Properties Of Mineral Trioxide Aggregate Research Articles

Effect of Fluorohydroxyapatite on Biological and Physical Properties of MTA Angelus.

This study aimed to assess the effect of addition of fluorohydroxyapatite (FHI) on biological and physical properties of mineral trioxide aggregate (MTA) Angelus. In this in vitro, experimental study, nano-FHI powder was first synthesized, and the morphology and chemical structure of particles were evaluated by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Three groups were evaluated in this study: MTA Angelus, MTA modified with 10% FHA, and MTA modified with 15% FHA. After mixing, the materials were applied to ring molds (10 mm diameter, 1 mm height), and the setting time of the three groups was evaluated according to ISO6876 and ASTMC266-03 with a Gillmore needle. The pH was measured using a pH meter at 24 and 48 hours and 7 days after mixing. The cytotoxicity of the materials was assessed in freshly mixed form and after 1 and 7 days using the methyl thiazolyl tetrazolium (MTT) assay according to ISO10993-5. Data were analyzed by one-way and repeated measures ANOVA and Tukey's test (alpha = 0.05). The addition of FHA to MTA significantly decreased the initial setting time (P < 0.05) and had no significant effect on cell viability (compared with pure MTA Angelus) at 1 and 7 days. However, modified MTA groups in freshly mixed form showed significantly lower cell viability (P < 0.05). The pH remained alkaline at all time points. Addition of 15% FHA to MTA Angelus decreased its setting time with no adverse effect on cell viability (except for fresh form) or pH.

Comparative Evaluation of the Physical and Antimicrobial Properties of Mineral Trioxide Aggregate, Biodentine, and a Modified Fast-Setting Mineral Trioxide Aggregate Without Tricalcium Aluminate: An In Vitro Study.

Background Tricalcium aluminate, one of the major constituents of mineral trioxide aggregate (MTA), has been shown to have cytotoxic properties. Mineral trioxide aggregate has moderate to low antimicrobial activity against the most common endodontic pathogen, Enterococcus faecalis. Aim To assess the physical and antimicrobial properties of a newly modified formulation of mineral trioxide aggregate. Materials & methods The final setting time, compressive strength, and antimicrobial properties were tested for three groups of materials. The material used for Group 1 was mineral trioxide aggregate (white MTA, Angelus, Londrina, Brazil); the material for Group 2 was Biodentine (Septodont, Saint Maur des Fossés, France); and for Group 3, a modified MTA formulation was used. Results Group 1 had the longest setting time, and Group 2 had the shortest setting time. Group 3's material was set at 83.65 ± 0.28 minutes. This difference among the groups was statistically significant (p < 0.05). The highest mean compressive strength during all the time periods was seen in Group 2, followed by Group 3, and the least in Group 1. This difference in compressive strength was statistically significant (p=0.001). The largest zone of inhibition against Enterococcus faecalis, Candida albicans, and Streptococcus mutans was seen in Group 3, followed by Group 2 and Group 1. Conclusion Under the limitations of the present study, the newly modified MTA could serve as an alternative to the conventional MTA in terms of faster setting, higher strength, and better antimicrobial properties.

The Addition of Copper Nanoparticles to Mineral Trioxide Aggregate for Improving the Physical and Antibacterial Properties

The physical and antibacterial properties of mineral trioxide aggregate (MTA) have been improved by adding copper nanoparticles (CuNP). The CuNP colloid was synthesized by reacting CuCl2·2H2O and NaBH4 as the reducing agent using C6H8O6 as the capping agent. The Cu(II) concentration was varied by 3.0, 6.0, and 9.0 mM to produce CuNP-3, CuNP-6, and CuNP-9 colloids, respectively. The CuNP colloids were characterized with a UV-Vis spectrophotometer and TEM. MTA was hydrated with CuNP at a mass-to-volume ratio of 2:1 to produce Cu-MTA-3, Cu-MTA-6, and Cu-MTA-9, respectively. All products were characterized with XRD and SEM-EDX. The compressive strength, pH, Ca ion release, and solubility were measured, and antibacterial activity was tested. The results showed a spherical shape of the synthesized CuNP with a particle size of ~28.08 nm. Adding CuNP-9 to hydrated MTA increased the compressive strength, pH, Ca ion release, and solubility, with the value of 4.78±0.38 MPa; 9.01±0.03; 1718±63 ppm, and 22.48±0.37%, respectively. The highest antibacterial activity occurred for Cu-MTA-9, with an inhibition zone of 10.15±0.47 mm against S. aureus and 11.93±1.16 mm against P. aeruginosa. The findings show a potential application of the product for endodontic materials containing antibacterial agents.

