Comparative Evaluation Of Mechanical Properties Research Articles

Revealing the Relationship between Critical Inlet Velocity and a Double-Layer Oxide Film Combined with Low-Pressure Casting Technology

In the context of low-pressure casting, an excessive inlet velocity may result in the introduction of an oxide film and air into a liquid metal, leading to the formation of a two-layer film structure within the casting. Such defects can significantly degrade the mechanical properties of the castings. In order to optimize the advantages of low-pressure casting, an empirically designed equation for the inlet velocity was formulated and the concept of critical inlet velocity was further refined. A comprehensive numerical simulation was conducted to meticulously analyze the liquid metal spreading phase within the cavity. Subsequently, low-pressure casting experiments were carried out with actual castings of an A357 alloy, using two different entrance velocities—one critical and the other exceeding the critical entrance velocity. Tensile test specimens were extracted from the castings for the comparative evaluation of mechanical properties. It was observed that the average tensile strength of specimens cast at the critical inlet velocity exhibited a notable 16% enhancement. In contrast, specimens cast at velocities exceeding the critical inlet velocity manifested the presence of double oxide film defects. This evidence suggests that casting at a velocity faster than the critical inlet velocity leads to the formation of double oxide film defects, which in turn reduces the mechanical properties of the castings.

Comparative Evaluation of Mechanical Properties and Color Stability of Dental Resin Composites for Chairside Provisional Restorations.

Resin composites have become the preferred choice for chairside provisional dental restorations. However, these materials may undergo discoloration, changes in surface roughness, and mechanical properties with aging in the oral cavity, compromising the aesthetics, functionality, and success of dental restorations. To investigate the color and mechanical stability of chairside provisional composite resins, this study evaluated the optical, surface, and mechanical properties of four temporary restoration resin materials before and after aging, stimulated by thermal cycling in double-distilled water. Measurements, including CIE LAB color analysis, three-point bending test, nanoindentation, scanning electron microscopy (SEM), and atomic force microscopy (AFM), were conducted (n = 15). Results showed significant differences among the materials in terms of optical, surface, and mechanical properties. Revotek LC (urethane dimethacrylate) demonstrated excellent color stability (ΔE00 = 0.53-Black/0.32-White), while Artificial Teeth Resin (polymethyl methacrylate) exhibited increased mechanical strength with aging (p < 0.05, FS = 68.40 MPa-non aging/87.21 MPa-aging). Structur 2 SC (Bis-acrylic) and Luxatemp automix plus (methyl methacrylate bis-acrylate) demonstrated moderate stability in optical and mechanical properties (Structur 2 SC: ΔE00 = 1.97-Black/1.38-White FS = 63.20 MPa-non aging/50.07 MPa-aging) (Luxatemp automix plus: ΔE00 = 2.49-Black/1.77-White FS = 87.72 MPa-non aging/83.93 MPa-aging). These results provide important practical guidance for clinical practitioners, as well as significant theoretical and experimental bases for the selection of restorative composite resins.

Comparative Evaluation of Mechanical Properties and Microleakage of Cention N and Titanium Dioxide Nanoparticles-Enriched Cention N: An In Vitro Study.

Aim This study aimed to assess and compare the mechanical properties, including compressive strength, diametral tensile strength, flexural strength, fracture resistance, microhardness, and microleakage, between Cention N(IvoclarVivadent, Gurugram, India) and Cention N enriched with titanium dioxide (TiO2) nanoparticles. Methodology A total of 120 samples were involved in the study, which were split into two experimental groups.For evaluation of each mechanical property, 20 samples were included, of which 10 samples were used for evaluating the properties of Cention N and 10 samples were used for TiO2nanoparticles-enriched Cention N.Samples, formed using Teflon molds, were filled with Cention N and TiO2-enriched Cention N powders mixed per the manufacturer's instructions. The universal testing machine (UTM) was used to assess compressive, flexural, diametral tensile strength, and fracture resistance. Microhardness was evaluated using a diamond indenter, while microleakage was examined utilizing a stereomicroscope. Results The nanotitania-enriched Cention N showed significantly increased mechanical properties and increased microhardness with the least microleakage. Conclusion The inclusion of TiO2 in Cention N has proved to yield promising results.

Comparative Evaluation of Mechanical Properties and Bond Strength of Glass Ionomer Cement reinforced with three different concentrations of Silver Nanoparticles as against Conventional Glass Ionomer Cement in Primary Teeth.

