly less apoptosis. None of the medicaments had adverse effects on wound closure. The expression of TGF-β1 was significantly upregulated in all groups, and OCN was highly expressed in the AgNP groups. AgNPs 0.06% showed the most enhanced ALP gene expression levels, activity, and marked cytochemical staining. In conclusion, AgNPs positively affect hMSCs, making them a potential biomaterial for various clinical applications.

Endodontic sealer-induced maxillary sinusitis: intraoral surgical approach and implant placement at a site of failed nasal endoscopic surgeries

A 28-year-old male patient was referred from an otorhinolaryngologist for managing unilateral chronic maxillary sinusitis (MS). The patient had undergone two functional endoscopic sinus surgeries (FESS), although the MS was not resolved. Based on his dental history, endodontic treatment had been done on the symptomatic area. A leak of endodontic sealer and peri-apical lesion on tooth #14 was found on cone-beam computed tomographic examination. Extraction of tooth #14 and the modified Caldwell-Luc operation were performed to remove the endodontic sealer material and relevant inflammatory tissue. The sinus membrane lining was maintained as much as possible during the surgery. Implant placement was performed on the tooth extraction site. All clinical symptoms disappeared after the surgery. Radiographic and endoscopic examination revealed successful osseointegration of the implant and complete resolution of the MS. FESS alone may not be sufficient to treat MS derived from dental origin. For unilateral MS, dental history should be carefully checked.

Subcutaneous Tissue Response to Adseal and Sure-Seal Root Sealers in Rats: a Histopathological Study

Introduction and objectives: One of the essential phases of root canal treatment is root canal obturation. Solid or semi-solid materials are the most common obturating materials (paste or softened form). Sealer is a biomaterial that enables the sealing process to be carried. This study aimed to evaluate the inflammatory response to Adseal sealer and Sure-Seal Root sealer in rats. Materials and methods:This experimental study was conducted on 28 Wistar rats that were divided into four groups of seven animals per group based on four time periods (7, 14, 30 and 60 days). Each rat received subcutaneous implants containing Adseal sealer (Meta Biomed, Cheongju, Korea) and Sure-Seal Root sealer (Sure Dent Corporation, Gyeonggi-do, South Korea) tubes as well as an empty tube as a control. After the insertion of the tubes, the first to fourth groups were sacrificed on days 7, 14, 30 and 60, respectively, by injecting a high dose of anesthetics. Subsequently, the histopathologic features of the samples were investigated. Data were analyzed in SPSS software (version 26) using Freidman, Wilcoxon, Kruskal-Wallis and Mann-Whitney U tests. A p-value less than 0.05 was considered statistically significant. Results:On day 7, the severity of inflammation was higher in the Adseal sealer and Sure-Seal Root sealer groups compared to the control group. Moreover, on day 14, the level of inflammation was higher in the Sure-Seal Root sealer group than the Adseal sealer and control groups. In addition, on days 30 and 60, the severity of inflammation was similar in both the case and control groups and decreased in all samples. Formation of granulation tissue was observed in all samples on day 14. There was fibrosis tissue in the Sure-Seal Root sealer samples (71.4%) on day 60; however, no fibrosis tissue was observed in the Adseal sealer and control groups. Conclusion:It is concluded that the Sure-Seal Root sealer might lead to a more inflammatory response compared to the Ad Seal sealer. However, due to decreasing inflammation in sealers over time, both sealers are biocompatible.

Strategies of Bioceramics, Bioactive Glasses in Endodontics: Future Perspectives of Restorative Dentistry

Prevalently, there is a primary strategy to cure caries using restorative materials notably bioceramics. Existing synthetic materials stimulate natural tooth structure with acceptable interfacial bonding and esthetic and biomechanical qualities with better durability. Several bioceramics have been introduced and investigated for their potentialities as restorative materials. Biomineralization of tooth initiates repair and regeneration of natural dental tissue and reinstating the integrity of periodontium. In the evolution of bioceramics in the aspects of different essential composition for dental application, recent technology and modern strategies revolutionize the restorative dentistry. Bioglass is one among the important bioceramics as a restorative material, and by regulating the properties of the material, it is possible to construct improved formulation towards restoration. This article reviews the current revolution of endodontics, existing restorative materials, and technologies to be achieve for engineering materials with the better design.