Influence of strontium containing fluorophosphate glass onto structural and mechanical behavior of MTA network

ObjectiveThis study aimed to evaluate the effect of incorporation of strontium based fluoro phosphate glass (SrFPG) 48P2O5–29CaO–14NaO–3CaF2–6SrO on physico chemical and biological properties of mineral trioxide aggregate (MTA). MethodsOptimized SrFPG glass powder were prepared using planetary ball mill and incorporated into MTA in varying proportion (1, 5, 10 wt%) to obtain SrMT1, SrMT5, SrMT10 bio-composite respectively. The bio-composites were characterized using XRD, FTIR and SEM-EDAX before and after soaking for 28 days in stimulated body fluid (SBF) solution. To assess the mechanical properties and biocompatibility of the prepared bio-composite, density, pH analysis, compressive strength and cytotoxicity evaluation using MTT assay were done before and after soaking for 28 days in SBF solution. ResultsA nonlinear variation in compressive strength and pH values was noted. Of the bio-composites, SrMT10 was evidenced with rich apatite formation in XRD, FTIR and SEM with EDAX analysis. MTT assay showed increased cell viability in all the samples before and after in vitro studies.

Effect of Different Mixing Methods on Physicochemical Properties of Mineral Trioxide Aggregate: A Systematic Review.

Mineral trioxide aggregate (MTA) is a commonly used endodontic biomaterial. The physicochemical properties of MTA have a crucial role in designating clinical outcome, and different factors can affect these properties. Various methods have been used for mixing MTA, including manual, mechanical, and ultrasonic. The aim of this systematic review was to evaluate the effect of different mixing methods on the physicochemical properties of MTA. Electronic databases including PubMed, Embase, Web of Science, and Scopus were searched up to May 2022. In order to cover gray literature, the ProQuest and Google Scholar databases were also searched to detect theses and conference proceedings. For quality assessment of the included studies, we used a modified version of the Cochrane risk of bias tool for randomized controlled trials (RCTs). Experimental studies which had assessed at least one property of MTA and compared at least two different mixing methods of MTA were included in this study. All animal studies, reviews, case reports, and case series were excluded. Fourteen studies were included. The results showed that the ultrasonic mixing method significantly improved some MTA characteristics, including microhardness, flowability, solubility, setting time, and porosity. However, the mechanical mixing method improved other properties including flowability, solubility, push-out bond strength, and hydration. The manual mixing method showed inferior results compared to other mixing methods in terms of microhardness, flowability, solubility, setting time, push-out bond strength, porosity, and hydration. Different mixing methods had a similar effect on compressive strength, sealing ability, pH and calcium ion release, volume change, film thickness, and flexural strength of MTA. Mechanical and ultrasonic mixing methods are superior to the manual mixing method in terms of improving physicochemical properties of MTA. No report of selection bias and varieties in methodologies were limitations of evidence.

Effects of a mineralization-promoting peptide on the physical and chemical properties of mineral trioxide aggregate

