Tensile Strength of Thin Resin Composite Layers as a Function of Layer Thickness

The successful restoration of teeth requires a good connection between the inlay and natural tissue. A strong bond may improve retention and reinforce tooth structure. The purpose of this study was to evaluate the influence of cement layer thickness on contraction stress generated during photopolymerization, and to determine the changes in stress state of the cement occurring during aging in water (over 84 days). Two cements were used: resin composite cement (NX3) and self-adhesive resin cement (Maxcem Elite Chroma). A cylindrical sample made of CuZn alloy was used to imitate the inlay. The stress state was measured by photoelastic analysis. The contraction stress of the inlay restoration was calculated for cement layer thicknesses of 25 µm, 100 µm, 200 µm, and 400 µm. For both tested materials, the lowest contraction stress was observed for the thinnest layer (25 µm), and this increased with thickness. Following water immersion, a significant reduction in contraction stress was observed due to hygroscopic expansion. Applying a thin layer (approximately 25 µm) of composite and self-adhesive resin cements resulted in high levels of expansion stresses (over −6 MPa) after water aging.

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Influence of Ambient Temperature and Light-curing Moment on Polymerization Shrinkage and Strength of Resin Composite Cements

Operative Dentistry ◽

10.2341/17-085-l ◽

2018 ◽

Vol 43 (6) ◽

pp. 619-630 ◽

Cited By ~ 2

Author(s):

N Rohr ◽

JA Müller ◽

J Fischer

Keyword(s):

Tensile Strength ◽

Resin Composite ◽

Indirect Tensile Strength ◽

Homogeneous Distribution ◽

Sem Images ◽

Polymerization Shrinkage ◽

Ambient Temperatures ◽

Light Curing ◽

Indirect Tensile ◽

Composite Cements

ABSTRACT Objective: The purpose of this study was to establish a clinically appropriate light-curing moment for resin composite cements while achieving the highest indirect tensile strength and lowest polymerization shrinkage. Methods and Materials: Polymerization shrinkage of seven resin composite cements (Multilink Automix, Multilink Speed Cem, RelyX Ultimate, RelyX Unicem 2 Automix, Panavia V5, Panavia SA plus, VITA Adiva F-Cem) was measured at ambient temperatures of 23°C and 37°C. Testing was done for autopolymerized and light-cured specimens after light application at either 1, 5, or 10 minutes after mixing. Indirect tensile strength of all cements was measured after 24 hours of storage at temperatures of 23°C and 37°C, for autopolymerized and light-cured specimens after light application 1, 5, or 10 minutes after mixing. To illustrate filler size and microstructures, SEM images of all cements were captured. Statistical analysis was performed with one-way ANOVA followed by post hoc Fisher LSD test (α=0.05). Results: Final polymerization shrinkage of the resin composite cements ranged from 3.2% to 7.0%. An increase in temperature from 23°C to 37°C as well as the light-curing moment resulted in material dependent effects on the polymerization shrinkage and indirect tensile strength of the cements. Polymerization shrinkage of the cements did not correlate with the indirect tensile strength of the cement in the respective groups. Highest indirect tensile strengths were observed for the materials containing a homogeneous distribution of fillers with a size of about 1 μm (Multilink Automix, Panavia V5, VITA Adiva F-Cem). Conclusion: The magnitude of the effect of light-curing moment and temperature increase on polymerization shrinkage and indirect tensile strength of resin composite cements is material dependent and cannot be generalized.

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Effect of resin thickness and light-curing distance on the diametral tensile strength of short fibre-reinforced resin composite

Journal of Physics Conference Series ◽

10.1088/1742-6596/1073/5/052015 ◽

2018 ◽

Vol 1073 ◽

pp. 052015

Author(s):

M Medikasari ◽

E Herda ◽

B Irawan

Keyword(s):

Tensile Strength ◽

Resin Composite ◽

Short Fibre ◽

Light Curing ◽

Diametral Tensile Strength

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Mechanical Behaviour of Polylactic Acid Parts Fabricated via Material Extrusion Process: A Taguchi-Grey Relational Analysis Approach

International Journal of Engineering Research in Africa ◽

10.4028/www.scientific.net/jera.46.32 ◽

2020 ◽

Vol 46 ◽

pp. 32-44

Author(s):

