Dynamic and Static Flexural Appraisal of Resin-based Composites: Comparison of the ISO and Mini-flexural Tests

2018 ◽  
Vol 43 (5) ◽  
pp. E223-E231 ◽  
Author(s):  
AU Yap ◽  
AH Eweis ◽  
NA Yahya
Keyword(s):  
Flexural Strength ◽  
Loss Tangent ◽  
Loss Modulus ◽  
Artificial Saliva ◽  
Pearson Correlation ◽  
Flexural Modulus ◽  
Flexural Properties ◽  
Test Analysis ◽  
Significance Level ◽  
Flexural Testing

SUMMARY The objective of this study was to determine the influence of specimen dimension and conditioning medium on the dynamic and static flexural properties of resin-based composites (RBCs). One conventional (Filtek Z350) and two bulk-fill RBCs (Filtek Bulk-fill and Beautifil-Bulk Restorative) were evaluated. Bar-shaped specimens with dimensions 25 × 2 × 2 mm (ISO flexural [IFT]) or 12 × 2 × 2 mm (mini-flexural [MFT]) were fabricated using customized stainless-steel molds, finished, measured, randomly divided into two groups, and conditioned in air or artificial saliva (SAGF) for seven days at 37°C. The specimens (n=10) were then subjected to dynamic and static three-point flexural testing. Data for storage modulus, loss modulus, loss tangent, flexural strength, and modulus were computed and subjected to t-test, analysis of variance/Tukey test, and Pearson correlation at a significance level of α = 0.05. For both IFT and MFT, significant differences in dynamic and static flexural properties were more prevalent between materials after storage in saliva. For both conditioning mediums, the strongest correlation between IFT and MFT was observed for flexural strength. While significant positive correlations were observed for all flexural properties with saliva, no significant correlations were detected for loss tangent and flexural modulus with air. For both IFT and MFT, storage in saliva appeared to be more discriminative than storage in air. As moderate to strong positive relationships exist between IFT and MFT for dynamic and static flexural properties, the mini-flexural test holds promise as a replacement for the ISO 4049 in view of its clinical relevance and greater efficiency.

Comparison of Flexural Properties of Bulk-fill Restorative/Flowable Composites and Their Conventional Counterparts

2020 ◽  
Vol 45 (1) ◽  
pp. 41-51 ◽  
Author(s):  
AH Eweis ◽  
AU Yap ◽  
NA Yahya
Keyword(s):  
Water Solution ◽  
Artificial Saliva ◽  
Flexural Modulus ◽  
Testing Machine ◽  
Flexural Properties ◽  
Significance Level ◽  
Tukey Test ◽  
Universal Testing ◽  
Flexural Testing ◽  
Flowable Composites

SUMMARY The objectives of the study were to compare the flexural modulus and strength of restorative and flowable bulk-fill resin-based composites (RBCs) to their conventional counterparts and to determine the effects of conditioning environment on their flexural properties. The materials evaluated included three conventional RBCs (Filtek Z350, Tetric N Ceram, and Beautifil II), three restorative bulk-fill RBCs (Filtek Bulk-Fill Restorative, Tetric N Ceram Bulk-Fill, and Beautifil Bulk-fill Restorative), as well as three flowable bulk-fill RBCs (Filtek Bulk-Fill Flowable, Tetric N Flow Bulk-Fill, and Beautifil Bulk-Fill Flowable). Specimens were fabricated using customized stainless-steel molds, finished, measured, and randomly divided into four groups. The various RBCs were conditioned in the following mediums (n=10) for seven days at 37°C: air, artificial saliva (SAGF), 0.02 N citric acid, and 50% ethanol-water solution. After conditioning, the specimens were rinsed, blotted dry, measured, and subjected to flexural testing using a universal testing machine. Data were subjected to statistical analysis using analysis of variance and the Tukey test at a significance level of α = 0.05. Significant differences in flexural properties were observed between materials and conditioning mediums. Bulk-fill restorative RBCs exhibited higher flexural modulus than their bulk-fill flowable and conventional counterparts. With the exception of Filtek Bulk-Fill Flowable, bulk-fill flowable RBCs had significantly higher flexural strength than bulk-fill restorative and conventional RBCs. Flexural properties were highest when RBCs were conditioned in air and generally the lowest after exposure to ethanol.