Introduction: Restorative dental materials are defined as substances that are used to repair, replace, or enhance a patient's teeth. Various materials used in paediatric dentistry are zinc oxide eugenol, glass ionomer cement, resin composite, calcium hydroxide, silver amalgam, giomers etc. GIC is a biocompatible material having a low thermal expansion coefficient and fluoride release property. There are still a few drawbacks of GIC due of their poor mechanical properties therefore addition of Silver Nanoparticles demonstrated improved mechanical and bactericidal capabilities. There hasn't been much study on the quality of the bond contact between silver nanoparticles and dentin, as well as the color's durability. Aim: To evaluate and compare the mechanical properties and bond strength of Glass ionomer cement reinforced with three different concentrations of silver nanoparticle as against conventional glass ionomer cement in primary Teeth. Materials and Method: Silver nanoparticles will be prepared using three chemicals namely, silver nitrate, sodium citrate and tannic acid. Traditional GIC (GC Fuji II, GC Corporation, Tokyo, Japan) will be purchased. Three different concentrations of silver nanoparticles will be prepared i.e., 0.2, 0.4, and 0.6%. The GIC specimens will then be divided into 4 groups: GIC without silver nanoparticles (AgNPs),0.2%,0.4% and 0.6% AgNPs. Mechanical properties will be checked such as compressive, tensile, and bond strength using Universal Testing Machine. Expected Results: GIC reinforced with silver nano particles is expected to have better mechanical strength, less microleakage and wear resistance, greater fracture resistance and adhesive bond strength. Conclusion: GIC reinforced with silver nano particles will be expected to have better mechanical and physical properties than conventional Type II GICs and is expected to be a promising material for restoration in primary teeth.

Comparative evaluation of mechanical properties of short aramid fiber on thermoplastic polymers

Abstract This study investigated the mechanical performance of short aramid fiber on polypropylene, polyethylene, polyamide 6, and polyamide 12. Extrusion, press molding, and CNC cutting methods were used in the production of composite samples. Tensile, three-point bending, drop weight and hardness tests of the composites were carried out. As the fiber volume fractions increased, the mechanical properties of the composites improved, but the most efficient fiber fractions for each matrix changed. To analyze the performance of the fibers in the matrix on the composites, scanning electron microscope (SEM) images of the fractured surfaces as a result of tensile and drop weight tests were examined. As the fiber volume fractions increased, the fiber deformation increased, and as a result, the mechanical performance of the composites was adversely affected. Analysis of variance (ANOVA) and F test were performed using signal/noise values to analyze in detail the effect of experimental parameters on output values. Finally, the results of a regression equation model were compared with the experimental readings. It was found to be in good agreement with the model and the results of the experiment.

An in-vitro comparative evaluation of mechanical properties of Cention N, FujiCEM 2 with a conventional glass ionomer cement

To evaluate and compare the diametral tensile strength and shear bond strength of Cention N, FujiCEM 2 with a conventional glass ionomer cement. A total of thirty samples were used for the evaluation and comparison of diametral tensile strength. Ten samples of each of the restorative material were prepared with the help of metallic moulds and stored in distilled for 24hrs, following which they were tested on the Universal Testing Machine at crosshead speed of 5.5 mm/min. A total of thirty-three premolars were used to evaluate the shear bond strength with eleven premolars in each group. The premolars were then grinded perpendicular to the long axis of the tooth, restored with the respective cements following the manufacturer’s instructions and stored in distilled water at room temperature for 7-10 days, later they were subjected to thermocycling. After 24 hours, the specimens were tested in the Universal Testing Machine at a crosshead speed of 0.5 mm/min. The obtained data was statistically analyzed. There was statistical difference in diametral tensile strength values of Cention N when compared to FujiCEM 2 and Fuji IX (p value= 0.00). The shear bond strength of Cention N was significantly higher than that of FujiCEM 2 and Fuji IX (p=0.005 and p=0.008 respectively). The results of our study concluded that Cention N performed better in terms of mechanical properties than FujiCEM 2 and Fuji IX.