In vitro physicochemical characterization of five root canal sealers and their influence on an ex vivo oral multi-species biofilm community

AIM

To evaluate the physicochemical properties of five root canal sealers and assess their effect on an ex vivo dental plaque-derived polymicrobial community.

METHODOLOGY

Dental plaque-derived microbial communities were exposed to the sealers (AH Plus [AHP], GuttaFlow Bioseal [GFB], Endoseal MTA [ESM], Bio-C sealer [BCS] and BioRoot RCS [BRR]) for 3, 6 and 18 h. The sealers' effect on the biofilm biomass and metabolic activity was quantified using crystal violet (CV) staining and MTT assay, respectively. Biofilm community composition and morphology were assessed by denaturing gradient gel electrophoresis (DGGE), 16S rRNA sequencing and scanning electron microscopy. The ISO6876:2012 specifications were followed to determine the setting time, radiopacity, flowability and solubility. Obturated acrylic teeth were used to assess the sealers' effect on pH. Surface chemical characterization was performed using SEM with coupled energy-dispersive spectroscopy. Data normality was assessed using the Shapiro-Wilk test. One-way anova and Tukey's tests were used to analyze data from setting time, radiopacity, flowability and solubility. Two-way anova and Dunnett's tests were used for the data analysis from CV, MTT and pH. 16S rRNA sequencing data were analyzed for alpha (Shannon index and Chao analysis) and beta diversity (Bray-Curtis dissimilarities). Differences in community composition were evaluated by analysis of similarity (p < .05).

RESULTS

The sealers significantly influenced microbial community composition and morphology. All sealers complied with ISO6876:2012 requirements for setting time, radiopacity and flowability. Although only AHP effectively reduced the biofilm biomass, all sealers, except BRR, reduced biofilm metabolic activity.

CONCLUSION

Despite adequate physical properties, none of the sealers tested prevented biofilm growth. Significant changes in community composition were observed. If observed in vivo, these changes could affect intracanal microbial survival, pathogenicity and treatment outcomes.

Antibacterial and Cytotoxicity of Root Canal Sealer with the Addition of Chitosan Nanoparticle at Various Concentrations

OBJECTIVES

 The aim of this study was to evaluate the addition of chitosan nanoparticle with concentrations of 0, 10, 20, and 30% to the epoxy resin-based (ERB) sealer on its antibacterial and cytotoxicity effect.

METHODS AND MATERIALS

 This research was divided into two studies, the first study was the addition of chitosan with a concentration of 0% (as control), 10, 20, and 30% to an ERB sealer on its antibacterial effect, and the second study was on its cytotoxicity. An agar diffusion test was employed to determine the antibacterial effect on Enterococcus faecalis. An MTT (3-{4,5-dimethylthiazol-2-yl}-2,5-diphenyl tetrazolium bromide) assay was utilized to test the cytotoxicity by evaluating cell viability.

STATISTICAL ANALYSIS

 One-way analysis of variance and Tukey's test (α = 0.05) were used to analyze data obtained from each evaluation with a significance level of 95%.

RESULTS

 The addition of chitosan nanoparticles at concentrations 10, 20, and 30% produced a greater inhibition zone of E. faecalis (p < 0.05), however, had less cytotoxicity compared with no addition of chitosan (0%) (p < 0.05).

CONCLUSION

 The addition of chitosan nanoparticles at concentrations 10, 20, and 30% to the ERB sealer produced greater antibacterial and less cytotoxicity compared with no addition of chitosan (0%).

