Initial In Vitro Biological Response to Contemporary Endodontic Sealers

Biological properties versus solubility of endodontic sealers and cements

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

Anti-Candida activity and biocompatibility of silver nanoparticles associated with denture glaze: a new approach to the management of denture stomatitis

The association of silver nanoparticles (AgNps) to sealant agent Palaseal® can be a promising alternative for complete denture wearers who may develop denture stomatitis (DS). The study aimed to evaluate the anti-Candida and biocompatible potential of silver nanoparticles synthesized by three routes associated with denture glaze to prevent and/or treat oral candidiasis. Surface acrylic resin specimens were treated with different associations of glaze with AgNps (VER+AgUV, VER+AgTurk and VER+AgGm). As controls, specimens were treated with glaze+nystatin (VER+Nyst), glaze only (VER) or submerged in PBS (PBS). Afterwards, Candida albicans biofilm was developed for 24 h, 15 d and 30 d. Subsequently, the biofilm was quantified by CFU/mL, XTT assay and confocal laser scanning microscopy. Fibroblasts were submitted to conditioned medium with the same associations for 24, 48 and 72 h and LIVE/DEAD® viability test was carried out. Regardless of the period, there was a significant reduction (p < 0.01) of viable fungal cells load, as well as inhibition of fungal metabolic activity, in specimens treated with glaze+AgNps associations, compared to VER and PBS. The anti-Candida effects of the associations were similar to the VER+Nyst group, with emphasis on VER+AgGm, which showed the highest percentage values of non-viable fungal cells maintained over time. The associations did not prove toxicity to fibroblasts. The AgNps exerted antimicrobial activity against C. albicans biofilms and are biocompatible. The most effective results were achieved with the association of glaze+silver nanoparticles synthesized by the green chemistry method (AgGm), proving to be an innovative alternative in the management of DS.

Evaluation of cytotoxicity and adaptability of a novel bioceramic root canal sealer: An in vitro and scanning electron microscope study

Context

Cytotoxicity and adaptability are among the highly imperative tests that should be performed on a novel endodontic material to ensure its successful implementation in endodontic treatment.

Aims

Assess a recently introduced bioceramic root canal sealer CeramoSeal with TotalFill BC and AH plus sealers regarding the cytotoxicity and adaptability.

Materials and Methods

Five sealer discs were prepared for each sealer and their extracts were cultured in 96-well plates containing human fibroblasts for 24 h. After their incubation, MTT solution was added to each well plate using an enzyme-linked immunosorbent assay plate reader was implemented to calculate the percentage of viable cells. Thirty mandibular single-rooted premolars were prepared using the Edge Endo rotary system, teeth were divided into three groups (n = 10) based on the sealer type: Group 1 CeramoSeal, Group 2 Totalfill, and Group 3 AH plus sealer. Teeth were sectioned longitudinally and viewed under a scanning electron microscope where the region with the gaps was identified and quantified as a percentage of the root canal's overall area.

Statistical Analysis

One-way ANOVA test was used for cytotoxicity, while Kruskal-Wallis and Friedman's tests were used for adaptability.

Results

Ceramoseal statistically significantly showed the lowest viability, at high concentrations AH plus showed the highest cell viability, while at lower concentration Totalfill BC sealer showed the highest cell viability percentage. The gap percentages were statistically significantly higher in Ceramoseal group, there was no statistically significant difference between AH Plus and Totalfill groups.

Conclusions

Ceramoseal sealer exhibited the lowest viability and highest gap percentage compared to the other sealers.

Biocompatibility of three different root canal sealers, experimental study

OBJECTIVES

This study was assessed the biocompatibility of three different root canal sealers (Well-Root St, GuttaFlow Bioseal, and AH-Plus) following implantation in rat subcutaneous tissues, using histopathological immunohistochemical analysis.

METHODS

Four groups of eighty-four male rats each underwent subcutaneous dorsal implantation of a polyethylene tube, either empty or filled. Tissues were collected, fixed, and processed for histological analysis after 7, 15, and 30 d. Slides were photographed and digitally processed to identify lymphocytes and macrophages using Cluster of differentiation 3 (CD3) and cluster of differentiation 68 (CD68) markers, respectively. P was set at 0.05, when lymphocyte and macrophage infiltration was compared between groups and observation times using one-way analysis of variance (ANOVA).

RESULTS

Histopathological analysis of all groups revealed an inflammatory reaction followed by the emergence of a fibrous capsule after 7 days. After 30 days, the thickness of the fibrous capsule and the inflammatory response subsided. CD3 staining for immunohistochemical analysis revealed that the AH-Plus group had the highest mean percentage of lymphocyte infiltration at 7 and 15 days, followed by the Well-Root St, GuttaFlow Bioseal, and Control groups. After 30 days, no discernible difference was observed between the groups in terms of the mean percentage of lymphocyte infiltration. After 7, 15, and 30 days, there was a significant difference in the mean percentage of macrophage infiltration across the groups, as demonstrated by CD68 staining. After 7, 15, and 30 days, the AH-Plus group had the highest mean percentage of macrophage infiltration, followed by the Well-Root St. and GuttaFlow Bioseal groups, while the control group had the lowest mean percentage.

