scholarly journals Mechanical Properties of Heat Cured Acrylic Resin Reinforced with Natural Sisal Fibers Powder

2021 ◽  
Vol 2114 (1) ◽  
pp. 012023
Author(s):  
Teba M. Hameed ◽  
Balqees M. Al-Dabbagh ◽  
Ragdaa K. Jasim
Keyword(s):  
Tensile Strength ◽  
Impact Strength ◽  
Flexural Strength ◽  
Acrylic Resin ◽  
Impact Testing ◽  
Bending Test ◽  
Heat Cure ◽  
Significant Difference ◽  
Sisal Fibers ◽  
The Impact

Abstract Materials and Methods: In total, 90 specimens were prepared to be used in the study. The specimens were divided into (3) main groups depended on the presence of sisal fibers powder, first group (30) specimens of heat cure PMMA without additives (control), second and third experimental groups of 60 specimens of heat cure PMMA with salinized sisal fibers powder with two different weight percentages (1 and 3%) wt. Three point bending test was used to measure the flexural strength of the specimens, while the impact strength was done by impact testing Charpy’s machine and tensile test was performed according to ASTM (D-638). Data analysis was performed using (ANOVA) test. The results of this study refer to a highly significant in the flexural strength and tensile strength of specimens reinforced with sisal fibers powder compared with control specimens. Non-significant difference was detected in impact strength among the reinforced groups and control gro. Reinforcement of acrylic resin with natural sisal fibers powder affects its flexural strength and tensile strength with non-significant in impact strength.

scholarly journals Effect of Incorporation of Different Concentrations of Silver Nanoparticles as an Antimicrobial Agent on the Flexural and Impact Strength of Heat-Cured Denture Base Resin

2021 ◽  
Author(s):  
Piyali Sarkar ◽  
Sandeep Garg ◽  
Nidhi Mangtani Kalra
Keyword(s):  
Silver Nanoparticles ◽  
Impact Strength ◽  
Flexural Strength ◽  
Antimicrobial Agent ◽  
Bending Test ◽  
Denture Base ◽  
Significant Difference ◽  
Base Resin ◽  
The Impact ◽  
Denture Base Resin

Abstract Aim This article evaluates the effect of incorporating different concentrations of silver nanoparticles as an antimicrobial agent on the flexural and impact strength of heat-cured denture base resin. Material and Methods A total of 80 specimens of polymethyl methacrylate resin were fabricated (40 for flexural strength and 40 for impact strength). Specimens were fabricated using stainless steel die of dimension 65 mm × 10 mm × 2.5 mm as per the American Dental Association specification no. 12, and 50 mm × 6 mm × 4 mm as per ISO 1567:1999 for flexural strength and impact strength, respectively, and were divided into four groups (A, B, C, and D) based on the concentrations of silver nanoparticles (0%, 2.5%, 5%, and 10%). The specimens were subjected to three-point bending test and Izod impact tester for testing flexural and impact strength, respectively. Data obtained was compiled and analyzed using one-way analysis of variance and post hoc tests. Results Results showed that for both the properties, maximum strength was observed in group A (control) followed by groups B and C, and minimum was observed in group D. A statistically significant difference in flexural strength was found among all the groups, whereas no statistically significant difference in impact strength was found among any of the groups. Conclusion Within the limitations of this in vitro study, it was concluded that though incorporation of silver nanoparticles exhibited no effect on the impact strength of heat cure denture base resin, it decreased the flexural strength, so it should be used cautiously.

scholarly journals Influence of Processing Techniques on Microhardness and Impact Strength of Conventional and Reinforced Heat Cured Acrylic Resin: A Comparative Study

2021 ◽  
Vol 58 (3) ◽  
pp. 239-246
Author(s):  
Aisha Kiran ◽  
Faiza Amin ◽  
Muneeb A Lone ◽  
Imran Alam Moheet ◽  
Maham M Lone ◽  
...  
Keyword(s):  
Impact Strength ◽  
Acrylic Resin ◽  
Water Bath ◽  
P Value ◽  
Dry Heat ◽  
Heat Cure ◽  
Significant Difference ◽  
Group A ◽  
Processing Techniques ◽  
The Impact

