scholarly journals Impact of Zr-Doped Bi2O3 Radiopacifier by Spray Pyrolysis on Mineral Trioxide Aggregate

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 453
Author(s):  
Tzu-Yu Peng ◽  
May-Show Chen ◽  
Ya-Yi Chen ◽  
Yao-Jui Chen ◽  
Chin-Yi Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spray Pyrolysis ◽  
Setting Time ◽  
Mineral Trioxide Aggregate ◽  
Solid Particles ◽  
Repair Material ◽  
Materials Analysis ◽  
Endodontic Surgery ◽  
A New Technique ◽  
Dental Applications

Mineral trioxide aggregates (MTA) have been developed as a dental root repair material for a range of endodontics procedures. They contain a small amount of bismuth oxide (Bi2O3) as a radiopacifier to differentiate adjacent bone tissue on radiographs for endodontic surgery. However, the addition of Bi2O3 to MTA will increase porosity and lead to the deterioration of MTA’s mechanical properties. Besides, Bi2O3 can also increase the setting time of MTA. To improve upon the undesirable effects caused by Bi2O3 additives, we used zirconium ions (Zr) to substitute the bismuth ions (Bi) in the Bi2O3 compound. Here we demonstrate a new composition of Zr-doped Bi2O3 using spray pyrolysis, a technique for producing fine solid particles. The results showed that Zr ions were doped into the Bi2O3 compound, resulting in the phase of Bi7.38Zr0.62O12.31. The results of materials analysis showed Bi2O3 with 15 mol % of Zr doping increased its radiopacity (5.16 ± 0.2 mm Al) and mechanical strength, compared to Bi2O3 and other ratios of Zr-doped Bi2O3. To our knowledge, this is the first study of fabrication and analysis of Zr-doped Bi2O3 radiopacifiers through the spray pyrolysis procedure. The study reveals that spray pyrolysis can be a new technique for preparing Zr-doped Bi2O3 radiopacifiers for future dental applications.

scholarly journals Effect of Silver Nanoparticles on Physicochemical and Antibacterial Properties of Calcium Silicate Cements

2016 ◽  
Vol 27 (5) ◽  
pp. 508-514 ◽  
Author(s):  
Fernando Vazquez-Garcia ◽  
◽  
Mário Tanomaru-Filho ◽  
Gisselle Moraima Chávez-Andrade ◽  
Roberta Bosso-Martelo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Silver Nanoparticles ◽  
Compressive Strength ◽  
Antibacterial Activity ◽  
Calcium Silicate ◽  
Setting Time ◽  
Antibacterial Properties ◽  
Mineral Trioxide Aggregate ◽  
Biological Properties ◽  
Calcium Silicate Cements

Abstract Mineral trioxide aggregate (MTA) and Portland cement (PC) are calcium silicate cements. They have similar physicochemical, mechanical and biological properties. The addition of zirconium oxide (ZrO2) to PC provides radiopacity. Silver nanoparticles (AgNPs) may improve some properties of cements. The aim of this study was to evaluate the effect of AgNPs on physicochemical/mechanical properties and antibacterial activity of white MTA (WMTA) and PC associated with ZrO2. The following materials were evaluated: WMTA; PC 70% + ZrO2 30%; WMTA+ AgNPs; and PC 70% + ZrO2 30% + AgNPs. The study evaluated radiopacity, setting time, pH, compressive strength and solubility. For radiopacity analysis, radiographs were made alongside an aluminum (Al) step wedge. To evaluate the antibacterial activity, direct contact test was performed on planktonic cells and Enterococcus faecalis biofilm induced on bovine root dentin for 14 days. The experimental periods were 5 and 15 h. Data were obtained as CFU mL-1. The obtained data were submitted to ANOVA and Tukey tests (p<0.05). The addition of AgNPs to WMTA increased the pH, lowered the solubility and the initial and final setting times. The addition of AgNPs to PC/ZrO2 maintained the pH, lowered the solubility, and increased the setting time and compressive strength. The radiopacity of all materials was higher than 4 mmAl. The addition of AgNPs promoted an increase in antibacterial activity for calcium silicate cements and favored the physicochemical and mechanical properties of the materials.

scholarly journals Effects of Steel Fiber Percentage and Aspect Ratios on Fresh and Harden Properties of Ultra-High Performance Fiber

2021 ◽  
Vol 2 (3) ◽  
pp. 501-515
Author(s):  
Rajib Kumar Biswas ◽  
Farabi Bin Ahmed ◽  
Md. Ehsanul Haque ◽  
Afra Anam Provasha ◽  
Zahid Hasan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
High Performance ◽  
Steel Fiber ◽  
Setting Time ◽  
Fiber Reinforced Concrete ◽  
Future Research ◽  
Manufacturing Cost ◽  
Aspect Ratios ◽  
High Performance Fiber