In Vitro Comparison of the Wettability of a Bioceramic Root Canal Sealer on Dentin With and Without Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) Laser Irradiation

Introduction: To evaluate and compare the wettability of bioceramic root canal sealer (BioRoot™ RCS, Septodont, Saint-Maur-des-Fossés, France) on dentin with and without erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation using different frequencies and energies.

Methods: A hundred single-rooted tooth samples were divided into five groups of 20 samples each. Each group was treated with different methods before sealer application as follows: Group 1: Treated with 2 ml 17% ethylenediaminetetraacetic acid (EDTA) irrigant for one minute (control group); group 2: Irradiated with Er:YAG laser for one minute (8 Hz frequency and 200mJ energy); group 3: Irradiated with Er:YAG laser for one minute (8 Hz frequency and 400mJ energy); group 4: Irradiated with Er:YAG laser for one minute (16 Hz frequency and 200mJ energy); group 5: (n=20) samples irradiated with Er:YAG laser for one minute (16 Hz frequency and 400mJ energy). Bioceramic root canal sealer application was done onto the treated dentin specimen using a micropipette. The contact angle of the drop of the sealer with the dentin surface was measured after five minutes using a contact angle analyzer.

Results: There was no significant difference in wettability between Er:YAG laser using 8Hz frequency and 200mJ energy and Er:YAG laser using 8Hz frequency and 400mJ energy. However, there was a significant difference between the other two groups of Er:YAG laser using 16Hz frequency and 400mJ energy and Er: YAG laser using 16Hz frequency and 200mJ energy.

Conclusion: Contact angle was found to be lowest in the group that was irradiated with Er:YAG laser for one minute (16 Hz frequency and 400mJ energy) before the sealer application. The test findings demonstrated that the control group had the highest contact angle (low wettability) and it was statistically significant with all other groups.

Cytotoxicity and biocompatibility of root canal sealers: A review on recent studies

Many types of endodontic root canal sealers have been employed for the purpose of filling voids and irregularities in root canals, as well as reducing/removing bacterial remnants/remains. Sealers are available in various formulations, and research work to find the most appropriate ones is still ongoing. Recently, many kinds of novel root canal sealers have been introduced under various commercial names. However, most sealers are known to exhibit different levels of cytotoxicity on tissues which would result in prolonged wound healing, inflammation, and bone resorption. Preferably, sealers need to have tolerable biological and physico-chemical properties along with biocompatibility. Additives promoting the biocompatibility and bioactivity of sealers are of major concern in clinical applications. The aim of this review was to compare, evaluate, and analyze comparatively the cytotoxic effects, biocompatibility, and antimicrobial properties of recently used root canal sealers. A comprehensive literature search was made to identify their properties involving biocompatibility and cytotoxicity. In general, the sealers reported in recent literature exhibited favorable biological features in comparison to conventional ones. They promoted better cell viability and biocompatibility. The incorporation of additives influences favorably the potential negative effects. However, it has been highlighted that there is a lack of well-designed long-term clinical applications, and more in vitro and in vivo research work would be helpful to confirm the sustainability of the sealers for further clinical practice.

A novel bioactive glass-based root canal sealer in endodontics

Background/purpose

Bioactive glass (BG), one type of bioceramics, shows similar or better characteristics to calcium silicate which has been regarded as a promising root filling material in endodontics. This study aimed to develop a novel BG-based root canal sealer for endodontics.

Materials and methods

The novel BG-based root canal sealer was composed of phytic acid derived bioactive calcium phosphosilicate glass named PSC mixed with zirconium oxide (ZrO₂) as powder, and phosphate solution (PS) dissolved with sodium alginate (SA) named PS-SA as liquid. Moreover, the physicochemical properties, mineralization, sealing ability and biocompatibility of the novel BG-based root canal sealer were evaluated.

