scholarly journals Effect of the Degree of Conversion on Mechanical Properties and Monomer Elution from Self-, Dual- and Light-Cured Core Composites

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5642
Author(s):  
Branislava Petronijevic Sarcev ◽  
Sebastian Balos ◽  
Dubravka Markovic ◽  
Ivan Sarcev ◽  
Marija Vukcevic ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Vickers Hardness ◽  
Modulus Of Elasticity ◽  
Testing Machine ◽  
Degree Of Conversion ◽  
Clinical Use ◽  
Universal Testing ◽  
Post Test ◽  
One Way Anova

The objective of this work was to measure and correlate the degree of conversion (DC), mechanical properties and monomer elution from self-, dual- and light-cured core composites. Five samples of each of the following materials were prepared for each test: Clearfil (Core, Photo Core, Automix), Bisco (Core-Flo, Light-Core and Bis-Core). DC was determined using FTIR, compressive and flexural strength and modulus of elasticity using a universal testing machine and microhardness using Vickers hardness. Elution was measured using HPLC. One-way ANOVA with Tukey’s post-test and Pearson’s correlation were used to statistically analyze the data. DC of Clearfil-Dual (70.1%) and Clerafil-Photo (66.8%) were higher than Clearfil-Self (55.4%) and all Bisco materials (51.4–55.3%). Flexural strength of Clearfilwas higher than that of Bisco composites. The Microhardness of Clearfil-Dual (119.8VHN) and Clearfil-Photo (118.0VHN) were higher compared to other materials. The greatest elution was detected from self-cured materials. DC positively correlated to microhardness and compressive/flexural strength and negatively to BisGMA elution. Clearfil-Photo and Automix showed higher conversion, lower monomer elution and, generally, better mechanical properties. Self-cured composites should not be recommended for routine clinical use as their performance was inferior to dual- and light-cured composites. Microhardness may be used as an indicator of elution.

scholarly journals Flexural Strength of E-glass-reinforced PMMA

2014 ◽  
Vol 3 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Merin Mathew ◽  
Kamalakanth Shenoy ◽  
KS Ravishankar
Keyword(s):  
Flexural Strength ◽  
Glass Fiber ◽  
Microstructural Analysis ◽  
Testing Machine ◽  
Weight Percentage ◽  
Monomer Ratio ◽  
Universal Testing ◽  
Detailed Statistical Analysis ◽  
One Way Anova

ABSTRACT Background Poly (methyl 2-methylpropenoate) (PMMA) is one of the most widely accepted biomaterials due to its acceptable advantageous but the limitations associated with these materials make them far from being ideal. So, the present study is to achieve desirable flexural strength by reinforcing PMMA with E-glass fiber. Aim Determination of flexural strength of PMMA by varying the weight percentage of glass fiber (2.5 wt%, 5 wt%, 10 wt%), and by varying the aspect ratio (3 mm/20 µm, 6 mm/20 µm, 12 mm/20 µm) of glass fiber. Materials and methods Specimens prepared using a standard rectangular mold of 62 mm length, 10 mm breadth and 2.5 mm thickness. A total of 60 samples prepared (6 samples in each group) polymer—monomer ratio 2.4:1 by weight used to prepare samples. Flexural strength is tested using universal testing machine Instron. The microstructural analysis using scanning electron microscopy performed in order to understand the fiber matrix bonding. Detailed statistical analysis done by one-way ANOVA. Results Highest flexural strength is observed for the PMMA reinforced with 6 mm/20 µm fiber 2.5 wt%. How to cite this article Mathew M, Shenoy K, Ravishankar KS. Flexural Strength of E-glass-reinforced PMMA. Int J Experiment Dent Sci 2014;3(1):24-28.

scholarly journals A comparative study of biaxial flexural strength and Vickers microhardness of different zirconia materials: Effect of glazing and thermal cycling

2015 ◽  
Vol 18 (2) ◽  
pp. 19 ◽  
Author(s):  
Esra Salihoglu Yener ◽  
Mutlu Ozcan ◽  
Ender Kazazoglu
Keyword(s):  
Flexural Strength ◽  
Thermal Cycling ◽  
Vickers Hardness ◽  
Vickers Microhardness ◽  
Testing Machine ◽  
Clinical Importance ◽  
Zirconia Ceramics ◽  
Biaxial Flexural Strength ◽  
Monolithic Zirconia ◽  
One Way Anova

