In: Science

Submitted By relicpassion
Words 4775
Pages 20

Biomaterials 28 (2007) 2908–2914

2D mapping of texture and lattice parameters of dental enamel
Maisoon Al-Jawada,Ã, Axel Steuwerb, Susan H. Kilcoynec, Roger C. Shorea, Robert Cywinskid, David J. Wooda a Leeds Dental Institute, University of Leeds, Leeds, LS2 9LU, UK FaME38 at the ILL-ESRF, 6 rue J Horowitz, 38042 Grenoble, France c Institute for Materials Research, University of Salford, Salford, M5 4WT, UK d School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK b

Received 19 December 2006; accepted 16 February 2007 Available online 25 February 2007

Abstract We have used synchrotron X-ray diffraction to study the texture and the change in lattice parameter as a function of position in a cross section of human dental enamel. Our study is the first to map changes in preferred orientation and lattice parameter as a function of position within enamel across a whole tooth section with such high resolution. Synchrotron X-ray diffraction with a micro-focused beam spot was used to collect two-dimensional (2D) diffraction images at 150 mm spatial resolution over the entire tooth crown. Contour maps of the texture and lattice parameter distribution of the hydroxyapatite phase were produced from Rietveld refinement of diffraction patterns generated by azimuthally sectioning and integrating the 2D images. The 002 Debye ring showed the largest variation in intensity. This variation is indicative of preferred orientation. Areas of high crystallite alignment on the tooth cusps match the expected biting surfaces. Additionally we found a large variation in lattice parameter when travelling from the enamel surface to the enameldentine junction. We believe this to be due to a change in the chemical composition within the tooth. The results provide a new insight on the texture and lattice parameter…...

Similar Documents


...also sees two other developments for metal- and ceramic-based coatings coming to the forefront in the near future. "Primary deposition technologies are PVD, PaCVD and CVD with PVD being currently used to deposit TiN (titanium nitride) on implants for patients with alloy sensitivity issues, currently used widely in Europe. A more recent introduction is a device coated with a multilayer coating, top layer being ZrN (zirconium nitride); addresses both wear and alloy sensitivity," he said. Advances in BioCeramic coatings for spine implant applications also will have a major impact to improve wear and eliminate current issues for MRI imaging that are produced by alloys such as CoCr, he said. "Ti (titanium is an excellent alternative biomaterial, but its wear properties are poor; hence, the need for a BioCeramic coating. The unique properties of IonBond's exclusive Medthin-Diamond (ADLC) has demonstrated positive performance results with cervical discs, for example." The Application OF Bioceramics IN Medical Implants The development of bioceramics fulfils a unique function as biomedical materials and built-up techniques that has broaden the diversity of medical implants application within the human body. “They are active materials. Once implanted in the patient, they interact with the surrounding fluids, and while they are being gradually absorbed by the body, they promote bone regeneration, acting only as an initial scaffold for the new bone.” Andres (2007:26) quotes......

Words: 5263 - Pages: 22

University Gkss Germay

...Association of German Research Centres (HGF). With its approximately 800 employees it undertakes, in collaboration with universities and industry, research and development in the areas of coastal research, materials research, regenerative medicine, and structure research with neutrons and synchrotron radiation. The Centre for Biomaterial Development of the Institute of Polymer Research of the GKSS in Teltow offers a PhD Student Position - Code-No. 2009/PB 10 in the fields of Polymer Science and Pharmaceutical Technology for activities in a DFG funded project on new applications of shape-memory polymers. The position will be for three years. You will investigate new capabilities of shape-memory polymers as drug carriers in the field of Pharmaceutical Technology. You will be responsible for the benchwork including polymer synthesis and comprehensive polymer characterization as well as analysis of the properties such as the thermomechanical behaviour of polymer-based drug carriers. Moreover, depending on your personal interest, there will be the opportunity to extent your personal expertise and to participate in the preparation of drug carriers or the biomaterial characterization in cell studies after training by experts in the respective fields. Furthermore, you will actively participate in the publication of the results and the preparation of patent applications. You have a strong background in both polymer and organic chemistry with a Diploma or Master in chemistry with a......

