Biocompatibility of New Calcium Aluminate Cement: Tissue Reaction and Expression of Inflammatory Mediators and Cytokines

Comparative biological properties of resin-free and resin-based calcium silicate-based endodontic repair materials on human periodontal ligament stem cells

OBJECTIVES

To investigate the effect of three different calcium silicate-based materials (CSBM) on the biological behavior of human periodontal ligament stem cells (hPDLSCs).

METHODS

Eluates of Biodentine, NeoPutty and TheraCal PT prepared at 1:1, 1:2, and 1:4 ratios were extracted under sterile conditions. The cytotoxicity of the extracts to the hPDLSCs was assessed using the MTT assay. Scratch wound healing assay was utilized for assessing cell migration. Scanning electron microscopy was used to detect cell attachment and morphology. Calcium ion release was measured using inductively coupled plasma-optical emission spectrometry; the pH-value was evaluated with a pH-meter. ANOVA with post hoc Tukey test was used for statistical analysis.

RESULTS

Cell viability was significantly higher for Biodentine and NeoPutty at day 1 with all dilutions (p < 0.05), while at day 3 and day 7 with dilutions 1:2 and 1:4; all materials showed similar behavior (p > 0.05). Biodentine had the highest percentage of cell migration into the scratched area at day 1 for all dilutions (p < 0.05). Stem cells were attached favorably on Biodentine and NeoPutty with evident spreading, and intercellular communications; however, this was not shown for TheraCal PT. Biodentine showed the highest pH values and calcium ion release (p < 0.05).

CONCLUSIONS

The resin-free CSBM showed better performance and favorable biological effects on hPDLSCs and were therefore considered promising for usage as endodontic repair materials.

CLINICAL SIGNIFICANCE

Proper selection of materials with favorable impact on the host stem cells is crucial to ensure outcome in different clinical scenarios.

Physicochemical properties of a calcium aluminate cement containing nanoparticles of zinc oxide

Objectives

This study evaluated the effect of different nanoparticulated zinc oxide (nano-ZnO) and conventional-ZnO ratios on the physicochemical properties of calcium aluminate cement (CAC).

Materials and Methods

The conventional-ZnO and nano-ZnO were added to the cement powder in the following proportions: G1 (20% conventional-ZnO), G2 (15% conventional-ZnO + 5% nano-ZnO), G3 (12% conventional-ZnO + 3% nano-ZnO) and G4 (10% conventional-ZnO + 5% nano-ZnO). The radiopacity (R_ad), setting time (S_et), dimensional change (D_c), solubility (S_ol), compressive strength (C_st), and pH were evaluated. The nano-ZnO and CAC containing conventional-ZnO were also assessed using scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Radiopacity data were analyzed by the 1-way analysis of variance (ANOVA) and Bonferroni tests (p < 0.05). The data of the other properties were analyzed by the ANOVA, Tukey, and Fisher tests (p < 0.05).

Results

The nano-ZnO and CAC containing conventional-ZnO powders presented particles with few impurities and nanometric and micrometric sizes, respectively. G1 had the highest R_ad mean value (p < 0.05). When compared to G1, groups containing nano-ZnO had a significant reduction in the S_et (p < 0.05) and lower values of D_c at 24 hours (p < 0.05). The C_st was higher for G4, with a significant difference for the other groups (p < 0.05). The S_ol did not present significant differences among groups (p > 0.05).

Conclusions

The addition of nano-ZnO to CAC improved its dimensional change, setting time, and compressive strength, which may be promising for the clinical performance of this cement.