scholarly journals Effect of Dietary Challenges on the Flexural Properties of Resin-based Composites

2021 ◽  
Vol 28 ◽  
pp. 52-60
Author(s):  
Noor Azlin Yahya ◽  
Shi Yin Lim ◽  
Maria Angela Garcia Gonzalez
Keyword(s):  
Flexural Strength ◽  
Material Selection ◽  
Water Solution ◽  
Artificial Saliva ◽  
Flexural Modulus ◽  
Dietary Advice ◽  
Flexural Properties ◽  
Air Exposure ◽  
Flexural Testing ◽  
The Impact

This study aims to compare flexural strength and flexural modulus of different resin-based composites (RBCs) and to determine the impact of dietary solvents on flexural properties. Forty specimens (12x2x2mm) for each of two conventional (Aura Easy [AE]; Harmonize [HN]) and one bulk fill (Sonic Fill 2 [SF2]) were fabricated using customised plastic moulds. Specimens were light-cured, measured and randomly divided into four groups. The groups (n=10) were conditioned for 7 days at 37°C: in one of media: air (control), artificial saliva (SAGF), 0.02N citric acid and 50% ethanol–water solution. After conditioning, the specimens subjected to flexural testing. Two-way ANOVA and one-way ANOVA (post hoc: Tukey’s or Dunnett T3 tests) were used at a=0.05. Significant differences in flexural properties were observed between materials and conditioning media. Flexural strength and modulus values ranged from 124.85MPa to 51.25MPa; and 6.76GPa to 4.03GPa, respectively. The highest flexural properties were obtained with conditioning in air. Exposure to aqueous solutions generally reduced flexural properties. In conclusion, the effect of dietary solvents on flexural properties were material and medium dependent. For functional longevity of restorations, patients’ alcohol intake should be considered during material selection. Dietary advice (reduce alcohol consumption) should be given to patients post operatively.

scholarly journals Influence of Fiber Volume and Fiber Length on Thermal and Flexural Properties of a Hybrid Natural Polymer Composite Prepared with Banana Stem, Pineapple Leaf, and S-Glass

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
K. B. Prakash ◽  
Yahya Ali Fageehi ◽  
Rajasekaran Saminathan ◽  
P. Manoj Kumar ◽  
S. Saravanakumar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Flexural Strength ◽  
Fiber Length ◽  
Natural Fiber ◽  
Loss Modulus ◽  
Flexural Modulus ◽  
Flexural Properties ◽  
Fiber Volume ◽  
Banana Stem

There is more demand for natural fiber-reinforced composites in the energy sector, and their impact on the environment is almost zero. Natural fiber has plenty of advantages, such as easy recycling and degrading property, low density, and low price. Natural fiber’s thermal properties and flexural properties are less than conventional fiber. This work deals with the changes in the thermal properties and mechanical properties of S-glass reinforced with a sodium hydroxide-treated pineapple leaf (PALF) and banana stem fibers. Banana stem and pineapple leaf fibers (PALF) were used at various volume fractions, i.e., 30%, 40%, and 50%, and various fiber lengths of 20 cm, 30 cm, and 40 cm with S-glass, and their effects on the thermal and mechanical properties were studied, and their optimum values were found. It was evidenced that increasing the fiber volume and fiber length enhanced the flexural and thermal properties up to 40% of the fiber volume, and started to decrease at 50% of the fiber volume. The fiber length provides an affirmative effect on the flexural properties and a pessimistic effect on the thermal properties. The PALF S-glass combination of 40% fiber load and 40 cm fiber length provides maximum flexural strength, flexural modulus, storage modulus, and lowest loss modulus based on hybrid Taguchi grey relational optimization techniques. PALF S-glass hybrid composite has been found to have 7.80%, 3.44%, 1.17% higher flexural strength, flexural modulus, and loss modulus, respectively, and 15.74% lower storage modulus compared to banana S-glass hybrid composite.