Results

This study developed a novel BG-based sealer named BGS-SA-Zr which contained the powder of PSC and ZrO₂ and the liquid of PS-SA. Results indicated that the flow, film thickness and radiopacity of BGS-SA-Zr conformed to ISO 6876:2012. The setting time and solubility of BGS-SA-Zr were 53.7 ± 1.5 min and 21.46 ± 0.54%, respectively. The pH value of the simulated body fluid (SBF) immersed with BGS-SA-Zr raised slightly up to 7.70. The CCK-8 assay indicated that BGS-SA-Zr had no cytotoxic effects on MG-63 cells. After immersion in SBF for 4 weeks, dense hydroxyapatite crystals were observed on the surface of BGS-SA-Zr. Furthermore, there was no difference in the sealing ability between BGS-SA-Zr and the bioceramic sealer iRoot SP whether setting at 1 day or immersed in SBF for 4 weeks (P > 0.05).

Conclusion

Our results suggest that the novel BG-based sealer may be a promising sealer for endodontic treatment.

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.

Nanomaterials Application in Endodontics

In recent years, nanomaterials have become increasingly present in medicine, especially in dentistry. Their characteristics are proving to be very useful in clinical cases. Due to the intense research in the field of biomaterials and nanotechnology, the efficacy and possibilities of dental procedures have immensely expanded over the years. The nano size of materials allows them to exhibit properties not present in their larger-in-scale counterparts. The medical procedures in endodontics are time-consuming and mostly require several visits to be able to achieve the proper result. In this field of dentistry, there are still major issues about the removal of the mostly bacterial infection from the dental root canals. It has been confirmed that nanoparticles are much more efficient than traditional materials and appear to have superior properties when it comes to surface chemistry and bonding. Their unique antibacterial properties are also promising features in every medical procedure, especially in endodontics. High versatility of use of nanomaterials makes them a powerful tool in dental clinics, in a plethora of endodontic procedures, including pulp regeneration, drug delivery, root repair, disinfection, obturation and canal filling. This study focuses on summing up the current knowledge about the utility of nanomaterials in endodontics, their characteristics, advantages, disadvantages, and provides a number of reasons why research in this field should be continued.

Characterization of a clonal human periodontal ligament stem cell line exposed to methacrylate resin-, bioactive glass-, or silicon-based root canal sealers

The aim of this study was to characterize a clonal human periodontal ligament (PDL) stem cell line (line 2-23 cells) cultured with root canal sealers based on methacrylate resin (SuperBond sealer; SB), bioactive glass (Nishika Canal Sealer BG; BG), or silicon (GuttaFlow 2; GF). The sealers were set in rubber molds to form sealer discs. Line 2-23 cells were cultured with or without the discs for 3 days. The cell viability was evaluated by direct cell counting and MTT assay. Inflammation-, PDL-, collagen-, and cell cycle-related gene expression was investigated by real-time RT-PCR. Collagen production was analyzed by Picro Sirius Red staining. Calcium ion concentration in the culture was measured by a QuantiChrom calcium assay kit. Line 2-23 cells survived when cultured with GF discs, but decreased cell viability was observed with SB and BG discs. The expression of inflammation-related genes was higher in cells cultured with SB discs, and expression of PDL-related genes was lower in cells exposed to SB and BG discs. These discs also down-regulated collagen production in line 2-23 cells. BG discs increased calcium ion concentration in the culture medium. Cells exposed to GF discs exhibited the same inflammation-, PDL-, collagen-, and cell cycle-related gene expression and collagen production as untreated cells. These results suggested that the characteristics of line 2-23 cells cultured with GF discs was highly resemble to untreated cells throughout the 3 days of the culture model.

Influence of adjunctive photodynamic therapy (curcumin) on the extrusion bond strength of radicular dentin to contemporary root canal sealers

OBJECTIVE

The aim was to compare Photodynamic therapy (PDT) as an adjunct to NaOCl and EDTA on the extrusion bond strength (EBS) of AH Plus (AH), Sealapex (SA) and MTA Fillapex (MF) root canal sealers.