Interleukin-6, tumor necrosis factor-α, and CD5 immunolabeling of new experimental endodontic sealer and repair material

The aim of this study was to evaluate the biocompatibility and immunoinflammatory response of the Sealepox and Sealepox-RP, based on interleukin (IL)-6, tumor necrosis factor (TNF)-α, and CD5 immunolabelling. The ProRoot MTA (PRMTA) was used for comparison. Polyethylene tubes (1.0-mm internal, 1.6-mm external diameter, and 10.0-mm length; ISO 10993) with or without (control) materials were randomly implanted in the dorsum of 35 rats (4 per rat). After 7, 15, 30, 60, and 90 days (n = 7), the tubes were removed for histological and immunohistochemical analysis. The Kruskal-Wallis and Dunn's test for non-parametric data and, ANOVA and Tukey test for parametric data were used (P < 0.05). Hematoxylin and eosin staining revealed that the concentration of inflammatory cells decreased over time with no differences between groups in all periods (P > 0.05). Regarding IL-6 immunostaining, there was no difference at 7 days (P > 0.05); all groups decreased over time, being faster for the PRMTA group and also, with no differences between groups in the last period (P > 0.05). For TNF-α, at 7 days there was no difference between groups (P > 0.05); there was an increase at 15 days for PRMTA and, at 30 and 60 days, for PRMTA and Sealepox compared to the control (P < 0.05). At 90 days, Sealepox RP showed the lowest immunostaining being similar to the control (P > 0.05). Regarding CD5 cells, at 7 days, there was high immunostaining for PRMTA compared to the control (P < 0.05); and significant reduction over time with difference for all groups at 30 and 60 days. (P < 0.05); Sealepox was similar to the control in all periods (P > 0.05). Sealepox RP showed the highest immunostaining at 15 days, being different from the control and PRMTA (P < 0.05); in the other periods it was similar to the control (P > 0.05). It can be concluded that Sealepox and Sealepox-RP were biocompatible and demonstrated similar immunoinflammatory response regarding IL-6, TNF-α, and CD5 compared to PRMTA.

Effect of root perforation repair with mineral aggregate-based cements on the retention of customized fiberglass posts

The purpose of this study was to investigate whether the root perforation repair with mineral aggregate-based cements affects the retention of customized fiberglass posts to bovine intraradicular dentin. Sixty-four bovine mandibular incisors had their root canals endodontically treated and prepared for fiberglass posts luting. Teeth were randomly distributed into four groups (n = 16), according to the cement used for the perforations repair (MTA HP; calcium aluminate cement-CAC; and CAC + calcium carbonate nanoparticles-nano-CaCO₃) and control group (no perforation). The groups were redistributed according to the fiberglass posts luting protocol (n = 8): total-etching (TE) (MTA HP/TE; CAC/TE; CAC + CaCO₃/TE and control/TE) and self-etching (SE) (MTA HP/SE; CAC/SE; CAC + CaCO₃/SE and control/SE). Roots were sectioned into 1.3 mm-thick dentin slices obtaining samples that were submitted to the push-out test in Universal Testing Machine (Instron, Model 4444-0.5 mm/min). The fractured samples were analyzed under stereomicroscope and Scanning Electron Microscope (SEM). CAC/TE and CAC/SE groups had significant difference between the cervical and middle thirds (p < 0.05). When the root thirds were not considered, CAC/SE had the lowest bond strength and differed statistically from CAC/TE and CAC + CaCO₃/TE groups, which had the highest mean bond strength values (p < 0.05). The root perforations repair did not affect the bond strength of resin cement/customized fiberglass posts to bovine dentin. The increase in bond strength is luting protocol dependent.

Comparative cytocompatibility of the new calcium silicate-based cement NeoPutty versus NeoMTA Plus and MTA on human dental pulp cells: an in vitro study

OBJECTIVES

The aim of the present in vitro study is to determine the cytocompatibility of the recently introduced NeoPutty in contact with human dental pulp cells compared with its precursor NeoMTA Plus and the classic gold standard MTA Angelus.

