Dental Implant Systems

Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities

Applications and multidisciplinary perspective on 3D printing techniques: Recent developments and future trends

In industries as diverse as automotive, aerospace, medical, energy, construction, electronics, and food, the engineering technology known as 3D printing or additive manufacturing facilitates the fabrication of rapid prototypes and the delivery of customized parts. This article explores recent advancements and emerging trends in 3D printing from a novel multidisciplinary perspective. It also provides a clear overview of the various 3D printing techniques used for producing parts and components in three dimensions. The application of these techniques in bioprinting and an up-to-date comprehensive review of their positive and negative aspects are covered, as well as the variety of materials used, with an emphasis on composites, hybrids, and smart materials. This article also provides an updated overview of 4D bioprinting technology, including biomaterial functions, bioprinting materials, and a targeted approach to various tissue engineering and regenerative medicine (TERM) applications. As a foundation for anticipated developments for TERM applications that could be useful for their successful usage in clinical settings, this article also examines present challenges and obstacles in 4D bioprinting technology. Finally, the article also outlines future regulations that will assist researchers in the manufacture of complex products and in the exploration of potential solutions to technological issues

Programme and The Book of Abstracts / Twelfth Annual Conference YUCOMAT 2010, Herceg Novi, September 6–10, 2010

The First Conference on materials science and engineering, including physics, physical chemistry, condensed matter chemistry, and technology in general, was held in September 1995, in Herceg Novi. An initiative to establish Yugoslav Materials Research Society was born at the conference and, similar to other MR societies in the world, the programme was made and objectives determined. The Yugoslav Materials Research Society (Yu-MRS), a nongovernment and non-profit scientific association, was founded in 1997 to promote multidisciplinary goal-oriented research in materials science and engineering. The main task and objective of the Society has been to encourage creativity in materials research and engineering to reach a harmonic coordination between achievements in this field in our country and analogous activities in the world with an aim to include our country into global international projects.\ud Until 2003, Conferences were held every second year and then they grew into Annual Conferences that were traditionally held in Herceg Novi in September of every year. In 2007 Yu-MRS formed two new MRS: MRS-Serbia (official successor of Yu-MRS) and MRS-Montenegro (in founding). In 2008, MRS – Serbia became a member of FEMS (Federation of European Materials Societies).\u

Nanostructural Materials with Rare Earth Ions: Synthesis, Physicochemical Characterization, Modification and Applications

This Special Issue of "Nanostructural Materials with Rare Earth Ions: Synthesis, Physicochemical Characterization, Modification and Applications" is related to studies of nanometer-sized materials doped and co-doped with rare earth ions and the creation of periodically ordered nanostructures based on single nanoparticles. A small particle size implies a high sensitivity and selectivity. These new effects and possibilities are mainly due to the quantum effects resulting from the increasing ratio of surface-to-volume atoms in low-dimensional systems. An important factor in this context is the design and fabrication of nanocomponents displaying new functionalities and characteristics for the improvement of existing materials, including photonic materials, conductive materials, polymers and biocomposites. With this concept in mind, the aim of the Special Issue is to publish research on innovative materials and their applications.Topics to be covered in this Special Issue include, but are not limited to, the following: Technology and applications of nanomaterials with rare earth ions; Advanced physicochemical properties, characterization and modification of nanomaterials with rare earth ions; Novel active materials, especially organic and inorganic materials, nanocrystalline materials, nanoceramics doped and co-doped with rare-earth ions with bio-related and emerging applications; Magnetic properties of nano-sized rare-earth compounds; Applications of nano-sized rare-earth-doped and co-doped optical materials

Advances in Understanding of Unit Operations in Non-ferrous Extractive Metallurgy 2021

Unit metallurgical operations processes are usually separated into three categories: 1) hydrometallurgy (leaching, mixing, neutralization, precipitation, cementation, and crystallization); 2) pyrometallurgy (roasting and smelting); and 3) electrometallurgy (aqueous electrolysis and molten salt electrolysis). In hydrometallurgy, the aimed metal is first transferred from ores and concentrates to a solution using a selective dissolution (leaching or dry digestion) under an atmospheric pressure below 100 °C and under a high pressure (40-50 bar) and high temperature (below 270°C) in an autoclave. The purification of the obtained solution was performed using neutralization agents such as sodium hydroxide and calcium carbonate or more selective precipitation agents such as sodium carbonate and oxalic acid. The separation of metals is possible using a liquid/liquid process (solvent extraction in mixer-settler) and solid–liquid (filtration in filter-press under high pressure). Crystallization is the process by which a metallic compound is converted from a liquid into a solid crystalline state via a supersaturated solution. The final step is metal production using electrochemical methods (aqueous electrolysis for basic metals such as copper, zinc, silver, and molten salt electrolysis for rare earth elements and aluminum). Advanced processes, such as ultrasonic spray pyrolysis and microwave-assisted leaching, can be combined with reduction processes in order to produce metallic powders

