scholarly journals Influence of artificial aging: mechanical and physicochemical properties of dental composites under static and dynamic compression

2021 ◽  
Author(s):  
D. C. Gornig ◽  
R. Maletz ◽  
P. Ottl ◽  
M. Warkentin
Keyword(s):  
Mechanical Properties ◽  
Water Sorption ◽  
Artificial Aging ◽  
Filler Content ◽  
Dynamic Compression ◽  
The Other ◽  
Chemical Degradation ◽  
Dental Composites ◽  
Compression Tests ◽  
Acid Ph

Abstract Objective The aim of the study was to evaluate the influence of filler content, degradation media and time on the mechanical properties of different dental composites after in vitro aging. Materials and Methods Specimens (1 mm3) of three commercially available composites (GrandioSO®, Arabesk Top®, Arabesk Flow®) with respect to their filler content were stored in artificial aging media: artificial saliva, ethanol (60%), lactic acid (pH 5) and citric acid (pH 5). Parameters (Vickers microhardness, compressive strength, elastic modulus, water sorption and solubility) were determined in their initial state (control group, n = 3 for microhardness, n = 5 for the other parameters) and after 14, 30, 90 and 180 days (n = 3 for microhardness, n = 5 for the other parameters for each composite group, time point and media). Specimens were also characterized with dynamic-mechanical-thermal analysis (compression tests, F =  ± 7 N; f = 0.5 Hz, 1 Hz and 3.3 Hz; t = 0–170 °C). Results Incorporation of fillers with more than 80 w% leads to significantly better mechanical properties under static and dynamic compression tests and a better water sorption behavior, even after chemical degradation. The influence of degradation media and time is of subordinate importance for chemical degradation. Conclusion Although the investigated composites have a similar matrix, they showed different degradation behavior. Since dentine and enamel occur only in small layer thickness, a test specimen geometry with very small dimensions is recommended for direct comparison. Moreover, the use of compression tests to determine the mechanical parameters for the development of structure-compatible and functionally adapted composites makes sense as an additional standard. Clinical relevance Preferential use of highly filled composites for occlusal fillings is recommended.

scholarly journals Efficient interfacial interaction for improving mechanical properties of polydimethylsiloxane nanocomposites filled with low content of graphene oxide nanoribbons

RSC Advances ◽  
2017 ◽  
Vol 7 (36) ◽  
pp. 22045-22053 ◽  
Author(s):  
Neng-Jian Huang ◽  
Jing Zang ◽  
Guo-Dong Zhang ◽  
Li-Zhi Guan ◽  
Shi-Neng Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Filler Content ◽  
Interfacial Interaction ◽  
Solvent Free ◽  
The Other ◽  
Graphene Oxide Nanoribbons ◽  
Free Process ◽  
Reinforcement Efficiency

GONR-filled H-t-PDMS nanocomposites were fabricated by using a facile solvent-free process, and the reinforcement efficiency of GONRs at low filler content is superior to those of the other carbon nano-fillers.

scholarly journals The Excellent Mechanical Properties of Cork: A Novel Approach through the Analysis of Contact Stress

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Antonio Díaz-Parralejo ◽  
Eduardo M. Cuerda-Correa ◽  
Antonio Macías-García ◽  
José Sánchez-González ◽  
M. Ángeles Díaz-Díez
Keyword(s):  
Mechanical Properties ◽  
Elastic Anisotropy ◽  
The Other ◽  
Homogeneous Distribution ◽  
Tangential Section ◽  
Compression Tests ◽  
Novel Approach ◽  
Indentation Tests ◽  
Cork Sample ◽  
Distribution Of Stresses

In many technological applications of cork, this biomaterial is under strongly localized contact stresses, which largely differ from the homogeneous distribution of stresses of the typical uniaxial compression tests. Indentation tests constitute an excellent form of determining the behavior of the materials under localized stresses. In the present study, the applicability of Hertzian and Brinell indentation tests to the evaluation of the mechanical properties of cork is tested. One of the main conclusions of the study is that the elastic anisotropy of the material is related to the anisotropic structure of the different sections cut from a cork sample, a clear difference between the back tangential section and the other sections being observed.

