Optimization of the Manufacturing Process by Molding Cobalt-Chrome Alloys in Assembled Dental Frameworks

In oral rehabilitation, the treatment of partial edentulism (PEd) is performed by removable partial dentures (RPD) or assembled prosthetic works (APW) composed of several components, fixed to the prosthetic field (Pa) and a removable one (Pb), in order to facilitate the daily hygiene but also the damping of the occlusal forces applied in mastication. Cobalt-Chromium alloys are materials used to manufacture modern prosthetic assembles. In order for this study to be relevant, it was necessary to standardize the design of the framework (Pa) in terms of shape and volume so that the experiment could be reproducible for the five Co-Cr alloys: 0-A (Co-Cr-Mo), 5-A and 10-A (Co-Cr-Mo-W), 15-A and 16.4-A (Co-Cr-W-Fe) and for the three fabrication methods of dental assembled prosthetic frameworks: refractory duplicate method (RD) resulting removable framework (Pb), direct construction method (DC) resulting removable framework (Pb-) and casting over metal method (CoM) resulting removable framework (Pb+). The time allocated to the adaptation process (AP), mechanical processing and sandblasting, in order to assemble the two components was between 43–70 min, even though the assembly between the Pa-framework and the complementary framework (Pb+) was not necessary, CoM-method hs been provide the elimination of AP step. By applying the arithmetic simple rule of three, the percentages for each of the three methods used were calculated, the values of the difference were obtained. The CoM method improves the joining precision between the components of the removable assembly of prosthetic frameworks by 91.7% compared to the RD method and by 80.62% compared to the DC method. According to the efficiency of the methods used in the precision of joining between frameworks components, their order is: casting over metal, direct construction and refractory duplicate method.

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Comparative Study of the Biomechanics of Materials Used in Stenting

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.188.76 ◽

2012 ◽

Vol 188 ◽

pp. 76-81 ◽

Cited By ~ 1

Author(s):

Angelica Enkelhardt ◽

Cristian Sorin Nes ◽

Nicolae Faur

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

Strain Curve ◽

Elastic Behavior ◽

High Price ◽

Cobalt Chromium ◽

Stainless Steel 316L ◽

Chromium Alloys ◽

Materials Used ◽

High Flexibility

This paper presents a comparative bibliographic study of different materials with elevated biomechanical biocompatibility regarding the stent-blood vessel interaction. Only the materials used in coronary stents’ manufacturing are considered: stainless-steel (316L), Cobalt-Chromium alloys (CoCrMo, CoNiCrMo), Nickel-Titanium alloys (Nitinol), Tantalum. The main characteristics that result from the stress-strain curve of each material are presented, as well as the biocompatibility and durability. The stainless-steel has good mechanical properties, excellent biocompatibility and low price. Cobalt-Chromium alloys have excellent mechanical properties, excellent biocompatibility, acceptable shape memory properties, but high density and low flexibility. The Nitinol represents the best choice, with excellent mechanical properties, excellent biocompatibility, good corrosion resistance, high flexibility (super-elastic behavior), low density, but high price. Tantalum alloys present the best biocompatibility and high flexibility, but the mechanical properties are relative modest.

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MODERN MATERIALS FOR IMPLANTS USED IN THE TREATMENT OF DOGS WITH WOBBLER SYNDROME

Scientific Notes Kazan Bauman State Academy of Veterinary Medicine ◽

10.31588/2413-4201-1883-248-4-123-128 ◽

2021 ◽

Vol 248 (4) ◽

pp. 123-128

Author(s):

N.A. Kozlov ◽

◽

A.A. Kholopova ◽

◽

Keyword(s):