Design and development of low elastic modulus Ti-Nb-Zr alloys for biomedical applications

The demand for implants has been increasing globally due to the rising population of the older people (aged ≥80 years), bone diseases, e.g., bone cancers, congenital disabilities, birth defects, revision needs, and accidents. It is essential to select both biologically and mechanically compatible implant materials for such applications. The commonly used implant materials today are austenitic stainless-steel alloys, Co–Cr alloys, Ti, Ta, and their alloys. Recently zirconium (Zr) alloys for biomedical applications are receiving increasing attention due to their two unique properties: 1) the formation of an intrinsic bonelike apatite layer on their surfaces in body environments, and 2) better compatibility with magnetic resonance imaging (MRI) diagnostics due to their intrinsically low magnetic susceptibility, as well as their overall excellent biocompatibility, mechanical properties, and bio-corrosion resistance. In particular, since both of the MRI quality and speed depend on magnetic field strength, there is a compelling drive for the use of high magnetic field strength (>3 Tesla) MRI systems. This requires the availability of implant alloys that can offer much lower susceptibility than the current Ti implant alloys. In that regard, Zr-based alloys offer more promise than Ti-based alloys. This thesis first presents a comprehensive review of the characteristics of commercially pure (CP) Zr and Zr-based alloys as potential orthopaedic and dental implant materials. These include their 1) phase transformations; 2) unique properties including corrosion resistance, biocompatibility, magnetic susceptibility, shape memory effect, and super-elasticity; 3) mechanical properties; 4) current orthopaedic and dental applications, and; 5) the d-electron theory for Zr alloy design and novel Zr-alloys, and 6) future directions for extending the use of Zr-alloys as orthopaedic and dental implants are discussed. Then following a detailed analysis of the design methods for low elastic modulus Ti alloys, the d-electron theory and the ⁄ ratio approach are used together to design nine strong, ductile, and low elastic modulus Ti-Nb-Zr alloys. Among them, five are Zr-based Ti-Nb-Zr alloys, and four are Tibased Ti-Nb-Zr alloys. To assess Ti-Nb-Zr alloys, it is important to understand the influence of Zr on the β-phase stability of Ti-Nb-Zr alloys. The concept of the Mo equivalence (MoEq), proposed by Molchanova (Phase Diagrams of Titanium Alloys, 1965), has been commonly used as a general guideline to gauge the stability of a β-Ti alloy. A critical literature review has shown that all four existing Mo-Eq expressions deviate substantially from experimental observations and the well-established d-electron theory in predicting the β-phase stability of Ti-Nb-Zr alloys. The reasons are that existing Mo-Eq expressions either completely neglect or significantly overestimate the β-stabilizing effect of Zr. In this thesis, a new Mo-Eq expression, i.e., (Mo-Eq) Ti-Nb-Zr = 0.238Nb (wt.%) + 0.11Zr (wt.%) + 0.97, has been defined for Ti-Nb-Zr alloys in order to properly address the β-stabilizing effect of Zr. This new Mo-Eq expression shows good consistency with both experimental observations and the d-electron theory in predicting the β-phase stability of various Ti-Nb-Zr alloys. With necessary modifications, the approach developed is expected to be also applicable to the assessment of the β-phase stability in other Zr-containing Ti alloys. Three different methods: tension, compression, and ultrasonic tests, are used to determine the elastic modulus of the five Zr-Ti-Nb alloys (Zr-45Ti-15Nb, Zr-33Ti-15Nb, Zr-28Ti-15Nb, Zr-35Ti-10Nb, and Zr-30Ti-20Nb, in at.%) alloys. The as-cast tensile, compressive and ultrasonic elastic moduli of these alloys range from 58-79GPa, 45-57GPa and 60-95GPa respectively. The two Zr-Ti-Nb alloys (Zr-based Ti-6Nb-53Zr and Ti-18Nb-51Zr) from the literature, which reportedly have the lowest elastic moduli, are prepared and tested for comparison as a point of reference. The dependence of elastic moduli on the test methods, phase constitutes as well as and ⁄ ratio is systematically investigated. The reassessed Mo-Eq. values change linearly with the ⁄ ratio for the above seven alloys. The current work also indicates that a small amount of the ω-phase along with β and α″-phases, and the condition of ⁄ ≈ 4.15, can lead to low elastic modulus for Zr-Ti-Nb alloys. Therefore, a modified relationship between the phases and the elastic modulus has been suggested, which is: Eα″ < 40 GPa < Eβ ≈ 60-90 GPa < Eα ≈ 100 GPa < Eω ≈ 130-220 GPa. This study identifies that as-cast Zr-28Ti-15Nb and Zr-33Ti-15Nb alloys can offer low elastic modulus (~60 GPa, tensile and ultrasonic), excellent tensile ductility (~16%), uniform plastic strain (greater than 10%) and sufficiently high tensile yield strength (~650 MPa) for implant applications. While designing the Zr-Ti-Nb alloys, this thesis author realized that Ti-Nb-Zr alloys could also offer low elastic modulus. As a result, four new Ti-Nb-Zr alloys (Ti-26Zr-10Nb, Ti25Zr-15Nb, Ti-22Zr-15Nb, and Ti-21Zr-20Nb) are designed by the d-electron theory and ⁄ ratio. The as-cast tensile, compressive and ultrasonic elastic moduli of these alloys are in the range of 58-71GPa, 34-60GPa and 52-83GPa respectively. The effects of alloying elements on microstructures, mechanical properties i.e. tensile strength, yield strength, compressive yield strength, elastic modulus, elastic energy, and microhardness of these newly designed alloys have been investigated. Ti-Nb-Zr alloys also show the linear relationship between MoEq values and ⁄ ratio. The results also confirm that a small amount of ω-phase is not clearly detrimental in reducing the elastic modulus along with β and α″-phase. Therefore, the results from Ti-Nb-Zr alloys strongly agree with the above proposed relationship sequence between the phases and the elastic modulus for Zr-Ti-Nb alloys

