scholarly journals INVESTIGATION OF PROPERTIES OF SYNTHETIC BONE SUBSTITUTES

2021 ◽  
Vol 13 (0) ◽  
pp. 1-4
Author(s):  
Lech Voinič ◽  
Andžela Šešok ◽  
Rimantas Stonkus ◽  
Nikolaj Šešok
Keyword(s):  
Tricalcium Phosphate ◽  
Testing Machine ◽  
Physiological Saline ◽  
Hardness Test ◽  
Bone Substitutes ◽  
Comparative Tests ◽  
Synthetic Bone ◽  
Natural Bone ◽  
Universal Testing ◽  
3D Printers

The article compares different materials of bone substitutes – bioceramics: hydroxyapatite (HA), tricalcium phosphate (CaP) and polymer: polylactide (PLA). In the paper determines which of the substitutes is mechanically similar to the natural bone. Universal testing machine for tensile, compression was used for research. The properties of the test substances were determined by a compression and hardness test. Comparative tests are conducted with HA, CaP, PLA which were kept for 3 weeks in physiological saline and with natural pig bone. The mechanical properties of PLA specimens produced by 3D printers have been found to be similar to natural bone. When held in saline, PLA does not change its properties and dissolves less quickly than tricalcium phosphate.

Osteoconductivity and biodegradation of synthetic bone substitutes with different tricalcium phosphate contents in rabbits

2013 ◽  
Vol 102 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Cheryl Yang ◽  
Otgonbayar Unursaikhan ◽  
Jung-Seok Lee ◽  
Ui-Won Jung ◽  
Chang-Sung Kim ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Bone Substitutes ◽  
Synthetic Bone

scholarly journals Effect of different initial light intensity by the soft-start photoactivation on the bond strength and Knoop hardness of a dental composite

2007 ◽  
Vol 18 (2) ◽  
pp. 107-112 ◽  
Author(s):  
Eduardo Dall'Magro ◽  
Mário Alexandre Coelho Sinhoreti ◽  
Américo Bortolazzo Correr ◽  
Lourenço Correr-Sobrinho ◽  
Simonides Consani ◽  
...  
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Hardness Test ◽  
Surface Region ◽  
Knoop Hardness ◽  
Dental Composite ◽  
The Other ◽  
Soft Start ◽  
Universal Testing ◽  
Push Out

This study evaluated the bond strength (push-out method) and Knoop hardness of Z250 composite resin, photoactivated with XL 2500 curing unit, using different protocols: continuous mode (700mW/cm² for 20s) (CO); soft-start (50 mW/cm² for 5 s, followed by 700 mW/cm² for 15 s) (SS1); soft-start (100 mW/cm² for 5 s, followed by 700 mW/cm² for 15 s) (SS2); soft-start (150 mW/cm² for 5 s, followed by 700mW/cm² for 15s) (SS3); soft-start (200mW/cm² for 5s, followed by 700mW/cm² for 15s) (SS4); soft-start (250mW/cm² for 5 s, followed by 700 mW/cm² for 15 s) (SS5); soft-start (300 mW/cm² for 5 s, followed by 700 mW/cm² for 15 s) (SS6). For the push-out test, the specimens were tested in a universal testing machine at a crosshead speed of 0.5 mm/min. For the hardness test, the specimens were polished for the hardness measurements, using a 50 g load for 15 s. Data were submitted to ANOVA and Tukey's test (alpha=5%). The results of bond strength showed that the SS3 group obtained the highest bond strength when compared to the CO group. There were no significant differences among the other modes in relation to the other groups. Regarding the other results in hardness, there were no significant differences among the groups in the surface region and up to 4 mm depth.

Development of Rice Husk and Wood Dust Filler Based Polyester Resin Based Composites

2015 ◽  
Vol 787 ◽  
pp. 607-611
Author(s):  
D. Ravindran ◽  
T. Sornakumar ◽  
P. Sankar ◽  
K. Janarthan
Keyword(s):  
Rice Husk ◽  
Polyester Resin ◽  
Testing Machine ◽  
Hardness Test ◽  
Dust Particles ◽  
Wood Dust ◽  
Mixed Solution ◽  
Waste Products ◽  
Universal Testing Machine ◽  
Universal Testing

Rice husk particles are one of the important agriculture waste products and wood dust particles are left to degrade of its own in many wood cutting industries. In the present work, polyester resin based composite laminates are manufactured by filling the mixed solution consisting of polyester resin with rice husk and wood dust fillers into a mould. The tensile test was conducted in a Universal testing machine as per ASTM: D638 standard. The flexural test was conducted in a Universal testing machine as per ASTM: D790 standard. The hardness test was conducted in a Shore hardness tester as per ASTM D2240 standard.