Stainless Steel ◽

Cervical Spinal Cord ◽

Neurological Deficits ◽

Cobalt Chromium ◽

Static Compression ◽

Advantages And Disadvantages ◽

Wobbler Syndrome ◽

Chromium Alloys ◽

Innovative Materials ◽

Materials Used

Wobbler's syndrome or caudal cervical spondylomyelopathy is a disease of the cervical spine in dogs of large and giant breeds, characterized by dynamic or static compression of the cervical spinal cord and nerve roots, which leads to neurological deficits and neck pain. Currently, there are many materials for the manufacture of various implants, as well as prosthetic discs, which are successfully used in the treatment of dogs with Wobbler syndrome, but veterinary neurologists have certain dissatisfaction with the results of surgical treatment, as a result of which a number of postoperative complications are noted. This makes it necessary to use new materials for the manufacture of implants. Currently, the vast majority of veterinary specialists use only titanium and stainless steel alloys (304V and 316LVM) as a material for cages, screws and plates. However, a number of shortcomings of these materials indicate the need for a search new innovative materials with improved characteristics. Currently, the materials used for the manufacture of implants in human medicine are of great interest, but have not yet found application in veterinary medicine (with the exception of stainless steel and titanium alloys). Among such materials are polyether etherketone (PEEK), carbon fiber reinforced polyether etherketone (CFR-PEEK), cobalt-chromium alloys, nitinol, tantalum. The article reflects the characteristics of these materials for the manufacture of implants, their advantages and disadvantages.

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CHARACTERISTICS OF METAL ALLOYS PROPERTIES FOR DENTAL CASTING AFTER THEIR REPEATED REMELTING

Wiadomości Lekarskie ◽

10.36740/wlek202110111 ◽

2021 ◽

Vol 74 (10) ◽

pp. 2423-2427

Author(s):

Petro A. Hasiuk ◽

Viktor Kindiy ◽

Volodymyr Radchuk ◽

Dmytro Kindiy ◽

Tetiana Dzetsiukh ◽

...

Keyword(s):

Tensile Deformation ◽

Experimental Studies ◽

Physical And Mechanical Properties ◽

Cost Effective ◽

Biologically Active ◽

Quantitative Composition ◽

Cobalt Chromium ◽

Nickel Chromium ◽

Chromium Alloys ◽

Materials Used

The aim: To study clinical and experimental substantiation of the possibility of using cobalt-chromium and nickel-chromium alloys after repeated remelting for non-removable one-piece prosthetics. Materials and methods: Experimental studies of Remanium GM 700 and Remanium CSe dental alloys have been carried out. To study the physical and mechanical properties of alloys, samples were obtained by sequential six-fold remelting in a Tiegelschleuder TS casting dental unit manufactured by Degussa. All samples were subjected to chemical analysis and metallographic studies by methods generally known in metallurgy, which included studies of microhardness, elasticity, tensile deformation, bending deformation and alloy structure after repeated remelting. Results: Thus, the obtained results of the chemical, physicomechanical and structural properties of the remelts indicate that the Remanium GM 700 and Remanium СSe alloys can be reused many times for the manufacture of one-piece orthopedic structures in that they are identical with certified alloys. Conclusions: In terms of structure, qualitative and quantitative composition of elements, physical and technological properties, the Remanium GM 700 and Remanium CSe alloys have been repeatedly remelted meet the requirements of materials used in biologically active environments of the patient’s body. High-quality and cost-effective remelted multiple times Remanium GM 700 and Remanium CSe alloys can be recommended for use in practical prosthetic dentistry six times.

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Study on the strength of glued laminated timber beams with round holes: difference in structural performance between homogeneous-grade and heterogeneous-grade timber

Journal of Wood Science ◽

10.1186/s10086-021-01941-3 ◽

2021 ◽

Vol 67 (1) ◽

Author(s):

Shigefumi Okamoto ◽

Nobuhiko Akiyama ◽

Yasuhiro Araki ◽

Kenji Aoki ◽

Masahiro Inayama

Keyword(s):

Scots Pine ◽

Maximum Shear Stress ◽

Material Strength ◽

Laminated Beams ◽

Strength Grade ◽

Glued Laminated Timber ◽

The Difference ◽

Materials Used ◽

Beam Height ◽

Timber Beams

AbstractVarious design codes and design proposals have been proposed for glued laminated timber beams with round holes, assuming that the entire beam is composed of homogeneous-grade timber. However, in Japan, glued laminated timber composed of homogeneous-grade timber is rarely used for beams. In this study, the difference in the load-bearing capacity of glued laminated beams composed of homogeneous-grade timber and heterogeneous-grade timber with round holes when fractured by cracking was investigated experimentally and analytically. The materials used in the tests were glued laminated beams composed of homogeneous-grade Scots pine timber with a strength grade of E105-F345 and heterogeneous-grade Scots pine timber with a strength grade of E105-F300. Experiments confirmed that although the glued laminated beams composed of heterogeneous-grade timber have a lower material strength in the lamina with holes, its resistance to fracturing due to cracks associated with the holes is almost the same as that of the glued laminated beams composed of homogeneous-grade timber. The stresses acting on the holes in the laminated timber with holes of less than half the beam height were lower in the glued laminated beams composed of heterogeneous-grade timber than in the glued laminated beams composed of homogeneous-grade timber. The ratio of the stresses was found to be approximately equal to the ratio of the maximum bending stress or the maximum shear stress acting on the inner layer lamina, as determined by Bernoulli–Euler theory.