MATERIALS AND METHODS

Sample disks were obtained for each of the tested materials (5 mm diameter; 2 mm thickness; n = 30), along with 1:1, 1:2, and 1:4 material eluents. HDPCs were extracted and cultured with the tested materials (test groups) or in unconditioned medium (control group), and the following biocompatibility assays were performed: MTT assay, scratch wound assay, cell cytoskeleton staining assays, and cell attachment assessment via SEM. Additionally, material ion release and surface element composition were evaluated via ICP-MS and SEM-EDX, respectively. Each experimental condition was carried out three times and assessed in three independent experiments. Statistical significance was established at p < 0.05.

RESULTS

1:2 dilutions of all the tested materials exhibited a comparable cell viability to that of the control group at 48 and 72 h of culture (p < 0.05). The same was observed for 1:4 dilutions of the tested materials at 24, 48, and 72 h of culture (p > 0.05). All the tested materials exhibited adequate cytocompatibility in the remaining biocompatibility assays. MTA exhibited a significantly higher calcium ion release compared to NeoPutty and NeoMTA Plus (p < 0.05).

CONCLUSION

The results from the present work elucidate the adequate cytocompatibility of NeoPutty, NeoMTA Plus, and MTA Angelus towards human dental pulp cells.

CLINICAL RELEVANCE

Within the limitations of the present in vitro study, our results may act as preliminary evidence for its use in vital pulp therapy as a pulp capper. However, results need to be interpreted with caution until further clinical supporting evidence is reported.

Fracture Resistance of Simulated Immature Teeth Reinforced with Different Mineral Aggregate-Based Materials

This study assessed the fracture resistance of simulated immature teeth reinforced with calcium aluminate cement (CAC) or mineral trioxide aggregate (MTA) containing calcium carbonate nanoparticles (nano-CaCO3). The microstructural arrangement of the cements and their chemical constitution were also evaluated. Forty-eight canines simulating immature teeth were distributed into 6 groups (n=8): Negative control - no apical plug or root canal filling; CAC - apical plug with CAC; CAC/nano-CaCO3 - apical plug with CAC+5% nano-CaCO3; MTA - apical plug with MTA; MTA/nano-CaCO3 - apical plug with MTA+5% nano-CaCO3; and Positive control - root canal filling with MTA. The fracture resistance was evaluated in a universal testing machine. Samples of the cements were analyzed under Scanning Electron Microscope (SEM) to determine their microstructural arrangement. Chemical analysis of the cements was performed by Energy Dispersive X-ray Spectroscopy (EDS). The fracture resistance of CAC/nano-CaCO3 was significantly higher than the negative control (p<0.05). There was no significant difference among the other groups (p>0.05). Both cements had a more regular microstructure with the addition of nano-CaCO3. MTA samples had more calcium available in soluble forms than CAC. The addition of nano-CaCO3 to CAC increased the fracture resistance of teeth in comparison with the non-reinforced teeth. The microstructure of both cements containing nano-CaCO3 was similar, with a more homogeneous distribution of lamellar- and prismatic-shaped crystals. MTA had more calcium available in soluble forms than CAC.

Tissue response to white mineral aggregate-based cement containing barium sulfate as alternative radiopacifier: A randomized controlled animal study

The purpose of this study was to investigate the tissue reaction stimulated by BaSO4 - and Bi2 O3 -containing White MTA Angelus, in comparison with Bi2 O3 -containing white Portland cement, and white ProRoot MTA. Thirty-six adult male Wistar rats (Rattus norvegicus), weighing between 250 and 300 g, were distributed into three groups (n = 12) in accordance with the period of sacrifice (15, 30, and 60 days). Four polyethylene tubes filled with the tested cements were implanted into the dorsum of each rat. Lateral wall of the tubes served as the negative control. After the experimental periods, the animals were euthanized by overdose of pentobarbital anesthetic solution, and the specimens were prepared for microscopic analysis under ×50, ×100, and ×400 magnifications. Inflammatory scores (0-3) were used to grade the tissue reaction. Data were analyzed by the Kruskal-Wallis test and Dunn's test for individual comparisons (p < .05). A mild to moderate inflammatory tissue reaction was observed at the 15-day period, which decreased over the course of the periods for all cements, except for Portland cement. There was no significant difference among the tissue responses for ProRoot MTA, BaSO4 - and Bi2 O3 -containing White MTA Angelus at the 60-day period (p > .05). The Portland group had moderate inflammatory reaction at the final period of analysis, which was statistically different when compared to the other groups (p < .05). The microscopic findings of this animal study suggest that the addition of BaSO4 to White MTA Angelus does not hampers the biocompatibility of the cement.