CONCLUSION

All observational periods showed minimal inflammatory reactions to GuttaFlow Bioseal. After subcutaneous tissue implantation in a rat model, the initial inflammatory reactions to Well-Root St and AH-Plus had abated by day 30, and all tested sealers had outstanding biocompatibility.

Trends of calcium silicate biomaterials in medical research and applications: A bibliometric analysis from 1990 to 2020

Background: Calcium silicate biomaterials (CSB) have witnessed rapid development in the past 30 years. This study aimed to accomplish a comprehensive bibliometric analysis of the published research literature on CSB for biomedical applications and explore the research hotspot and current status.

Methods: Articles related to CSB published in the last three decades (1990–2020) were retrieved from Web of Science Core Collection. The R bibliometrix package and VOSviewer were used to construct publication outputs and collaborative networking among authors, their institutes, countries, journals’ matrices and keywords plus.

Results: A total of 872 publications fulfilling the search criteria were included. CSB is mainly reported for bone tissues and dental applications. Among researchers, Chang J from Chinese Academy of Sciences and Gandolfi MG from the University of Bologna are the most productive author in these two fields, respectively. China was the leading contributor to the research on CSB in the medical field. A total of 130 keywords appeared more ten or more times were identified. The term “mineral trioxide aggregate” ranked first with 268 occurrences. The co-occurrence analysis identified three major clusters: CSB in dentistry, bone tissue and vitro bioactivity.

Conclusion: Calcium silicate biomaterials have a promising scope for various biomedical applications ranging from regeneration of hard tissues (bone and teeth) to skin, tumor, cardiac muscle and other soft tissues. This study may help researchers further understand the frontiers of the field.

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.

In vitro cytocompatibility and osteogenic potential of calcium silicate-based dental cements in a root canal-filling model

OBJECTIVE

To investigate the in vitro cytocompatibility and osteogenic potential of an experimental calcium silicate-based cement and the inflammatory response in human periodontal ligament stem cells (hPDLSCs).

METHODS

Cellular responses, osteogenic-related gene expression, and the production of inflammatory cytokines including interleukin (IL)-6 and IL-8 were studied in hPDLSCs exposed to the experimental root canal-filling material C-Root, the commercial tricalcium silicate-based material BioRoot RCS, and the epoxy resin-based material AH Plus. Differences were analyzed using one-way ANOVA with Bonferroni-adjusted pairwise comparison.

RESULTS

Exposure to BioRoot and C-Root caused time-dependent increases in cell proliferation. Significantly more mineralized nodules were formed in cells exposed to AH Plus and BioRoot compared with the negative control. Alkaline phosphatase (ALP) activity was significantly lower in AH Plus cells compared with negative control, BioRoot, and C-Root cells. ALP, osteocalcin (OCN), and runt-related transcription factor2 (RUNX2) mRNA expression levels were all significantly higher in C-Root compared with AH Plus cells at day 7. IL-6 and IL-8 levels differed significantly among the experimental groups, with the highest IL-8 levels in BioRoot cells at days 7 and 14.

CONCLUSION

The experimental root canal-filling material C-Root has similar in vitro cytocompatibility to BioRoot and better osteogenic potential than AH Plus.

Biocompatibility of Root Canal Sealers: A Systematic Review of In Vitro and In Vivo Studies

(1) Aim: To perform a systematic review of the literature on the biocompatibility of root canal sealers that encompasses the various types of sealers that are commercially available as well as both in vitro and in vivo evidence. (2) Methods: This systematic review has been registered in PROSPERO (ID 140445) and was carried out according to PRISMA guidelines using the following databases: PubMed, Cochrane Library, ClinicalTrials.gov, Science Direct, and Web of Science Core Collection. Studies published between 2000 and 11 June 2019 that evaluated cytotoxicity (cell viability/proliferation) and biocompatibility (tissue response) of root canal sealers were included. (3) Results: From a total of 1249 studies, 73 in vitro and 21 in vivo studies were included. In general, studies suggest that root canal sealers elicit mild to severe toxic effects and that several factors may influence biocompatibility, e.g., material setting condition and time, material concentration, and type of exposure. Bioactive endodontic sealers seem to exhibit a lower toxic potential in vitro. (4) Conclusions: The available evidence shows that root canal sealers exhibit variable toxic potential at the cellular and tissue level. However, the methodological heterogeneity among studies included in this systematic review and the somewhat conflicting results do not allow a conclusion on which type of sealer presents higher biocompatibility. Further research is crucial to achieve a better understanding of the biological effects of root canal sealers.