scholarly journals Effect of Stirring Speed and Stirring Time on Distribution of Nano Al2O3 Particles in Al7075 Metal Matrix Composite

2019 ◽  
Vol 8 (2) ◽  
pp. 86-89
Author(s):  
H. P. Raju ◽  
M. S. Prashanth Reddy
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Mixing Time ◽  
Testing Machine ◽  
Hardness Test ◽  
Processing Parameters ◽  
Stir Casting ◽  
Casting Method ◽  
Universal Testing ◽  
Stirring Time

Al7075 was successfully synthesized with the addition of Nano Al2O3 with 1.00Wt% by stir casting method by considering various stirring speeds and stirring times during this study. Scanning Electron Microscopy (SEM) is adapted to examine the microstructure of prepared composites. Tensile strength are tested on composite specimens (as per ASTM E8M-09) using computerized Universal Testing Machine (UTM). Micro Vicker’s hardness test was carried out on top of the polished composite specimens. The results showed the microstructure, ultimate tensile strength and hardness of the composite were influenced by the stirring speed and stirring time. From the microstructure it is revealed that, the particle clustering was more at a lower stirring speed with a lower stirring time. Increased mixing speed and mixing time resulted in better particle distribution. The results of the hardness test also demonstrated that, the composite’s hardness is affected by the stirring speed and time. At 400 rpm with a stirring time of 10 minutes, the uniform hardness levels are achieved. But the properties degraded again after an interval of certain time. Present study is conducted to determine microstructure, ultimate tensile strength, and hardness of composite and the tendency between processing parameters such as stirring speed and time.

Biphasic composite of Tricalcium phosphate reinforced with Hydroxyapatite Whiskers

2005 ◽  
Vol 898 ◽  
Author(s):  
B Viswanath ◽  
Ravishankar Narayanan
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Tricalcium Phosphate ◽  
Body Fluid ◽  
Calcium Phosphates ◽  
Testing Machine ◽  
Microstructural Characterization ◽  
The Body ◽  
Universal Testing ◽  
Scanning Electron

AbstractBiphasic calcium phosphates have received considerable attention due to their optimum dissolution rate in the human body after implantation. These materials are composed of hydroxyapatite (HA) and resorbable tricalcium phosphate (TCP). In the present investigation, HA whiskers are reinforced into TCP to enhance the mechanical properties of this biphasic composite. Various amounts (30-50 wt%) HA whiskers are reinforced in TCP matrix. Microstructural characterization has been carried out using field-emission scanning electron microscope. Mechanical properties have been investigated by microindentation in a universal testing machine (UTM). As TCP is resorbable, it will dissolve in body fluid and there is a strong possibility for the faceted HA whiskers to interact with functional groups present in the body fluid surroundings.

Crush Response of Polyurethane Foam-Filled Aluminium Tube Subjected to Axial Loading

2014 ◽  
Vol 875-877 ◽  
pp. 534-541 ◽  
Author(s):  
Chawalit Thinvongpituk ◽  
Nirut Onsalung
Keyword(s):  
Energy Absorption ◽  
Polyurethane Foam ◽  
Testing Machine ◽  
Axial Loading ◽  
Asymmetric Mode ◽  
Pu Foam ◽  
Universal Testing ◽  
Collapse Mode ◽  
Empty Tube ◽  
Foam Filled

In this paper, the experimental investigation of polyurethane (PU) foam-filled into circular aluminum tubes subjected to axial crushing was presented. The purpose of this study is to improve the energy absorption of aluminium tube under axial quasi-static load. The aluminium tube was made from the AA6063-T5 aluminium alloy tubes. Each tube was filled with polyurethane foam. The density of foam was varied from 100, 150 and 200 kg/mP3P including with empty tube. The range of diameter/thickness (D/t) ratio of tube was varied from 15-55. The specimen were tested by quasi-static axial load with crush speed of 50 mm/min using the 2,000 kN universal testing machine. The load-displacement curves while testing were recorded for calculation. The mode of collapse of each specimen was analyzed concerning on foam density and the influence of D/t ratio. The results revealed that the tube with foam-filled provided significantly increment of the energy absorption than that of the empty tube. While the density of foam and D/t ratios increase, the tendency of collapse mode is transformed from asymmetric mode to concertina mode.

scholarly journals Effect of Gold Nanoparticles and Silicon on the Bioactivity and Antibacterial Properties of Hydroxyapatite/Chitosan/Tricalcium Phosphate-Based Biomicroconcretes

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3854
Author(s):  
Joanna Czechowska ◽  
Ewelina Cichoń ◽  
Anna Belcarz ◽  
Anna Ślósarczyk ◽  
Aneta Zima
Keyword(s):  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
Tricalcium Phosphate ◽  
Setting Time ◽  
Antibacterial Properties ◽  
Bone Substitutes ◽  
Bacterial Strains ◽  
Setting Times ◽  
Biological Studies