Water sorption and mechanical properties of dental composites

Biomaterials ◽  
1990 ◽  
Vol 11 (3) ◽  
pp. 219-223 ◽  
Author(s):  
C. Bastioli ◽  
G. Romano ◽  
C. Migliaresi
Keyword(s):  
Mechanical Properties ◽  
Water Sorption ◽  
Dental Composites

Mechanical Properties of Machinable Zirconia Dental Composites

2007 ◽  
Vol 336-338 ◽  
pp. 1587-1589
Author(s):  
Wen Xu Li ◽  
Hua Zhao ◽  
Ying Song ◽  
Bin Su ◽  
Fu Ping Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Calcium Phosphate ◽  
Flexural Strength ◽  
Dental Composite ◽  
The Other ◽  
Dental Composites ◽  
Composite Ceramics ◽  
Cad Cam ◽  
The Common

Ca3(PO4)2/ZrO2 dental composite ceramics using for CAD/CAM system were prepared and the effects of weak phases on microstructures and mechanical properties were studied. The results showed that intergranular spreads happened with the increasing Ca3(PO4)2 contents due to the discontinuity of weak interfaces between Zirconia and Calcium phosphate in matrix. So the flexural strength and hardness of the Ca3(PO4)2/ZrO2 composite ceramics were decreased effectively, which improved the machinability of the composites. On the other hand, strong interfaces between Zirconias increased the integrality of the ceramic structures. ZrO2 composite Ceramics with 15% Ca3(PO4)2 were sintered at 1350°C. The flexural strength is 300.44MPa, fracture toughness is 4.36 MPam1/2, and hardness is 6.69 GPa. The cutting exponent of the Ca3(PO4)2/ZrO2 composite ceramics is obviously lower than that of the common commercial Vita Mark II and Dicor MGC ceramics, which shows good mechanical properties and machinability.

Impact Compressive Fracture of Synthetic Quartz Accompanied by Electromagnetic Phenomenon

2016 ◽  
Vol 715 ◽  
pp. 13-20
Author(s):  
Hidetoshi Kobayashi ◽  
Keitaro Horikawa ◽  
Kenichi Tanigaki ◽  
Kinya Ogawa
Keyword(s):  
Mechanical Properties ◽  
Electromagnetic Waves ◽  
Dynamic Compression ◽  
Compression Tests ◽  
Ferrite Core ◽  
Static Tests ◽  
Synthetic Quartz ◽  
Loading Direction ◽  
Electromagnetic Phenomenon ◽  
The Relationship

In order to clarify the relationship between the mechanical properties of synthetic quartz and the electromagnetic phenomena during its fracture, a series of uniaxial compression tests were carried out at quasi-static and dynamic rates. Not only the stress-strain curves but also the output of ferrite-core antenna located close to the specimens were measured in a shield box made of permalloy plates. Since the synthetic quartz has three characteristic axes, i.e. optical axis, electric axis and machine axis, the effect of loading direction on the mechanical properties and electromagnetic phenomena of quarts was also examined. The dynamic compressive strength was greater than those in static tests and there is strain-rate dependence in their strength of synthetic quartz. It was also found that there are not any remarkable differences due to the loading direction with respect to the intensity of electromagnetic waves measured in the dynamic compression tests, i.e. the electromagnetic phenomenon does not depend on the loading direction.

Heat Treatment of Ultrafine Grained AA 6061 Consolidation by Equal Channel Angular Pressing

2015 ◽  
Vol 771 ◽  
pp. 252-256 ◽  
Author(s):  
Agus Pramono ◽  
Lauri Kollo ◽  
Renno Veinthal ◽  
Kaspar Kallip ◽  
Jaana Kateriina Gomon
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Equal Channel Angular Pressing ◽  
Treatment Effect ◽  
Artificial Aging ◽  
The Other ◽  
Copper Sheet ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Recent Developments

During the last decade Equal Channel Angular Pressing (ECAP) has emerged as a widely known procedure for the fabrication of ultrafine grained metals and alloys. This review examines recent developments related to the use of ECAP for grain refinement. In the current study the part of capsules wrapper for powder material to be compressed where the powder AA6061 was wrapped in copper sheet and heated at a temperature of 400 OC in hot pressed under the pressure of 400 MPa. Afterward the powder in solid condition was cooled in the air and then does analysis characterization. The sample results of AA6061 are ECAP as is and heat treatment with type Anneal and Artificial Aging (T6) where heat treatment is heated at a temperature of 530 °C for 1 h followed by heating at a temperature of 100 °C for one day and the other for heating at a temperature of 415°C for 2.5 hours followed by heating at a temperature of 177 °C for 8 hours. This paper explains the characteristics of each sample where analyses are based on the mechanism of properties to determine how much change of mechanical properties and microstructure. Heat treatment effect on grain coarsening so that the mechanical properties can be engineered.