Biological assessment of a new ready-to-use hydraulic sealer

Objectives

This study compared the cytotoxicity, biocompatibility, and tenascin immunolabeling of a new ready-to-use hydraulic sealer (Bio-C Sealer) with MTA-Fillapex and white MTA-Angelus.

Materials and Methods

L929 fibroblasts were cultivated and exposed to undiluted and diluted material extracts. Polyethylene tubes with or without (the control) the materials were implanted into the dorsa of rats. At 7 days and 30 days, the rats were euthanized, and the specimens were prepared for analysis; inflammation and immunolabeling were measured, and statistical analysis was performed (p < 0.05).

Results

MTA-Fillapex exhibited greater cytotoxicity than the other materials at all time points (p < 0.05). The undiluted Bio-C Sealer exhibited greater cytocompatibility at 6 and 48 hours than white MTA-Angelus, with higher cell viability than in the control (p < 0.05). White MTA-Angelus displayed higher cell viability than the control at 24 hours, and the one-half dilution displayed similar results at both 6 and 48 hours (p < 0.05). At 7 days and 30 days, the groups exhibited moderate inflammation with thick fibrous capsules and mild inflammation with thin fibrous capsules, respectively (p > 0.05). At 7 days, moderate to strong immunolabeling was observed (p > 0.05). After 30 days, the control and MTA-Fillapex groups exhibited strong immunolabeling, the white MTA-Angelus group exhibited moderate immunolabeling (p > 0.05), and the Bio-C Sealer group exhibited low-to-moderate immunolabeling, differing significantly from the control (p < 0.05).

Conclusions

Bio-C Sealer and white MTA-Angelus exhibited greater cytocompatibility than MTA-Fillapex; all materials displayed adequate biocompatibility and induced tenascin immunolabeling.

Biocompatibility, Biomineralization, and Maturation of Collagen by RTR®, Bioglass and DM Bone® Materials

This study evaluated the biocompatibility, biomineralization, and collagen fiber maturation induced by Resorbable Tissue Replacement (RTR®; β-tricalcium phosphate [TCP]), Bioglass (BIOG; bioactive glass), and DM Bone® (DMB; hydroxyapatite and β-TCP) in vivo. Sixty-four polyethylene tubes with or without (control group; CG) materials (n=8/group/period) were randomly implanted in the subcutaneous tissue of 16 male Wistar rats (four per rat), weighting 250 to 280 g. The rats were killed after 7 and 30 days (n=8), and the specimens were removed for analysis of inflammation using hematoxylin-eosin; biomineralization assay using von Kossa (VK) staining and polarized light (PL); and collagen fiber maturation using picrosirius red (PSR). Nonparametric data were statistically analyzed by Kruskal-Wallis and Dunn tests, and parametric data by one-way ANOVA test (p<0.05). At 7 days, all groups induced moderate inflammation (p>0.05). At 30 days, there was mild inflammation in the BIOG and CG, and moderate inflammation in the RTR and DMB groups, with a significant difference between the CG and RTR (p<0.05). The fibrous capsule was thick at 7 days and predominantly thin at 30 days in all groups. All materials exhibited structures that stained positively for VK and PL. Immature collagen fibers were predominant at 7 and 30 days in all groups (p>0.05), although DMB exhibited more mature fibers than BIOG at 30 days (p<0.05). RTR, BIOG, and DMB were biocompatible, inducing inflammation that reduced over time and biomineralization in the subcutaneous tissue of rats. DMB exhibited more mature collagen fibers than BIOG over a longer period.