Flexural Properties of Bioactive Restoratives in Cariogenic Environments

2021 ◽  
Author(s):  
AU Yap ◽  
HS Choo ◽  
HY Choo ◽  
NA Yahya
Keyword(s):  
Flexural Strength ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Flexural Properties ◽  
Glass Ionomer ◽  
Bioactive Materials ◽  
Flexural Testing ◽  
Resin Modified Glass Ionomer ◽  
Ph Cycling ◽  
Acidic Conditions

Clinical Relevance The strength of some bioactive materials can be compromised by cariogenic challenges. This may impact the clinical longevity of restorations, especially in stress-bearing areas. SUMMARY This study determined the mechanical performance of bioactive restoratives in cariogenic environments and compared the flexural properties of various bioactive materials. The materials evaluated included a conventional resin-based composite (Filtek Z350 [FZ]) and 3 bioactive restoratives, namely an alkasite (Cention N [CN]), a giomer (Beautifil-bulk Restorative [BB]), and an enhanced resin-modified glass ionomer (Activa Bioactive Restorative [AV]). Beam-shaped specimens (12 x 2 x 2 mm) were produced, randomly allocated to 4 groups (n=10), and conditioned in deionized solution, remineralizing solution, demineralizing solution (DE), or pH cycled for 14 days at 37°C. After conditioning/pH cycling, the specimens were subjected to 3-point flexural testing. Flexural data were subjected to statistical analysis using analysis of variance or Tukey’s test (α=0.05). Mean flexural modulus and strength ranged from 3.54 ± 0.33 to 7.44 ± 0.28 GPa, and 87.07 ± 8.99 to 123.54 ± 12.37 MPa, respectively. While the flexural modulus of the bioactive restoratives was not affected by cariogenic/acidic conditions, flexural strength usually decreased, with the exception of CN. The strength of BB was significantly reduced by DE and pH cycling, while that of AV was lowered by DE. For all conditioning mediums, AV had a significantly lower modulus than the other materials. Apart from conditioning in DE, where differences in flexural strength was insignificant, FZ and AV were generally significantly stronger than BB and CN. The effect of cariogenic environments on flexural strength was found to be material dependent, and aside from the alkasite material (CN), cariogenic conditions were observed to significantly decrease the strength of bioactive restoratives.

scholarly journals Enhanced flexural properties of aramid fiber/epoxy composites by graphene oxide

2019 ◽  
Vol 8 (1) ◽  
pp. 484-492 ◽  
Author(s):  
Yinqiu Wu ◽  
Bolin Tang ◽  
Kun Liu ◽  
Xiaoling Zeng ◽  
Jingjing Lu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Flexural Strength ◽  
Interfacial Shear Strength ◽  
Flexural Modulus ◽  
Weight Fraction ◽  
Interfacial Shear ◽  
Aramid Fiber ◽  
Epoxy Composites ◽  
Flexural Properties ◽  
Pure Epoxy

Abstract The reinforcing effect of graphene oxide (GO) in enhancing the flexural strength and flexural modulus of aramid fiber (AF)/epoxy composites were investigated with GO-AFs at a weight fraction of 0.1-0.7%. The flexural strength and flexural modulus of the composite reached 87.16 MPa and 1054.7 MPa, respectively, which were about 21.19% and 40.86% higher than those of the pure epoxy resin, respectively. In addition, the flexural properties and interfacial shear strength (IFSS) of composite reinforced by GO-AFs were much higher than the composites reinforced by AFs due to GO improved the interfacial bonding between the reinforcement material and matrix.

scholarly journals The Performance of Filava-Polysiloxane, Silres® H62C Composite in High Temperature Application

2021 ◽  
Vol 5 (6) ◽  
pp. 144
Author(s):  
Klaudio Bari ◽  
Thozhuvur Govindaraman Loganathan
Keyword(s):  
High Temperature ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Fire Retardant ◽  
Bending Test ◽  
Ongoing Research ◽  
Flexural Testing ◽  
Temperature Application ◽  
High Temperature Tensile ◽  
In Fire

The research aim is to investigate the performance of novel enriched mineral fibres (Filava) in polysiloxane SLIRES H62 resin. Specimens were manufactured using a vacuum bagging process and oven cured at 250 °C. Specimens were prepared for flexural testing according to BS EN ISO 14125:1998 to obtain flexural strength, modulus, and elongation. The mechanical strength was compared to similar composites, with the aim of determining composite performance index. The flexural modulus (9.7 GPa), flexural strength (83 MPa), and flexural strain (2.9%) were obtained from a three-point bending test. In addition, the study investigates the thermal properties of the composite using a state-of-art Zwick Roell high temperature tensile rig. The results showed Filava/Polysiloxane Composites had an ultimate tensile strength 400 MPa, Young’s modulus 16 GPa and strain 2.5% at 1000 °C, and no smoke and ash were observed during pyrolysis. Ongoing research is currently taking place to use Filava-H62 in fire-retardant enclosure for lithium-ferro-phosphate Batteries used in electric trucks.

