Study of Ti-Enriched CoCrMo Alloy for Dental Application

Metallic materials can be considered to be in a peculiar position for production of medical devices, because of their attractive properties. In this paper, a new enriched Co-based composition is proposed for dental application, starting from a conventional CoCrMo alloy. Macrostructural and microstructural investigations, mechanical and corrosion resistance evaluation, and metal ions release are carried out. The best composition, among the studied alloys, is identified for dental purpose

Multidisciplinary investigations on the use of TiNb alloy orthopedic device equipped with low profile antenna as smart sensor

In this paper, a new complex medical device is proposed using TiNb based metallic alloy, acting also as a ground plane for a low profile printed antenna sited on a Polydimethylsiloxane (PDMS) substrate. The first step of the research is oriented on the experimental study of the properties of TiNb based alloy and on the development of the orthopedic device. The second step is focalized on the electromagnetic characterization of the implanted printed antennas. The resulting smart orthopedic device incorporating the antenna and when embedded in a body environment is numerically analyzed from communication point of view. In particular, the radiation characteristics, necessary for the calculation of the link budget when the device is used for communication with the external to the body receiver is considered. Such scenario finds its applications in monitoring some vital human functions for example in post chirurgical rehabilitation or other long-term surveys

Mutual Coupling Reduction Between Implanted Microstrip Antennas on a Cylindrical Bio-Metallic Ground Plane

The mutual coupling between two antennas within a human body model is studied. Our multilayer cylindrical body model includes highly lossy body tissues under which a biocompatible metal implant is inserted. This cylindrical bio-metal implant serves as the common ground plane for the conformal antennas. The mutual coupling between two such conformal microstrip antennas is studied and quantified for different spacing between them. Three methods are proposed to reduce mutual coupling between the two antennas. Each of them are investigated in details and their effectiveness is compared

Up-to-Date Knowledge and Outlooks for the Use of Metallic Biomaterials: Review Paper

In all cases, when a material has to be used in medical applications, the knowledge of its physical, chemical and biological properties is of fundamental significance, since the direct contact between the biological system and the considered device could generate reactions whose long-term effects must be clearly quantified. The class of materials that exhibits characteristics that allow their use for the considered applications are commonly called biomaterials. Patients suffering from different diseases generate a great demand for real therapies, where the use of biomaterials are mandatory. Commonly, metallic biomaterials are used because their structural functions; the high strength and resistance to fracture they can offer, provide reliable performance primarily in the fields of orthopedics and dentistry. In metals, because of their particular structure, plastic deformation takes place easier, inducing good formability in manufacturing. The present paper is not encyclopaedic, but reports in the first part some current literature data and perspectives about the possibility of use different class of metallic materials for medical applications, while the second part recalls some results of the current research in this field carried out by the authors

Multidisciplinary investigations on the use of TiNb alloy orthopedic device equipped with low profile antenna as smart sensor

Abstract In this paper, a new complex medical device is proposed using TiNb based metallic alloy, acting also as a ground plane for a low profile printed antenna sited on a Polydimethylsiloxane (PDMS) substrate. The first step of the research is oriented on the experimental study of the properties of TiNb based alloy and on the development of the orthopedic device. The second step is focalized on the electromagnetic characterization of the implanted printed antennas. The resulting smart orthopedic device incorporating the antenna and when embedded in a body environment is numerically analyzed from communication point of view. In particular, the radiation characteristics, necessary for the calculation of the link budget when the device is used for communication with the external to the body receiver is considered. Such scenario finds its applications in monitoring some vital human functions for example in post chirurgical rehabilitation or other long-term surveys

Atomic layer deposition of conformal silver as an ultra-thin anti-microbial coating for orthopaedic implants

The controlled deposition of ultra-thin conformal silver nanoparticle films is of interest for applications including anti-microbial surfaces, plasmonics, catalysts and sensors. Although various techniques can produce silver films, only a limited number of techniques can offer highly conformal ultra-thin coatings on high aspect ratio surfaces and complex geometries, together with sub-nanometre control and scalability. Here we develop a self-limiting atomic layer deposition (ALD) process for the deposition of conformal metallic silver nanoparticle films. In this study, silver films have been deposited using direct liquid injection thermal ALD with ((hexafluoroacetylacetonato) silver (I) (1,5-cyclooctadiene)) as the metal source. The ALD process has been compared and contrasted by using propan-1-ol as a co-reactant with the ALD process using tertiary butyl hydrazine as a co-reactant. A narrow ALD temperature window between 123 and 128 °C is identified for the propan-1-ol process with a nominal mass deposition rate of ~17.5 ng/cm2/cycle. The ALD reaction mechanisms have been elucidated using in-situ quartz crystal microbalance (QCM) measurements, showing chemisorption of the silver precursor, followed by heterogeneous catalytic dehydrogenation of the alcohol to form metallic silver and an aldehyde. A significantly wider temperature window between 105 and 128 °C (23 °C) is identified for the hydrazine based process with a nominal mass deposition rate of ~20.2 ng/cm2/cycle (a nominal growth rate of 0.18 Å/cycle). The effects of temperature, co-reactant dose and cycle number on the deposition rate and on the physico- chemical and electrical properties of the films have been systematically investigated. Under self- limiting conditions, films grown using propan-1-ol are non-conductive metallic silver with a nano- textured surface topography. The size distribution of nanoparticles is narrow under ALD conditions and the number of ALD cycles can be used to accurately control nanoparticle sizes up until neighbouring particles begin to merge. The hydrazine based process produces less textured, more film like coatings. The films are found to be metallic silver and are electrically conductive. Also, better surface adhesion was achieved with scotch tape test in hydrazine based process compared with propan-1-ol. Silver is the most favourable metal for antimicrobial coatings due to its excellent antimicrobial activity against a wide range of microorganisms including inhibition of bacterial adhesion, broad anti-bacterial spectrum, and its tendency for being less prone to the increase of bacteria resistance compared to antibiotic. The need for artificial implants has raised due to aging populations and obesity and resulted in the number of implant-related infections. These infections result in the implant failure, revision surgeries, pain for the patients, more hospitalisation time and also hugely increase the financial burden on health services. One of the major bacteria associated with joint replacement complications is Staphylococcus epidermidis, having strong biofilm forming capabilities in deep wounds and on prostheses. In order to inhibit biofilm formation on surfaces of implants we developed 3D titanium structures using the selective laser melting technique and subsequently coated them with an ultra-thin conformal layer of metallic silver nanoparticles using (ALD). Silver coated implants showed high antimicrobial effect on S. epidermidis by reducing it up to 2-log fold. Ultrastructural examination of human fibroblasts (HS27), keratinocytes (HaCaT), endothelium (HMVEC and HUVEC) and bone (SAOS2) cells showed robust growth on both silver coated and control Titanium implant surfaces. The study shows that a nano-layer of silver coated SLM manufactured titanium implants have significant effect in reducing the pathogenic biofilm formation while retaining their biocompatible properties, making these surface-modified implants promising candidates for clinical orthopaedic applications