Analysis on the Performance of Nano-Composite Resin Dental Restorative Materials

2021 ◽  
Vol 13 (5) ◽  
pp. 927-937
Author(s):  
Fang Liu ◽  
Cheng Qian ◽  
Li Xu ◽  
Rongxiu Zhang ◽  
Liang Liu ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Flexural Modulus ◽  
Nano Particles ◽  
Resin Matrix ◽  
Nano Composite ◽  
E Coli ◽  
Antibacterial Ability ◽  
Gram Positive Bacteria ◽  
Aggregation Effect ◽  
Adhesion Ability

After long-term use of resin materials for dental repair, plaque is easy to accumulate on the surface to form biofilms, which can cause caries. Although antibacterial agents are applied to oral resins, the antibacterial ability, mechanical performance, and biocompatibility of the material have to be considered. In this study, the cationic polymer NPVP with different lengths of alkyl chain is adopted to modify the carbon–nanodiamond (CND), and hydroxyethyl methacrylate (HEMA) is introduced to reduce the cytotoxicity of the modified particles and improve the compatibility with the resin matrix. Among the multiple composite samples obtained, MND-H10 shows the best de-aggregation effect, with a particle size of 70 nm. In addition, it plays a good antibacterial effect against Gram-negative bacteria (GNB) Escherichia coli (E. coli) and Gram-positive bacteria (GPB) Staphylococcus aureus (S. aureus). On this basis, the polymerizable antibacterial nano-composite particles (modified nano-diamonds, MNDs) are prepared and polymerized with the resin matrix Bisphenol A bis-methyl/glycidyl acrylate (Bis-GMA)/Triglycol dimethacrylate (TEGDMA) to construct an antibacterial dental repair material. After testing, the Vickers hardness, flexural strength, and flexural modulus of the 0.6 wt% modified resin material all increase by more than 45%. Due to the addition of nano-particles, the material shows a certain antibacterial ability, an increased hydrophilicity, and antibacterial adhesion ability. 10 patients with clinically defective or missing dentition during June 2017 to October 2017 are selected from the affiliated hospitals of the college, who are treated with the threaded implants. After a year of clinical observation, the threaded implants have achieved better osseointegration results.

scholarly journals Synthesis of Nano-Pomegranate Peel via Sol-Gel Method and Screen Characterization

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Awatif I. Muhammed ◽  
Quraish A. Kazem ◽  
Rana A. Kamal ◽  
Ahmed J. Issa ◽  
Inas F. Abed ◽  
...  
Keyword(s):  
Scanning Probe Microscopy ◽  
Sol Gel ◽  
Nano Particles ◽  
Scanning Probe ◽  
Cumulative Distribution ◽  
Pomegranate Peel ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Average Grain Size ◽  
Measurement Area

Nano peel solution was prepared using Sol-gel technology at a temperature of (80) Celsius. A number of tests were performed to describe the properties and structure of Nano material, including scanning probe microscopy (SPM), which showed the symmetric cumulative distribution of the solution Nanoparticles and the average grain size equal to 64.5 nm and the identical distribution of the Nanoparticles with a diameter of 37.75 nanometers, with a measurement area ranging between (1531.23-1558.19) nanometers. Nano-solution analyzed with a scanning electron microscope (SEM), Inspect type (S50), with a magnification power up to X2000, where dense flakes of Nano particles with a diameter of (50 ± 10) nanometers were observed. The antibacterial activity of Nano-solution by using gram- positive bacteria St. aurous and gram-negative E. coli show the inhibition diameter of (St. aurous) was 27 mm and 25 mm in (E. coli).

scholarly journals A New Nano-Platform of Erythromycin Combined with Ag Nano-Particle ZnO Nano-Structure against Methicillin-Resistant Staphylococcus aureus

Pharmaceutics ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 841 ◽  
Author(s):  
Atanu Naskar ◽  
Sohee Lee ◽  
Yunhee Lee ◽  
Semi Kim ◽  
Kwang-sun Kim
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Nano Particles ◽  
Nano Composite ◽  
Nano Structure ◽  
Methicillin Resistant ◽  
X Ray ◽  
Gram Positive Bacteria