Physical Properties of Vanillin Incorporated Self-Curing Orthodontic Polymethylmethacrylate Resin

2020 ◽  
Vol 853 ◽  
pp. 46-50
Author(s):  
Thongchai Poonpiriya ◽  
Pornrachanee Sawaengkit ◽  
Sroisiri Thaweboon ◽  
Pornkiat Churnjitapirom
Keyword(s):  
Flexural Strength ◽  
Physical Properties ◽  
Flexural Modulus ◽  
Orthodontic Appliances ◽  
Surface Porosity ◽  
Significance Level ◽  
Removable Orthodontic Appliances ◽  
Pmma Resin ◽  
One Way Anova

Polymethylmethacrylate (PMMA) resin is the main polymeric material used in removable orthodontic appliances. However, it can promote the adhesion of microbes due to its surface porosity and from long-term use. While vanillin incorporated PMMA resin has been reported to have antimicrobial effects against Candida albicans, the influence of vanillin incorporation on the physical properties of self-curing orthodontic PMMA resin has not been studied. Objective: To determine the flexural strength and flexural modulus of self-curing orthodontic PMMA resin incorporated with vanillin in different concentrations. Materials and methods: Three groups of self-curing orthodontic PMMA with incorporated vanillin concentrations of 0.1%, 0.5% as well as PMMA without vanillin as a control were prepared with ten specimens per group. Flexural strength and flexural modulus were tested by a 3-point bending machine according to ISO 20795-2:2013 specifications. One-way ANOVA and Tukey’s multiple comparison tests at a p<0.05 significance level were used to analyse the data. Results: The 0.1% vanillin incorporated group met ISO standard requirements (flexural strength = 60.48 MPa, flexural modulus = 1756.60 MPa), while the 0.5% vanillin incorporated group failed to pass this standard (flexural strength = 46.94 MPa, flexural modulus = 1423.49 MPa). The means of both flexural strength and flexural modulus showed significant differences among the three groups. Increasing the concentration of vanillin would decrease the flexural strength and flexural modulus of PMMA resin. Conclusion: The incorporation of vanillin into self-curing orthodontic PMMA resin can affect its physical properties, namely flexural strength and flexural modulus. At a concentration of 0.1% vanillin incorporation, PMMA resin displayed physical properties within the ISO standards.

FLEXURAL PROPERTIES OF INJECTION-MOLDED BAMBOO/PBS COMPOSITES

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2838-2843 ◽  
Author(s):  
KAZUYA OHKITA ◽  
HITOSHI TAKAGI
Keyword(s):  
Flexural Strength ◽  
Natural Fiber ◽  
Flexural Modulus ◽  
Fiber Surface ◽  
Flexural Properties ◽  
Pull Out ◽  
Polybutylene Succinate ◽  
Injection Molded ◽  
Bamboo Powder ◽  
Opposite Tendency

In recent years, from an environmental perspective, there has been increasing interest in the change to a sustainable society. The use of natural-fiber-reinforced biodegradable composites has been proposed as one solution. Bamboo is an often used renewable bio-resource; it has an inherent advantage of rapid growth. Polybutylene succinate ( PBS ), used as matrix resin, has biodegradable characteristics. This paper describes flexural properties of bamboo/ PBS composites prepared by injection molding. The following results were obtained. The flexural modulus was improved with increasing bamboo powder contents when the cylinder temperature of the injection molder was 140°C. However, the flexural strength showed the opposite tendency to be decreased with increasing bamboo powder contents. An SEM photomicrograph of the fracture surface for bamboo/ PBS composites showed typical fracture behavior of pull-out fibers without fiber fracture. Furthermore, there was no adhesion of PBS resin on the bamboo fiber surface. Processing conditions affected mechanical properties of bamboo/ PBS composites, imparting higher flexural strength and flexural modulus at high cylinder temperatures such as 180°C and 200°C.