Mineral trioxide aggregate (MTA) has been used widely in dentistry due to its sealing ability and biocompatibility. Delayed setting time is one of the major limitations of MTA. Various additives have been studied to further improve the properties of MTA with varied degrees of success. In this study, we have investigated the effect of a calcium phosphate mineralization promoting-peptide (MPP3) on the physical and chemical properties of MTA in comparison with Na2HPO4. Based on the reported effects of MPP3 on calcium-phosphate mineralization reaction, our hypothesis was that MPP3 may also show beneficial effects on the calcium-silicate mineralization system of MTA. Na2HPO4 was used for comparison since its setting accelerant effect on MTA has been well documented. The cements were prepared by mixing with distilled water, 0.40 mM MPP3 solution, 15% Na2HPO4 solution, and a combination of MPP3 and Na2HPO4 solution. Initial and final setting times were measured via Vicat needle. Microhardness values were measured via Vickers indenter at 1,3,7, and 28 days after hydration. Compressive strength after setting was measured via universal testing machine. Morphological and compositional analyses were performed via FESEM imaging, XRD and Raman spectroscopy. The microhardness data was evaluated via repeated-measures ANOVA. Setting time and compressive strength data were evasluated via one-way ANOVA. Initial setting time was reduced to ∼3 min in the Na2HPO4 containing groups but remained at ∼5 min in the control and MPP3 groups. Final setting times were significantly reduced in all groups compared to the control group. The reduction in the final setting times in the Na2HPO4 containing groups were significantly higher compared to the MPP3 group. Microhardness was significantly higher in the MPP3 group at all time points. No statistically significant difference in compressive strength was observed among the groups. FESEM analysis showed presence of ettringite crystals in the MPP3 group, and NaBiO3 crystals in the Na2HPO4 containing groups. XRD analysis showed a broadening of peaks at 2θ = 32° in the Na2HPO4 containing groups, possibly due to presence of NaBiO3. Raman spectroscopy showed statistically higher ettringite content in the MPP3 containing groups. Our findings indicate that MPP3 is a beneficial additive to eliminate some of the drawbacks associated with MTA with no detrimental effects on mechanical properties and without resulting in phases that potentially cause discoloration, such as NaBiO3. We propose that the reduced final setting time and increased microhardness by MPP3 may be associated with the increased ettringite content. Future studies, where wider range of MPP3 concentrations are studied may help elucidate and optimize the beneficial effects of MPP3 observed in this study.

Enhancing Compressive Strength and Dentin Interaction of Mineral Trioxide Aggregate by Adding SrO and Hydroxyapatite

In this research, the effect of strontium oxide (SrO) and hydroxyapatite (HA) on the properties of mineral trioxide aggregate (MTA) have been studied. MTA contained 20% SiO2, 60% CaO, and 2% Al2O3. Bi2O3 and SrO have been added with 18% (w/w) total percentage. MTA was prepared with a sol-gel process using a weak base (NH3) as a catalyst and calcined at 1000 °C for 3 h. The effect of HA was investigated by adding various percentages (3, 6, and 9%) on the MTA modified with 5% SrO. The modified MTA (MTA-SrO-HA) products were hydrated using water with the MTA to water weight ratio of 3:1. The results showed that tricalcium silicate (C3S), dicalcium silicate (C2S), Bi2O3, and strontium silicate peaks were detected in the XRD patterns. An increase in the intensity in the infrared spectra of CaO occurred after hybridization with HA. In addition, bonding of Ca-O-Si appeared at 879 and 995 cm−1, indicating the formation of cement. MTA modified with 5% SrO and 6% HA showed similar compressive strength to the commercial MTA (ProRoot brand). Furthermore, MTA-SrO5/HA6 showed a strong interface interaction with dentin adheres without any gaps, indicating a potential dental material for the future.

Biocompatibility and osteogenic potential of mineral trioxide aggregate mixed with hydrophilic synthetic polymer: An in vitro and in vivo study.

This study aimed to investigate in vitro biologic properties of mineral trioxide aggregate (MTA) mixed with 3% PVA (MTA-3% PVA) and in vivo dental pulp responses to direct capping in comparison with MTA mixed with distilled water (MTA-DW). Cell proliferation and osteogenic differentiation in culture of human dental pulp cells (hDPCs), and pH changes were evaluated. Pulps in 24 mandibular premolars of four 9-month-old beagle dogs were mechanically exposed and direct pulp capping was performed. Histological specimens were scored according to the degree of mineralization. MTA-3% PVA showed similar cell proliferation and similar or superior osteogenic differentiation of hDPCs compared with MTA-DW. All specimens were associated with calcified bridge formation and there were no significant differences in mineralization scores between the groups (p>0.05). The results suggested that MTA-3% PVA exhibited favorable biocompatibility and osteogenic differentiation in vitro compared with MTA-DW. Furthermore, both groups demonstrated similar results when used as pulp-capping agents in vivo.