Nano-particles have been combined with antibiotics in recent studies to overcome multidrug-resistant bacteria. Here, we synthesized a nano-material in which Ag nano-particles were assembled with a ZnO nano-structure to form an Ag-ZnO (AZO) nano-composite at low temperature. This material was combined with erythromycin (Ery), an antibiotic effective towards gram-positive bacteria, using three different approaches (AZO + Ery (AZE) [centrifuged (AZE1), used separately after 1-h gap (AZE2), without centrifugation (AZE3)]) to prepare a nano-antibiotic against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). X-ray diffraction analysis and transmission electron microscopy confirmed the presence of Ag nano-particles and ZnO nano-structure. The elemental and chemical state of the elements present in the AZO nano-composite were assessed by X-ray photoelectron spectroscopy. The antibacterial activity of AZE samples against both Escherichia coli and S. aureus strains including MRSA was evaluated in antibacterial and morphological analyses. The AZE3 sample showed greater antibacterial activity than the other samples and was comparable to erythromycin. AZE3 was ~20-fold less prone to developing bacterial resistance following multiple exposures to bacteria compared to erythromycin alone. The AZE3 nano-composite showed good biocompatibility with 293 human embryonic kidney cells. Our newly synthesized nano-platform antibiotics may be useful against multidrug-resistant gram-positive bacteria.

scholarly journals Effect of Nanoiron Particles Reinforced Blended Polymer Nanocomposites on Mechanical Properties

2019 ◽  
Vol 9 (2) ◽  
pp. 4430-4435
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Mechanical Performance ◽  
Chemical Reduction ◽  
Property Values ◽  
Strength Properties ◽  
Nano Particles ◽  
Resin Matrix ◽  
Software Analysis ◽  
The Matrix

We report on the preparation of nanocomposites using epoxy and vinylester blend in which nanoiron filler was dispersed to evaluate the mechanical performance. Different weight ratios viz.1,2,3,4,5 & 7wt.% of nanoiron particles were dispersed into the matrix to prepare different systems to evaluate the optimization of performance. Nanoiron was also prepared by chemical reduction method and nanocomposites were prepared by hand layup process. Three blade Mechanical stirrer and ultra-sonicator was used while preparing the modified to keep the non-homogeneity nanoparticle at bay. Mechanical properties such as hardness, tensile strength, flexural strength, impact strength and compression strength properties were performed. Nanoiron particles functionalization nepotisms the fabrication composites through the remedial temperature at low as associated to the as-synthesised nano particles occupied vinylester nano composites. Mechanical property values improved owing to the standardized nanoparticle chemical bonding and spreading between vinylester matrix and nanoparticles. Then the combination nanoiron particles into the vinylester resin matrix it becomes magnetically harder. Machines generated mechanical property values were compared and analysed with system generated software analysis of variance (ANOVA) values. Machine values and ANOVA values were measured for the specimens of epoxy+vinylester+nanoiron, where the nanoiron is varying viz. 1, 2, 3, 4, 5 and 7 wt.%.

Synthesis of Chalcones and Nucleosides Incorporating [1, 3, 4]Oxadiazolenone Core and Evaluation of their Antifungal and Antibacterial Activities

2020 ◽  
Vol 15 (6) ◽  
pp. 665-679
Author(s):  
Alok K. Srivastava ◽  
Lokesh K. Pandey
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Antifungal Activity ◽  
Aspergillus Niger ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Good Antibacterial Activity