This study determined and compared the influences of various processing techniques including air circulating oven (ACO), dry heat oven (DHO) and water bath (WB) on the impact strength (IS) and microhardness (HV) of the conventional heat cure acrylic resin (CHCAR) and rubber reinforced heat cure acrylic resin (RRHCAR). Samples were fabricated using CHCAR (control Group A; n=114) and RRHCAR (experimental Group B; n=114). Group A and B were further divided into subgroups according to processing techniques: ACO, DHO and WB (n=38 each) for both testing variables microhardness and impact strength (n=19 each). Charpy testing machine and Vickers microhardness tester were utilized. Analysis of variance was applied to determine the presence of significant differences among processing techniques while P-value ≤ 0.05 was considered as significant. Water bath (P-value [0.001) and DHO technique (p-value [0.001) showed significant differences between both groups� impact strength and microhardness. Microhardness of group A and B showed a significant difference (p-value 0.002) when processed by ACO. Impact strength and micro hardness were improved in RRHCAR compared to CHCAR processed by ACO and DHO in comparison to WB technique. Rubber reinforced heat cure acrylic resin revealed improvement in the impact strength and microhardness. The air circulating oven exhibited highest microhardness in both testing materials. Dry heat oven showed improved values of impact strength in conventional heat cure acrylic resin.

scholarly journals Polymethylmethacrylate Incorporating Nanodiamonds for Denture Repair: In Vitro Study on the Mechanical Properties

2021 ◽  
Author(s):  
Mohammed Moustafa Ahmed Gad ◽  
Mohamed Saber Ali ◽  
Ahmad M. Al-Thobity ◽  
Yousif A. Al-Dulaijan ◽  
Mai El Zayat ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Impact Strength ◽  
Flexural Strength ◽  
In Vitro Study ◽  
Acrylic Resin ◽  
Bending Test ◽  
Control Group ◽  
Nd Addition ◽  
The Impact

Abstract Objective This study aimed to evaluate the effect of nanodiamond (ND) addition to repair resin with repair gap modifications on the flexural and impact strength of repaired polymethylmethacrylate denture base. Materials and Methods Heat-polymerized acrylic resin specimens (N = 100/test) were prepared and sectioned to half creating two repair gaps: 2.5- and 0 mm with 45 degrees beveling. They were further divided into subgroups (n = 20) according to ND concentration (control, 0.25%ND, and 0.50%ND), thermocycling (500 cycles) was done to half the specimens in each subgroup. Flexural strength was tested using 3-point bending test and impact strength was tested by Charpy's impact test. Analysis of variance and post-hoc Tukey's tests were performed for data analysis (α = 0.05). Scanning electron microscope was employed for fracture surface analysis and ND distribution. Results Before and after thermocycling, the addition of ND significantly increased the flexural strength and elastic modulus in comparison to control group (p ˂ 0.001), while 0 mm repair gap showed insignificant difference between ND-reinforced groups (p ˃ 0.05). Regarding impact strength, ND addition increased the impact strength with 0 mm gap in comparison to control and 2.5 mm with ND (p˂0.001), while later groups showed no significant in between (p ˃ 0.05). Comparing thermocycling effect per respective concentration and repair gap, thermocycling adversely affected all tested properties except elastic modulus with 0 mm–0.25 and 0 mm–0.5% and impact strength with 2.5 mm, 2.5 mm–0.25%, 2.5 mm– 0.5% (p ˃ 0.05). Conclusion ND addition combined with decreased repair gap improved the flexural strength, elastic modulus, and impact strength of repaired denture resin, while thermocycling has a negative effect on denture repair strength.