Words: 492 - Pages: 2


...billion and Japan 750 million dollars.[3] Nanotechnology as defined by size is naturally very broad, including fields of science as diverse as surface science, organic chemistry, molecular biology, semiconductor physics, microfabrication, etc.[4] The associated research and applications are equally diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly, from developing new materials with dimensions on the nanoscale to direct control of matter on the atomic scale. Scientists currently debate the future implications of nanotechnology. Nanotechnology may be able to create many new materials and devices with a vast range of applications, such as in medicine, electronics, biomaterials and energy production. On the other hand, nanotechnology raises many of the same issues as any new technology, including concerns about the toxicity and environmental impact of nanomaterials,[5] and their potential effects on global economics, as well as speculation about various doomsday scenarios. These concerns have led to a debate among advocacy groups and governments on whether special regulation of nanotechnology is warranted....

Words: 377 - Pages: 2


...industry of choice selected for this week analysis is: Biomaterials industry. Biomaterials are used in the manufacturing of medical devices, thus making them biocompatible, accepted by the human tissue without interaction, in other words inert. Biomaterials are either synthetic in nature or natural origin. Biomaterials applications cover a variety of diseases treatments such as: cardiovascular, dental, tissue damage, bone cancer, orthopedic surgeries. Examples of safe, reliable and affordable biomaterials are: ceramics, metals, polymers and biomaterials derived from natural origin. Metals and polymers are the fastest growing segments due to the increase demand in implant procedures. The biomaterials market is segmented based on the types of materials and their applications. The major driving force behind this industry is the changes in technologies. The biomaterials market invites innovators, however extensive research is necessary to introduce a superior product at competitive prices (thus not an easy entry). Another influencing factor is the regulations that need to be streamlined which in turn can lead to the development of the new and improved products, new opportunities in the application areas and potentially boost the market size. The need for cooperation between the materials suppliers and the manufactures of medical implants is required in order to achieve major developments (paired economies of scale). Biomaterials products are expensive; an improvement......

Words: 773 - Pages: 4


...Although sophisticated medical technology is already available in health systems in developed countries, further advances are constantly being made. As a result of the addition of medical nanotechnology to existing knowledge of molecular and cellular biology, it seems likely that new, more personalised, more accurate and more rapid diagnostic techniques will be devised in the future, as well as new treatments that are also more personalised and promote regeneration of the organism. Clearly, as areas of research such as biomaterials or tissue engineering are developed for use in regenerative medicine, the range of opportunities will increase dramatically. Josep Anton Planell, the director of the Institute for Bioengineering of Catalonia (IBEC), which was formed by the UB, the UPC and the Generalitat (Government of Catalonia) and has its headquarters in Barcelona Science Park, considers that “in the future, it will be possible to design intelligent biomaterials that, when placed where damaged tissue needs to be regenerated, will be able to stimulate the stem cells to do what we want them to do”. However, more knowledge is needed to perfect the process. He states, “We are beginning to understand which biochemical, biophysical or mechanical signals activate cells to regenerate tissue. To be able to intervene, therefore, we first need to be able to quantify and assess the signals that generate the cell response and form a language.” These processes occur at the molecular level......