MATERIALS AND METHOD

Root canal treatment for human teeth (n = 60) using protaper universal system was performed followed by irrigation with NaOCl/ EDTA. Samples were divided (n = 30) based on disinfection technique, NaOCl/EDTA and NaOCl/EDTA with PDT (Curcumin-PS-CP) as an adjunct. Specimens were divided in three subgroups (n = 10) based on sealers used (Gp 1-Na-E-AH, Gp 2-Na-E-PDT-AH, Gp 3-Na-E-SA, Gp 4-Na-E-PDT-SA, Gp 5-Na-E-MF & Gp 6-Na-E-PDT-MF). Canals were dried and obturated followed by sectioning at coronal and middle third. EBS testing was performed using a universal testing machine (UTM) and modes of failure were assessed. Analysis of variance (ANOVA) and Tukey multiple comparison tests were used to compare the means of EBS. (p < 0.05).

RESULTS

Sealers showed a significant influence on EBS, as Gp 1 (Co: 9.21 ± 0.62, Mid: 8.54 ± 0.55) and Gp 2 (Co: 7.11 ± 0.68, Mid: 7.30 ± 0.37) showed higher EBS than Gp 3 (Co: 5.21 ± 0.63, Mid: 4.36 ± 0.83) and Gp 4 (Co: 5.39 ± 0.72, Mid: 4.46 ± 0.74). Gp 5 (Co: 9.04 ± 0.13, Mid: 8.14 ± 0.91) and Gp 6 (Co: 8.67 ± 0.42, Mid: 8.07 ± 0.07) exhibited higher EBS than Gp 3 and Gp 4 specimens. Adjunctive use of PDT for AH sealer (Gp 2) showed decreased EBS compared to Gp 1 specimens. EBS remained comparable for both MTA-Fillapex and Sealapex with and without PDT.

CONCLUSION

AH Plus (Gp 1 and 2) and MTA-Fillapex (Gp 5 and 6) sealers displayed better EBS compared to Sealapex (Group 3 and 4). Adjunctive Application of PDT (CP) did not show a significant improvement in bond strength of sealers to root dentin.

Genotoxicity of root canal sealers: a literature review

OBJECTIVES

Root canal sealers are widely used worldwide in endodontics to prevent reinfection and growth of surviving microorganisms. Considering the strong correlation between genetic damage and carcinogenesis, evaluation of genotoxicity induced by endodontic sealers is recommended for elucidating the true health risks to patients and professionals. The purpose of this article was to provide a comprehensive review of studies involving genotoxicity analysis of endodontic sealers and the used methodologies.

MATERIALS AND METHODS

A literature search was made in PubMed using the following combination of words "genotoxicity," "mutagenicity," "endodontic sealers," and "root canal sealers." A total of 39 articles with genotoxicity studies were selected for the present study.

RESULTS

Sealers have been ranked in decreasing order of their genotoxicity as: ZOE sealers > GIC sealers > S sealers > ER sealers > MR sealers > Novel sealers > CH sealers > CS sealers.

CONCLUSIONS

All published data showed some evidence of genotoxicity for most of the commercial root canal sealers; however, contradictory results were found, mainly for AH Plus, the most studied sealer.

CLINICAL RELEVANCE

The information provided would direct the endodontists to use the less genotoxic materials in endodontic treatment in a way to reduce DNA damage promoting oral healthcare.

Structural, fluoride release, and 3D interfacial adhesion analysis of bioactive endodontic sealers

The experimental bioactive sealers were synthesized by incorporating fluoridated-nano-bioactive glass (F-nBG; 2.5 and 5wt%) in AH Plus^® (Dentsply DeTrey, Konstanz, Germany) sealer and denoted as AH-FBG2.5 and AH-FBG5, respectively. Structural pattern, setting time, flowability, and water sorption analysis were performed. The fluoride release behavior was evaluated periodically over the course of 40 days using inductively coupled plasma optical emission spectroscopy. For sealing ability, post-extraction single-rooted teeth were obturated with sealers. The percentage of voids and sealing ability were evaluated periodically using micro-computed tomography (micro-CT) followed by push-out bond strength. The Fourier transform infrared spectra showed a change in peak height with an increase in the concentration of fillers. The setting time, flowability, and water sorption of experimental groups were within the acceptable clinical range. The fluoride release, sealing ability, and bond strength of experimental sealers were significantly high. The experimental sealers have potential to overcome sealing ability issues of sealers.