Assessment of Extrusion and Postoperative Pain of a Bioceramic and Resin-Based Root Canal Sealer

Objectives  The objective of this study was to compare a bioceramic and a resin-based endodontic sealer with regard to extrusion and postoperative pain.

Materials and Methods  Sixty-four patients requiring endodontic treatment of single-rooted maxillary teeth with necrotic pulps were included in this study. The root canal treatments were performed in a single visit using a size 40.06 single-file reciprocating system under 2.5% NaOCl irrigation. After irrigation with 17% ethylenediaminetetraacetic acid (EDTA) and 2.5% NaOCl, the canals were dried and randomly divided into two different groups ( n = 32) depending on the sealer used: resin-based group (RG) in which the canals were filled with the AH Plus, and the bioceramic group (BG) in which the canals were filled with the Sealer Plus BC. Ibuprofen (600 mg) was prescribed every 6 hours if the volunteers experienced pain. The patients registered their pain sensation in a visual analog scale (VAS) card, ranging from 0 to 10 at 24-hour, 48-hour, 72-hour, and 1-week intervals. Statistical analysis  For statistical analysis, the level of significance was set at p < 0.05.

Results  Sealer extrusion occurred in nine patients of the RG and in 19 patients of the BG ( p < 0.05). The average pain level at 24-hour and 48-hour intervals was, respectively, 1.46 ± 1.96 and 0.44 ± 0.86 for RG, and 1.21 ± 2.09 and 0.09 ± 0.38 for BG. There was no report of pain after 48 hours. The mean number of tablets taken for pain relief was 0.03 ± 0.17 for RG and 0.06 ± 0.24 for BG. No statistically significant difference was found with regard to pain level and intake of pain killer tablets ( p > 0.05).

Conclusions  The BG sealer presented significantly more extrusion than the RG sealer. Sealer extrusion was not associated with pain. The average pain level and the mean number of tablets taken for pain relief were similar in both groups.

Assessment of cell viability in four novel endodontic sealers

Objective

The aim of this study was to evaluate the viability of human periodontal ligament (PDL) cells on MTA-Fillapex, GuttaFlow 2, TotalFill Sealer, and BioRoot™ RCS in comparison to conventional epoxy resin-based (AH Plus) and zinc oxide-eugenol-based (Roth's 801) sealers.

Materials and Methods

Sealers were divided into two groups, and five coverslips for each material per group were prepared. In the first group, PDLs were added immediately after the preparation of sealers (Fresh Group), and in the second, PDLs were added after 24 h. PDLs were cultured for 72 h and afterward, counted using standard hematocytometry. A Mann-Whitney U-test and Kruskal-Wallis test were used for the statistical analysis. The level of significance was set at 5%. Furthermore, cell morphology was assessed by confocal microscopy.

Results

The number of viable cells for the 24 h-set groups was higher than the freshly mixed in all sealers except Roth's 801. In both groups, GuttaFlow 2 presented the highest number of viable cells. In a descending order of cells' survival, TotalFill, BioRoot, and MTA-Fillapex are following and the conventional sealers, AH Plus and Roth's 801, seem not to exhibit the biological properties of the others. Cells grown on GuttaFlow 2, TotalFill, and BioRoot were observed to be well-formed. In contrast, MTA-Fillapex exhibited untypical morphology. No cells were detected on the surfaces of AH Plus, as well as Roth's 801.

Conclusions

All novel sealers presented increased cell viability in comparison to conventional sealers. GuttaFlow 2 exhibited the highest cell viability.

Biocompatibility of a bioceramic silicone-based sealer in subcutaneous tissue

This study evaluated the biocompatibility of a new silicone-based sealer (GuttaFlow Bioseal) in rat subcutaneous tissue and compared the results with those for GuttaFlow2 and AH Plus. Each of 16 Wistar rats received four subcutaneous tissue implants, namely, GuttaFlow Bioseal, GuttaFlow2, AH Plus, and one empty polyethylene tube. Eight rats were euthanized at day 8 and the remaining eight at day 30. Histological sections were stained with haematoxylin and eosin and analysed with a light microscope. Scores were established for inflammatory reaction, macrophage infiltrate, thickness of the fibrous capsule, and vascular changes. Differences between groups were assessed by using the Friedman test with Bonferroni correction. Histological analysis showed that GuttaFlow Bioseal had the lowest inflammatory reaction of all tested sealers at day 8. At day 30, the silicone-based sealers had similar inflammation profiles, but inflammation scores were nonsignificantly higher for AH Plus than for the negative control. The inflammatory reaction decreased from day 8 to day 30 in all sealers. GuttaFlow Bioseal had the most macrophage infiltrate. Under the present experimental conditions, GuttaFlow Bioseal induced limited inflammatory reactions at days 8 and 30, and initial inflammatory reactions to GuttaFlow2 and AH Plus subsided within 30 days. All tested sealers exhibited satisfactory biocompatibility at day 30 after subcutaneous implantation.