Background: [1, 3, 4]oxadiazolenone core containing chalcones and nucleosides were synthesized by Claisen-Schmidt condensation of a variety of benzaldehyde derivatives, obtained from oxidation of substituted 5-(3/6 substituted-4-Methylphenyl)-1, 3, 4-oxadiazole-2(3H)-one and various substituted acetophenone. The resultant chalcones were coupled with penta-O-acetylglucopyranose followed by deacetylation to get [1, 3, 4] oxadiazolenone core containing chalcones and nucleosides. Various analytical techniques viz IR, NMR, LC-MS and elemental analysis were used to confirm the structure of the synthesised compounds.The compounds were targeted against Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and Aspergillus flavus, Aspergillus niger and Fusarium oxysporum for antifungal activity. Methods: A mixture of Acid hydrazides (3.0 mmol) and N, Nʹ- carbonyl diimidazole (3.3 mmol) in 15 mL of dioxane was refluxed to afford substituted [1, 3, 4]-oxadiazole-2(3H)-one. The resulted [1, 3, 4]- oxadiazole-2(3H)-one (1.42 mmol) was oxidized with Chromyl chloride (1.5 mL) in 20 mL of carbon tetra chloride and condensed with acetophenones (1.42 mmol) to get chalcones 4. The equimolar ratio of obtained chalcones 4 and β -D-1,2,3,4,6- penta-O-acetylglucopyranose in presence of iodine was refluxed to get nucleosides 5. The [1, 3, 4] oxadiazolenone core containing chalcones 4 and nucleosides 5 were tested to determined minimum inhibitory concentration (MIC) value with the experimental procedure of Benson using disc-diffusion method. All compounds were tested at concentration of 5 mg/mL, 2.5 mg/mL, 1.25 mg/mL, 0.62 mg/mL, 0.31 mg/mL and 0.15 mg/mL for antifungal activity against three strains of pathogenic fungi Aspergillus flavus (A. flavus), Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum) and for antibacterial activity against Gram-negative bacterium: Escherichia coli (E. coli), and two Gram-positive bacteria: Staphylococcus aureus (S. aureus) and Bacillus subtilis(B. subtilis). Result: The chalcones 4 and nucleosides 5 were screened for antibacterial activity against E. coli, S. aureus and B. subtilis whereas antifungal activity against A. flavus, A. niger and F. oxysporum. Compounds 4a-t showed good antibacterial activity whereas compounds 5a-t containing glucose moiety showed better activity against fungi. The glucose moiety of compounds 5 helps to enter into the cell wall of fungi and control the cell growth. Conclusion: Chalcones 4 and nucleosides 5 incorporating [1, 3, 4] oxadiazolenone core were synthesized and characterized by various spectral techniques and elemental analysis. These compounds were evaluated for their antifungal activity against three fungi; viz. A. flavus, A. niger and F. oxysporum. In addition to this, synthesized compounds were evaluated for their antibacterial activity against gram negative bacteria E. Coli and gram positive bacteria S. aureus, B. subtilis. Compounds 4a-t showed good antibacterial activity whereas 5a-t showed better activity against fungi.

scholarly journals A novel bis(pyrazolyl)methane compound as a potential agent against Gram-positive bacteria

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pedro Seguí ◽  
John J. Aguilera-Correa ◽  
Elena Domínguez-Jurado ◽  
Christian M. Sánchez-López ◽  
Ramón Pérez-Tanoira ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Effect ◽  
Eukaryotic Cell ◽  
Liver Carcinoma ◽  
Gram Positive ◽  
Minimal Inhibitory Concentrations ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Therapeutic Compounds ◽  
Toxic Concentrations

AbstractThis study was designed to propose alternative therapeutic compounds to fight against bacterial pathogens. Thus, a library of nitrogen-based compounds bis(triazolyl)methane (1T–7T) and bis(pyrazolyl)methane (1P–11P) was synthesised following previously reported methodologies and their antibacterial activity was tested using the collection strains of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Moreover, the novel compound 2P was fully characterized by IR, UV–Vis and NMR spectroscopy. To evaluate antibacterial activity, minimal inhibitory concentrations (MICs), minimal bactericidal concentrations (MBCs), minimum biofilm inhibitory concentrations (MBICs), and minimum biofilm eradication concentrations (MBECs) assays were carried out at different concentrations (2–2000 µg/mL). The MTT assay and Resazurin viability assays were performed in both human liver carcinoma HepG2 and human colorectal adenocarcinoma Caco-2 cell lines at 48 h. Of all the synthesised compounds, 2P had an inhibitory effect on Gram-positive strains, especially against S. aureus. The MIC and MBC of 2P were 62.5 and 2000 µg/mL against S. aureus, and 250 and 2000 µg/mL against E. faecalis, respectively. However, these values were > 2000 µg/mL against E. coli and P. aeruginosa. In addition, the MBICs and MBECs of 2P against S. aureus were 125 and > 2000 µg/mL, respectively, whereas these values were > 2000 µg/mL against E. faecalis, E. coli, and P. aeruginosa. On the other hand, concentrations up to 250 µg/mL of 2P were non-toxic doses for eukaryotic cell cultures. Thus, according to the obtained results, the 2P nitrogen-based compound showed a promising anti-Gram-positive effect (especially against S. aureus) both on planktonic state and biofilm, at non-toxic concentrations.