Effect of Titania and Silver Nanoparticles on the Tensile Strength of Cement-Like Mineral Trioxide Aggregate

Several attempts have been conducted to improve the mechanical properties of mineral trioxide aggregate (MTA), including the addition of various nanoparticle materials such as silver and titania. The smaller the added material, the higher the material’s ability to fill the cavity of MTA, thus increasing the tensile strength of MTA after hydration. In this study, the effect of silver nanoparticles (AgNP) concentration and titania (TiO2) mass variation on the tensile strength of MTA was investigated. The ratio of MTA mass to AgNP volume used was 1 g to 330 μL, while TiO2 was added to MTA powder in a solid-solid state with a mass variation. The results show that the addition of AgNP and TiO2 to MTA powder can significantly increase the tensile strength of MTA from 0.404±0.125 to 1.044±0.021 and 1.378±0.391 MPa for 1.5% Ag and 0.5% TiO2, respectively.

Morphological and Chemical Analysis of Different Types of Calcium Silicate-Based Cements.

Objectives Particle size and shape can influence the properties of materials. However, to improve the physicochemical and biological properties of mineral trioxide aggregate (MTA), silicate-based hydraulic cements were introduced. This study aimed to evaluate and compare the major constituents and crystalline structures along with the surface morphology of different types of calcium silicate-based cement (CSC). Materials and Methods Six different types of CSC (white Portland cement, white ProRoot MTA, white MTA Angelus, Biodentine, and Endosequence, both putty and paste) were used in this study. Five samples of each material were analyzed in both uncured and cured cement using scanning electron microscopy/energy-dispersive X-ray (SEM/EDX), X-ray diffraction (XRD), and Fourier transform-infrared spectroscopy (FTIR). Results SEM analysis showed that the surfaces of all materials consisted of particle sizes ranging from 0.194 μm to approximately 51.82 μm. The basic elements found in both uncured and cured cement of all tested materials using EDX were carbon, calcium, silicon, and oxygen. A difference was observed in the presence or absence of magnesium, aluminum, bismuth, zirconium, and tantalum. XRD showed that all tested materials were composed mainly of tricalcium silicate and dicalcium silicate, which are the main components of Portland cement. FTIR analysis showed aromatic rings, phosphine PH, alkyl halides, and alcohol O-H groups in all tested materials but at different wavenumbers. Conclusions The different types of CSCs tested in this study were primarily modified types of Portland cement with the addition of radiopacifiers. ProRoot MTA and MTA Angelus contained bismuth oxide, Biodentine contains zirconium oxide, whereas Endosequence root repair materials (both putty and paste) contained zirconium oxide and tantalum oxide. Endosequence root repair materials showed smaller particle sizes than the other groups. White PC had the most irregular and large particle sizes. CSC had a smaller particle size, except for MTA Angelus. Clinical Relevance. The composition of CSC has a direct influence on the properties of these cements, which may affect the clinical outcome of the treatment.

Management of Oblique Root Fracture Using Mineral Trioxide Aggregate: A Case Report

Management of Oblique Root Fracture Using Mineral Trioxide Aggregate: A Case Report

The additive effect of iloprost on the biological properties of Mineral trioxide aggregate on mesenchymal stem cells