Novel Fast-Setting Mineral Trioxide Aggregate: Its Formulation, Chemical-Physical Properties, and Cytocompatibility

One of the main drawbacks that limits the application of mineral trioxide aggregate (MTA) in dental field is its long setting time. Mineral trioxide aggregate with accelerated setting properties and excellent chemical-physical and biological properties is still required. In this study, an innovative mineral trioxide aggregate, which consists of calcium silicates, calcium aluminates, and zirconium oxide, was designed to obtain fast-setting property. The optimized formulation can achieve initial setting in 10 min and final setting in 15 min, which are much faster than commercial mineral trioxide aggregate. In addition, the optimized fast-setting MTA showed adequate radiopacity and good biocompatibility. The ion concentrations after storage in water for 1 day were 52.3 mg/L Ca, 67.7 mg/L Al, 48.8 mg/L Si, and 11.7 mg/L Mg. The hydration products of hardened cements were investigated by X-ray diffraction, scanning electron microscopy, and Fourier transform infrared, showing the accelerated setting time was due to the formation of honeycomb-like calcium silicate hydrate gel. The novel MTA could be a promising material for dental applications.

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.

Neurotoxicity evaluation of three root canal sealers on cultured rat trigeminal ganglion neurons

Background

The aim of this study was to investigate the possible neurotoxic effects of 3 root canal sealers (RCSs) (AH Plus, GuttaFlow, iRoot SP) on cultured rat trigeminal ganglion (TG) neurons.

Material and Methods

Primary cultures of TG neurons were obtained from 1 to 2-day old rats. Freshly mixed RCSs were incubated in sterile phosphate buffered saline and cells were incubated with supernatants of the RCSs for different time intervals (1-, 3-, 6- and 24-h; 1 or 1/10 diluted) and viability/cytotoxicity was tested by counting the number of live cells. Pair of dishes with cells from the same culture incubated with only culture medium was considered as negative controls. Cell images were captured and acquired at x200 magnification using a microscope equipped with a camera using special image program. The viable cells were manually counted assigned from the images for each dose and incubation duration. Data was analysed by using 1-way analysis of variance with Tukey post hoc tests.

Results

There was no significant change in cell viability after short duration of incubation (1- and 3-h) with the supernatant of any of RCSs, except for undiluted-AH Plus at 3-h. When AH Plus was compared with other RCSs, for diluted supernatants, there was only significant difference between iRoot SP and AH Plus at 24-h (P<0.05). Whereas undiluted-AH Plus was significantly more cytotoxic for 3-, 6- and 24-h periods as compared to respective incubation periods of undiluted other groups (P<0.05). GuttaFlow groups had similar neurotoxic effect on cells for all test periods.

Conclusions

All tested RCSs exhibited a variable degree of neurotoxicity on these primary sensory neurons of orofacial tissues, depending on their chemical compositions. GuttaFlow and iRoot SP evoked a less toxic response to TG cells than AH Plus.

Key words:Neurotoxicity, trigeminal ganglia, cell culture, root canal sealer, AH Plus, GuttaFlow, iRoot SP.

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.

Discoloration Potential of Endodontic Sealers: A Brief Review

Tooth discoloration induced by endodontic sealers, is a common finding that impairs aesthetic outcome of endodontic treatment. The aim of the present mini literature review, was to summarize the existing data on discoloration potential of different endodontic sealers. The research covered the article published in PubMed and Google Scholar from 2000 to 2015. The searched keywords included ‘tooth discoloration AND endodontic’, ‘tooth discoloration AND sealer, ‘tooth discoloration AND zinc-oxide eugenol sealer’, ‘tooth discoloration AND Calcium Hydroxide Sealer’, ‘tooth discoloration AND Glass Ionomer Sealer’, ‘tooth discoloration AND epoxy-resin Sealer’, ‘tooth discoloration AND Silicon Based Sealer’, ‘tooth discoloration AND Bioceramic Sealer’ and ‘Spectrophotometry’.

Cytotoxicity and gelatinolytic activity of a new silicon-based endodontic sealer

PURPOSE

To compare the cytotoxicity, gelatinolytic activity, and protein levels (MMP-2 and MMP-9) produced by 3T3 fibroblasts cells after stimulation with GuttaFlow 2 and AH Plus.

METHODS

3T3 fibroblasts were incubated with elutes of GuttaFlow 2 and AH Plus for 24 h. The cytotoxicity of tested materials was determined using the MTT and the LDH assay. Supernatants of cell cultures incubated with sealers were collected to determine the levels of MMP-2 and MMP-9 gelatinolytic activity by gelatin zymography. Cell lysates were used to determine MMP-2 and MMP-9 protein levels by Western Blot. Data were analyzed using ANOVA and Tukey test (P&lt;0.05).