Electrical and Mechanical Properties of Carbon Aerogels / Phenolic Resin for Nanocomposites

2011 ◽  
Vol 236-238 ◽  
pp. 1725-1730 ◽  
Author(s):  
Wei Jen Chen ◽  
Ming Yuan Shen ◽  
Yi Luen Li ◽  
Chin Lung Chiang ◽  
Ming Chuen Yip
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Flexural Strength ◽  
Phenolic Resin ◽  
Surface Conductivity ◽  
Carbon Aerogels ◽  
Polymer Resin ◽  
The Impact ◽  
Humidity Environment

This study used carbon aerogels (CA) and phenolic resin in fixed proportations to produce nano high polymer resin, and used poly ehtylene oxide (PEO) as the modifying agent for phenolic resin to improve the mechanical properties of phenolic resin and promote the surface conductivity. The prepared nano high polymer resin and carbon cloth were made into nano-prepreg by using ultrasonic impregnation method, and a nano-prepreg composite material was prepared by using hot compacting and cut to test pieces to measure its mechanical properties and surface conductivity as well as the influence of temperature-humidity environment (85°C/168hr and 85°C/85%RH/168hr) on mechanical properties. The result showed that the surface conductivity increased by 64.55%, the tensile strength at room temperature increased by 35.7%, the flexural strength increased by 18.4%, and the impact strength increased by 101%. In hot environment (85°C/168hr), the tensile strength decreased by 23.8%, the flexural strength increased by 3.1%, and the impact strength increased by 84.6%. In high temperature-high humidity environment (85°C/85% RH/168hr), the tensile strength decreased by 29.6%, the flexural strength decreased by 17%, and the impact strength increased by 95.7%.Introduction

scholarly journals Effect of repeated disinfections by microwave energy on the physical and mechanical properties of denture base acrylic resins

2009 ◽  
Vol 20 (2) ◽  
pp. 132-137 ◽  
Author(s):  
Rafael Leonardo Xediek Consani ◽  
Douglas Duenhas de Azevedo ◽  
Marcelo Ferraz Mesquita ◽  
Wilson Batista Mendes ◽  
Paulo César Saquy
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
Knoop Hardness ◽  
Microwave Energy ◽  
Bending Test ◽  
Denture Base ◽  
Acrylic Resins ◽  
The Impact

The present study evaluated the effect of repeated simulated microwave disinfection on physical and mechanical properties of Clássico, Onda-Cryl and QC-20 denture base acrylic resins. Aluminum patterns were included in metallic or plastic flasks with dental stone following the traditional packing method. The powder/liquid mixing ratio was established according to the manufacturer's instructions. After water-bath polymerization at 74ºC for 9 h, boiling water for 20 min or microwave energy at 900 W for 10 min, the specimens were deflasked after flask cooling and finished. Each specimen was immersed in 150 mL of distilled water and underwent 5 disinfection cycles in a microwave oven set at 650 W for 3 min. Non-disinfected and disinfected specimens were subjected to the following tets: Knoop hardness test was performed with 25 g load for 10 s, impact strength test was done using the Charpy system with 40 kpcm, and 3-point bending test (flexural strength) was performed at a crosshead speed of 0.5 mm/min until fracture. Data were analyzed statistically by ANOVA and Tukey's test (α= 0.05%). Repeated simulated microwave disinfections decreased the Knoop hardness of Clássico and Onda-Cryl resins and had no effect on the impact strength of QC-20. The flexural strength was similar for all tested resins.

scholarly journals Influence of Concentrations of Methacrylate and Acrylate Monomers on the Properties of Fiber Reinforced Polymethyl Methacrylate Denture Base Materials

2018 ◽  
Vol 26 (2) ◽  
pp. 329-350 ◽  
Author(s):  
Faik Tugut ◽  
Mehmet Turgut ◽  
Dursun Saraydin
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Testing Machine ◽  
Weight Ratio ◽  
Acrylic Resin ◽  
Bending Test ◽  
Control Group ◽  
Test Machine ◽  
Fiber Reinforced ◽  
Significant Difference