<p class="western" lang="en-GB" align="left"><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Objective:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">This study evaluated the effect of glazing and thermal cycling on biaxial flexural strength and Vickers hardness of different zirconia core materials. </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Material and </strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Methods: </strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">Disc shaped zirconia specimens (15 mm x </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">1.15 mm</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">) were fabricated out of three systems (ZirkonZahn, Cercon, </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">Ceramill</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">) according to each manufacturer`s instructions. The specimens of each system were randomly divided into initially 2 groups. While half of the specimens were glazed, the other half was left unglazed. Each group was further divided into 4 subgroups to be subjected to thermal cycling (0-control, 1000, 3000, 5000 cycles, 5-55 ºC). Biaxial flexural strength was tested in a universal testing machine (1 mm/min). Another set of unglazed zirconia specimens were made and tested for Vickers microhardness with and without thermocycling (0-control, 1000, 3000, 5000 cycles, 5-55 ºC). Data were statistically analyzed using one-way ANOVA, two-way ANOVA and Tukey’s test (</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">p &lt;</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"> 0.05). </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Results:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"> In non-aged conditions (11034-1388 MPa), glazing significantly decreased the biaxial flexural strength of all zirconia ceramics (845.65-897.35 MPa) (p = 0.000). While in the non-glazed groups, all thermal cycling regimens significantly decreased the biaxial flexural strength (864-1156 MPa) (p=0.000), in glazed groups thermal cycling did not affect the results (829.4-854.9 MPa) (p = 0.405). Compared to the non-aged group (1414.1 VHN), thermal cycling decreased the Vickers hardness significantly only for Cercon (1365.9 VHN) (p = 0.005). </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Conclusion:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"> Glazing decreased the biaxial flexural strength of the zirconia ceramics tested. Unglazed zirconia ceramics were weaker against thermal cycling compared to glazed ones. For monolithic zirconia restorations, this information may have clinical importance.</span></span></p><p class="western" align="justify"><span style="font-family: 'Times New Roman', serif;"><span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>K</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>eywords:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">Biaxial flexural strength; Glazing; Thermal cycling; Vickers microhardness; Zirconia.</span></span></span></span></p>

Dependence of the Physical-Mechanical Properties of Cured Epoxy-Amine Resin on the Ratio of its Components

2019 ◽  
Vol 816 ◽  
pp. 146-150
Author(s):  
Nilson O. Garifullin ◽  
Boris A. Komarov ◽  
Artur T. Kapasharov ◽  
Georgiy V. Malkov
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Testing Machine ◽  
Curing Temperature ◽  
Molar Ratio ◽  
Glass Temperature ◽  
Elongation At Break ◽  
Three Point Bending ◽  
Epoxy Amine ◽  
Universal Testing

The results of studying of the physical-mechanical properties of DGEBA-epoxy resin cured by 4,4'-diaminodiphenylmethane (DDM) are presented. The molar ratio of the concentrations of amine (NH) and epoxy (EP) groups are: 0.5; 0.6; 0.7; 0.75; 0.8; 0.9; 1; 1.11; 1.25; 1.33; 1.43; 1.66; 2. Samples of the cured resin were examined in tension and three-point bending according to ASTM D638-10 and ASTM D 3039 standards, respectively, using the Zwick / Roel TC-FR010 universal testing machine. As a result, the dependencies of the resins physical-mechanical properties (modulus of elasticity, strength, elongation at break, glass temperature) on the NH / EP ratio and the curing temperature were obtained.

scholarly journals Mechanical Properties of Glass Ionomer Cements after Incorporation of Marine Derived Hydroxyapatite

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3542
Author(s):  
Maja Bilić-Prcić ◽  
Valentina Brzović Rajić ◽  
Ana Ivanišević ◽  
Ana Pilipović ◽  
Sevil Gurgan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Testing Machine ◽  
Descriptive Statistics ◽  
Glass Ionomer Cements ◽  
Glass Ionomer ◽  
Universal Testing ◽  
Diametral Tensile Strength ◽  
One Way Anova

