Bioactivity of EndoSequence Root Repair Material and Bioaggregate

Assessment of the biocompatibility of mineral trioxide aggregate, bioaggregate, and biodentine in the subcutaneous tissue of rats

OBJECTIVE

The objective of this study was to evaluate the tissue inflammation caused by three endodontic repair materials.

MATERIALS AND METHODS

The materials included micro mega-mineral trioxide aggregate (MM-MTA), bioaggregate (BA), and biodentine (BD), which were implanted into the subcutaneous tissue of rats. The tissue samples for histological examination were prepared. The infiltration of lymphocytes and macrophages into the tissue was examined to assess the inflammatory response.

RESULTS

Lymphocyte infiltration: A significant increase was detected in the MM-MTA and BA groups on the 7th and 14th days as compared with the control (7th day P=0.0001, 14th day P=0.0176). There was no difference between the groups on the 45th day (P=0.1730). Lymphocyte infiltration had decreased over time in all groups. Macrophage infiltration: There was a significant increase by the 7th day in the test groups as compared to the control group (P=0.007). However, there was no difference between the experimental groups on the 14th (P=0.2708) and 45th (P=0.1291) days.

CONCLUSION

While MM-MTA and BA showed a similar biocompatibility, BD was more biocompatible than MM-MTA and BA in the 1 st week of the experiment. However, there was no difference between the materials at the end of the 45th day. MM-MTA, BA, and BD can be considered suitable endodontic repair materials.

Surface microhardness of different thicknesses of a premixed bioceramic material with or without the application of a moist cotton pellet

Background:

This study was conducted to assess the effect of thickness and hydration condition on the surface microhardness of Endosequence Root Repair Material putty (ERRM; Brasseler USA, Savannah, GA), a premixed bioceramic material.

Materials and Methods:

Polymethyl methacrylate cylindrical molds with an internal diameter of 4 mm and three heights of 2, 4, and 6 mm were fabricated. In Group 1 (dry condition), the molds with heights of 2, 4, and 6 mm (10 molds of each) were filled with ERRM. In Groups 2 and 3 (wet condition), a distilled water- or phosphate-buffered saline (PBS)-moistened cotton pellet was placed directly on the upper surface of ERRM, respectively. The lower surface of ERRM was in contact with floral foams soaked with human blood. After 4 days, Vickers microhardness of the upper surface of ERRM was tested. The data were analyzed using two-way analysis of variance. Significance level was set at P < 0.05.

Results:

No significant difference was found between the microhardness of three thicknesses of ERRM (2, 4, and 6 mm) with or without placing a distilled water- or PBS-moistened cotton pellet over the material (P > 0.05).

Conclusion:

Based on the results of this study, it could be concluded that placing a moistened cotton pellet on ERRM putty up to 6 mm thick might be unnecessary to improve its surface microhardness and hydration characteristics.

Determination of trace elements in rat organs implanted with endodontic repair materials by ICP-MS

To investigate the levels of seven elements using an inductively coupled plasma-mass spectrometry (ICP-MS) method in rat organs after the implantation of Micro Mega Mineral Trioxide Aggregate (MM-MTA), Bioaggregate (BA) and Biodentine (BD) materials. MM-MTA, BA and BD were implanted into the subcutaneous tissue of 15 Wistar albino rats; three control animals had no operation. After 45 days, the rats were sacrificed and their brains, kidneys and livers were removed. The ICP-MS analysis was used to determine trace elements. Data were analysed using the Kruskal-Wallis and Connover post hoc tests. There was no significant difference between the control groups and the MM-MTA, BA and BD groups according to the concentration of aluminum, calcium, arsenic and lead in the rats' organs. Beryllium was not detected in all tissue samples. Chromium levels of these materials were higher than the control group in brain and kidney samples (P = 0.038 and P = 0.037); magnesium levels were higher than the control group in kidney and liver samples (P = 0.030 and P = 0.008). MM-MTA, BA and BD were nontoxic according to trace element levels in brain, kidney and liver samples of rats. Further investigation is required to understand the systemic effects of these materials.

Evaluation of cytocompatibility of calcium silicate-based endodontic sealers and their effects on the biological responses of mesenchymal dental stem cells

AIM

To investigate in vitro the cytocompatibility of the calcium silicate-containing endodontic sealers MTA Fillapex and TotalFill BC Sealer on human periodontal ligament stem cells (hPDLSCs) by assaying their biological responses and compare them with that observed when using an epoxy resin-based sealer (AH Plus).