Background/purposeIloprost has been proposed as a potential biomaterial owing to angiogenic and odontogenic properties. However, the liquid form can limit its use during clinical applications. Mineral trioxide aggregate (MTA) has been used for various dental applications in which cell–material interaction is essential. This study aimed to investigate additive effects of iloprost on the biological properties of MTA on the viability, attachment, migration and differentiation of human mesenchymal stem cells (hMSCs). Materials and methodsStandardized human dentin disks were prepared. MTA was prepared by mixing distilled water or iloprost solution, and the lumen of the disks was filled with MTA or MTA-iloprost. hMSCs on disk alone and hMSCs on culture plates were used as controls. Cell viability and attachment were measured after 1, 7 and 14 days using AlamarBlue assay and scanning electron microscopy (SEM). Cell migration in MTA or MTA-iloprost extracts was determined using a wound-healing model.Osteogenic differentiation was evaluated by real-time reverse transcriptase polymerase chain reaction for alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN), and osteopontin (OSP) gene expressions after 7 and 14 days of osteogenic induction. ResultsCells on MTA-iloprost surface showed similar viability with MTA at 1 and 14 days but enhanced cellular viability and cell spreading compared to MTA at 7 days (p < 0.05). Cell migration was similar by MTA-iloprost and MTA extracts (p > 0.05). MTAiloprost significantly upregulated BSP, OCN and OSP expressions compared to MTA (p < 0.05). ConclusionThe addition of iloprost to MTA improved the initial cell viability and osteogenic potential of hMSCs.

Assessment of Mineral Trioxide Aggregate Setting in Simulated Root Canal with Different Root Canal Wall Thickness: In Vitro Study

Setting of mineral trioxide aggregate (MTA) is affected by various factors. The purpose of this in vitro study was to evaluate the influence of root canal wall thickness on mechanical properties of MTA along the whole apical plug. Bovine bone mold tubes with internal diameter of 2 mm, height of 5 mm, and wall thickness of 0.8 mm, 1.2 mm, and 1.6 mm were filled with 3 mm ProRoot MTA and were kept in 37 °C and relative humidity of 100% for 7 days. The indentation hardness and reduced modulus of elasticity were measured in a large overview matrix and detailed matrix placed 1.5 mm from simulated apical foramen in order to obtain particularized information about gradient of altering mechanical properties. The uppermost layer of material in contact with simulated apical foramen had reduced mechanical properties irrespective of root canal wall thickness. The most distinct decrease of microhardness (32%) and reduced modulus of elasticity (27%) in interfacial layer were present in specimen with thinnest root canal wall. This effect could be observed in detailed measurement up to 190 µm in material. The interfacial layer of MTA, which was in contact during setting with root canal wall thinner than 1.2 mm, had reduced mechanical properties.

Effect of bioactive glass addition on the physical properties of mineral trioxide aggregate

BackgroundThe addition of bioactive glass (BG), a highly bioactive material with remineralization potential, might improve the drawback of weakening property of mineral trioxide aggregates (MTA) when it encounters with body fluid. This study aims to evaluate the effect of BG addition on physical properties of MTA.MethodsProRoot (MTA), and MTA with various concentrations of BG (1, 2, 5 and 10% BG/MTA) were prepared. Simulated body fluid (SBF) was used to investigate the effect of the storage solution on dentin remineralization. Prepared specimens were examined as following; the push-out bond strength to dentin, compressive strength, setting time solubility and X-ray diffraction (XRD) analysis.ResultsThe 2% BG/MTA showed higher push-out bond strengths than control group after 7 days of SBF storage. The 2% BG/MTA exhibited the highest compressive strength. Setting times were reduced in the 1 and 2% BG/MTA groups, and solubility of all experimental groups were clinically acceptable. In all groups, precipitates were observed in dentinal tubules via SEM. XRD showed the increased hydroxyapatite peaks in the 2, 5 and 10% BG/MTA groups.ConclusionIt was verified that the BG-added MTA increased dentin push-out bond strength and compressive strength under SBF storage. The addition of BG did not negatively affect the MTA maturation reaction; it increased the amount of hydroxyapatite during SBF maturation.