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Processing Development and Properties of Cobalt-Chromium Alloys Fabricated by Traditional Method

Materials Today Proceedings ◽

10.1016/j.matpr.2020.04.627 ◽

2021 ◽

Vol 43 ◽

pp. 2629-2634

Author(s):

Wanwilai Vittayakorn ◽

Phieraya Poolphol ◽

Kantapon Aimprakod ◽

Tosapol Maluangnont

Keyword(s):

Traditional Method ◽

Cobalt Chromium ◽

Chromium Alloys

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Influence of loading rates on mechanical properties of cobalt-chromium alloys

BDJ ◽

10.1038/sj.bdj.4803441 ◽

1975 ◽

Vol 138 (8) ◽

pp. 295-298 ◽

Cited By ~ 2

Author(s):

M H Reisbick ◽

A A Caputo

Keyword(s):

Mechanical Properties ◽

Cobalt Chromium ◽

Loading Rates ◽

Chromium Alloys

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Cobalt-chromium alloys in dentistry: An evaluation of metal ion release

Journal of Prosthetic Dentistry ◽

10.1016/j.prosdent.2015.03.002 ◽

2015 ◽

Vol 114 (4) ◽

pp. 602-608 ◽

Cited By ~ 19

Author(s):

Maria Claudia Lucchetti ◽

Giovanni Fratto ◽

Federica Valeriani ◽

Elisabetta De Vittori ◽

Saverio Giampaoli ◽

...

Keyword(s):

Metal Ion ◽

Cobalt Chromium ◽

Ion Release ◽

Chromium Alloys ◽

Metal Ion Release

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Cobalt-chromium alloys in fixed prosthodontics in Sweden

Acta Biomaterialia Odontologica Scandinavica ◽

10.1080/23337931.2017.1360776 ◽

2017 ◽

Vol 3 (1) ◽

pp. 53-62 ◽

Cited By ~ 8

Author(s):

Maria Kassapidou ◽

Victoria Franke Stenport ◽

Lars Hjalmarsson ◽

Carina B. Johansson

Keyword(s):

Cobalt Chromium ◽

Fixed Prosthodontics ◽

Chromium Alloys

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Effect of recasting on the elastic modulus of metal-ceramic systems from nickel-chromium and cobalt-chromium alloys

Vojnosanitetski pregled ◽

10.2298/vsp0707469m ◽

2007 ◽

Vol 64 (7) ◽

pp. 469-473 ◽

Cited By ~ 4

Author(s):

Nemanja Mirkovic

Keyword(s):

Elastic Modulus ◽

Testing Machine ◽

Fracture Load ◽

Bending Test ◽

Chromium Alloy ◽

Cobalt Chromium ◽

Nickel Chromium ◽

Ceramic Samples ◽

Chromium Alloys ◽

Metal Ceramic

Background/Aim. Elastic modulus of metal-ceramic systems determines their flexural strength and prevents damages on ceramics during mastication. Recycling of basic alloys is often a clinical practice, despite the possible effects on the quality of the future metal-ceramic dentures. This research was done to establish recasting effects of nickel-chromium and cobalt-chromium alloys on the elastic modulus of metalceramic systems in making fixed partial dentures. Methods. The research was performed as an experimental study. Six metal-ceramic samples of nickel-chromium alloy (Wiron 99) and cobalt-chromium alloy (Wirobond C) were made. Alloy residues were recycled through twelve casting generations with the addition of 50% of new alloy on the occasion of every recasting. Three- point bending test was used to determine elastic modulus, recommended by the standard ISO 9693:1999. Fracture load for damaging ceramic layer was recorded on the universal testing machine (Zwick, type 1464), with the speed of 0,05 mm/min. Results. The results of this research revealed significant differences between elasticity modules of metal-ceramic samples in every examined recycle generation. Recasting had negative effect on the elastic modulus of the examined alloys. This research showed the slight linear reduction of elastic modulus up to the 6th generation of recycling. After the 6th recycling there was a sudden fall of elastic modulus. Conclusion. Recasting of nickelchromium and cobalt-chromium alloys is not recommended because of the reduced elastic modulus of these alloys. Instead of reusing previously recasted alloys, the alloy residues should be returned to the manufacturer. .

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