Marginal adaptation, solubility and biocompatibility of TheraCal LC compared with MTA-angelus and biodentine as a furcation perforation repair material

BACKGROUND

This study evaluated the marginal adaptation, solubility and biocompatibility of TheraCal LC compared with mineral trioxide aggregate (MTA-Angelus) and Biodentine when used as a furcation perforation repair material.

METHODS

The marginal adaptation was assessed by scanning electronic microscope and presence of any gap between the dentin surface and filling material in each quadrant of the sample was analyzed at 1000 X magnification. The solubility was measured after one week by the ISO standard method. Biocompatibility was evaluated by the inflammatory response and radiography after one month and three months of repair of experimental furcation perforations in dog's teeth.

RESULTS

There were significant differences in the marginal adaptation, solubility and biocompatibility of the tested materials (P < 0.05). TheraCal LC showed the highest frequency distribution of gap presence that was followed by the MTA-Angelus then Biodentine. The least soluble material after one week was TheraCal LC that was followed by the MTA-Angelus and Biodentine. After one month and three months, TheraCal LC showed the highest inflammatory response and highest frequency distribution of radiolucency that was followed by the Biodentine then MTA-Angelus.

CONCLUSION

Unlike Biodentine, TheraCal LC is incapable of alternating the MTA in furcation perforation repair due to its poor biocompatibility and poor marginal adaptation.

Role(s) of cytokines in pulpitis: Latest evidence and therapeutic approaches

Pulpitis is known as a typical inflammation of dental pulp tissue, and microorganisms of the oral microbiome are involved in this opportunistic infection. Studies indicated that several factors related to host response have a crucial role in pulpitis. Among these factors, inflammatory mediators of the immune system such as cytokines and chemokines contribute to pulpal defense mechanisms. A wide range of cytokines have been observed in dental pulp and these small molecules are able to trigger inflammation and participate in immune cell trafficking, cell proliferation, inflammation, and tissue damage in pulp space. Therefore, the aim of this review was to describe the role of cytokines in the pathogenesis of pulpitis.

Biocompatibility of new bioactive resin composite versus calcium silicate cements: an animal study

Background

The purpose of this study was to compare the biocompatibility of three bioactive materials, namely ACTIVA bioactive restorative resin composite, iRoot BP plus and Mineral Trioxide Aggregate (MTA) Angelus-HP.

Methods

Seventy-five Wistar male rats were subjected to subcutaneous implantation of four polyethylene tubes; one empty tube was used as control (Group 1), and the other tubes were filled with ACTIVA (Group 2), iRoot BP (Group 3) and MTA-HP (Group 4). Then, the rats were subdivided into 3 groups according to the sacrification time into one, two and 4 weeks (n = 25 rats). Tissue specimens were submitted to histopathological and immunohistochemical analysis of α-SMA and caspase 3.

Results

The one-way Anova test revealed that ACTIVA group exhibited minimal inflammation in comparison to calcium silicate cements (iRoot BP and MTA-HP groups). iRoot BP group significantly revealed a more severe degree of chronic inflammation in comparison to other groups (P < 0.05). ACTIVA group showed marked regression of inflammation and fibrosis comparable to the control, while iRoot BP group revealed remarkable fibrosis and calcification, with less degrees in MTA-HP group (P < 0.05). Immunostaining of both α-SMA and caspase 3 revealed lower indexes in ACTIVA group consistent with the control (P < 0.05).

Conclusions

ACTIVA showed a higher degree of biocompatibility to subcutaneous tissues in comparison to both iRoot BP and MTA-HP cements in regard to decrease the intensity of inflammation, with subsequent fibrous connective tissue remodeling and better healing patterns.