Steel fibers and their aspect ratios are important parameters that have significant influence on the mechanical properties of ultrahigh-performance fiber-reinforced concrete (UHPFRC). Steel fiber dosage also significantly contributes to the initial manufacturing cost of UHPFRC. This study presents a comprehensive literature review of the effects of steel fiber percentages and aspect ratios on the setting time, workability, and mechanical properties of UHPFRC. It was evident that (1) an increase in steel fiber dosage and aspect ratio negatively impacted workability, owing to the interlocking between fibers; (2) compressive strength was positively influenced by the steel fiber dosage and aspect ratio; and (3) a faster loading rate significantly improved the mechanical properties. There were also some shortcomings in the measurement method for setting time. Lastly, this research highlights current issues for future research. The findings of the study are useful for practicing engineers to understand the distinctive characteristics of UHPFRC.

scholarly journals Utilization of Solid Waste from Brick Industry and Hydrated Lime in Self-Compacting Cement Pastes

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1109
Author(s):  
Mati Ullah Shah ◽  
Muhammad Usman ◽  
Muhammad Usman Hanif ◽  
Iqra Naseem ◽  
Sara Farooq
Keyword(s):  
Mechanical Properties ◽  
Solid Waste ◽  
Manufacturing Industry ◽  
Setting Time ◽  
Hydrated Lime ◽  
Pozzolanic Reaction ◽  
Early Age ◽  
Cement Pastes ◽  
Brick Powder ◽  
High Degree

The huge amount of solid waste from the brick manufacturing industry can be used as a cement replacement. However, replacement exceeding 10% causes a reduction in strength due to the slowing of the pozzolanic reaction. Therefore, in this study, the pozzolanic potential of brick waste is enhanced using ultrafine brick powder with hydrated lime (HL). A total of six self-compacting paste mixes were studied. HL 2.5% by weight of binder was added in two formulations: 10% and 20% of waste burnt brick powder (WBBP), to activate the pozzolanic reaction. An increase in the water demand and setting time was observed by increasing the replacement percentage of WBBP. It was found that the mechanical properties of mixes containing 5% and 10% WBBP performed better than the control mix, while the mechanical properties of the mixes containing 20% WBBP were found to be almost equal to the control mix at 90 days. The addition of HL enhanced the early-age strength. Furthermore, WBBP formulations endorsed improvements in both durability and rheological properties, complemented by reduced early-age shrinkage. Overall, it was found that brick waste in ultrafine size has a very high degree of pozzolanic potential and can be effectively utilized as a supplementary cementitious material.

scholarly journals Assessment of Mechanical, Chemical, and Biological Properties of Ti-Nb-Zr Alloy for Medical Applications

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 126
Author(s):  
Viktoria Hoppe ◽  
Patrycja Szymczyk-Ziółkowska ◽  
Małgorzata Rusińska ◽  
Bogdan Dybała ◽  
Dominik Poradowski ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Base Material ◽  
Biological Properties ◽  
Β Phase ◽  
Alloy Base ◽  
Static Tensile ◽  
Examination Methods ◽  
13Zr Alloy ◽  
Dental Applications

The purpose of this work is to obtain comprehensive reference data of the Ti-13Nb-13Zr alloy base material: its microstructure, mechanical, and physicochemical properties. In order to obtain extensive information on the tested materials, a number of examination methods were used, including SEM, XRD, and XPS to determine the phases occurring in the material, while mechanical properties were verified with static tensile, compression, and bending tests. Moreover, the alloy’s corrosion resistance in Ringer’s solution and the cytotoxicity were investigated using the MTT test. Studies have shown that this alloy has the structure α’, α, and β phases, indicating that parts of the β phase transformed to α’, which was confirmed by mechanical properties and the shape of fractures. Due to the good mechanical properties (E = 84.1 GPa), high corrosion resistance, as well as the lack of cytotoxicity on MC3T3 and NHDF cells, this alloy meets the requirements for medical implant materials. Ti-13Nb-13Zr alloy can be successfully used in implants, including bone tissue engineering products and dental applications.

scholarly journals Dental Applications of Carbon Nanotubes

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4423
Author(s):  
Marco A. Castro-Rojas ◽  
Yadira I. Vega-Cantu ◽  
Geoffrey A. Cordell ◽  
Aida Rodriguez-Garcia
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Oral Cavity ◽  
Current Status ◽  
Glass Ionomer ◽  
Oral Infections ◽  
Functional Behavior ◽  
The Status ◽  
Comprehensive Survey ◽  
Dental Applications

Glass ionomer cements and resin-based composites are promising materials in restorative dentistry. However, their limited mechanical properties and the risk of bulk/marginal fracture compromise their lifespan. Intensive research has been conducted to understand and develop new materials that can mimic the functional behavior of the oral cavity. Nanotechnological approaches have emerged to treat oral infections and become a part of scaffolds for tissue regeneration. Carbon nanotubes are promising materials to create multifunctional platforms for dental applications. This review provides a comprehensive survey of and information on the status of this state-of-the-art technology and describes the development of glass ionomers reinforced with carbon nanotubes possessing improved mechanical properties. The applications of carbon nanotubes in drug delivery and tissue engineering for healing infections and lesions of the oral cavity are also described. The review concludes with a summary of the current status and presents a vision of future applications of carbon nanotubes in the practice of dentistry.