Comparative Evaluation of Physicochemical Properties and Apical Sealing Ability of a Resin Sealer Modified with Pachymic Acid

Objective:

The addition of pachymic acid (PA) to AH Plus (an epoxy resin sealer) offsets the cytotoxicity of the latter. Prior to the clinical implementation of this formulation, a thorough knowledge of its physicochemical properties and sealing ability becomes mandatory. Hence, this in vitro study aimed to characterize and evaluate the physicochemical properties and apical sealing ability of AH Plus (AHP) with and without the addition of PA.

Methods:

Flow, setting time, film thickness, solubility and radiopacity of AHP (group 1) and AHP modified with PA (AHP/PA, group 2) were evaluated in accordance with the guidelines put forth by ISO 6876:2012. The percentage was determined under each parameter. Apical sealing ability was assessed using fluid filtration device. An independent samples t-test was used for inter- and intra-group comparisons of mean fluid flow (MFF).

Results:

Incorporating PA to AHP decreased its flow, setting time and film thickness by 24.34%, 2.14% and 31.71% respectively. The solubility of group 2 increased on day 1 by 85.71% and decreased on days 3, 7 and 14 by 46.67%, 34.79% and 13.8% respectively. The radiopacity of AHP was not altered by the addition of PA. MFF rates of group 2 was significantly higher than group 1 on day 1, but not significantly different on day 7.

Conclusion:

AHP/PA exhibited physicochemical properties that were within the requirements of ISO and with time, and showed fluid flow similar to AHP.

Maintenance of oral function in 3 cats with dental resorption

Mandibular molar tooth function is important for cats, however, current veterinary dental practice is to extract teeth affected by even very small resorptive lesions. The aim of this article was to describe an attempt at salvaging mandibular molar teeth where the mesial root and associated crown remained unaffected by resorption. Three cats presented with localised resorption of the distal root of a mandibular molar tooth were treated by hemisection, extraction of the distal root and endodontic treatment of the mesial root. The oral function was maintained in all three cats with no clinical evidence of pain or further resorption at follow-up 10 months post treatment. One cat was also examined at 27 months post treatment, at which stage there was still no oral discomfort and the tooth appeared fine but there were radiographic signs suggestive of early apical resorption. Whilst longer term follow-up is required, it appears that hemisection may be an acceptable treatment for these localised resorptive lesions, at least for the short to medium term.

Comparative evaluation of sealing ability of gutta percha and resilon as root canal filling materials- a systematic review

This systematic review aims to comparatively evaluate the sealing ability gutta-percha and resilon as root canal filling materials. A Medline search was conducted to identify in-vitro studies published between October 01, 2004 and October 01, 2019, conducted on human extracted teeth, published in English and testing the sealing ability of gutta-percha and resilon as root canal filling materials using fluid filtration method. The search identified fifty-five published articles. After a thorough screening, five articles meeting the selection, and validity assessment criteria were critically appraised. The results indicated that during the initial time-period, resilon/epiphany sealer has better sealing ability than gutta-percha. However, over a period of time the resilon system demonstrated increased fluid flow. Gutta-percha with AH plus sealer showed the best long term sealing ability.

Comparative apical sealing evaluation of two bioceramic endodontic sealers

AIM

The current study aims to evaluate, using scanning electronic microscopy, the sealing ability of two bioceramic endodontic sealers, one consecrated and one experimental.

METHODS

Twenty monoradicular teeth were included in the study. The teeth were endodontically prepared at the working length. The shaping and cleaning involved the use of chelating gel MM EDTA 19% and continuous irrigation with sodium hypochlorite 2.5%. The radicular filling was performed using gutta-percha in association with a sealer. Ten teeth were filled with consecrated endodontic filling material and the others ten with the experimental bioceramic based sealer.