Clinical significance

Preliminary data suggests that the application of ACTIVA in retrograde fillings.

Cytotoxicity, Biocompatibility and Biomineralization of a New Ready-for-Use Bioceramic Repair Material

New mineral trioxide aggregate (MTA) formulations are constantly introduced in the market, usually in a powder-and-liquid form. Bioceramic (Bio-C) Repair is a ready-for-use material suggested as substitute for MTA, but its properties need to be studied. This study evaluated the cytotoxicity, biocompatibility and biomineralization of Bio-C Repair compared to MTA Repair High-Plasticity (MTA-HP) and white MTA-Angelus (MTA-Ang). L929 fibroblasts were exposed to material-extracted (undiluted, ½ and ¼ dilutions; 6, 24 and 48h). Polyethylene tubes with material or empty (control) were implanted in the subcutaneous tissue of rats. After 7 and 30 days (n=8), the specimens were removed for analysis (hematoxylin-eosin, von Kossa and polarized light). Cytotoxicity data were statistically analyzed by two-way ANOVA, and biocompatibility data by Kruskal-Wallis and Dunn tests (p<0.05). The cells exposed to the materials had greater viability at most of the periods compared with control (p<0.05). The undiluted and ½ dilutions of MTA-HP extract showed higher cytocompatibility than Bio-C Repair at 6 h and with the ¼ dilution at 24 h (p<0.05); the white MTA-Ang showed higher cytocompatibility than Bio-C Repair at most of periods (p<0.05). The undiluted white MTA-Ang extract had higher cytocompatibility at 6 and 24h than MTA-HP, and with ½ dilution at 24h (p<0.05). The materials' cytocompatibility was similar at 48h for most dilutions (p>0.05). At 7 and 30 days, the groups had moderate and mild inflammation, respectively (p>0.05). All materials showed positive structures for von Kossa and polarized light. In conclusion, Bio-C Repair had similar cytocompatibility to MTA-based materials is biocompatible and induces biomineralization.

Influence of nanostructured calcium aluminate and calcium silicate on the liver: histological and unbiased stereological analysis

AIM

To examine the potential systemic toxicity of nanostructured materials based on calcium silicate and calcium aluminate, for potential application in Dentistry.

METHODOLOGY

Twenty-four Albino Wistar rats aged 2 months were used as an in vivo animal model for subcutaneous implantation of the investigated materials, placed in polyethylene tubes. Thirty days after implantation, the livers of the rats were analysed and following histological and stereological parameters were evaluated for volume density of hepatocytes and blood sinusoids, number and numerical density of hepatocytes, surface of hepatocytes and their nucleuses, nucleocytoplasmic ratio and mitotic index of hepatocytes. Stereological measurements were achieved using Cavalieri's principle, with grid P2 and unbiased analysis. Additionally, immunohistochemistry studies were performed to further analyse changes in liver tissue. Several haematological and biochemical parameters of blood of experimental animals were also analysed, as well as local tissue reactions around the implants. Statistical analysis was performed using parametric (anova and t-test) and nonparametric tests (Kruskal-Wallis and Mann-Whitney U-test) depending on data distribution.

RESULTS

Implanted dental cements led to an increase in stereological and histological parameters in liver tissue compared to control rats. Although the investigated parameters mostly showed significant differences between control and experimental animals, the liver tissue of the experimental animals did not have visible signs of pathological changes. This was supported by the analysis of blood parameters which were not significantly different between control and experimental animals. Also, the subcutaneous tissues had minimal inflammatory reactions. Immunohistochemistry studies revealed that nanostructured materials induced proliferation of hepatocytes, but that the immunological response to the materials was not strong enough to induce proliferation of immunoreactive cells in liver in the observed time period.

CONCLUSIONS

This study was performed as a contribution to the attestation of the biocompatibility of dental cements based on calcium silicate and calcium aluminate. Although these materials induced several changes in the liver structure, they were not clinically relevant and represent a normal and reversible response of the liver to the presence of biocompatible materials in the body. Blood and immunohistochemistry analyses and local tissue reactions further confirmed that these materials possess good biocompatible potential.