scholarly journals Enhancing the mechanical properties and cytocompatibility of magnesium potassium phosphate cement by incorporating oxygen-carboxymethyl chitosan

2020 ◽  
Author(s):  
Changtian Gong ◽  
Shuo Fang ◽  
Kezhou Xia ◽  
Jingteng Chen ◽  
Liangyu Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physicochemical Properties ◽  
Bone Cement ◽  
Ph Value ◽  
Setting Time ◽  
Potassium Phosphate ◽  
Carboxymethyl Chitosan ◽  
Bioactive Substances ◽  
Magnesium Potassium Phosphate Cement

Abstract Incorporating bioactive substances into synthetic bioceramic scaffolds is challenging. In this work, oxygen-carboxymethyl chitosan (O-CMC), a natural biopolymer that is nontoxic, biodegradable and biocompatible, was introduced into magnesium potassium phosphate cement (K-struvite) to enhance its mechanical properties and cytocompatibility. This study aimed to develop O-CMC/magnesium potassium phosphate composite bone cement (OMPC), thereby combining the optimum bioactivity of O-CMC with the extraordinary self-setting properties and mechanical intensity of the K-struvite. Our results indicated that O-CMC incorporation increased the compressive strength and setting time of K-struvite and decreased its porosity and pH value. Furthermore, OMPC scaffolds remarkably improved the proliferation, adhesion and osteogenesis related differentiation of MC3T3-E1 cells. Therefore, O-CMC introduced suitable physicochemical properties to K-struvite and enhanced its cytocompatibility for use in bone regeneration.

Comparison of the Osteogenic Potential of Mineral Trioxide Aggregate and Endosequence Root Repair Material in a 3-dimensional Culture System

2016 ◽  
Vol 42 (5) ◽  
pp. 760-765 ◽  
Author(s):  
Hisham S. Rifaey ◽  
Max Villa ◽  
Qiang Zhu ◽  
Yu-Hsiung Wang ◽  
Kamran Safavi ◽  
...  
Keyword(s):  
Culture System ◽  
Mineral Trioxide Aggregate ◽  
Osteogenic Potential ◽  
Repair Material ◽  
3 Dimensional ◽  
Root Repair

Effect of Heat Setting Methods on Structures and Properties of High Strength Polyvinyl Alcohol Fibre

2015 ◽  
Vol 815 ◽  
pp. 643-648
Author(s):  
Yin Zhu ◽  
Jiong Xin Zhao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Setting Time ◽  
High Strength ◽  
Single Fibre ◽  
X Ray Diffraction ◽  
Heat Setting ◽  
Heat Treated ◽  
Setting Process

The effect of heat setting methods on the structures and mechanical properties of high strength polyvinyl alcohol (PVA) fibre is studied in this article. The microstructure and mechanical properties of heat treated PVA fibre is investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and single fibre electronic tensile strength tester. Results show that the heat setting method with constant tension is a good heat setting method which can largely enhance the tensile strength of PVA fibre. During the heat setting process, the mechanical properties of PVA fibre are greatly affected by the temperature, tension and setting time. When the temperature is 220°C, tension is 5cN/dtex and setting time is 90sec, the tensile strength of PVA fibre increases from 12.0cN/dtex to 16.4cN/dtex in compare with the PVA fibre without heat setting

scholarly journals Physical-Mechanical Properties of Cupola Slag Cement Paste

2021 ◽  
Vol 11 (15) ◽  
pp. 7029
Author(s):  
Carlos Thomas ◽  
José Sainz-Aja ◽  
Israel Sosa ◽  
Jesús Setién ◽  
Juan A. Polanco ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Circular Economy ◽  
Setting Time ◽  
Casting Process ◽  
Industrial Sector ◽  
Sulphate Attack ◽  
Experimental Campaign ◽  
High Consumption ◽  
Superior Mechanical Properties ◽  
Environmental Savings

The high consumption of natural resources in the industrial sector makes it necessary to implement measures that enable the reuse of the waste generated, seeking to achieve circular economy. This work assesses the viability of an alternative to the use of CEM III B 32.5 R cement in mortars for the internal coating of centrifugally spun cast iron pipes for water piping. The proposal is to reuse the slag generated in the casting process after being finely ground, as an addition mixed with CEM I 52.5 R cement, which is basically Portland clinker. In order to analyse this possibility, an extensive experimental campaign was carried out, including the analysis of the cupola slag (micro-structural and chemical composition, leachates, setting time, vitrification, puzzolanicity and resistance to sulphate) and regarding the mortars (workability and mechanical properties). The experimental programme has shown that the optimum substitution is achieved with a replacement percentage of 20% of the cement, with which similar workability, superior mechanical properties and guaranteed resistance to sulphate attack are obtained. In addition, both economic and environmental savings are achieved by not having to transport or landfill the waste. In addition, the new cement is cheaper than the cement currently used.

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