Comparative Evaluation of Mechanical Properties of Resin Luting Cement with Tooth-colored Nanoparticles: An In Vitro Study

Comparative Evaluation of Mechanical Properties of Resin Luting Cement with Tooth-colored Nanoparticles: An In Vitro Study

Comparative Evaluation of Mechanical Properties of Healthy and Decayed Dental Tissues by Nanoindentation Method

Comparative Evaluation of Mechanical Properties of Healthy and Decayed Dental Tissues by Nanoindentation Method

Comparative evaluation of mechanical properties of three different direct posterior restorative materials: An in vitro study

Aim: The aim of this study was to evaluate and compare the compressive strength, Vickers microhardness number, and wear resistance of amalgam (DPI), Filtek Z350 nanohybrid (3M ESPE), and Zirconomer (Shofu) restorative materials after 24 h and 3 months. Methodology: The restorative materials were divided into Zirconomer (Group I), Filtek Z350 (Group II), and amalgam (Group III). These materials were placed in cylindrical molds to prepare the specimens. The specimens were stored in distilled water at 37°C. The specimens were tested at 24 h and 3 months for compressive strength, wear resistance, and microhardness. Results: Group I showed significantly less maximum load (N) and compression strength (MPa) when compared with Group III (control) and Group II (P < 0.01). There was no significant difference in microhardness between the three groups. Group I showed significantly more wear (weight loss [g]) and wear (weight loss [%]) when compared with Group III (control) and Group II. Conclusion: The study concludes that amalgam and nanohybrid composite performed better than Zirconomer at the end of 24 h and 3 months.

Comparative evaluation of mechanical properties of lactose-based excipients co-processed with lipophilic glycerides as meltable binders

The introduction of the high-speed tableting machines and the lack of excipients with good flow and compaction properties required for direct compression process have increased research interest in the development of co-processed excipients. Melt granulation, as an environmentally friendly and cost-effective method, has recently been recognized as a promising co-processing technique. The aim of the present study was to prepare lipid-based co-processed excipients by in situ fluidized bed melt granulation and to investigated their suitability for direct compression process. Lactose monohydrate was co-processed with glyceryl dibehenate (Compritol® 888 ATO) or glyceryl palmitostearate (Precirol® ATO 5), as lipophilic meltable binders. Besides the flowability testing, dynamic compaction analysis was applied for thorough investigation into the tableting properties of developed co-processed excipients. Solid state characterization, performed by means of XRPD and DRIFT, confirmed the absence of chemical changes of the single components of co-processed excipients. Co-processed excipients showed improved flowability in comparison with single ingredients and corresponding physical mixtures. Novel co-processed excipients were found to have better tabletability profiles than physical mixtures of the ingredients, and were able to retain acceptable tensile strength values at high content of paracetamol in tableting mixture. Tablets with high tensile strength could be obtained with less work of compression needed in comparison with the commercial lactose-based excipients. Furthermore, novel lipid-based co-processed excipients were found to be highly superior regarding the antiadhesive and lubricating properties, with no additional lubricants required.

Comparative Evaluation of Mechanical Properties of Titanium Dioxide Nanoparticle Incorporated in Composite Resin as a Core Restorative Material

To compare and evaluate the mechanical properties of 2.5% titanium dioxide nanoparticle (TiO2 NP) incorporated as filler in an experimental composite resin with everX Flow and MultiCore Flow. TiO2 was prepared and incorporated into experimental dental composite resin. The experimental and traditional composite resin was grouped as follows: Group I: The experimental composite resin with 2.5% of TiO2 fillers, Group II: everX Flow (GC EUROPE), and Group III: MultiCore Flow (Ivoclar Vivadent). Based on International Standards Organization (ISO) 4049, the samples were prepared for the compressive, diametral tensile, and flexural test. Statistical analysis was done, and the results were tabulated. Compared to the other tested materials, the experimental composite resin had relatively high compressive strength, diametral tensile strength, and flexural strength. Compared to MultiCore Flow, the everX Flow showed strong mechanical properties. Based on the result of the study, it can be concluded that the 2.5% TiO2 NP incorporated as filler in an experimental composite resin demonstrated higher mechanical properties compared to the conventional material. The unique photoactivities of TiO2 NP and their superior mechanical properties make them one of the ideal additives to enhance the performance of polymeric materials.

Comparative evaluation of mechanical properties and shaping performance of heat-treated nickel titanium rotary instruments used in the single-length technique.