Repair of Bone Defects with Chitosan-Collagen Biomembrane and Scaffold Containing Calcium Aluminate Cement

Innovative biomaterials can provide a promising new direction for the treatment of bone defects, stimulating a proper repair process, with no damage to adjacent tissues. The purpose of this in vivo study was to evaluate the biocompatibility and the osteoinductive capacity of chitosan-collagen biomembrane and scaffold containing calcium aluminate cement. Eighteen New Zealand white rabbits (Oryctolagus cuniculus) were distributed according to the experimental times of analysis (7, 15 and 30 days). Four bone defects were created in the rabbits calvaria, which were individually filled with the biomembrane, scaffold, blood clot (negative control) and autologous bone (positive control). Histopathological analysis was performed using optical microscope at 32´, 64´, 125´ and 320´ magnifications. Cell response to inflammation and new bone tissue formation was quantified using a score system. The biomembrane group presented greater inflammatory response at 15 days, with significant difference to autologous bone group (p<0.05). There was no statistically significant difference for foreign body type reaction among groups (p>0.05). Concerning new bone formation, linear closure of the defect area was observed more evidently in the group with autologous bone. The scaffold group presented similar results compared with the autologous bone group at 30 days (p>0.05). Both tested biomaterials presented similar biocompatibility compared with the control groups. In addition, the biomembrane and scaffold presented similar osteoinductive capacity, stimulating bone repair process in the course of the experimental time intervals.

Genotoxicity and Hemocompatibility of a Novel Calcium Aluminate-Based Cement

Objective:

The aim of this in vitro study was to evaluate the genotoxicity and hemocompatibility of a novel calcium aluminate-based cement, EndoBinder (EB) (Binderware, São Carlos, SP, Brazil) and compare it with Angelus White Mineral Trioxide Aggregate (MTA) (AWMTA) (Angelus, Soluções Odontológicas, Londrina, PR, Brazil).

Methods:

For evaluation of genotoxicity, a comet assay was performed with Chinese hamster ovary (CHO) cells that had been grown for 24 h in Dulbecco’s Modified Eagle Medium incubated with each of the cements for 24 h at 37°C. DNA percentage in head and Olive tail moment were analyzed. For assessment of hemocompatibility, erythrocyte lysis quantification, and concentration of plasma fibrinogen were determined in human blood samples placed in contact with each of the materials. One way analysis of variance (ANOVA) followed by post hoc Tukey test and Student t-test were used for data analysis of genotoxicity and hemocompatibility, respectively.

Results:

Results showed that the genotoxic effects of EB and AWMTA were comparable to that of the negative control, with no statistically significant differences between AWMTA and negative control (P>0.05). Compared to AWMTA, EB showed greater hemolytic potential when placed in direct contact with erythrocytes (P<0.05). Fibrinogen values were low for both materials, with protein concentration being greater in samples exposed to EB than to AWMTA.

Conclusion:

Both materials presented a higher hemolytic behaviour compared to what is established by international standards. Fibrinogen formation was low for both materials, and DNA damage induction was not observed in a comet assay.

Systemic effect of mineral aggregate-based cements: histopathological analysis in rats

Objective:

Several studies reported the local tissue reaction caused by mineral aggregate-based cements. However, few studies have investigated the systemic effects promoted by these cements on liver and kidney when directly applied to connective tissue. The purpose of this in vivo study was to investigate the systemic effect of mineral aggregate-based cements on the livers and kidneys of rats.

Material and Methods:

Samples of Mineral Trioxide Aggregate (MTA) and a calcium aluminate-based cement (EndoBinder) containing different radiopacifiers were implanted into the dorsum of 40 rats. After 7 and 30 d, samples of subcutaneous, liver and kidney tissues were submitted to histopathological analysis. A score (0-3) was used to grade the inflammatory reaction. Blood samples were collected to evaluate changes in hepatic and renal functions of animals.

