scholarly journals The effect of UDMA and Bis-GMA irradiation period on residual monomers in resin packable composite

2019 ◽  
Vol 52 (1) ◽  
pp. 24
Author(s):  
Jayanti Rosha ◽  
Adioro Soetojo ◽  
Putu Dewi Purnama Sari Budha ◽  
M. Mudjiono
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Composite Resin ◽  
Ethanol Solution ◽  
Composite Resins ◽  
Polymerization Process ◽  
Test Results ◽  
Glycol Dimethacrylate ◽  
Irradiation Period ◽  
Urethane Dimethacrylate

Background: Residual monomers are non-polymerized monomers which can cause clinical harm, for example inflammation, to oral cavity tissue while the remaining monomers can potentially be carcinogenic. The more residual monomers that remain due to an imperfect polymerization processes, the lower the compressive strength level and the higher the number of micro slits that can cause secondary caries and tooth sensitivity. Urethane dimethacrylate (UDMA) and bisphenol A glycol dimethacrylate (Bis-GMA) constitute two of the resins most frequently used in packable composites. During the short irradiaton period forming part of the polymerization process, UDMA and Bis-GMA have the potential to produce residual monomers. Purpose: This study aimed to compare the number of residual monomers in packable composite resin following irradiation lasting 1x20 seconds and 2x20 seconds. Methods: 28 samples of cylindrical packable composite with a thickness of 2 mm and a diameter of 5 mm were divided into four groups. Groups 1 and 2 were irradiated for 1x20 seconds, and groups 3 and 4 for 2x20 seconds with the composite subsequently being immersed in ethanol solution for 24 hours. The number of residual monomers using high-performance liquid chromatography (HPLC) devices was calculated and the results statistically analyzed using a Mann-Whitney Test. Results: Repeated irradiation had no effect on the amount of residual monomers in packable composite resins. However, there were differences in the number of residual monomers in the material contained in packable composite resins Bis-GMA and UDMA, while the remaining monomers in UDMA outnumbered those in Bis-GMA. Conclusion: The number of residual monomers in Bis-GMA is lower than in the remaining UDMA after 1x20 seconds irradiation, while the number of residual monomers in Bis-GMA and UDMA following 2x20 seconds irradiation was no different to that after irradiation of 1x20 seconds duration.

Effect of layer thickness on residual monomer release in polymerization of bulk-fill composites

2021 ◽  
pp. 096739112199958
Author(s):  
Vahti Kılıç ◽  
Feridun Hurmuzlu ◽  
Yılmaz Ugur ◽  
Suzan Cangul
Keyword(s):  
Stainless Steel ◽  
Layer Thickness ◽  
Composite Resin ◽  
Ethanol Solution ◽  
Composite Resins ◽  
Residual Monomer ◽  
Steel Mold ◽  
Nanohybrid Composite ◽  
Composite Samples

The aim of the present study was to investigate and compare the quantity of residual monomers leached from the bulk-fill composites with different compositions polymerized at varying layer thickness. Three bulk-fill (X-tra-fil, Beautifil Bulk Restorative, Fill-Up) and a nanohybrid composite (Filtek Z550) were used for the study. The composite resin samples were prepared with a stainless steel mold. For each composite, two groups were constructed. The samples in the first group were prepared using the 2 + 2 mm layering technique. In the second group, the composite samples were applied as a 4 mm-thick one layer and polymerized. Then, each composite samples were kept in a 75% ethanol solution and residual monomers released from composite resins were analyzed with an HPLC device after 24hour and 1 month. The data were analyzed using Kruskal-Wallis and Mann-Whitney U tests. Except the Fill-Up, all of residual monomer elution from the bulk-fill composites was significantly affected by the layer thickness (p < 0.05). The greatest monomer release was detected at 1 month after polymerization as a single 4 mm layer for Beautifil Bulk Restorative. Fill-Up composite showed similar residual monomer release in polymerization at different layer thicknesses compared to other composite resins. In the 2 + 2 mm layering technique, the least monomer elution was detected in the Filtek Z550 composite group. While Bis-GMA was the most released monomer in X-tra fil composite, UDMA was the most released monomer in all other composite resins. During polymerization of the bulk-fill composite, the layer thickness of the composite applied may affect the amount of residual monomers released from the composite resins. Conventional composites may release less monomer than bulk-fill composites when used with layering.