Words: 1133 - Pages: 5

Non.Cytotoxic Antibacterial Silver Coumarin

...coating had the highest antibiofilm property. XPS confirmed the presence of silver in the nanoparticulate state (Ag0 ) at the coating surface where it remained after 4 days of exposure to bacterial culture. Comparative cytotoxicity studies revealed that the Ag-complex coatings were less toxic than the AgN coating. Thus, it can be concluded that a sol–gel matrix with Ag–coumarin complexes may provide non-toxic surfaces with antibacterial properties. © 2012 Elsevier B.V. All rights reserved. Article history: Received 29 May 2012 Received in revised form 27 July 2012 Accepted 31 July 2012 Available online 16 August 2012 Keywords: Antibacterial Cytotoxicity Ag–coumarin complexes Surface coating 1. Introduction A critical problem facing the biomaterials sector is how to retard bacterial growth and prevent biofilm formation on susceptible surfaces. Bacteria can adhere to surfaces, multiply and form a compact biofilm matrix, which protects the underlying bacteria from the action of antibiotics, antibacterial agents and host defence mechanisms. If this occurs with biomedical devices, such as prosthetic implants and catheters, it can result in serious infection, leading to implant failure [1,2]. The risk of this occurring can be reduced by the biomedical devices having antimicrobial surfaces in the form of treatments or coatings which prevent microbe adhesion and proliferation [3]. For such applications, coatings need to combine antibacterial efficacy and low toxicity to eukaryotic......

Words: 6951 - Pages: 28


...1.2 INTRODUCTION TO BIOMATERIALS There is a necessity for replacing bone substance which has been lost due to traumatic or nontraumatic events. The lost bone can be replaced by endogenous or exogenous bone tissues, which is connected with several problems. The use of endogenous bone substance involves additional surgery; moreover the endogenous bone is available only in limited quantities. In case of exogeneous bone implants, the major disadvantage is that they may be rejected by human body, disease may be transmitted together with the implant, and also the clinical performance of exogenous bone is considerably inferior to fresh endogenous graft material. For these reasons there is growing need for fabrication of artificial hard tissue replacement implants. Research into novel materials for biomedical applications is ever increasing as the medical community look to improve the way in which disorders and trauma are treated. Issues with current materials and the additional trauma associated with the use of bone grafts has pushed research towards new materials to aid the required repair and/or the regeneration of bone after fracture or the removal of bony defects or cancerous bone. Many new materials have been developed in an attempt to address these concerns but there are still some issues surrounding the appropriateness of their mechanical properties, the ability of degradable materials to retain their properties once implanted and the ability to form the material in......

Words: 5256 - Pages: 22

Biocompatibility of Coronary Stents

...| Biocompatibility of Coronary Stents | | By | Josh DeBoer | Prepared for Dr. Lim Term PaperAdvanced Biomaterials (Engm 491)4/27/11 | | Abstract Right now, endovascular stents have less than desirable biocompatibility, resulting in many unwanted complications. Plasma activated coatings (PAC) have shown great promise to make endothelial cell interactions more active by using recombinant human tropoelastin. These articles seek to alter the plasma vapor composition of these coating properties by adding oxygen, argon, nitrogen, or hydrogen. Each of these gases had pros and cons, and these articles seek to find the best combination for these coatings. Background Coronary heart disease (CHD) is the leading cause of death in the world, killing more than 15 million people according to the American Heart Association. It has many risk factors, including: * Diabetes * High blood pressure * High LDL "bad" cholesterol * Low HDL "good" cholesterol * Menopause * Not getting enough physical activity or exercise * Obesity * Radiotherapy to the chest, * Hypertension, * Hyperlipidemia. * Smoking Coronary heart disease is usually caused by a condition called atherosclerosis, which occurs when fatty material and a substance called plaque builds up on the walls of a person’s arteries. This causes the coronary arteries to narrow, blocking or slowing blood flow to the heart, causing chest pain (stable angina), shortness of......

Words: 2445 - Pages: 10

Nano Technology

...billion and Japan 750 million dollars.[3] Nanotechnology as defined by size is naturally very broad, including fields of science as diverse as surface science, organic chemistry, molecular biology, semiconductor physics, microfabrication, etc.[4] The associated research and applications are equally diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly, from developing new materials with dimensions on the nanoscale to direct control of matter on the atomic scale. Scientists currently debate the future implications of nanotechnology. Nanotechnology may be able to create many new materials and devices with a vast range of applications, such as in medicine, electronics, biomaterials energy production, and consumer products. On the other hand, nanotechnology raises many of the same issues as any new technology, including concerns about the toxicity and environmental impact of nanomaterials,[5] and their potential effects on global economics, as well as speculation about various doomsday scenarios. These concerns have led to a debate among advocacy groups and governments on whether special regulation of nanotechnology is warranted. ...