This study aimed to evaluate the mechanical properties of contemporary heat-treated nickel-titanium (NiTi) rotary instruments used in the single-length technique [ProTaper Next (PTN), HyFlex EDM (EDM), and JIZAI (JZ)]. Bending loads, cyclic fatigue resistance, torque/force values and canal-centering ratios were evaluated for the three instruments and a non-heat-treated experimental NiTi instrument with the same geometry as JZ (nJZ). EDM and JZ exhibited significantly lower bending load and more cycles to failure compared with nJZ and PTN (p<0.05). PTN and JZ exhibited significantly better centering ability than nJZ and EDM (p<0.05). JZ and nJZ generated significantly smaller upward force and maximum torque than PTN and EDM (p<0.05). Under the present experimental condition, JZ exhibited flexibility and cyclic fatigue resistance comparable to EDM, better maintained the canal curvature than the other instruments, and generated smaller torque and screw-in force than PTN and EDM.

Comparative evaluation of mechanical properties of three resin composite materials with different filler particle sizes

Aim: The aim of this study was to evaluate and compare the mechanical properties of three resin composites core materials with different filler particle sizes. Materials and methods: nanofilled (Filtek Z350 XT , 3M, ESPE USA), microhybrid (Te Econom, Ivoclar, Vivadent, India) and nanohybrid (Nexcomp, Meta biomed, korea) resin composites were used during this study. Mechanical properties regarding the compressive strength, diametral tensile strength and surface hardness were tested and results were collected and evaluated. Data were statistically analyzed using one-way Analysis of Variance and Tukey HSD test. Results: The nanofilled type revealed the highest significant compressive and diametral tensile strength values while the nanohybrid type showed the least significant hardness values among the results of the two types of composite resin for the three tests. Conclusions: after evaluation it was shown that the tested nanofilled resin composite type is more appropriate for use as core material compared to the other tested types.

Comparative Evaluation of Mechanical Properties of Ceramic Reinforced Glass Ionomer Cement and Type IX GIC:An Invitro Study

Background and Objectives: Dental caries is one of the most common problem encountered in pediatric patients. Despite modern advances in prevention of dental caries, many teeth are still lost prematurely leading to loss of function, esthetics, arch length and arch symmetry. Various restorative materials are available for the treatment of dental caries. Physical and mechanical tests were applied to analyze the structural designs of restorative materials. Various researches have been carried out in search of an ideal restorative material. Hence, the present in-vitro study was done to evaluate and compare the mechanical properties(compressive strength,flexural strength and knoop microhardness) of Ceramic Reinforced Glass Ionomer Cement (Amalgomer CR) and Type IX GIC. Results: The study showed a statistically significant difference in the compressive strength, flexural strength and knoop microhardness of ceramic reinforced glass ionomer cement (Amalgomer CR) and is superior when compared to Type IX GIC. Conclusion: The study concluded that the mechanical properties (compressive strength, flexural strength and knoop microhardness) of ceramic reinforced glass ionomer cement (Amalgomer CR) is superior to Type IX GIC.

Comparative Evaluation of Mechanical Properties and Wear Ability of Five CAD/CAM Dental Blocks.

This study compares the mechanical properties and wear ability of five CAD/CAM (computer-aided design/computer-aided manufacturing) millable dental blocks. All the discs, including Amber Mill Hybrid, Vita Enamic, Katana Avencia, Lava Ultimate, and Amber Mill, were cut in dimensions of 1.2 mm in thickness and 12 mm in diameter, polished to a machined surface, and immersed in distilled water for seven days. Vickers hardness was measured and the indentations were observed using microscope. The discs were brushed under a 150 g load. Mean surface roughness (Ra) and topography were determined after 100,000 cycles. Finally the biaxial flexure strength of the discs was measured and the broken surfaces were observed using scanning electron microscopy (SEM). The data was subjected to Weibull analysis. All data were analyzed by one-way analysis (ANOVA). The results of Vickers hardness are shown as: Amber Mill > Vita Enamic > Amber Mill Hybrid > Lava Ultimate > Katana Avencia. Katana Avencia showed the highest volume percentage reduction and the roughest surface after toothbrushing. The biaxial flexural strength is shown as: Amber Mill > Katana Avencia > Lava Ultimate > Amber Mill Hybrid > Vita Enamic. All the tested materials exhibited varying degrees of mass loss and surface roughness. The properties of the composite materials are related to the filler content, filler volume, and polymerization methods.

A Comparative Evaluation of Mechanical Properties of Four Different Restorative Materials: An In Vitro Study.