RESULTS

The evaluation of the sealers using SEM analysis allowed the identification and the measurement of gaps on the radicular dentin/sealer interface and the degree of apical sealing ability. No significant statistical difference was observed between the gap dimensions in the three areas for the tested bioceramic materials (p<0.005). In the apical region a homogenous layer with extensions intersecting the hybrid layer was observed when the experimental bioceramic sealer was used. In case of teeth filled with commercial sealer, peripheral hybrid extended areas were identified.

CONCLUSIONS

The two bioceramic sealers presented similar apical sealing. Gaps were identified in both sealers but also the presence of hybrid layer was identified.

Assessment of pain and dissolution of apically extruded sealers and their effect on the periradicular tissues

Aim:

This study aimed to evaluate the intensity of pain after unintentional extrusion of resin-based and calcium hydroxide (Ca[OH]₂)-based endodontic sealers as well as their influence on the periradicular tissues.

Materials and Methods:

A total of 120 single-rooted teeth exhibiting extrusion of sealer in the postoperative radiographs were included in the study. According to the sealers used, the teeth were divided into four groups (n = 30): Group I – AH Plus^®, Group II – Resino Seal, Group III – Sealapex™, and Group IV – Apexit^® Plus. Postoperative pain was assessed at 0–6 h, 6–12 h, 12–24 h, and 24–48 h of obturation using Visual Analog Scale. Radiographs were taken at 3, 6, and ≥9 months to 1-year follow-up and compared with baseline radiographs to assess the dissolution of extruded sealers and healing of periradicular tissues.

Statistical Analysis:

ANOVA, Kruskal–Wallis, and Pearson's Chi-square test were used. Statistical significance level was set at P ≤ 0.05.

Results:

Postoperative pain intensity was higher in case of AH Plus^® sealer followed by Sealapex™ up to 12 h of obturation and was statistically nonsignificant. Apexit^® Plus at all time intervals showed statistically significant less pain intensity than AH Plus^® and Sealapex™ but not from Resino Seal group. At 9-month follow-up, better healing of periradicular tissues was shown by AH Plus^® (48.1%) followed by Apexit^® Plus (44.4%) and Sealapex™ (41.2%) with statistically nonsignificant difference.

Conclusion:

In case of periapical extrusion, both resin-based and Ca(OH)₂-based sealers caused postoperative pain. Both Ca(OH)₂- and resin-based sealers did not influence the treatment outcome.

Effect of root canal sealers on human periodontal ligament fibroblast viability: ex vivo study

The aim of the study was to compare ex vivo the toxic effects of six root canal sealers immediately after mixing or setting on human periodontal ligament fibroblasts (HPdLF). Freshly mixed (I group) or set (allowed to dry for 24 h) (II group) specimens of AH Plus Jet (AH), Apexit Plus (AP), MTA Fillapex (FL), GuttaFlow (GF), MetaSEAL Soft (META), and Tubli-Seal (TS) were prepared. HPdLF were exposed for 24 h to the specimens. 3-(4,5-dimethylthiazolo-2-yl)-2,5-diphenyltetrazolium bromide assay was used to examine the effect of the root canal sealers on mitochondrial metabolic activity. Fluorescein isothiocyanate (FITC)-annexin V (AnV) and propidium iodide staining followed by flow cytometry was used to identify the effects of the materials on cell apoptosis/necrosis. Statistical analyses were performed by one-way ANOVA followed by post hoc tests, and significance was determined at P < 0.05. Most materials from the two groups reduced the viability of the cultured cells compared with the control group (P < 0.05). Statistical analysis showed significant differences in HPdLF viability between the individual materials in each group (P < 0.001). AH and AP induced a significant increase in the percentage of apoptotic cells, while TS, FL, and META elevated the proportion of necrotic cells compared with other materials and the controls (p < 0.05). The cytotoxic effects of the tested root canal sealers (both fresh and set) on HPdLF varied. Both forms of sealers were able to cause toxic effects by inducing apoptosis and necrosis in HPdLF. The cytotoxicity of FL, META, TS was mainly associated with necrosis, while AH and AP with apoptosis.