Words: 377 - Pages: 2

Bme Paper Osteoblast Maturation

...ORIGINAL ARTICLE Osteoblast Maturation and New Bone Formation in Response to Titanium Implant Surface Features Are Reduced With Age Rene Olivares-Navarrete, 1 * Andrew L Raines, 1,2 * Sharon L Hyzy, 1 Jung Hwa Park, 1 Daphne L Hutton, 1 David L Cochran , 3 Barbara D Boyan , 1 and Zvi Schwartz 1,3 1 Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA St. Joseph’s Translational Research Institute, Atlanta, GA, USA 3 University of Texas Health Science Center at San Antonio, San Antonio, TX, USA 2 ABSTRACT The surface properties of materials contribute to host cellular response and play a significant role in determining the overall success or failure of an implanted biomaterial. Rough titanium (Ti) surface microtopography and high surface free energy have been shown to enhance osteoblast maturation in vitro and increase bone formation in vivo. Whereas the surface properties of Ti are known to affect osteoblast response, host bone quality also plays a significant role in determining successful osseointegration. One factor affecting host bone quality is patient age. We examined both in vitro and in vivo whether response to Ti surface features was affected by animal age. Calvarial osteoblasts isolated from 1-, 3-, and 11-month-old rats all displayed a reduction in cell number and increases in alkaline phosphatase–specific activity and osteocalcin in response to increasing Ti surface microtopography......

Words: 8554 - Pages: 35

Journel Article Review

...remainder of their lives with a foreign object in their bodies. What happens to these implants and devices inside the body post surgery could become threatening and dangerous to the patient and must therefore must be studied. A) Why did the scientists perform the study (i.e. description of background)? Any medical device that is used in a surgery to replace any joint, used as an implantation, or any catheter or graft is known as a biomaterial because they are being used more often in modern medicine. Unfortunately, a biomaterial inside the body strongly increases the chances at developing a biomaterial-associated infection caused by staphylococci—specifically Staphylococcus epidermidis and Staphylococcus aureus. The hygiene measures, or lack thereof, are what cause the infections to take place. The patient’s skin and surgical equipment carry bacteria, and if these bacteria adhere to the device being implanted, a biofilm (is any group of microorganisms in which cells stick to each other on a surface) forms and are the factors in a biomaterial-associated infection. When this occurs, however, the effectiveness of antibiotics are often reduced, and therefore require a more intense method of intervention. In order to avoid these infections, the scientists studied whether or not bacteria being present on the implant itself is the source for colonization of bacteria in the surrounding tissue. B) What was the hypothesis (or hypotheses) under investigation? The scientists......

Words: 821 - Pages: 4


...November 21, 2015, Reference Fisher, L. E., Hook, A. L., Ashraf, W., Yousef, A., Barrett, D. A., Scurr, D. J., … Bayston, R. (2015). Biomaterial modification of urinary catheters with antimicrobials to give long-term broadspectrum antibiofilm activity. Journal of Controlled Release, 202, 57-64. doi:10.1016/j.jconrel.2015.01.037.Epub Retrieved November 15,2015, from Since urinary catheter infections are so prevalent in hospitalized patients; short-term bladder drainage or long-term management of bladder dysfunction can posed serious infections. The purpose of this research is to see, if applying Biomaterial modification to urinary catheters such as anti-microbial agents will prevent foley catheters related infections. The aim is to try to keep the indwelling catheter as long as possible without the development of catheter related infection.(Fisher,2015). The questions to keep in mind are that is it effective to apply the Biomaterial agent in reducing catheter related infection? What is the objective of patients who has an indwelling catheter with anti-microbial agent? Applicability The variables used in this study are silicone catheters. The independent variable used to run this test are pathogens such as Esherichia Coli, Proteus Mirabis, and Klebsiella Pneumaniae and anti-microbial agents are 0.2% Rifampin, 1% Triclosan, and 1% Sparloxacin.(Fisher et al,2015) In this study, there were no actual people samples, but the specimens......