Biomedical Engineering

Biomedical engineering is currently relatively wide scientific area which has been constantly bringing innovations with an objective to support and improve all areas of medicine such as therapy, diagnostics and rehabilitation. It holds a strong position also in natural and biological sciences. In the terms of application, biomedical engineering is present at almost all technical universities where some of them are targeted for the research and development in this area. The presented book brings chosen outputs and results of research and development tasks, often supported by important world or European framework programs or grant agencies. The knowledge and findings from the area of biomaterials, bioelectronics, bioinformatics, biomedical devices and tools or computer support in the processes of diagnostics and therapy are defined in a way that they bring both basic information to a reader and also specific outputs with a possible further use in research and development

Shape memory effect of nano-ferromagnetic particle doped NiTi for orthopedic devices and rehabilitation techniques

© 2017 IEEE. This paper introduces a novel shape memory alloy (SMA) material for the controllability in the shape recovery of traditional SMA for orthopedic devices and rehabilitation techniques. The proposed material is formed by doping nano-ferromagnetic particle into porous NiTi alloy. The finite element analysis of shape memory effect property of the different distribution of nano-ferromagnetic particle is done and compared for same load and boundary conditions. The comparative analysis of the percentage change in volume deformation when load is released (for 2nd step) shows an average of 2.55 % with standard deviation of 1.69 whereas on thermal loading (for 3rd step) shows an average of 94.94% with standard deviation of 7.75 for all heterogeneous distribution of nano-particles in porous NiTi alloy. Our findings are, all the different conditions of heterogeneous distributions of nano-ferromagnetic particle doped NiTi alloy exhibits its inherent SME property

Shape memory effect of nano-ferromagnetic particle doped NiTi for orthopedic devices and rehabilitation techniques

This paper introduces a novel shape memory alloy (SMA) material for the controllability in the shape recovery of traditional SMA for orthopedic devices and rehabilitation techniques. The proposed material is formed by doping nano-ferromagnetic particle into porous NiTi alloy. The finite element analysis of shape memory effect property of the different distribution of nano-ferromagnetic particle is done and compared for same load and boundary conditions. The comparative analysis of the percentage change in volume deformation when load is released (for 2 nd step) shows an average of 2.55 % with standard deviation of 1.69 whereas on thermal loading (for 3 rd step) shows an average of 94.94% with standard deviation of 7.75 for all heterogeneous distribution of nano-particles in porous NiTi alloy. Our findings are, all the different conditions of heterogeneous distributions of nano-ferromagnetic particle doped NiTi alloy exhibits its inherent SME property