Bioactive, chemically bonded bone substitutes with antibacterial properties are highly recommended for medical applications. In this study, biomicroconcretes, composed of silicon modified (Si-αTCP) or non-modified α-tricalcium phosphate (αTCP), as well as hybrid hydroxyapatite/chitosan granules non-modified and modified with gold nanoparticles (AuNPs), were designed. The developed biomicroconcretes were supposed to combine the dual functions of antibacterial activity and bone defect repair. The chemical and phase composition, microstructure, setting times, mechanical strength, and in vitro bioactive potential of the composites were examined. Furthermore, on the basis of the American Association of Textile Chemists and Colorists test (AATCC 100), adapted for chemically bonded materials, the antibacterial activity of the biomicroconcretes against S. epidermidis, E. coli, and S. aureus was evaluated. All biomicroconcretes were surgically handy and revealed good adhesion between the hybrid granules and calcium phosphate-based matrix. Furthermore, they possessed acceptable setting times and mechanical properties. It has been stated that materials containing AuNPs set faster and possess a slightly higher compressive strength (3.4 ± 0.7 MPa). The modification of αTCP with silicon led to a favorable decrease of the final setting time to 10 min. Furthermore, it has been shown that materials modified with AuNPs and silicon possessed an enhanced bioactivity. The antibacterial properties of all of the developed biomicroconcretes against the tested bacterial strains due to the presence of both chitosan and Au were confirmed. The material modified simultaneously with AuNPs and silicon seems to be the most promising candidate for further biological studies.

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.

Photoelastic Analysis on Different Retention Methods of Implant-Supported Prosthesis

2015 ◽  
Vol 41 (3) ◽  
pp. 258-263 ◽  
Author(s):  
Angélica Castro Pimentel ◽  
Marcello Roberto Manzi ◽  
Cristiane Ibanhês Polo ◽  
Claudio Luiz Sendyk ◽  
Maria da Graça Naclério-Homem ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Axial Load ◽  
Testing Machine ◽  
Compressive Load ◽  
Lower Intensity ◽  
Photoelasticity Method ◽  
Universal Testing ◽  
Isochromatic Fringes ◽  
Photoelastic Analysis ◽  
Compressive Axial Load

The aim of this study was to evaluate the stress distribution of different retention systems (screwed, cemented, and mixed) in 5-unit implant-supported fixed partial dentures through the photoelasticity method. Twenty standardized titanium suprastructures were manufactured, of which 5 were screw retained, 5 were cement retained, and 10 were mixed (with an alternating sequence of abutments), each supported by 5 external hexagon (4.0 mm × 11.5 mm) implants. A circular polariscope was used, and an axial compressive load of 100 N was applied on a universal testing machine. The results were photographed and qualitatively analyzed. We observed the formation of isochromatic fringes as a result of the stresses generated around the implant after installation of the different suprastructures and after the application of a compressive axial load of 100 N. We conclude that a lack of passive adaptation was observed in all suprastructures with the formation of low-magnitude stress in some implants. When cemented and mixed suprastructures were subjected to a compressive load, they displayed lower levels of stress distribution and lower intensity fringes compared to the screwed prosthesis.

scholarly journals Vascularization of Nanohydroxyapatite/Collagen/Poly(L-lactic acid) Composites by Implanting Intramuscularly In Vivo

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Hai Wang ◽  
Xiao Chang ◽  
Guixing Qiu ◽  
Fuzhai Cui ◽  
Xisheng Weng ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Orthopaedic Surgery ◽  
Bone Substitutes ◽  
Bone Defects ◽  
Large Defect ◽  
Natural Bone ◽  
Composition And Structure ◽  
Large Bone ◽  
Large Bone Defects

It still remains a major challenge to repair large bone defects in the orthopaedic surgery. In previous studies, a nanohydroxyapatite/collagen/poly(L-lactic acid) (nHAC/PLA) composite, similar to natural bone in both composition and structure, has been prepared. It could repair small sized bone defects, but they were restricted to repair a large defect due to the lack of oxygen and nutrition supply for cell survival without vascularization. The aim of the present study was to investigate whether nHAC/PLA composites could be vascularized in vivo. Composites were implanted intramuscularly in the groins of rabbits for 2, 6, or 10 weeks (n=5×3). After removing, the macroscopic results showed that there were lots of rich blood supply tissues embracing the composites, and the volumes of tissue were increasing as time goes on. In microscopic views, blood vessels and vascular sprouts could be observed, and microvessel density (MVD) of the composites trended to increase over time. It suggested that nHAC/PLA composites could be well vascularized by implanting in vivo. In the future, it would be possible to generate vascular pedicle bone substitutes with nHAC/PLA composites for grafting.

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