The purpose of this study was to evaluate the effects of the incorporation of hydroxyapatite (HA) derived from cuttlefish bone on the mechanical properties of glass ionomer cements (GIC). Fuji II LC and Fuji IX GP Extra (GC Corporation, Tokyo, Japan) were used in the study. There were four groups (n = 11–18) for each material: a group without the addition of HA particles and three groups modified by incorporation of 2, 5, and 10 wt% HA. The tests were performed on a universal testing machine (Shimadzu, Duisburg, Germany) and descriptive statistics, two-way analysis of variance (ANOVA) for the comparison of three mechanical properties, and one-way ANOVA for the comparison of different concentrations for each material were performed. Regarding the Fuji IX groups, compressive strength (CS) and flexural strength (FS) were highest in the group without HA particles added. The differences in CS between the Fuji IX group without HA particles and the Fuji IX groups with 2 wt% HA and 10 wt% HA were significant. The Fuji II 5 wt% HA group exhibited higher diametral tensile strength (DTS) and CS than other Fuji II groups, but not significantly. The Fuji II group, modified with 10 wt% HA, exhibited significantly higher FS than the Fuji II group without HA particles (p < 0.05). Porous HA incorporated into the Fuji IX groups had a significant impact on mechanical properties only in the Fuji IX 5 wt% HA group. Fuji II groups modified with 10 wt% HA showed the most favorable results with respect to FS.

Investigation into the Mechanical Properties of Nanometric Zirconia Dental Ceramics

2011 ◽  
Vol 211-212 ◽  
pp. 31-35 ◽  
Author(s):  
Ya Li Hou ◽  
Chang He Li ◽  
Li Li Wang ◽  
Yu Cheng Ding
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Vickers Hardness ◽  
Testing Machine ◽  
Apparent Porosity ◽  
Length Variation ◽  
Dental Ceramics ◽  
Linear Contraction ◽  
Before And After

This study was focused on the testing and assessment of the mechanical properties of nanometric zirconia dental ceramics. The density and the apparent porosity of specimens were tested with the Archimedes drainage method. The length variation of the specimens before and after sintering was measured with a vernier caliper, and the linear contraction was tested. An X-ray diffractometer was used for the specimen phase analysis. SEM was used to observe the section micrograph of the specimens. A universal mechanical testing machine was used to test the three-point flexural strength and the fracture toughness. A microhardness tester was used to test the Vickers hardness of the test specimens. Results indicates that the flexural strength of the test specimens ≥ 890MPa, the fracture toughness ≥6Mpa.m1/2, the Vickers hardness ≥ 1240MPa, the linear contraction ≥ 21%, and the apparent porosity ≥ 0.32%. Fully satisfying the requirements in oral medicine, the ceramic is an ideal material for biological joints and dental prosthesis.

scholarly journals Mechanical Properties of the Composite Material consisting of β-TCP and Alginate-Di-Aldehyde-Gelatin Hydrogel and Its Degradation Behavior

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1303
Author(s):  
Michael Seidenstuecker ◽  
Thomas Schmeichel ◽  
Lucas Ritschl ◽  
Johannes Vinke ◽  
Pia Schilling ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Protein Concentration ◽  
Failure Load ◽  
Testing Machine ◽  
Experimental Period ◽  
Flow Chamber ◽  
Degradation Behavior ◽  
Gelatin Hydrogel ◽  
Universal Testing

This work aimed to determine the influence of two hydrogels (alginate, alginate-di-aldehyde (ADA)/gelatin) on the mechanical strength of microporous ceramics, which have been loaded with these hydrogels. For this purpose, the compressive strength was determined using a Zwick Z005 universal testing machine. In addition, the degradation behavior according to ISO EN 10993-14 in TRIS buffer pH 5.0 and pH 7.4 over 60 days was determined, and its effects on the compressive strength were investigated. The loading was carried out by means of a flow-chamber. The weight of the samples (manufacturer: Robert Mathys Foundation (RMS) and Curasan) in TRIS solutions pH 5 and pH 7 increased within 4 h (mean 48 ± 32 mg) and then remained constant over the experimental period of 60 days. The determination surface roughness showed a decrease in the value for the ceramics incubated in TRIS compared to the untreated ceramics. In addition, an increase in protein concentration in solution was determined for ADA gelatin-loaded ceramics. The macroporous Curasan ceramic exhibited a maximum failure load of 29 ± 9.0 N, whereas the value for the microporous RMS ceramic was 931 ± 223 N. Filling the RMS ceramic with ADA gelatin increased the maximum failure load to 1114 ± 300 N. The Curasan ceramics were too fragile for loading. The maximum failure load decreased for the RMS ceramics to 686.55 ± 170 N by incubation in TRIS pH 7.4 and 651 ± 287 N at pH 5.0.