scholarly journals Evaluation of the Antimicrobial Activity of Some Components of the Essential Oils of Plants Used in the Traditional Medicine of the Tehuacán-Cuicatlán Valley, Puebla, México

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 295
Author(s):  
Sebastián Candelaria-Dueñas ◽  
Rocío Serrano-Parrales ◽  
Marisol Ávila-Romero ◽  
Samuel Meraz-Martínez ◽  
Julieta Orozco-Martínez ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Qualitative Evaluation ◽  
Bactericidal Effect ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Diffusion Technique ◽  
Agar Dilution

In Tehuacán-Cuicatlán valley (Mexico), studies have been carried out on the essential oils of medicinal plants with antimicrobial activity and it was found that they present compounds in common such as: α-pinene, β-pinene, carvacrol, eugenol, limonene, myrcene, ocimene, cineole, methyl salicylate, farnesene, and thymol. The goal of this study was to assess the antimicrobial activity of essential oils’ compounds. The qualitative evaluation was carried out by the Kirby Baüer agar diffusion technique in Gram-positive bacteria (11 strains), Gram-negative bacteria (18 strains), and yeasts (8 strains). For the determination of the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), the agar dilution method was used. All the evaluated compounds presented antimicrobial activity. The compounds eugenol and carvacrol showed the largest inhibition zones. Regarding yeasts, the compounds ocimene, cineole, and farnesene did not show any activity. The compounds eugenol, carvacrol, and thymol presented the lowest MIC; bactericidal effect was observed at MIC level for S. aureus 75MR, E. coli 128 MR, and C albicans CUSI, for different compounds, eugenol, carvacrol, and thymol. Finally, this study shows that the essential oils of plants used by the population of Tehuacán-Cuicatlán valley share compounds and some of them have antibacterial and fungicidal activity.

scholarly journals Long-fibre reinforced polymer composites by 3D printing: influence of nature of reinforcement and processing parameters on mechanical performance

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Francis Dantas ◽  
Kevin Couling ◽  
Gregory J. Gibbons
Keyword(s):  
Carbon Fibre ◽  
Polymer Composites ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Matrix Material ◽  
Processing Parameters ◽  
Fibre Reinforcement ◽  
Reinforced Polymer ◽  
Unreinforced Material ◽  
Fibre Reinforced Polymer

Abstract The aim of this study was to identify the effect of material type (matrix and reinforcement) and process parameters, on the mechanical properties of 3D Printed long-fibre reinforced polymer composites manufactured using a commercial 3D Printer (Mark Two). The effect of matrix material (Onyx or polyamide), reinforcement type (Carbon, Kevlar®, and HSHT glass), volume of reinforcement, and reinforcement lay-up orientation on both Ultimate Tensile Strength (UTS) and Flexural Modulus were investigated. For Onyx, carbon fibre reinforcement offered the largest increase in both UTS and Flexural Modulus over unreinforced material (1228 ± 19% and 1114 ± 6% respectively). Kevlar® and HSHT also provided improvements but these were less significant. Similarly, for Nylon, the UTS and Flexural Modulus were increased by 1431 ± 56% and 1924 ± 5% by the addition of carbon fibre reinforcement. Statistical analysis indicated that changing the number of layers of reinforcement had the largest impact on both UTS and Flexural Strength, and all parameters were statistically significant.

Preparation of bioactive and antibacterial PMMA-based bone cement by modification with quaternary ammonium and alkoxysilane

2021 ◽  
pp. 088532822110044
Author(s):  
Haiyang Wang ◽  
Toshinari Maeda ◽  
Toshiki Miyazaki
Keyword(s):  
Antibacterial Activity ◽  
Methyl Methacrylate ◽  
Bone Cement ◽  
Setting Time ◽  
Antibacterial Properties ◽  
The Body ◽  
Apatite Formation ◽  
Gram Positive ◽  
E Coli ◽  
Gram Positive Bacteria