The ability of high performance concrete to resist high temperature

2017 ◽  
Vol 8 (4) ◽  
pp. 392-401 ◽  
Author(s):  
Hassan A.M. Mhamoud ◽  
Jia Yanmin
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Mass Loss ◽  
High Performance ◽  
Elevated Temperatures ◽  
High Performance Concrete ◽  
Sharp Decrease ◽  
Test Results ◽  
Content Type ◽  
Chinese Standard

Purpose This study aims to focus on the resistance to elevated temperatures of up to 700ºC of high-performance concrete (HPC) compared to ordinary Portland concrete (OPC) with regards to mass loss and residual compressive and flexural strength. Design/methodology/approach Two mixtures were developed to test. The first mixture, OPC, was used as the control, and the second mixture was HPC. After 28 days under water (per Chinese standard), the samples were tested for compressive strength and residual strength. Findings The test results showed that at elevated temperatures of up to 500ºC, each mixture experienced mass loss. Below this temperature, the strength and the mass loss did not differ greatly. Originality/value When adding a 10 per cent silica fume, 25 per cent fly, 25 per cent slag to HPC, the compressive strength increased by 17 per cent and enhanced the residual compressive strength. A sharp decrease was observed in the residual flexural strength of HPC when compared to OPC after exposure to temperatures of 700ºC.

Study on the Compressive Strength and Mixing of Ultra-High Performance Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 825-828
Author(s):  
Su Li Feng ◽  
Peng Zhao
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Strength Properties ◽  
Test Method ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Ultra High Performance Concrete ◽  
Mixture Ratio

The test in order to obtain liquidity, higher intensity ultra-high performance concrete(UHPC), in the course of preparation, high intensity quartz sand to replace the ordinary sand,reasonable mixture ratio control low water-cement ratio,the incorporation of part of the test piece ofsteel fibers, produced eight specimens . In the ordinary molding and the standard conservation 28d thecase, the ultra-high-performance concrete compressive strength of more than 170MPa.Thepreparation of the test method and test results will provide the basis for further study of the law of themechanical properties of ultra high strength properties of concrete.

scholarly journals Effects of Water Reducing Admixture on Rheological Properties, Fiber Distribution, and Mechanical Behavior of UHPFRC

2018 ◽  
Vol 9 (1) ◽  
pp. 29 ◽  
Author(s):  
Su-Tae Kang ◽  
Jae Kim ◽  
Bang Lee
Keyword(s):  
Compressive Strength ◽  
Rheological Properties ◽  
High Performance ◽  
Fiber Reinforced Concrete ◽  
Test Results ◽  
Fiber Distribution ◽  
Flexural Performance ◽  
Tensile Performance ◽  
High Performance Fiber ◽  
Hardened Properties

The rheological properties of ultra-high-performance fiber-reinforced concrete (UHPFRC) according to the amount of water reducing admixture (WRA) and their effects on the fiber distribution and the tensile performance of UHPFRC were investigated. Four types of mixtures with a high compressive strength over 150 MPa were designed according to the amount of WRA and the flowability, rheological properties, compressive strength, flexural performance, and fiber distribution were measured. Test results showed that the amount of WRA influences both the freshly mixed and hardened properties. It was also revealed that the flexural strength has a strong correlation with rheological properties, compressive strength, and fiber distribution.

Compressive behavior of steel spiral confined engineered cementitious composites in circular columns

2020 ◽  
Vol 23 (14) ◽  
pp. 3075-3088
Author(s):  
Wei Hou ◽  
Guan Lin ◽  
Xiaomeng Li ◽  
Pandeng Zheng ◽  
Zixiong Guo
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Uniaxial Tensile ◽  
Cementitious Composites ◽  
Test Results ◽  
Cementitious Composite ◽  
Compression Tests ◽  
Compressive Behavior ◽  
Engineered Cementitious Composites ◽  
Engineered Cementitious Composite