A Study on Reaction Bonded Ceramics Fabricated by Silicon Infiltration to B4C Preforms

2012 ◽  
Vol 724 ◽  
pp. 343-346 ◽  
Author(s):  
Rong Zhen Liu ◽  
Qing Wen Duan ◽  
Wen Wei Gu ◽  
Hai Yun Jin ◽  
Shao Chun Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Theoretical Result ◽  
Boron Carbide ◽  
Theoretical Calculation ◽  
Vickers Hardness ◽  
Volume Expansion ◽  
Maximum Density ◽  
Infiltration Process

Silicon was infiltrated into B4C preforms to fabricate B4C based composites ceramics at 1600 °C under vacuum circumstance. In this paper, silicon infiltration process was discussed by theoretical calculation. The volume expansion caused by reactions between silicon and boron carbide was about 89.1% from the calculation. In our study, the maximum density of B4C preform for the infiltration of silicon was about 1.5g/cm3 which was larger than theoretical result. The results of mechanical behavior showed that B4C based composites had excellent mechanical properties with a density lower than 2.6g/cm3, Vickers-hardness of this material was 27.2GPa, and this material showed a flexural strength of 349MPa and fracture toughness of 3.8 MPa*m1/2.

scholarly journals Influence of Different Concentration and Ratio of a Photoinitiator System on the Properties of Experimental Resin Composites

2017 ◽  
Vol 28 (6) ◽  
pp. 726-730 ◽  
Author(s):  
Caio Vinícius Signorelli Grohmann ◽  
Eveline Freitas Soares ◽  
Eduardo José Carvalho Souza-Junior ◽  
William Cunha Brandt ◽  
Regina Maria Puppin-Rontani ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Tertiary Amine ◽  
Water Sorption ◽  
Water Solubility ◽  
Distilled Water ◽  
Resin Composites ◽  
Amine Concentration ◽  
One Way Anova

Abstract The aim in this study was to evaluate the influence of different ratio of camphorquinone/tertiary amine concentration on the flexural strength (FS), elastic modulus (EM), degree of conversion (DC), yellowing (YL), water sorption (WS) and water solubility (WSL) of experimental composites. Thus, acrylate blends were prepared with different camphorquinone (CQ) and amine (DABE) concentrations and ratios by weight: (CQ/DABE%): 0.4/0.4% (C1), 0.4/0.8% (C2), 0.6/0.6% (C3), 0.6/1.2% (C4), 0.8/0.8% (C5), 0.8/1.6% (C6), 1.0/1.0% (C7), 1.0/2.0% (C8), 1.5/1.5% (C9), 1.5/3.0% (C10). For the FS and EM, rectangular specimens (7x2x1 mm, n=10) were photo-activated by single-peak LED for 20 s and tested at Instron (0.5 mm/min). Then, the same specimens were evaluated by FTIR for DC measurement. For YL, disks (5x2 mm, n=10) were prepared, light-cured for 20 s and evaluated in spectrophotometer using the b aspect of the CIEL*a*b* system. For WS and WSL, the volume of the samples was calculated (mm³). For WS and WSL, composites disks (5x0.5 mm, n=5) were prepared. After desiccation, the specimens were stored in distilled water for 7 days and again desiccated, in order to measure the WS and WSL. Data were submitted to one-way ANOVA and Tukey’s test (5%). The groups C8, C9 and C10 showed higher DC, EM and YL means, compared to other composites. Therefore, the FS and WS values were similar among all groups. Also, C1, C2 and C3 presented higher WSL in 7 days, compared to other composites. In general, higher concentrations of camphorquinone promoted higher physical-mechanical properties; however, inducing higher yellowing effect for the experimental composites

scholarly journals PENGEMBANGAN PAPAN PEREDAM BUNYI MELALUI MODIFIKASI NANO SILIKAT AMPAS TEBU PG KREMBOENG DENGAN TEMPLATE SERAT SABUT KELAPA