Bone cement based on poly(methyl methacrylate) (PMMA) powder and methyl methacrylate (MMA) liquid is a very popular biomaterial used for the fixation of artificial joints. However, there is a risk of this cement loosening from bone because of a lack of bone-bonding bioactivity. Apatite formation in the body environment is a prerequisite for cement bioactivity. Additionally, suppression of infection during implantation is required for bone cements to be successfully introduced into the human body. In this study, we modified PMMA cement with γ-methacryloxypropyltrimetoxysilane and calcium acetate to introduce bioactive properties and 2-( tert-butylamino)ethyl methacrylate (TBAEMA) to provide antibacterial properties. The long-term antibacterial activity is attributed to the copolymerization of TBAEMA and MMA. As the TBAEMA content increased, the setting time increased and the compressive strength decreased. After soaking in simulated body fluid, an apatite layer was detected within 7 days, irrespective of the TBAEMA content. The cement showed better antibacterial activity against Gram-negative E. Coli than Gram-positive bacteria; however, of the Gram-positive bacteria investigated, B. subtilis was more susceptible than S. aureus.

scholarly journals Poly(Vinylamine) Derived N-Doped C-Dots with Antimicrobial and Antibiofilm Activities

2021 ◽  
Vol 7 (2) ◽  
pp. 40
Author(s):  
Semiha Duygu Sutekin ◽  
Mehtap Sahiner ◽  
Selin Sagbas Suner ◽  
Sahin Demirci ◽  
Olgun Güven ◽  
...  
Keyword(s):  
Blood Clotting ◽  
Minimum Bactericidal Concentration ◽  
Blood Compatibility ◽  
Weight Ratio ◽  
Gram Negative Bacteria ◽  
Biofilm Inhibition ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

Nitrogen-doped carbon dots (N-doped C-dots) was synthesized by using poly(vinyl amine) (PVAm) as a nitrogen source and citric acid (CA) as a carbon source via the hydrothermal method. Various weight ratios of CA and PVAm (CA:PVAm) were used to synthesize N-doped C-dots. The N-doped C-dots revealed emission at 440 nm with excitation at 360 nm and were found to increase the fluorescence intensity with an increase in the amount of PVAm. The blood compatibility studies revealed no significant hemolysis for N-doped C-dots that were prepared at different ratios of CA:PVAm for up to 500 μg/mL concentration with the hemolysis ratio of 1.96% and the minimum blood clotting index of 88.9%. N-doped C-dots were found to be more effective against Gram-positive bacteria than Gram-negative bacteria, with the highest potency on Bacillus subtilis (B. subtilis). The increase in the weight ratio of PVAm in feed during C-dots preparation from 1 to 3 leads to a decrease of the minimum bactericidal concentration (MBC) value from 6.25 to 0.75 mg/mL for B. subtilis. Antibiofilm ability of N-doped C-dots prepared by 1:3 ratio of CA:PVAm was found to reduce %biofilm inhibition and eradication- by more than half, at 0.78 mg/mL for E. coli and B. subtilis generated biofilms and almost destroyed at 25 mg/mL concentrations.

scholarly journals Self-Crosslinked Ellipsoidal Poly(Tannic Acid) Particles for Bio-Medical Applications

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2429
Author(s):  
Nurettin Sahiner
Keyword(s):  
Tannic Acid ◽  
Hydrolytic Degradation ◽  
Single Step ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Total Phenol Content ◽  
Frap Assay ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Trolox Equivalent ◽  
Free Media

Self-crosslinking of Tannic acid (TA) was accomplished to obtain poly(tannic acid) (p(TA)) particles in single step, surfactant free media using sodium periodate (NaIO4) as an oxidizing agent. Almost monodisperse p(TA) particles with 981 ± 76 nm sizes and −22 ± 4 mV zeta potential value with ellipsoidal shape was obtained. Only slight degradation of p(TA) particles with 6.8 ± 0.2% was observed at pH 7.4 in PBS up to 15 days because of the irreversible covalent formation between TA units, suggesting that hydrolytic degradation is independent from the used amounts of oxidation agents. p(TA) particles were found to be non-hemolytic up to 0.5 mg/mL concentration and found not to affect blood clotting mechanism up to 2 mg/mL concentration. Antioxidant activity of p(TA) particles was investigated by total phenol content (TPC), ferric reducing antioxidant potential (FRAP), trolox equivalent antioxidant capacity (TEAC), total flavanoid content (TFC), and Fe (II) chelating activity. p(TA) particles showed strong antioxidant capability in comparison to TA molecules, except FRAP assay. The antibacterial activity of p(TA) particles was investigated by micro-dilution technique on E. coli as Gram‑negative and S. aureus as Gram-positive bacteria and found that p(TA) particles are more effective on S. aureus with over 50% inhibition at 20 mg/mL concentration attained.

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