METHODOLOGY

Specimens from the three different endodontic sealers were eluated with culture medium for 24 h. The cytotoxicity of these eluates was evaluated using the MTT assay. In addition, an in vitro scratch wound healing model was used to determine their effects on cell migration. Cell adhesion to collagen type I after treatment with the different sealer eluates was also measured, whereas cytotoxicity was determined using the DNA-specific fluorochrome Hoechst 33342. Finally, to assess cell morphology and attachment to the different sealers, hPDLSCs were directly seeded onto the material surfaces and analysed by scanning electron microscopy (SEM). One-way analysis of variance (anova) followed by a Bonferroni post-test were performed (P < 0.05).

RESULTS

hPDLSCs exposed to different dilutions of TotalFill BC Sealer eluates had significantly higher cell proliferation compared with that observed when cells were treated with AH Plus and MTA Fillapex eluates (P < 0.001). In addition, TotalFill eluates were associated with significantly increased cell adhesion to collagen type I and migration of hPDLSCs in a concentration-dependent manner than displayed after treatment with MTA Fillapex or AH Plus eluates (P < 0.001). Moreover, TotalFill BC Sealer-induced cytotoxicity was significantly lower than observed using AH Plus and MTA Fillapex eluates (P < 0.001). Finally, SEM studies revealed suitable proliferation, cell spreading and attachment, especially when using TotalFill BC Sealer discs.

CONCLUSION

TotalFill BC Sealer exhibited a higher cytocompatibility than AH Plus and MTA Fillapex. Further investigations using in vivo animal models are required to validate the potential biological responses of TotalFill BC Sealer on hPDLSCs.

Calcium silicate-based cements: composition, properties, and clinical applications

Mineral trioxide aggregate (MTA) is a calcium silicate-based cement (CSC) commonly used in endodontic procedures involving pulpal regeneration and hard tissue repair, such as pulp capping, pulpotomy, apexogenesis, apexification, perforation repair, and root-end filling. Despite the superior laboratory and clinical performance of MTA in comparison with previous endodontic repair cements, such as Ca(OH)₂ , MTA has poor handling properties and a long setting time. New CSC have been commercially launched and marketed to overcome the limitations of MTA. The aim of the present review was to explore the available literature on new CSC products, and to give evidence-based recommendations for the clinical use of these materials. Within the limitations of the available data in the literature regarding the properties and performance of the new CSC, the newer products could be promising alternatives to MTA; however, further research is required to support this assumption.

An ex-vivo comparative study of root-end marginal adaptation using grey mineral trioxide aggregate, white mineral trioxide aggregate, and Portland cement under scanning electron microscopy

Context:

Where nonsurgical endodontic intervention is not possible, or it will not solve the problem, surgical endodontic treatment must be considered. A major cause of surgical endodontic failures is an inadequate apical seal, so the use of the suitable substance as root-end filling material that prevents egress of potential contaminants into periapical tissue is very critical.

Aims:

The aim of the present ex-vivo study was to compare and evaluate the three root-end filling materials of mineral trioxide aggregate (MTA) family (white MTA [WMTA], grey MTA [GMTA] and Portland cement [PC]) for their marginal adaptation at the root-end dentinal wall using scanning electron microscopy (SEM).

Materials and Methods:

Sixty human single-rooted teeth were decoronated, instrumented, and obturated with Gutta-percha. After the root-end resection and apical cavity preparation, the teeth were randomly divided into three-experimental groups (each containing 20 teeth) and each group was filled with their respective experimental materials. After longitudinal sectioning of root, SEM examination was done to determine the overall gap between retrograde materials and cavity walls in terms of length and width of the gap (maximum) at the interface. Descriptive statistical analysis was performed to calculate the means with corresponding standard errors, median and ranges along with an analysis of variance and Tukey's test.

Results:

The least overall gap was observed in GMTA followed by PC and WMTA. While after statistically analyzing the various data obtained from different groups, there was no significant difference among these three groups in terms of marginal adaptation.