Abstract The study aimed to evaluate the effects of adding different concentrations of 2 hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), ethyl methacrylate (EA) and isobutyl methacrylate (IBMA) monomers on the structural, thermal and mechanical properties of a fiber reinforced heat-polymerized acrylic resin. For each test, 126 acrylic resin specimens were fabricated and divided into 6 groups with 7 specimens each. One group was the control group, the other one is a fiber reinforced group and others were the test groups, which were formed according to the different concentrations of monomers. 6 mm length, and the weight ratio of 3% short glass fibers are added to acrylic powder polymerized by heating. The 2%, 5%, 10%, at 20 % ratios of different comonomers added to a monomer of MMA are composed of copolymer structures. Flexural strength was assessed with a three-point bending test using a universal testing machine. Impact strength testing was conducted using an impact test machine by the Charpy method. The analysis of the connection between acrylic resin and fiber by SEM and structural changes in the acrylic resin was investigated by FTIR spectroscopy. Data analyses using analysis of Kruskal-Wallis and Mann-Whitney U tests (α=0.05) significant difference tests showed that adding 2%, 5% HEMA and IBMA monomers significantly increased the flexural and impact strength compared to the control, only fiber and others group (P< 0.05). It is observed that the process of adding low concentration of HEMA and IBMA monomers improved certain mechanical properties of fiber reinforced with polymethylmethacrylate.

scholarly journals Influence of Different Reline Materials and Processing Methods on Flexural Strength of Denture Base Material

2021 ◽  
Vol 25 (2) ◽  
pp. 108-113
Author(s):  
Ozlem Gurbuz Oflezer ◽  
Hakan Bahadır ◽  
Senem Ünver ◽  
Ceyhan Oflezer
Keyword(s):  
Flexural Strength ◽  
Base Material ◽  
Acrylic Resin ◽  
Bending Test ◽  
Control Group ◽  
Processing Methods ◽  
Denture Base ◽  
Three Point Bending ◽  
Heat Cure ◽  
And Control

Summary Background/Aim: Relining is defined as the procedure used to resurface the tissue side of a denture with new base material, thus producing an accurate adaptation is provided at the denture foundation area. During mastication, relined dentures have to withstand masticatory forces to prevent fracture. The aim of this study was to evaluate the flexural strength of acrylic resin denture base relined with different methods and materials. Material and Methods: Fourteen experimental groups and one control group were determined to consider different reline materials and processing methods. Acrylic resin specimens were prepared with the dimensions of 65× 10× 1.5 mm and reline materials (1.5 mm thickness) were placed on acrylic resins. Reline material was not used in control group specimens. Flexural strength values of relined and control specimens were measured with three-point bending test at a speed of 5 mm/min. Data were analyzed with using one way Anova and Student t tests. Results: The highest flexural strength values were shown in control group (86.51±1.08 MPa). There were significant differences among relined specimens (p< 0.05). For the relined specimens, the highest flexural strength values were found in the relined specimens with denture base material (77.90±1.93 MPa), and the lowest values were found in relined with autopolymerize acrylic material (59.81±1.50 MPa). Conclusions: Relining of the heat cure denture base material significantly decreases the flexural strength for all processing methods and materials.

scholarly journals Enhancing the impact strength of acrylic resin base plate by adding non-dental E-glass fiber

2021 ◽  
Vol 6 (2) ◽  
pp. 106
Author(s):  
Mara Gustina ◽  
Widjijono Widjijono ◽  
Endang Wahyuningtyas
Keyword(s):  
Impact Strength ◽  
Glass Fiber ◽  
Fiber Orientation ◽  
Base Plate ◽  
Acrylic Resin ◽  
Impact Testing ◽  
Control Group ◽  
Anova Test ◽  
The Impact ◽  
One Way Anova