2019 ◽  
Author(s):  
Hengky Herdianto ◽  
Mochamad Alfi Zahwanul Farich
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Modulus Of Elasticity ◽  
Internal Bond ◽  
Testing Machine ◽  
Sound Level ◽  
Sound Level Meter ◽  
Universal Testing ◽  
Level Meter ◽  
Scanning Electron

Manusia memiliki batas kemampuan mendengar suara pada rentang hingga 140 dB, lebih daripada itu akan terjadi kerusakan pada organ-organ dalam gendang telinga. Ampas tebu PG Kremboeng mengandung 70,97% silikat murni yang berpotensi memberikan penguatan pada papan serat dan meningkatkan performa serap bunyi. Metode yang digunakan untuk sintesis nano silikat ampas tebu dilakukan dengan cara Pretreatment BBA, tukar kation silikat, dan pencucian gel kering. Komponen silikat dan produk lain dalam ampas tebu ditentukan menggunakan difraksi sinar-X (XRD). Morfologi xerogels nano silikat dan papan serat telah diteliti dengan menggunakan Scanning Electron Microscopy (SEM). Daya serap ditentukan dari berat sebelum dan sesudah perendaman dalam air 24 jam. Pengujian keteguhan patah dan Modulus of Elasticity dilakukan dengan Universal Testing Machine. Uji Internal Bond direkatkan pada dua buah blok alumunium dengan perekat besi dan dibiarkan mengering. Koefisien serap diukur dengan sound level meter. Berdasarkan pola XRD, dapat diketahui bahwa terdeteksi medium silicate hydroxide. Berdasarkan mikrograf SEM dapat diketahui suatu struktur bongkahan yang memanjang halus terdiri atas kumpulan-kumpulan partikel nano silikat pada papan dengan template serat sabut kelapa. Sampel terbaik dalam penelitian ini adalah I (60%;17%;23%) dengan nilai DSA 82,38%, MOR 102,84 kg/cm2, MOE 11.228,52 kg/cm2, dan IB 0,83 kg/cm2. Interval nilai koofisien serap taraf intensitas bunyi antar sampel adalah 0,527 &lt; x &lt; 1,000 pada pagi hari, 0,544 &lt; x &lt; 1,000 pada siang hari, dan 0,538 &lt; x &lt; 1,000 pada malam hari. Sehingga secara keseluruhan interval pada segala kondisi waktu adalah 0,527 &lt; x &lt; 1,000.

scholarly journals EFFECT OF STORAGE DURATION ON MECHANICAL PROPERTIES OF BELLO EGGPLANT FRUIT UNDER QUASI COMPRESSION LOADING

2019 ◽  
Vol 7 (5) ◽  
pp. 311-320
Author(s):  
Umurhurhu Benjamin ◽  
Uguru Hilary
Keyword(s):  
Mechanical Properties ◽  
Strong Dependence ◽  
Testing Machine ◽  
Storage Period ◽  
Maturity Stage ◽  
Rupture Force ◽  
Storage Duration ◽  
Compression Loading ◽  
Universal Testing ◽  
Rupture Energy

The mechanical properties of eggplant fruit (cv. Bello) harvested at physiological maturity stage were evaluated in three storage periods (3d, 6d and 9d). These mechanical parameters (rupture force, rupture energy and deformation at rupture point) were measured under quasi compression loading, using the Universal Testing Machine (Testometric model). The fruit’s toughness and rupture power were calculated from the data obtained from the rupture energy and deformation at rupture point. Results obtained showed that mechanical properties of the Bello eggplant fruit exhibited strong dependence on the storage period. The results showed that as the Bello fruit stored longer, its rupture force and rupture energy decreased from 812 N to 411 N, and 5.58 Nm to 3.11 Nm respectively. While the rupture power decreased from 1.095 W to 0.353 W. On the contrary, the toughness and deformation at rupture increased from 0.270 mJ/mm3 to 0.403 mJ/mm3, and 16.99 mm to 25.22mm respectively during the 9 days storage period. The knowledge of the mechanical properties of fruits is important for their harvest and post-harvest operations, therefore, information obtained from this study will be useful in the design and development of machines for the mechanization of eggplant production.

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