ABSTRACTObjectivesThe purpose of this study is to compare the mechanical properties (compressive strength (CS) and diametral tensile strength (DTS)) of four different restorative materials: conventional glass ionomer (Fuji IX), ClearFil AP-X, Filtex Z350-XT, and Cention N.Materials and methodsSpecimens (n = 80) were prepared from Fuji IX, ClearFil AP-X, Filtex Z350-XT, and Cention N for testing compressive strength and DTS.Statistical analysisResults obtained were subjected to one-way ANOVA and Tukey's post hoc test at significance (p < 0.001).ResultsThere were significant differences among restorative materials tested. ClearFil AP-X exhibits the highest mechanical properties (CS and DTS) and least values were obtained by the Fuji IX.ConclusionStrength is one of the most important criteria for the selection of a restorative material. Stronger materials better resist deformation and fracture, presenting more equitable stress distribution, greater probability, and greater stability of clinical success.How to cite this articleIftikhar N, Devashish, et al. A Comparative Evaluation of Mechanical Properties of Four Different Restorative Materials: An In Vitro Study. Int J Clin Pediatr Dent 2019;12(1):47–49.

Comparative Evaluation of Mechanical Properties of Cention N with Conventionally used Restorative Materials—An In Vitro Study

Comparative Evaluation of Mechanical Properties of Cention N with Conventionally used Restorative Materials—An <i>In Vitro</i> Study

Comparative Evaluation of Mechanical Properties of Fibre-Reinforced Concrete and Approach to Modelling of Bearing Capacity Ground Slab

The use of steel fibre-reinforced concrete is becoming gradually widespread in the engineering design of buildings. Typical cases include concrete foundations or floors. The actual design approach is often different. The proposal significantly encompasses the knowledge and range of the material properties of steel fibre-reinforced concrete. This article presents a comprehensive research programme, which has been focused on extensive laboratory testing, in situ testing and advanced numerical modelling using computing models and nonlinear models of concrete. It aims at a comprehensive description of the material properties of concrete, according to the degree of reinforcement, using 8 types of laboratory tests for description. In total, over 74 specified laboratory tests and four slab tests in situ are carried out. Selected evaluated material properties are also provided for the regression curve according to the degree of reinforcement, 0 to 3%. Subsequently, the detailed description of steel fibre is used in advanced modelling of tests of concrete slabs in situ. Numerical models simulate the behaviour of the steel fibre-reinforced concrete base structure in the interaction with the subsoil, where the objective was to verify the total carrying capacity of the slab structure.

Comparative Evaluation of Mechanical Properties of Sisal-Epoxy Composites With and Without Addition of Aluminium Powder

A new trend in engineering research is to replace heavy metals with polymer material reinforced with natural fibers such as different plant, animal and wood fibers. In this study, two separate composites have been manufactured by the combination of hand layup technique and compression molding process. Sisal fiber is used for fabrication of the two composites with and without use of aluminium powder to it. Their physio-mechanical properties such as density, micro-hardness, tensile strength and impact strength are evaluated. The moisture absorption test is also performed. The results indicate that the plain sisal-epoxy composite exhibit less density but superior micro-hardness than composite with aluminium powder. The tensile strength, elastic modulus and impact strength of sisal-epoxy composite with aluminium powder are better than the other.

Comparative Evaluation of Mechanical Properties of Dental Nanomaterials

This study examines the properties of nanobased dental restorative materials with nanoindentation method in a precise, repeatable, and comparable way. Microhybrid and nanohybrid composites, conventional glass ionomer materials, and light cured nanoionomer materials were utilised for the study. Specimen discs (r=10 mm,h=2 mm) were prepared to test the hardness, modulus of elasticity, yield strength, and fracture toughness values for each sample in a nanoindentation device with an atomic force microscopy add-on (n=25). Comparative analyses were performed by one-way ANOVA and post hoc Tukey tests. The hardness and modulus of elasticity values of nanocomposite were higher (2.58 GPa and 32.86 GPa, resp.) than those of other dental materials. Although glass ionomer exhibited a hardness that was similar to a nanoionomer (0.81 versus 0.87 GPa), glass ionomer had the lowest fracture toughness value (Kc=0.83 MPa/mm0.5). The mechanical properties of resin composites improve with additional nanoscale fillers, unlike the glass ionomer material.