Extensive research has been conducted on the uniaxial tensile and compressive behavior of engineered cementitious composites. Despite the high tensile ductility and high toughness of engineered cementitious composites, transverse steel reinforcement is still necessary for high-performance structural members made of engineered cementitious composites. However, very limited research has been concerned with the compressive behavior of steel-confined engineered cementitious composites. This article presents the results of axial compression tests on a series of circular engineered cementitious composite columns confined with steel spirals. The test variables included the engineered cementitious composite compressive strength, the spiral pitch, and the spiral yield stress. The test results show that steel-confined engineered cementitious composites in the test columns exhibited a very ductile behavior; the steel spiral confinement contributed effectively to the enhancement of both strength and ductility of engineered cementitious composites. The test results were then interpreted by comparing them with the predictions from some existing models. It was found that the existing models previously developed for confined concrete failed to predict the compressive strength of steel-confined engineered cementitious composites with sufficient accuracy. New fitting equations for the compressive properties of steel-confined engineered cementitious composites were then obtained on the basis of the test results of this study as well as those from an existing study.

Confined capping system for compressive strength testing of high performance concrete cylinders

1995 ◽  
Vol 22 (3) ◽  
pp. 617-620 ◽  
Author(s):  
Claude D. Johnson ◽  
S. Ali Mirza
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Concrete Specimen ◽  
Strength Testing ◽  
Test Results ◽  
Testing Procedures ◽  
Testing Method ◽  
Concrete Cylinders

This paper presents a simple, inexpensive confined cap testing method which can be employed in the compressive strength testing of high performance concrete cylinders. An inexpensive customized cylinder capping apparatus and standard concrete laboratory testing equipment are employed. The paper describes the capping apparatus, capping and testing procedures, as well as test results for concrete compressive strengths up to and exceeding 100 MPa. Key words: capping, capping confinement, compressive strength, cylinders, end condition, grinding, high-strength concrete, specimen size, testing.

Application and Study of C80 High Performance Concrete in Freezing Shaft Sinking Techniques

2013 ◽  
Vol 353-356 ◽  
pp. 1577-1582
Author(s):  
Qian Wang ◽  
Tong Wei Lu ◽  
Lei Guo
Keyword(s):  
Compressive Strength ◽  
Diffusion Coefficient ◽  
High Performance ◽  
High Performance Concrete ◽  
Chloride Ion ◽  
Test Results ◽  
Mine Shaft ◽  
Deep Freezing ◽  
Thawing Cycle ◽  
Shaft Sinking

A study on C80 high performance concrete used in deep freezing mine shaft liner is made. Test results are listed as follows: (1) Concretes compressive strength at 1 day is 53.0 MPa, while the compressive strength at 28 days is 93.5 MPa. (2) The diffusion coefficient of chloride ion at 28 days is 9.8×10-14m2/s, and freezing-thawing cycle is over 1000 times. The evidence above proves that this concrete can satisfy the requirements of C80 high performance concrete used in freezing shaft sinking techniques.

Influence of Metakaolin on Mechanical Properties of High-Performance Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 1904-1909
Author(s):  
Bao Min Wang ◽  
Wei Liu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Equal Mass ◽  
Test Results ◽  
Optimum Temperature ◽  
Compressive Strength Of Concrete ◽  
And Performance

Kaolin is a material with broad sources and a low price. Metakaolin is made from kaolin which is calcined, finely ground at an optimum temperature of 750 being kept constant for 4 hours. High strength and performance concrete can be mixed from metakaolin as a substitute for equal mass cement. The influences of 5%, 10% and 15% metakaolin in substitution of equal cement masses were studied on the mechanical properties of high-performance concrete. The test results showed that the addition of metakaolin improved the cubic compressive strength, splitting tensile strength and flexural strength of HPC, among which the improvement in compressive strength was the most siginificant, and simultaneously, there was also an improvement in concrete toughness in a certain degree. The optimum content of metakaolin is 10% resulting in an increase of the cubic compressive strength of concrete by 8.3% correspondingly.

scholarly journals Effects of filler volume of nanosisal in compressive strength of composite resin