Conclusion:

GMTA showed the best overall adaptation to root dentinal wall compared to PC and WMTA. Being biocompatible and cheaper, the PC may be an alternative but not a substitute for MTA.

A Review on Perforation Repair Materials

Perforation is an artificial communication between the root canal system and supporting tissues of the teeth. Root perforation complicates the treatment and deprives the prognosis if not properly managed. A wide variety of materials to seal the perforations have been suggested in literature. There are many comparative studies showing the efficacy of one material over the other. Literature shows many reviews on diagnosis, treatment plan and factors affecting prognosis of perforation repair; but none of these articles elaborated upon various materials available to seal the perforation. The present article aims at describing all the materials used for perforation repair from the past till date; it also offers a literature review of all the articles published over last four decades referred to the treatment of perforation with various root repair materials.

Can Mineral Trioxide Aggregate and Nanoparticulate EndoSequence Root Repair Material Produce Injurious Effects to Rat Subcutaneous Tissues?

INTRODUCTION

The aim of this study was to evaluate the injurious effects of mineral trioxide Aggregate (MTA) and EndoSequence Bioceramic Root Repair Material (ERRM; Brassler USA, Savannah, GA) 7 and 30 days after their implantation into rat subcutaneous tissues.

METHODS

Twelve Wistar rats were selected for the present study. Each animal received 3 implants: one contained MTA, one contained ERRM, and one was an empty tube that served as a control. Half of the animals were killed after 7 days, and the remaining animals were killed 30 days after implantation. Histologic sections prepared from the skin specimens were stained with H&E, toluidine blue, Masson trichrome, and Congo red. The data were statistically analyzed with 1-way analysis of variance and paired t tests. The P value for significance was set at .05.

RESULTS

After 7 days, MTA produced a significantly greater inflammatory reaction that involved the deposition of amyloidlike protein and an increase in the mast cell population compared with ERRM (P < .05). After 30 days, the ERRM group exhibited significantly reduced inflammatory reactions compared to the MTA groups (P < .05). Areas of mononuclear cell aggregation, abscess formation, and necrosis were observed more frequently in the MTA group. The thickness of the fibrous capsule was significantly increased in the MTA compared with the ERRM groups (P < .05). Amyloidlike proteins were more frequently observed around the fibrous capsule and subdermal blood vessels and were more frequently deposited in the MTA than the ERRM specimens.

CONCLUSIONS

The findings of the present study suggest that both ERRM and MTA cause an injurious effect when implanted in rat subcutaneous tissues after 7 and 30 days. ERRM is significantly less injurious to tissues than MTA.

Effect of BioAggregate on osteoclast differentiation and inflammatory bone resorption in vivo

AIM

To investigate the effect of BioAggregate (Innovative Bioceramix, Vancouver, BC, Canada) on lipopolysaccharide (LPS)-induced bone destruction in vivo and to compare its performance with that of mineral trioxide aggregate (MTA; Dentsply Tulsa Dental, Tulsa, OK, USA).

METHODOLOGY

Mouse bone marrow macrophages (BMMs) were primary cultured and treated with several concentrations of BioAggregate and MTA extracts. Cell viability was measured with a Cell Counting Kit-8 assay, whilst in vitro osteoclast differentiation was evaluated with tartrate-resistant acid phosphatase (TRAP) staining. LPS-induced mouse calvarial bone destruction model was established to assess the effect of BioAggregate and MTA extracts in vivo. Mice were killed on day 7, and calvarial bones were prepared for microcomputed tomography scanning, histologic analysis and double-immunofluorescence staining. Statistical tests used were one-way anova followed by Student-Newman-Keuls test.

RESULTS

BioAggregate extracts displayed no obvious cytotoxicity to BMMs and significantly inhibited (P < 0.01) the differentiation of RANKL-stimulated BMMs. Comparable effects were induced by MTA. BioAggregate and MTA extracts markedly reduced (P < 0.01) osteoclast numbers and attenuated (P < 0.05) bone resorption in LPS-challenged mouse calvaria. The expression levels of osteoclastogenic cathepsin K and its upstream regulator nuclear factor of activated T-cell cytoplasmic 1 and c-Fos were also decreased by BioAggregate and MTA extracts.

CONCLUSIONS

BioAggregate and MTA showed comparable inhibitory effect on osteoclast differentiation and inflammatory bone resorption in vivo.