Results:

The moderate inflammatory reaction (2) observed for 7 d in the subcutaneous tissue decreased with time for all cements. The thickness of inflammatory capsules also presented a significant decrease with time (P<.05). Systemically, all cements caused adverse inflammatory reactions in the liver and kidney, being more evident for MTA, persisting until the end of the analysis. Liver functions increased significantly for MTA during 30 d (P<.05).

Conclusion:

The different cements induced to a locally limited inflammatory reaction. However, from the systemic point of view, the cements promoted significant inflammatory reactions in the liver and kidney. For MTA, the reactions were more accentuated.

Cytotoxicity of New Calcium Aluminate Cement (EndoBinder) Containing Different Radiopacifiers

Abstract This study aimed to evaluate the cytotoxicity of a calcium aluminate cement (EndoBinder) containing different radiopacifiers, Bi2O3, ZnO or ZrO2, compared with Mineral Trioxide Aggregate (MTA). According to ISO 10993-12:2012 (E) recommendations, 0.2 g of each cement were applied in transwell inserts and placed in 24-well culture plates containing 1 mL of culture medium (DMEM). After 24 h of incubation, the extracts (DMEM containing components released from the cements) were applied to immortalized odontoblast-like MDPC-23 cells. Cell viability (MTT test), alkaline phosphatase activity (ALP), total protein production and cell morphology (Scanning Electron Microscopy - SEM) were evaluated. The volume of 50 µL of extract was used to determine the chemical elements released by the cements using Energy Dispersive Spectroscopy (EDS). The following groups were established (n=6): NC - negative control (without treatment); EB - EndoBinder without radiopacifier; EBBO - EndoBinder+Bi2O3; EBZnO - EndoBinder+ZnO; EBZrO - EndoBinder+ZrO2 and WMTA - White MTA. Data were subjected to statistical analysis (Kruskal-Wallis test, level of significance=5%). Cells exposed to the different versions of EndoBinder presented small reduction in viability, total protein production and ALP activity, with values similar to the NC and WMTA groups (p>0.05). Different elements (C, O, Na, Al, P, Si, Cl, Bi, K) released by the cements were detected in the extracts. However, the cells had no significant changes in their morphology. EndoBinder and MTA did not affect negatively the metabolism of the odontoblastic-like cells, showing it to be cytocompatible, irrespective of the used radiopacifier.

Effects of a discoloration-resistant calcium aluminosilicate cement on the viability and proliferation of undifferentiated human dental pulp stem cells

Discoloration-resistant calcium aluminosilicate cement has been formulated to overcome the timely problem of tooth discoloration reported in the clinical application of bismuth oxide-containing hydraulic cements. The present study examined the effects of this experimental cement (Quick-Set2) on the viability and proliferation of human dental pulp stem cells (hDPSCs) by comparing the cellular responses with commercially available calcium silicate cement (white mineral trioxide aggregate; WMTA) after different aging periods. Cell viability and proliferation were examined using assays that examined plasma membrane integrity, leakage of cytosolic enzyme, caspase-3 activity for early apoptosis, oxidative stress, mitochondrial metabolic activity and intracellular DNA content. Results of the six assays indicated that both Quick-Set2 and WMTA were initially cytotoxic to hDPSCs after setting for 24 h, with Quick-Set2 being comparatively less cytotoxic than WMTA at this stage. After two aging cycles, the cytotoxicity profiles of the two hydraulic cements were not significantly different and were much less cytotoxic than the positive control (zinc oxide-eugenol cement). Based on these results, it is envisaged that any potential beneficial effect of the discoloration-resistant calcium aluminosilicate cement on osteogenesis by differentiated hDPSCs is more likely to be revealed after outward diffusion and removal of its cytotoxic components.

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.