The effect of TiO2 nanotubes reinforcement on the mechanical properties and wear resistance of silica micro-filled dental composites

2018 ◽  
Vol 53 (23) ◽  
pp. 3217-3228 ◽  
Author(s):  
Abolfazl Mirjalili ◽  
Ali Zamanian ◽  
Seyed Mohammad Mahdi Hadavi
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Flexural Strength ◽  
Water Sorption ◽  
Hydrothermal Process ◽  
Physical And Mechanical Properties ◽  
Dental Composite ◽  
Dental Composites ◽  
Dental Resin ◽  
Electron Microscopies

One of the most important aspects of dental resin composites is the ability to improve mechanical properties by adding reinforcing filler particles. TiO2 nanotubes are expected to improve the physical and mechanical properties of silica micro-filled dental composite. Therefore, TiO2 nanotubes were synthesized using an alkaline hydrothermal process and then functionalized with 3-methacryloxypropyl-trimethoxysilane. TiO2 nanotubes were characterized by scanning and transmission electron microscopies, X-ray diffraction and Fourier transform infrared spectroscopy. Different quantities of TiO2 nanotubes and silica microparticles were reinforced in bisphenol A-glycidyl methacrylate (Bis-GMA) and tri-ethylene glycol dimethacrylate to prepare dental composite samples. Thereafter, the flexural strength and modulus, compressive strength, degree of conversion of monomers, wear resistance and water sorption were utlized to examine the prepared composites. The flexural strength and wear resistance of composites with 3 wt% TiO2 nanotubes significantly increased in comparison with other composites. On the other hand, due to the stability of composite, the water sorption was decreased. Therefore, TiO2 nanotubes reinforcement could be a promising solution for the improvement of mechanical properties in dental composites.

Recycling of Waste Epoxy-Polyester Powders for Foam Production

2011 ◽  
Vol 1 (3) ◽  
pp. 10-20 ◽  
Author(s):  
Carmine Lucignano ◽  
Erica Anna Squeo ◽  
Alessandro Guglielmotti ◽  
Fabrizio Quadrini
Keyword(s):  
Mechanical Properties ◽  
Filler Content ◽  
Physical And Mechanical Properties ◽  
Industrial Applications ◽  
Compression Tests ◽  
Cold Compaction ◽  
Composite Foams ◽  
Domestic Appliances ◽  
Foam Production ◽  
Foaming Technology

This paper proposes a new foaming technology (solid-state foaming) to produce structural foams from waste thermosetting resins. The proposed technology is easy and does not require specific and expensive equipments. Solid tablets are produced by cold compaction of resin powder, and foam by heating in an oven. Composite foams can be produced by mixing fillers and resin powder before the cold compaction. In the experiment, an epoxy-polyester (EP-PE) resin powder, deriving from the waste of a manufacturer of domestic appliances, was used with montmorillonite (MMT) particles. Resulting foams with a filler content ranging from 0 to 10 wt% were characterized in terms of physical and mechanical properties (by compression tests). Although the effect of the MMT content seems to be negative for the adopted resin, the feasibility of producing composite foams by recycling waste industrial powders is shown. The properties of the unfilled foams are sufficient for many industrial applications.

Compression Tests of High Strength Steels

2008 ◽  
Vol 59 ◽  
pp. 293-298
Author(s):  
Vaclav Mentl ◽  
Josef Bystricky
Keyword(s):  
Mechanical Properties ◽  
Mechanical Testing ◽  
High Speed ◽  
Dynamic Compression ◽  
Testing Machine ◽  
High Strength Steels ◽  
High Strength ◽  
Strain Rates ◽  
Compression Tests ◽  
Impact Compression

Mathematical modelling and virtual testing of components and structures represent a useful and economic tool for design and safety assessment. The basic mechanical properties which can be found in material standards are not relevant in cases where the real service conditions differ from those applied during standardised testing. Thus e.g. mechanical behaviour at higher strain rates can be interesting for the car components when the simulation of crash situations is used during structure development. The dynamic compression tests are usually performed by means of drop towers, by means of high speed hydraulic testing machines or Hopkinson bar method. At the Mechanical Testing Laboratory of the SKODA Research Inst. in Pilsen, Czech Republic, an instrumentation of Charpy pendulum testing machine was realised in order that it was possible to perfom dynamic compression tests, [1], and the compatibility of obtained results in comparison with traditional impact compression tests was verified within the round–robin carried out by TC5 ESIS Sub-Committee on “Mechanical Testing at Intermediate Strain Rates“, [2]. A new striking tup and load measurement system were designed and callibrated. At the same time, a new software was developed which makes it possible to evaluate the test force-deformation record. The goal of this study was 1. to check the possibility of compression testing of high strength materilas by mens of Charpy pendulum, and 2. to study the strain rate influence on basic mechanical properties.

Sign in / Sign up

Export Citation Format

Share Document