2017 ◽  
Vol 50 (4) ◽  
pp. 183
Author(s):  
Dwi Aji Nugroho ◽  
W. Widjijono ◽  
N. Nuryono ◽  
Widya Asmara ◽  
Wijayanti Dwi Aastuti ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fossil Fuels ◽  
Composite Resin ◽  
Testing Machine ◽  
Natural Fibers ◽  
Composite Resins ◽  
Inorganic Filler ◽  
Filler Materials ◽  
Significant Difference ◽  
Volume Group

Background: One of the composite resin composition is inorganic filler. The production of inorganic filler materials was highly dependent on non-degradable, and nonrenewable fossil fuels. Therefore, natural fibers can be used as substitute for inorganic fillers. One that can be developed is sisal. Purpose: This study aimed to determine the effects of nanosisal filler volume on compressive strength of composite resin. Methods: In this study, composite resins with nano-sized sisal as filler were manufactured and labeled as nanosisal composites. This research processed sisal fibers into nano size and mixed them with Bis-GMA, UDMA, TEGDMA, Champhorquinone (Sigma Aldrich). Nanofiller composite (Z350 XT, 3M, ESPE) was utilized as a control. The 20 samples utilized were divided into 4 groups (each group containing five samples): Group A contained nanosisal composite of 60% filler volume, group B, nanosisal composite of 65% filler volume, group C, nanosisal composite of 70% filler volume and group D, nanofiller composite (Z350 XT, 3M, ESPE). Samples were 2 mm in diameter and 6 mm in height. The sample was tested for compressive strength using a universal testing machine (UTM). Data was analyzed by means of a Kruskal Wallis procedure. Results: The mean of the compressive strength of the nanosisal composite 60% was 16.80 MPa; the nanosisal composite 65% was 10.80 MPa, the nanosisal composite 70% was 7.20 MPa and the nanofiller composite was 7.40 MPa. There was a significant difference in data analysis (p = 0.033; p < 0.05). Conclusion: In this study, the filler volume of nanosisal influenced the compressive strength of a composite resin and the nanosisal filler volume was recomended at 60%.

scholarly journals Pengaruh Penyinaran Qth Dan Led Pada Kekuatan Tekan Resin Komposit Bulkfilldengan Berbagai Ketebalan

2017 ◽  
Vol 6 (1) ◽  
pp. 7
Author(s):  
Atia Nurul Sidiqa ◽  
Badi Soerachman
Keyword(s):  
Compressive Strength ◽  
Composite Resin ◽  
Resin Composite ◽  
Standard Procedure ◽  
Testing Machine ◽  
Polymerization Process ◽  
Light Emitting ◽  
Significant Difference ◽  
Qth Light ◽  
Thickness Variations

The incremental layering technique with a 2mm maximum depth is a standard procedure to produce a perfect resin composite with a high mechanical strength. Recent studies has developed bulkfill composite resin that can be done to a depth of more than 4mm. Composite resin polymerization process through irradiation can be obtained by the use of Quartz-Tungsten-Halogen (QTH) and Light Emitting Diodes (LED). One of the mechanical properties needed for the restorative material is good compressive strength to withstand a load of chewing time during the process of mastication function. The purpose of this study to determine the effect of irradiation QTH and LED on the compressive strength of composite resin bulkfill with thickness variations of 4 and 6mm. Teflon mold were used to prepare the resin bulkfill spesimen (6mm in diameter x 4mm in length) bulkfill disk 6mm diameter with a thickness of 4mm (n=5) and 6mm (n=5). Samples were soaked in distilled water with a temperature of 37ºC for 24 hours and then do the pressure test measurements by using Universal Testing Machine (UTM) with 250kgf load and speed of 0.5 mm/min. Shapiro-Wilk normality test and unpaired t-test used in this study.The results of the study there is no influence thickness was statistically significant (a=0.05) in the composite resin bulkfill thickness of 4mm and 6mm in LED and QTH irradiation group with a value of compressive strength 4mm group (147.82 ± 24,35MPa) and sample 6mm (133.76±30.63 MPa), QTH light source sample 4mm (158,21 ± 18,61Mpa), 6mm (154,23±21,43Mpa). LED and QTH no significant difference (p>0.05) in a thickness of 4mm and 6mm. Conclusion, bulkfill composite resin can be applied to the LED and QTH to a depth of 6mm without effecting the bulkfill compressive strength.

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