RESULTS

AH Plus showed significantly less cell viability (mitochondrial activity of cells) than GuttaFlow 2 (P&lt;0.01). Moreover, GuttaFlow 2 was noncytotoxic, showing no statistically significant difference in LDH leakage levels compared to the control group (P&gt;0.05). Specific characterization of MMPs demonstrated that GuttaFlow 2 seemed not to affect MMP-2 levels compared with the control group, while AH Plus had elevated gelatinolytic activity and protein levels of MMP-2 as confirmed by quantitative measurements. No detectable gelatinolytic activity or protein levels of MMP-9 (92 kDa) was observed in any tested group.

CONCLUSIONS

GuttaFlow 2 did not showed cytotoxic effects and did not induce MMP-2 or MMP-9 expression.

Cytotoxicity of a New Nano Zinc-Oxide Eugenol Sealer on Murine Fibroblasts

Introduction:

The aim of this study was to evaluate the cytotoxicity of a new nano zinc-oxide eugenol (NZOE) sealer in comparison with AH-26 and Pulpdent root canal sealers.

Methods and Materials:

The L929 mouse fibroblast cells were cultivated and incubated for 24, 48 or 72 h with different dilutions (1/1, 1/2, 1/4, 1/8, 1/16 and 1/32) of culture media previously exposed to either of the test sealers naming NZOE, AH-26 or Pulpdent. At the end of incubation period, the effect of sealers on cell viability was evaluated using Mosmann’s Tetrazolium Toxicity (MTT) colorimetric assay. The data was compared using the one-way analysis of variance (ANOVA) followed by the Tukey’s post hoc test for multiple comparisons.

Results:

After 24, 48 or 72 h, both NZOE and Pulpdent sealers inhibited cell viability at 1/1, 1/2 and 1/8 dilutions. Within the 24 and 48 h, the AH-26 sealer reduced the cell viability at all dilutions except the 1/32 solution; however after 72 h even the 1/32 dilution was cytotoxic.

Conclusion:

The biocompatibility of the nano zinc-oxide eugenol sealer was comparable to Pulpdent sealer and lower than AH-26.

Antimicrobial and cytotoxic effects of phosphoric acid solution compared to other root canal irrigants

Phosphoric acid has been suggested as an irrigant due to its effectiveness in removing the smear layer.

Evaluation of Biocompatibility of Root Canal Sealers on L929 Fibroblasts with Multiscan EX Spectrophotometer

INTRODUCTION

The purpose of the current study was to estimate the biocompatibility of endodontic sealers with different bases on L929 mouse fibroblasts permanent cell line using Multiscan EX Spectrophotometer.

MATERIALS AND METHODS

Endodontics sealers used in this study were GuttaFlow (Roeko) silicone based sealer, AH plus (De Tray-DENTSPLY) epoxy resin based, Apexit (Vivadent) calcium hydroxide based and Endorez (Ultradent) methacrylate based sealer. Sealer were tested trough time, freshly mixed 24 h, 48h and 7 days after setting. Biocompatibility was determinate on permanent cell lines L929 mouse fibroblasts trough cytotoxicity using MTT assay. Level of absorption was measured with multi scan EX spectrophotometer on length 420-600 nm.

RESULTS

Sealer based on calcium hydroxide Apexit Plus, GuttaFlow silicone based sealer and AH plus epoxy resin based sealer, have shown a low cytotoxicity through the all periods of time on culture of L292 mouse fibroblasts. Methacrylate based sealer, Endorez showed moderate cytotoxicity when freshly mixed and after 7 days. After 24 hours the visibility of the cells was 74,0% and after 48 hours 65,1%. which is slightly cytotoxic.

CONCLUSIONS

According to results of this study there is a statistically significant difference among the groups p<0,05 for all the tested sealers. Apexit Plus, GuttaFlow and AH plus can be considered as biocompatibile. EndoREZ sealer which is based on methacrylate, after 7 days shows 50,1% of visible live cells which is considered as moderate cytotoxicity.

Antibacterial Properties Associated with Chitosan Nanoparticle Treatment on Root Dentin and 2 Types of Endodontic Sealers

INTRODUCTION

The aim of this study was to evaluate the efficacy of carboxymethyl chitosan (CMCS) and chitosan nanoparticles (CNps) to inactivate bacteria and prevent biofilm formation at sealer-dentin interfaces.