Words: 1119 - Pages: 5

Projection Based Stereolithography Process for 3d Biomanufacturing of Biomaterials.

...Projection based stereolithography process for 3D biomanufacturing of biomaterials. Abstract Stereolithography is highly versatile and precise process of solid free form additive manufacturing technique. Process requires biocompatible liquid photopolymer resin as a material which is one of the limitation of the process also. Curing liquid resin with a high intensity UV radiations at times causes over-curing which is highly undesirable. In this project, behavior of different biomaterials have been observed under same condition and the results have been plotted and regression analysis for each has been done. The study of graphs and coefficient of determination of process with different materials shows how accurate the process is and it also helps ultimately to conclude the linear relationship between curing depth and exposure time. In any stereolithography case these curing depth and exposure time are chief governing parameters along with critical exposure and penetration depth. 1. Introduction Stereolithography (also known as SL or SLA) builds parts layer-by-layer using a UV laser to solidify liquid photopolymer resins. It is commonly used to produce concept models, master patterns, large prototypes and investment casting patterns. [01] This process is based on spatially controlled solidification of a liquid resin by photo-polymerization. Stereolithography Apparatus which is also known as SLA is chiefly comprised of Ultraviolet laser device, tank full of......

Words: 4548 - Pages: 19

Nanotechnology on Tissue

...combinations of cells Accepted 27 February 2013 with biomaterials and/or biologically active molecules and it helps to produce materials Available online xxx which very much resembles to body’s native tissue/tissues. From tissue engineering current therapies got revolutionised and life quality of several millions patient got Keywords: improved. Tissue engineering is the connecting discipline between engineering materials Bio-scaffold science, medicine and biology. In typical tissue engineering cells are seeded on Electrospinning biomimicked scaffold providing adhesive surfaces, then cells deposit their own protein to Grafting make them more biocompatible, but unable to vascularise properly, lack of functional cells, Nanobiotechnology low mechanical strength of engineered cells, not immunologically compatible with host Tissue engineering and Nutrient limitation are a classical issue in the field of tissue and tissue engineering. Through the article we will understand the technology involved, need and application of nanobiotechnology based tissue engineering. Copyright ª 2013, JPR Solutions; Published by Reed Elsevier India Pvt. Ltd. All rights reserved. 1. Introduction Tissue engineering is very fast growing scientific area in this era and used to create, repair, and/or replace cells, tissues and organs by using cell and/or combinations of cells with biomaterials and/or biologically active molecules and helps......

Words: 3254 - Pages: 14

Nanotechnology Paper

...and most of all less expensive but more precise. The world of nanotechnology is so broad, and touches on almost every topic of science. Nanotech is one of our biggest pushes into the future of our everyday living. There are hundreds of billions of research being conducted all around the world every day; in fact products seem to be changing as much as a daily routine nowadays. The research seems to be limitless on what we are able to do using nanotech, for instance when looking at the most common things we use such as: automobiles, computers, cell phones, televisions they seem to change instantly. Nanotechnology has the potential to change every part of our lives. Nanotechnology affects all materials: ceramics, metals, polymers, and biomaterials. New materials are the foundation of major technological advances. In the coming decade nanotechnology will have an enormous impact. Future advances could change our approaches to manufacturing, electronics, IT and communications technology making previous technology redundant and leading to applications which could not have been developed or even thought about, without this new approach. Scientists are experimenting with nanomaterials that grow or assemble themselves. In the nanotechnology world, you start with atoms and build things up, giving you incredible control. This study will aid in our food, water, air, gas and list goes on and on. Works......

Words: 290 - Pages: 2

DC: Legends of Tomorrow | Zeo Zebra | Editing/Proofreading Have any errors in your writing corrected