Surface microhardness of three thicknesses of mineral trioxide aggregate in different setting conditions

Objectives

This study aimed to compare the surface microhardness of mineral trioxide aggregate (MTA) samples having different thicknesses and exposed to human blood from one side and with or without a moist cotton pellet on the other side.

Materials and Methods

Ninety cylindrical molds with three heights of 2, 4, and 6 mm were fabricated. In group 1 (dry condition), molds with heights of 2, 4, and 6 mm (10 molds of each) were filled with ProRoot MTA (Dentsply Tulsa Dental), and the upper surface of the material was not exposed to any additional moisture. In groups 2 and 3, a distilled water- or phosphate-buffered saline (PBS)-moistened cotton pellet was placed on the upper side of MTA, respectively. The lower side of the molds in all the groups was in contact with human blood-wetted foams. After 4 day, the Vickers microhardness of the upper surface of MTA was measured.

Results

In the dry condition, the 4 and 6 mm-thick MTA samples showed significantly lower microhardness than the 2 mm-thick samples (p = 0.003 and p = 0.001, respectively). However, when a distilled water- or PBS-moistened cotton pellet was placed over the MTA, no significant difference was found between the surface microhardness of samples having the abovementioned three thicknesses of the material (p = 0.210 and p = 0.112, respectively).

Conclusions

It could be concluded that a moist cotton pellet must be placed over the 4 to 6 mm-thick MTA for better hydration of the material. However, this might not be necessary when 2 mm-thick MTA is used.

"Evaluation of sealing ability of MM-MTA, Endosequence, and biodentine as furcation repair materials: UV spectrophotometric analysis"

AIM

To evaluate the sealing ability of MICRO-MEGA Mineral Trioxide Aggregate, Endosequence, Biodentine as furcation repair materials using a dye extraction leakage method.

MATERIALS AND METHODS

Forty mandibular molars were randomly divided according to the material used for perforation repair. Group I- (left unsealed) control, Group II-MICRO-MEGA Mineral Trioxide Aggregate, Group III - Endosequence, Group IV - Biodentine. All samples were subjected to orthograde and retrograde methylene blue dye challenge followed by dye extraction with 65% nitric acid. Samples were then analyzed using Ultra violet (UV) Visible Spectrophotometer.

RESULTS

Biodentine showed highest dye absorbance, whereas Endosequence showed lowest dye absorbance when compared with other repair materials.

CONCLUSION

Within the limitations of this study, it was observed that Endosequence showed better sealing ability when compared with other root repair materials.

A review of the bioactivity of hydraulic calcium silicate cements

OBJECTIVES

In tissue regeneration research, the term "bioactivity" was initially used to describe the resistance to removal of a biomaterial from host tissues after intraosseous implantation. Hydraulic calcium silicate cements (HCSCs) are putatively accepted as bioactive materials, as exemplified by the increasing number of publications reporting that these cements produce an apatite-rich surface layer after they contact simulated body fluids.

METHODS

In this review, the same definitions employed for establishing in vitro and in vivo bioactivity in glass-ceramics, and the proposed mechanisms involved in these phenomena are used as blueprints for investigating whether HCSCs are bioactive.

RESULTS

The literature abounds with evidence that HCSCs exhibit in vitro bioactivity; however, there is a general lack of stringent methodologies for characterizing the calcium phosphate phases precipitated on HCSCs. Although in vivo bioactivity has been demonstrated for some HCSCs, a fibrous connective tissue layer is frequently identified along the bone-cement interface that is reminiscent of the responses observed in bioinert materials, without accompanying clarifications to account for such observations.

CONCLUSIONS

As bone-bonding is not predictably achieved, there is insufficient scientific evidence to substantiate that HCSCs are indeed bioactive. Objective appraisal criteria should be developed for more accurately defining the bioactivity profiles of HCSCs designed for clinical use.

Comparative evaluation of push-out bond strength of ProRoot MTA, bioaggregate and biodentine

OBJECTIVE

To evaluate the push-out bond strength of Biodentine (BD) in comparison with two available calcium silicate based materials, bioaggregate (BA) and ProRoot MTA (WMTA).