scholarly journals Influence of microfillers addition on the flexural properties of carbon fiber reinforced phenolic composites

2021 ◽  
pp. 002199832110316
Author(s):  
IA Abdulganiyu ◽  
INA Oguocha ◽  
AG Odeshi
Keyword(s):  
Carbon Fiber ◽  
Flexural Strength ◽  
Carbon Fibers ◽  
Colloidal Silica ◽  
Flexural Modulus ◽  
Flexural Properties ◽  
Fiber Reinforced ◽  
Cfrp Composites ◽  
Sic Particles ◽  
Flexural Loading

The effects of microfiller addition on the flexural properties of carbon fiber reinforced phenolic (CFRP) matrix composites were investigated. The CFRP was produced using colloidal silica and silicon carbide (SiC) microfillers, 2 D woven carbon fibers, and two variants of phenolic resole (HRJ-15881 and SP-6877). The resins have the same phenol and solid content but differ in their viscosities and HCHO (formaldehyde) content. The weight fractions of microfillers incorporated into the phenolic matrix are 0.5 wt.%, 1 wt.%, 1.5 wt.%, and 2 wt.%. Flexural properties were determined using a three-point bending test and the damage evolution under flexural loading was investigated using optical and scanning electron microscopy. The results indicated that the reinforcement of phenolic resins with carbon fibers increased the flexural strength of the HRJ-15881 and SP-6877 by 508% and 909%, respectively. The flexural strength of the CFRP composites further increased with the addition of SiC particles up to 1 wt.% SiC but decreased with further increase in the amount of SiC particles. On the other hand, the flexural modulus of the CFRP composites generally decreased with the addition of SiC microfiller. Both the flexural strength and flexural modulus of the CFRP did not improve with the addition of colloidal silica particles. The decrease in flexural properties is caused by the agglomeration of the microfillers, with colloidal silica exhibiting more tendency for agglomeration than SiC. The fractured surfaces revealed fiber breakage, matrix cracking, and delamination under flexural loading. The tendency for failure worsened at microfiller addition of ≥1.5 wt.%.

The Effect of Fiber Position and Polymerization Condition on the Flexural Properties of Fiber-Reinforced Composite

2004 ◽  
Vol 5 (2) ◽  
pp. 14-26 ◽  
Author(s):  
Lippo V.J. Lassila ◽  
Pekka K. Vallittu
Keyword(s):  
Flexural Strength ◽  
Glass Fibers ◽  
Flexural Modulus ◽  
Flexural Properties ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Monomer Content ◽  
Light Curing ◽  
Polymerization Condition

Abstract The aim of this study was to investigate the influence of the position of the fiber rich layer on the flexural properties of fiber-reinforced composite (FRC) construction. In addition, the total residual monomer content of FRC was quantitatively determined to find out the difference of the effectiveness of two types of light-curing units using liquid chromatography (HPLC). Unidirectional continuous E-glass FRC and hybrid particulate filler composite resins were used in the fabrication of test specimens. Four different positions of the FRC layer were used: compression, neutral, tension, and vertical side position. A three-point bending test (ISO 10477) was performed to measure the flexural properties of the specimens. Position of the FRC layer had a significant effect on the flexural strength (p<0.001, ANOVA). Also, the type of light-curing device had an effect on flexural strength (p<0.001). Specimens with FRC positioned on the compression side showed flexural strength of approximately 250 MPa, whereas FRC positioned on the tension side showed strength ranging from 500 to 600 MPa. Mean flexural modulus with FRC placed horizontally ranged between 9-12 GPa; no significant difference was found between these groups. However when fiber reinforcement was positioned vertically, the flexural modulus raised up to 16 GPa. Specimens with 24 vol% glass fibers contained 52% less residual monomer than specimens without glass fibers. The monomer content was lower in specimens polymerized with the curing device with higher polymerization temperature. In order to optimize flexural strength of low fiber volume fraction, the fibers should be placed at the tension side of the specimen. Citation Lassila LVJ, Vallittu PK. The Effect of Fiber Position and Polymerization Condition on the Flexural Properties of Fiber-Reinforced Composite. J Contemp Dent Pract 2004 May;(5)2:014-026.

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