METHODS

The study was divided into 3 stages: first stage, the experiment was conducted to analyze the antibacterial properties of CMCS in different formulations against biofilms; second stage, direct-contact and membrane-restricted methods were used to evaluate the antibacterial properties of an epoxy resin (ThermaSeal Plus; Dentsply Tulsa Dental, Tulsa, OK) and calcium silicate (MTA Fillapex; Angelus SA, Londrina, PR, Brazil) based-sealers with or without CNps; and third stage, biofilm formation at the sealer dentin interfaces of root dentin treated with CMCS and filled with gutta-percha and CNp incorporated sealer were analyzed after 1- and 4-week aging periods. The samples were treated and filled as follows: (1) distilled water: unaltered sealer (control group), (2) CMCS: sealer+CNps (CMCS group), and (3) CMCS/rose bengal: sealer+CNps (CMCS/RB group). Enterococcus faecalis was used to infect all the samples. Microbiological and microscopic analyses were used to assess the antibacterial characteristics.

RESULTS

CMCS-based treatments effectively killed bacteria adherent on root dentin (P < .05). The addition of CNps to ThermaSeal enhanced its antibacterial ability by direct-contact and membrane-restricted tests (P < .05). The CNp incorporation significantly increased the antibacterial efficacy of root canal sealers even after a 4-week aging time (P < .05).

CONCLUSIONS

This study highlighted the ability of CMCS to disinfect root canal dentin and inhibit bacterial adhesion. CNps in root canal sealers are capable of maintaining their antibacterial activity even after prolonged aging.

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.

In vitro comparison of cytotoxicity of four root canal sealers on human gingival fibroblasts

The goal of this in vitro study was to evaluate the relative biocompatibility of four endodontic sealers on the cell culture of the human fibroblast through cytotoxicity.

MATERIALS AND METHODS

In this study four endodontics sealers was used GuttaFlow (Roeko)silicone based sealer, AH plus (De Tray-DENTSPLY) epoxy resin based, Apexit (Vivadent) calcium hydroxide based and Endorez (Ultradent) methacrylate based sealer. Sealers were tested on primary cell lines of human gingival fibroblasts. Experiments were preformed in laboratories of Hacettepe University of Ankara, Turkey and Faculty of Dentistry, University of Sarajevo, Bosnia and Herzegovina Cytotoxicity was determinate using WST-1 assay.

RESULTS

Results were analyzed by SPSS 19 program. Kolgomorov-Smirnov test, Shapiro-Wilk and descriptive statistics also were used, as well as Kriskall-Wallis, ANOVA test and T- test. According to our results all four sealers showed different cytotoxicity effects on human gingival fibroblast cell culture, but all of them are slightly cytotoxic.

CONCLUSIONS

According to results of this study it can be concluded: all four sealers showed different cytotoxicity effects on primary cell lines of human gingival fibroblasts, but all of them are slightly cytotoxicity.

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.

A comparative study on root canal repair materials: a cytocompatibility assessment in L929 and MG63 cells

Cytocompatibility of repair materials plays a significant role in the success of root canal repair. We conducted a comparative study on the cytocompatibility among iRoot BP Plus, iRoot FS, ProRoot MTA, and Super-EBA in L929 cells and MG63 cells. The results revealed that iRoot FS was able to completely solidify within 1 hour. iRoot BP Plus required 7-day incubation, which was much longer than expected (2 hours), to completely set. ProRoot MTA and Super-EBA exhibited a similar setting duration of 12 hours. All the materials except Super-EBA possessed negligible in vitro cytotoxicity. iRoot FS had the best cell adhesion capacity in both L929 and MG63 cells. With rapid setting, negligible cytotoxicity, and enhanced cell adhesion capacity, iRoot FS demonstrated great potential in clinical applications. Future work should focus on longer-term in vitro cytocompatibility and an in vivo assessment.

Effects of a dental adhesive on cell cycle regulatory proteins

Dental bonding agents may affect the cell cycle patterns and induce cell cycle arrest by blocking its progression. This study tested the cell cycle effects through cyclin-dependent kinase (cdc2) and Rb phosphorylation. Human lung fibroblasts (MRC5) were used for the experiments. The bonding agent tested was the total-etch XP bond. Extracts of the bonding agent were prepared and serial dilutions were tested. The effects of the bonding agent on cell survival, proliferation and DNA synthesis were tested by the SRB and BrdU assays. Analysis of cell cycle distribution was performed by flow cytometry. XP bond exhibited strong inhibition of DNA synthesis and after 48 h of exposure cells were accumulated in the G2/M phase. Cells exposed to the half maximal cell growth inhibitory concentration (IC50) showed an increase in cdc2 kinase and Rb phosphorylation. The results most likely indicate mutagenic effect of the tested agent.