Tannic acid speeds up the setting of mineral trioxide aggregate cements and improves its surface and bulk properties

HypothesisThe setting time and mechanical properties of cements are a major technical concern for a long time in civil engineering. More recently those practical problems became a major concern for biomedical applications -in bone surgery and in dentistry- in particular concerning the setting time which should be minimized. The possibility to add organic additives to interact with the different constituting ions in cements constitutes a way to modify the setting kinetics. We made the assumption that a hydrolysable polyphenol like tannic acid could modify the setting time and the physical properties of Mineral Trioxide Aggregate (MTA). ExperimentsTannic acid is added in variable proportions to the water used to set MTA. The formation of the hybrid organic-mineral cements is investigated using a combination of structural, chemical and mechanical methods. X-ray tomography was also used to investigate the changes in porosity and pore size distribution upon incorporation of tannic acid in MTA based cements. The hydrophilicity of the cements was evaluated by measuring the permeation kinetics of small water droplets. FindingsWe found that tannic acid allowed to reduce markedly the setting time of MTA based cements. The obtained cements have an increased hydrophilicity and display excellent resistance to compression. The number of pores but not the average pore size is also affected. The possible roles of tannic acid in modifying the cement properties are discussed.

Comparative evaluation of antibacterial and antifungal efficacy of mineral trioxide aggregate angelus®, mineral trioxide aggregate plus™, and intermediate restorative material – A microbiological In vitro study

Objective: The study objective was to evaluate the antibacterial and antifungal properties of Mineral Trioxide Aggregate (MTA) Angelus® (MTA-A), MTA Plus™ (MTA-P), and intermediate restorative material (IRM). Materials and Methods: Pellets of MTA-P, MTA-A, and IRM were prepared to test the influence of these cements on the growth of four oral microbial strains, Enterococcus faecalis and Candida albicans, using agar diffusion method. The agar was removed, and the manipulated material was placed in the wells thus formed. The pellets were lodged in the seeded wells and incubated at 37°C for 24–72 h, after which the growth inhibition was measured. The data were analyzed using Student's t-test to compare the differences among the three cements at different concentrations. Results: The test results indicated that the antimicrobial activity of MTA-P, on both the microorganisms tested, was very strong, showing a mean inhibition zone of 3.1 mm, which extends over time toward all the strains. The diameters of the inhibition zones for E. faecalis were statistically significantly larger than that for Candida (P < 0.05) for MTA-P, IRM, and MTA-A. Conclusion: The materials showed antimicrobial activity against the tested strains. IRM showed no antimicrobial activity on Candida. The largest inhibition zone was observed for E. fecalis group. MTA-P created larger inhibition zones than MTA-A and IRM.

Effect of Incorporating Hydroxyapatite and Zinc Oxide Nanoparticles on the Compressive Strength of White Mineral Trioxide Aggregate.

Statement of the Problem: Many efforts have been made to improve the properties of mineral trioxide aggregate (MTA), including the incorporation of nanoparticles. Purpose: The aim of this study was to investigate the incorporation of zinc oxide and hydroxyapatite nanoparticles on the compressive strength of white MTA (WMTA). Materials and Method: In this in vitro study, the following materials were evaluated: MTA, MTA+5% zinc oxide (ZnO) nanoparticles, MTA+10% zinc oxide nanoparticles, MTA+5% hydroxyapatite (HA) nanoparticles, MTA+10% zinc oxide nanoparticles. The compressive strength of the groups under investigation was measured on days 4 and 21 after mixing the MTA using a universal testing machine. Two-way ANOVA test was used to compare the groups and determine the significance of the effect of time and material on the compressive strength (p<0.05). Results: The highest and lowest compressive strength values were respectively measured for the second group, MTA/21 days, and the fourth group, MTA+Nano ZnO/4 days. Two-way ANOVA indicated that incorporation of zinc oxide and hydroxyapatite nanoparticles into MTA did not have a significant effect on compressive strength (p= 0.05). Compressive strength in all the groups increased over time from day 4 to day 21. However, this increase was not statistically significant (p= 0.06) except for the MTA group, which exhibited significant increase in compressive strength over time from day 4 to day 21 (p=0.007). Conclusion: Incorporation of HA and ZnO nanoparticles into MTA had no detrimental effects on its strength and these nanoparticles can be used to improve the other properties of MTA.