Non-dental glass fiber is one of the materials that can be used to increase the impact strength of a acrylic resin base plate, containing a similar composition to that of dental e-glass fiber. Orientation and positions of fiber affect the reinforcement effectiveness. This research aimed to examine the effect of the orientation of non-dental glass fiber in the compression position on the impact strength of an acrylic resin base plate. The research was conducted on 16 acrylic resin plates with fiber (65 mm x 10 mm x 2.5 mm) addition. The samples were divided into 4 groups (combination of different woven orientation unidirectional, bidirectional woven in the compression position, and control). The material used in this study was heat-cured acrylic resin QC-20 brand, non-dental glass fiber (without any brand). Impact strength was tested using an impact testing machine. The data obtained were analyzed using one-way ANOVA test and LSD (p<0.05). In this research the impact strength of the base plate with the addition of fiber increased 8.54 ± 2.21; 13.21 ± 2.34; 16.81 ± 2.80 kJ/m2 compared to that of the control group, i.e. 4.98 ± 1.05 kJ/m2. One-way ANOVA test showed a significant effect (p<0.05) of the fiber orientation variations on the compression position. This research concluded that the addition of nondental e-glass fiber (composed of SiO252.56-56.88%), diameter 17.12–20.03 µm) in the compression zone increases theimpact strength of acrylic resin base plate. Fibers with unidirectional orientationprovides the highest increase in the impact strength of acrylic resin base plate.

scholarly journals Impact Strength of Ferrocement Panel under Low Velocity Impact Loading

2021 ◽  
Vol 10 (5) ◽  
pp. 285-291
Author(s):  
Darshan G. Gaidhankar ◽  
Mohammad Omid Naqshbandi ◽  
M. S. Kulkarni
Keyword(s):  
Impact Strength ◽  
Flexural Strength ◽  
Energy Absorption ◽  
Experimental Work ◽  
Impact Load ◽  
Impact Testing ◽  
Steel Fibers ◽  
Wire Mesh ◽  
Drop Weight ◽  
The Impact

The capability to absorb energy, often called as toughness, is of importance in actual service conditions of mesh reinforced composites, when they may be subjected to static, dynamic and fatigue loads. Toughness evaluated under impact loads is the impact strength. The toughness of materials are determined by two methods, (i) by measuring deformation under impact load, (ii) by determining energy adsorption capacity of materials under impact load. Several methods were used to investigate to determining toughness of materials. In this research work, drop weight impact test were used. The present experimental work describes testing of flat ferrocement panels with different number of layer steel mesh as well as enhancement of panels with steel fiber. The main purpose of this study is to investigate the effect of using different number of wire mesh layer on the flexural strength and impact strength and also effect of varying thickness of panels on the energy absorption of ferrocement panels. The experimental work includes preparation of ferrocement panels reinforced with welded square mesh, woven square mesh with and without hooked steel fibers The ferrocement panels of different sizes were prepared and tested for flexural strength under the two point loading as well as drop weight for impact testing. It is expected that as the mesh layers will be increased the energy absorption capacity of the panel should be increased and the also its effect should be seen for addition of hooked steel fibers.

scholarly journals Properties of Pavement Quality Concrete Prepared with Recycled Coarse Aggregate

2020 ◽  
Vol 8 (5) ◽  
pp. 3186-3192 ◽  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Impact Strength ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Strength Characteristics ◽  
Laboratory Environment ◽  
Recycled Coarse Aggregate ◽  
The Impact ◽  
Remarkable Reduction

The investigation is intended to evaluate the impact of substitution of demolished concrete debris as coarse aggregate (CA) in pavement quality concrete (PQC). The strength characteristics of PQC such as compressive strength, tensile strength, flexural strength and impact strength after adding recycled coarse aggregate (RCA) are experimentally determined in laboratory environment. Specimens of M30 grade concrete were prepared and tested. The RCA was substituted up to 50% by replacing CA content. Based on the investigation results, it was found that reduction of slump value due to the substitution of RCA in concrete. There is no remarkable reduction of compressive strength and flexural strength up to 30% and 40 % replacement of CA respectively in all the curing periods. The impact strength was reduced due to addition of RCA and observed 8% reduction after adding 20% RCA. It is suggested that RCA may be used up to 20% as CA in PQC.

Sign in / Sign up

Export Citation Format

Share Document