In Vitro Cytotoxicity of a New Nano Root Canal Sealer on Human Gingival Fibroblasts

Introduction:

The aim of this in vitro study was to evaluate the cytotoxicity of a new nano zinc-oxide eugenol (NZOE) sealer on human gingival fibroblasts (HGFs) compared with Pulpdent (micro-sized ZOE sealer) and AH-26 (resin-based sealer).

Methods and Materials:

The Pulpdent, AH-26, and NZOE sealers were prepared and exposed to cell culture media immediately after setting, and 24 h and one week after setting. Then, the primary cultured HGFs were incubated for 24 h with different dilutions (1:1 to 1:32) of each sealer extract. Cell viability was evaluated by methyl thiazolyl diphenyl tetrazolium bromide (MTT) assay. The results were compared using two-way analysis of variance followed by Tukey’s post hoc test. The level of significance was set at 0.05.

Results:

All sealer extracts, up to 32 times dilutions, showed cytotoxicity when exposed to HGF immediately after setting. The extracts obtained 24 h or one week after setting showed lower cytotoxicity than extracts obtained immediately after setting. At all setting times, NZOE showed lower cytotoxicity than Pulpdent and AH-26. While one-week extracts of NZOE had no significant effect on the viability of HGF at dilutions 1:4 to 1:32, both Pulpdent and AH-26 decreased the cell viability at dilutions of 1:4 and 1:8.

Conclusion:

NZOE exhibited lower cytotoxicity compared to Pulpdent and AH-26 on HGF and has the potential to be considered as a new root canal filling material.

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.

Bioceramic-Based Root Canal Sealers: A Review

Bioceramic-based root canal sealers are considered to be an advantageous technology in endodontics. The aim of this review was to consider laboratory experiments and clinical studies of these sealers. An extensive search of the endodontic literature was made to identify publications related to bioceramic-based root canal sealers. The outcome of laboratory and clinical studies on the biological and physical properties of bioceramic-based sealers along with comparative studies with other sealers was assessed. Several studies were evaluated covering different properties of bioceramic-based sealers including physical properties, biocompatibility, sealing ability, adhesion, solubility, and antibacterial efficacy. Bioceramic-based sealers were found to be biocompatible and comparable to other commercial sealers. The clinical outcomes associated with the use of bioceramic-based root canal sealers are not established in the literature.

The effect of temperature on rheological properties of endodontic sealers

Aim:

The purpose of this study was to investigate temperature-dependent rheological properties of three endodontic sealers MTA Fillapex (Angelus, Brazil), AH Plus (Dentsply, Germany), and EndoREZ (Ultradent, USA).

Materials and Methods:

Five samples of each group of endodontic sealers (n = 30) were freshly mixed and placed on the plate of a rheometer (MCR 301, AntonPaar, Physica) and examined at 25°C and 37°C temperature, respectively. Rheological properties of the sealers were calculated according to the loss modulus (G″), storage modulus (G′), loss factor (Tan δ), and complex viscosity (η*) using dynamic oscillatory shear tests.

Results:

Statistical analysis (Wilcoxon signed-rank test) demonstrated that MTA Fillapex exhibited higher loss modulus (G″ > G′) and a crossover region. AH Plus and EndoREZ had a higher storage modulus (G′ > G″) at both temperatures. Loss factor (Tan δ) of MTA Fillapex was the highest compared to AH Plus, followed by EndoREZ. With a temperature change from 25°C to 37°C, MTA Fillapex exhibited a decrease while AH Plus exhibited an increase and, EndoREZ exhibited the least change, in complex viscosity (η*).

Conclusions:

EndoREZ exhibited better rheological properties compared to the other two test sealers.