Rapid kill-novel endodontic sealer and Enterococcus faecalis

With growing concern over bacterial resistance, the identification of new antimicrobial means is paramount. In the oral cavity microorganisms are essential to the development of periradicular diseases and are the major causative factors associated with endodontic treatment failure. As quaternary ammonium compounds have the ability to kill a wide array of bacteria through electrostatic interactions with multiple anionic targets on the bacterial surface, it is likely that they can overcome bacterial resistance. Melding these ideas, we investigated the potency of a novel endodontic sealer in limiting Enterococcus faecalis growth. We used a polyethyleneimine scaffold to synthesize nano-sized particles, optimized for incorporation into an epoxy-based endodontic sealer. The novel endodontic sealer was tested for its antimicrobial efficacy and evaluated for biocompatibility and physical eligibility. Our results show that the novel sealer foundation affixes the nanoparticles, achieving surface bactericidal properties, but at the same time impeding nanoparticle penetration into eukaryotic cells and thereby mitigating a possible toxic effect. Moreover, adequate physical properties are maintained. The nanosized quaternary amine particles interact within minutes with bacteria, triggering cell death across wide pH values. Throughout this study we demonstrate a new antibacterial perspective for endodontic sealers; a novel antibacterial, effective and safe antimicrobial means.

Antifungal activity of several root canal sealers against Candida albicans

OBJECTIVE

The purpose of this in vitro study was to evaluate the antifungal activity of several root canal sealers (iRoot SP, MTA Fillapex and GuttaFlow) against Candida albicans and compare them to that of AH Plus Jet.

MATERIALS AND METHODS

A 10 μL fungi in suspension was allowed to directly contact the sealers, which were freshly mixed or allowed to set for 1 or 7 days. Fresh media was then added and survival of fungi was determined by using 10-fold serial dilution and inoculated onto agar plates. After incubation for 48 h, colony-forming units (CFU) were calculated and their log10 values converted. The data were analyzed using ANOVA and Tukey tests (α = 0.05).

RESULTS

Freshly mixed AH Plus Jet totally inhibited the growth of fungi and showed the highest antifungal activity. GuttaFlow did not show any significant antifungal activity at all times. Freshly mixed iRoot SP and MTA Fillapex were found to be antifungal. Statistical differences were found between freshly mixed and set samples (p < 0.05) in favor of the former, except GuttaFlow. No statistically significant differences were found among the tested sealers at the 1 and 7-day samples (p > 0.05).

CONCLUSIONS

Fresh AH Plus Jet had very potent antifungal activity. All sealers, except GuttaFlow, exhibited antifungal activity when freshly mixed.

Resilon: a comprehensive literature review

Background and aims. An ideal root canal filling material should completely seal the entire root canal space and block communication between the root canal system and its surrounding tissues; it should also be nontoxic, noncarcinogenic, non-genotoxic, biocompatible, insoluble in tissue fluids and dimensionally stable. Bonding to dentin is a promising property, which can prevent leakage and improve the sealing ability of root canal filling materials. Resilon was developed and rec-ommended initially because the existing rootcanal filling materials did not bond to root canal dentin. Since its introduction in 2004, numerous reports have been published regarding various aspects of this material. The aim of this literature review is to present investigations regarding Resilon's physical and chemical properties and leakage studies. Materials and methods. A review of the literature was performed by using electronic and hand searching methods for Resilon from May 2004 to April 2012. Results. There are many published reports regarding Resilon. The searchshowed that Resilon is composed of a parent polymer, polycaprolactone or Tone, which is a biodegradable aliphatic polyester, with filler particles consisting of bioactive glass, bismuth oxychloride and barium sulfate. It possesses some antibacterial and antifungal properties. It is a promising material for root canal filling. Despite the presence of numerous case reports and case series regarding these applications, there are few designed research studies on clinical applications of this material. Resilon has some drawbacks such as high cost. Conclusion. Resilon seals well and is a biocompatible material. However, more clinical studies are needed to confirm its efficacy compared with other materials.

An in vitro comparison of bond strengths of Gutta-percha/AH Plus, Resilon/Epiphany self-etch and EndoREZ obturation system to intraradicular dentin using a push-out test design

Aim:

To evaluate and compare the push-out bond strengths of three obturation materials; Gutta-percha/AH Plus, Resilon/Epiphany self-etch (SE) and EndoREZ obturation system to intraradicular dentin.

Materials and Methods:

Sixty single-canal anterior teeth were prepared and assigned to experimental groups (n = 20), designated as Group I: Gutta-percha/AH Plus, Group II: Resilon/Epiphany SE and Group III: EndoREZ sealer/EndoREZ points. After obturation, each tooth was prepared for push-out assessment with root slices of 2 mm thickness using universal testing machine.

Statistical Analysis:

Two way analysis of variance and Scheffe's test.

Results:

Gutta-percha/AH Plus root fillings showed significantly highest bond strength. Also, root segment location did not have a significant influence on bond strength.

Conclusion:

The adhesiveness quality to root dentin promoted by newer methacrylate resin-based obturation systems like Resilon/Epihany SE and EndoREZ is compromised even when teeth with simple anatomic features were obturated under well-monitored laboratory conditions.