MATERIALS AND METHODS

One hundred and twenty-three Root dentin slices of freshly extracted single Rooted human teeth were randomly divided into three groups (n = 41) according to the used test material: WMTA, BA, BD. After canal space preparation, the filling materials were placed inside the lumen of the slices. After 72 hours, the maximum force applied to materials at the time of dislodgement was recorded and slices were then examined under a stereomicroscope at ×40 magnification to determine the nature of bond failure. Analysis of variance (ANOVA) test was used to compare means of push-out bond strength. Post-hoc test was then accomplished for multiple comparisons. Chi-square test was used to determine if there is significant association between the type of material and type of failure.

RESULTS

The mean push-out bond strength ± standard deviation in MPa values of WMTA, BA and BD were 23.26 ± 5.49, 9.57 ± 3.45, 21.86 ± 6.9, respectively. There was no significant difference between the means of WMTA and BD (p = 0.566), but the mean of BA was significantly lower than those of WMTA and BD (p = 0.000). Under stereomicroscope, WMTA and BA showed a majority of mixed type of failure than cohesive failure, while BD showed the opposite. No adhesive failure was observed in any specimen.

CONCLUSION

The findings of the present study imply that the force needed for BD displacement is similar to WMTA and significantly higher than the force required to displace BA.

In vitro cytotoxicity of four calcium silicate-based endodontic cements on human monocytes, a colorimetric MTT assay

Objectives

This study was performed to evaluate the cytotoxicity of four calcium silicate-based endodontic cements at different storage times after mixing.

Materials and Methods

Capillary tubes were filled with Biodentine (Septodont), Calcium Enriched Mixture (CEM cement, BioniqueDent), Tech Biosealer Endo (Tech Biosealer) and ProRoot MTA (Dentsply Tulsa Dental). Empty tubes and tubes containing Dycal were used as negative and positive control groups respectively. Filled capillary tubes were kept in 0.2 mL microtubes and incubated at 37℃. Each material was divided into 3 groups for testing at intervals of 24 hr, 7 day and 28 day after mixing. Human monocytes were isolated from peripheral blood mononuclear cells and cocultered with 24 hr, 7 day and 28 day samples of different materials for 24 and 48 hr. Cell viability was evaluated using an MTT assay.

Results

In all groups, the viability of monocytes significantly improved with increasing storage time regardless of the incubation time (p < 0.001). After 24 hr of incubation, there was no significant difference between the materials regarding monocyte viability. However, at 48 hr of incubation, ProRoot MTA and Biodentine were less cytotoxic than CEM cement and Biosealer (p < 0.01).

Conclusions

Biodentine and ProRoot MTA had similar biocompatibility. Mixing ProRoot MTA with PBS in place of distilled water had no effect on its biocompatibility. Biosealer and CEM cement after 48 hr of incubation were significantly more cytotoxic to on monocyte cells compared to ProRoot MTA and Biodentine.

Effect of bismuth oxide on white mineral trioxide aggregate: chemical characterization and physical properties

AIM

To assess the effect of bismuth oxide (Bi2 O3 ) on the chemical characterization and physical properties of White mineral trioxide aggregate (MTA) Angelus.

METHODOLOGY

Commercially available White MTA Angelus and White MTA Angelus without Bi2 O3 provided by the manufacturer especially for this study were subjected to the following tests: Rietveld X-ray diffraction analysis (XRD), energy-dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), compressive strength, Vickers microhardness test and setting time. Chemical analysis data were reported descriptively, and physical properties were expressed as means and standard deviations. Data were analysed using Student's t-test and Mann-Whitney U test (P = 0.05).

RESULTS

Calcium silicate peaks were reduced in the diffractograms of both hydrated materials. Bismuth particles were found on the surface of White MTA Angelus, and a greater amount of particles characterized as calcium hydroxide was observed by visual examination on White MTA without Bi2 O3 . The material without Bi2 O3 had the shortest final setting time (38.33 min, P = 0.002), the highest Vickers microhardness mean value (72.35 MPa, P = 0.000) and similar compressive strength results (P = 0.329) when compared with the commercially available White MTA Angelus containing Bi2 O3 .

CONCLUSION

The lack of Bi2 O3 was associated with an increase in Vickers microhardness, a reduction in final setting time, absence of Bi2 O3 peaks in diffractograms, as well as a large amount of calcium and a morphology characteristic of calcium hydroxide in EDX/SEM analysis.