Evaluation of the properties of Mineral Trioxide Aggregate mixed with Zinc Oxide exposed to different environmental conditions

Addition of zinc oxide (ZnO) to Mineral Trioxide Aggregate (MTA) has been shown to rectify tooth discoloration caused by Angelus MTA. This study evaluated the microhardness, compressive strength, calcium ion release and crystalline structures of MTA mixed with ZnO in different environmental conditions. Molds with a diameter of 4 mm and a height of 6 mm were used for compressive strength, calcium ion release and X-ray diffraction (XRD) evaluations. Molds with 6 mm diameter and 4 mm height were used for surface microhardness evaluations. Cements evaluated include Angelus MTA (Angelus, Brail), Angelus MTA + ZnO, ProRoot MTA (Dentsply Tulsa Dental, OK), and ProRoot MTA + ZnO. Each group was divided into 3 subgroups according to exposure conditions: normal saline (NS), phosphate buffered saline (PBS) or blood. After 7 days incubation, surface microhardness, compressive strength and XRD analysis was performed. Calcium ion release was evaluated after 3, 24 and 168h incubation using atomic absorption spectrophotometry. Data were analyzed by One Way Anova followed by the Tukey HSD Post hoc tests and T-Test. The significance level was set at 0.05. Addition of ZnO to Angelus and ProRoot MTA significantly decreased the compressive strength of these cements regardless of the environmental conditions (P < 0.001); however, it had no significant effect on their microhardness or calcium ion release. In conclusion, adding ZnO to Angelus and ProRoot MTA can adversely affect the compressive strength of Angelus and ProRoot MTA.

Improvement of the Bonding Properties of Mineral Trioxide Aggregate by Elastin-Like Polypeptide Supplementation.

Introduction Elastin-like polypeptide (ELP) supplementation was previously reported to enhance the physical properties of mineral trioxide aggregate (MTA). The aim of this study was to investigate the effect of ELP supplementation on the bonding properties of MTA to dentin. Methods Two types of ELPs were synthesized and mixed with MTA in a 0.3 liquid/powder ratio. The push-out bond strength test and interfacial observation with scanning electron microscopy were performed for ELP-supplemented MTA. The porosity of MTA fillings in the cavity was observed with microcomputed tomography. The stickiness, flow rate, and contact angle were additionally measured for potential increased bonding properties. Results ELP supplementation improved the bond strength of MTA to dentin. MTA supplemented by a specific ELP exhibited a less porous structure, higher stickiness, and higher flow rate. ELPs also decreased the contact angle to dentin. Conclusions This research data verifies that ELP improves the bonding properties of MTA to a tooth structure. The sticky and highly flowable characteristics of ELP-supplemented MTA may provide intimate contact with dentin and supply a less porous cement structure, which might improve the bonding properties of MTA.

The influence of particle size and multi-walled carbon nanotube on physical properties of mineral trioxide aggregate

The objectives of this study are to reduce the particle size distribution of Mineral Trioxide Aggregate (MTA) and to investigate its impact on setting time, radiopacity, flexural and compressive strength. Furthermore, the effect of adding multi-walled carbon nanotube to MTA composite was studied. MTA particles sizes were decreased using Wet-Stirred-Media-Milling (time intervals of 5, 10, 15 and 20 h). The distilled water and multi-walled carbon nanotube (0.25%, 0.5%, 0.75% and 1 wt%) were mixed and added to the MTA for hydration. MTA setting time, flexural and compressive strength and radiopacitiy were measured. Moreover, the unset MTA was analysed using x-ray-diffraction and the surface of the set MTA was observed by scanning electron microscopy. Tukey’s HSD test shows that initial and final setting times were decreased significantly up to 15 h of milling (p < 0.05). Flexural/Compressive strength of MTA were significantly decreased after milling for 10 and 20 h (p < 0.05). The flexural strength and compressive strength of the specimens reinforced with MCNTs show an increase of 76% and 10.2%, over plain MTA specimens. The results suggest that MTA setting-time can be accelerated and regulated by reducing particle size distribution without adding chemicals. The mechanical properties of MTA were significantly improved with the addition of multi-walled carbon nanotube without negative impact on setting time. In this study, a Nano Fast Cement composite with short setting time and high strength was developed by modification of MTA material.