Cytotoxicity evaluation of three resin-based sealers on an L929 cell line

Background:

Endodontic sealers usually come in contact with adjacent tissues and their biocompatibility is key in a successful treatment. The purpose of this study was to assess the cytotoxicity of three resin-based sealers, namely AH Plus, EndoREZ, and Epiphany in set and fresh states on an L929 cell line.

Materials and Methods:

In this in vitro experimental study, the materials were mixed according to the manufacturers’ instructions, and were divided into two groups, fresh and set. The elutes of materials were prepared separately and were incubated with L929 fibroblasts for 1 hour, 24 hours, and 72 hours. Pulp Canal Sealer and Dulbecco's Modified Eagle Medium (DMEM) served as positive and negative controls respectively. Cell viability was evaluated by MTT assay ([3-4,5-dimethyl thiazol-2-yl]-2,5-diphenyltetrazolium bromide succinate), after 1 hour, 24 hours, and 72 hours. The data were analyzed by analysis of variance (ANOVA), and Tukey multiple comparison test.

Results:

After 1 hour, fresh Epiphany and fresh AH Plus were significantly more cytotoxic than their set samples. No significant difference was perceived between cytotoxicity of fresh state of sealers and positive control, or between set state and negative control. After 24 hours, both fresh and set samples of all materials were significantly more cytotoxic than the negative control group, and were less cytotoxic than the positive control group. After 72 hours, the fresh and set samples of all materials were as cytotoxic as the positive control group. At each time point, no significant difference was perceived among different materials in terms of cell viability.

Conclusion:

The observed differences among the cytotoxicity of AH Plus, EndoREZ, and Epiphany did not reach a significant level at comparable time points after exposure.

Effect of time of extraction on the biocompatibility of endodontic sealers with primary human fibroblasts

The aim of this work was to evaluate the effects of different times of extraction on the cytotoxicity of six representatives of different root canal sealer groups-Real Seal SE, AH Plus, GuttaFlow, Sealapex, Roth 801, and ThermaSeal Plus-with human gingival fibroblasts. The materials were prepared according to manufacturers' specifications, and were incubated in culture medium (DMEM) at 37ºC for 1, 7, 14, 21, and 28 days, with daily washing, to simulate periodontal ligament clearance. Human fibroblasts were exposed to the final extracts at 24 hours, and cell viability was determined by MTT assay, with exposure to unconditioned DMEM as a negative control. Statistical analysis comparing cytotoxicities at each exposure time was performed by ANOVA with Scheffé adjustment for multiple comparisons at a 95% confidence level. Results indicated that GuttaFlow was significantly less cytotoxic than all other sealers (p < 0.05) at 1 day of extraction. After 7 days of extraction, cell viability for GuttaFlow was significantly increased as compared with that of all groups except sealer AH Plus. At day 14, cytotoxicity of Sealapex was significantly higher than that of all other sealers (p < 0.05). At days 21 and 28, there were no significant differences in cytotoxicity among sealer groups. All materials presented some level of cytotoxicity to fibroblasts, while GuttaFlow was the least cytotoxic sealer tested. However, the cytotoxicity of all materials seemed to decrease similarly in a time-dependent manner.

In vitro analysis of the cytotoxicity and the antimicrobial effect of four endodontic sealers

Introduction

The aim of this study was to investigate in vitro the cytotoxicity and antibacterial properties of four different endodontic sealers using human periodontal ligament fibroblast cell proliferation and visual analysis of growth inhibition.

Methods

A silicone (GuttaFlow), silicate (EndoSequence BC), zinc oxide eugenol (Pulp Canal Sealer EWT) and epoxy resin (AH Plus Jet) based sealer were incubated with PDL fibroblasts (10⁴ cells/ml, n = 6) up to 96 h. Cell proliferation (RFU) was determined by means of the Alamar Blue assay. Cell growth and morphology was visualized by means of fluorescent dyes. Possible antibacterial properties of the different sealers were visualized by means of SEM (Enterococcus faecalis; Parvimonas micra).

Results

Fibroblast proliferation depended on sealer and cultivation time. After 72 and 96 h GuttaFlow and EndoSequence BC showed relatively non-cytotoxic reactions, while Pulp Canal Sealer EWT and AH Plus Jet caused a significant decrease of cell proliferation (p < 0.001). Visualization of cell growth and morphology with various fluorescent dyes supplemented the results. No antibacterial effect of EndoSequence BC to P. micra was found, whereas GuttaFlow showed a weak, Pulp Canal Sealer EWT and AH Plus Jet extensive growth inhibition. Also, no antibacterial effect of GuttaFlow, EndoSequence BC or AH Plus Jet to E. faecalis could be detected.

Conclusions

These in vitro findings reveal that GuttaFlow and EndoSequence BC can be considered as biocompatible sealing materials. However, prior to their clinical employment, studies regarding their sealing properties also need to be considered.