Peter Kayode Farayibi ◽

Babatunde Olamide Omiyale

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Impact Strength ◽

Layer Thickness ◽

Polylactic Acid ◽

Process Parameters ◽

Grey Relational Analysis ◽

Extrusion Temperature ◽

Relational Analysis ◽

Grey Relational

The acceptance and application of functional parts produced via additive manufacturing technologies is faced with challenges of poor surface finish, dimensional accuracy and mechanical properties among other which is mostly dependent on process parameters employed. In this study, the effect of infill density, layer thickness and extrusion temperature on mechanical properties of polylactic acid (PLA) part manufactured using fused deposition modelling process was investigated to obtain optimum process parameters to achieve the best properties. Solid cuboid bars were produced from which tensile, impact and hardness test specimens were obtained. A statistical approach based on Taguchi design of experiment was employed with process parameters varied and grey relational analysis coupled with principal component analysis was employed to obtain the unified optimum parameter. The single optimisation results showed that 50% infill density, 220°C extrusion temperature and 0.4 mm layer thickness resulted in best tensile strength; 30% density, 210°C temperature and 0.2 mm layer thickness is required to achieve the best impact strength, while 50% density, 215°C temperature and 0.3 mm thickness is required for highest hardness. The multi-response optimisation indicated that for the best of all the three properties to be achieved at once in a PLA built part, 50% infill density, 220°C extrusion temperature and 0.3 mm is required which yielded tensile strength of 30.02±2.15 MPa, impact strength 4.20±0.12 J and hardness of 76.80±0.38 BHN.

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Relation between Critical Fiber Length and Tensile Strength for Glass Fiber - Polypropylene Resin Composite

Polymer Composites ◽

10.1515/9783110856934-013 ◽

1986 ◽

pp. 183-190

Author(s):

T. Ohsawa ◽

M. Miwa

Keyword(s):

Tensile Strength ◽

Glass Fiber ◽

Fiber Length ◽

Resin Composite ◽

Critical Fiber Length

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Experimental determination of impact tensile properties of adhesive butt joints with the split Hopkinson bar

The Journal of Strain Analysis for Engineering Design ◽

10.1243/030932403765310563 ◽

2003 ◽

Vol 38 (3) ◽

pp. 233-245 ◽

Cited By ~ 53

Author(s):

T Yokoyama

Keyword(s):

Tensile Strength ◽

Layer Thickness ◽

Energy Absorption ◽

Loading Rate ◽

Adhesive Layer ◽

Hopkinson Bar ◽

Butt Joints ◽

Cyanoacrylate Adhesive ◽

Split Hopkinson ◽

The Impact

The tensile strength and energy absorption of adhesive butt joints at high rates of loading are determined with a tensile split Hopkinson bar using a cylindrical specimen. A commercially available single-component cyanoacrylate adhesive (instantaneous adhesive) and two different adherend materials are used in the adhesion tests. The impact tensile strength of the cyanoacrylate adhesive butt joints is determined from the applied tensile stress history at failure initiation. The impact absorbed energy is obtained by numerical integration of dynamic tensile load-adhesive deformation data. Comparative tension tests at low and intermediate rates of loading are performed on an Instron testing machine. An axisymmetric finite element analysis is carried out to investigate the stress distributions in the adhesive layer of the cyanoacrylate adhesive butt joints. The effects of loading rate, adherend material and adhesive layer thickness on the tensile strength and energy absorption of the cyanoacrylate adhesive butt joints are examined in detail. It is shown that the joint tensile strength increases significantly with increasing loading rate and is greatly affected by both the adhesive layer thickness and the adherend materials. The limitations of the technique are discussed.

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Effects of Accelerated Aging Period of Time at 150°C on Tensile Strength of 3-Dimension-4-Direction Braided/Epoxy Resin Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.399-401.461 ◽

2011 ◽

Vol 399-401 ◽

pp. 461-464

Author(s):

Wei Geng ◽

Lei Lei Song ◽

Jia Lu Li

Keyword(s):

Tensile Strength ◽

Epoxy Resin ◽

Resin Composite ◽

Accelerated Aging ◽

Tensile Load ◽

Resin Composites ◽

Braided Composite ◽

Aging Period ◽

Epoxy Resin Composites ◽

Composite Samples

In this paper, the tensile strength of 3-dimension-4-direction braided/epoxy resin composites after accelerated aging for different period of time at 150°C was investigated. The tensile tests of 3-dimension-4-direction braided/epoxy resin composite samples without aging and aged 60 hours, 120 hours, 180 hours, at 150°C were carried out. The damage forms of braided composite samples tested were investigated. The experiment result indicates that the accelerated aging process at 150°C has some effect on the tensile strength of braided composite samples. The average tensile strengths of composite samples aged 60 hours, 120 hours, and 180 hours period of time at 150°C are 92.44%, 91.62% and 84.91% of average tensile strength of braided composite samples without aging, respectively. This means that the tensile strength will be decreased when the aging period of time increases at 150°C. The damage form of samples tested shows that when accelerated aging, the resin in the composite samples is damaged, which makes the adhesive force between fiber bundles and epoxy resin decline, so that the ability of fiber and resin bearing the tensile load together decreases.

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