DOCSLIB.ORG

Imaging Hard – Inside the Skeleton Timothy G

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Imaging Hard – Inside the Skeleton Timothy G Imaging hard – inside the skeleton Timothy G. Bromage, Santiago Gomez, Alan Boyde Vertebrate hard tissue biologists study the surface and below-surface microanatomical features and compositional characteristics of bones and teeth of the skeleton (fish scales also deposit calcium phosphate and calcium carbonate into their structure, and we include them among the tissues we study). The variability in bone and tooth histology rivals that of all other organ systems, making it an ideal tissue for understanding the development, function, and physiology of organisms. What is more, in deference to soft tissues, bones and teeth survive as fossils, permitting all that we can know from the skeleton about an organism living today to be extrapolated to animals living millions of years ago. Bromage TG, Gomez S, Boyde A. Imaging hard – inside the skeleton. Royal Microscopy Society infocus 49: 4-31, 2018. 4 ISSUE 49 MARCH 2018 5 By and large, hard tissues are formed by cells that Bright-field microscopy two axes furthest from the maximum transmission air present themselves as superior surface reflection secrete an organic matrix, which then mineralises. Bright-field is the simplest yet most versatile form axes of the two filters. Brightness in images derived instruments for metrology. In addition to this, by But in some cases they may be made from soft tissues of microscopy. Specimens imaged by bright-field from linear polarising microscopes is thus not easily using an immersion objective lens or by placing a such as cartilage or ligament that subsequently microscopy - usually histological sections - are quantifiable nor always fully interpretable because of glass coverslip with a medium onto the specimen mineralise. While it may appear counterintuitive, illuminated by transmitted light from below in an this artefact. when using an objective in air, specular reflections the development of a bone often also requires upright microscope (or from above in an inverted are eliminated and the illuminating beam is allowed The linear polarising problem is eliminated by bone-removing cells to allow the re-sizing and re- microscope). The specimen must provide all of to penetrate deep to the surface. The consequence steering photons into a helical trajectory rather than shaping of a bone during development. These bone- the potential contrast. Contrast mechanisms vary, of these conditions for both laser and white light a plane one, and under this condition, the light is removing cells also assist in the maintenance of bone and those typically used in our laboratories include confocal microscopes begs the most interesting polarised in all 360 degree rotational positions; this throughout life by a process of removal of small manipulating the obliquity of the illuminating light by question; what if we drive the plane of focus of the is called circularly polarised light (CPL) (Boyde et al., packets of tissue followed by the replacement of opening-closing the back aperture, or by employing objective lens below the surface of our opaque 1984; Bromage et al., 2003b). This is accomplished by tissue by forming cells. darkfield, phase, and differential interference contrast material? The result is an image composed of only placing a complementary quarter wave filter between techniques. that light emitted or reflected from the Z region Bones and teeth are hard because of the largely the specimen and each linear polarising filter. Image occupied by the depth of focus of the objective lens. calcium and phosphate mineral deposited into Applying histological stains to sections imaged by brightness under CPL conditions is a true signal them. Regarding this point, the first mistake most bright-field microscopy also provides useful contrast; representative of the orientation of the collagen There is a lot of material in the world we would like hard tissue biologists make is to give their research in our laboratories, Stevenel’s blue and Toluidine in bone, dentine, and cementum. The contrast to image. Most of it is not in the lab, nor is there specimens to a routine histology laboratory that blue are commonly used, which, on bone, produce generated provides insight on the development and any evidence to suggest that it will come to the lab commences to demineralise their specimens and coloured optical density variability relating to function of the tissue. any time soon. Thus, we have to accept that if we make them soft! This permits the laboratory to mineralisation density differences. We do not stain wish to acquire knowledge about it at a microscopic Further contrast enhancing techniques associated make paraffin embedded thin sections using specialist tissues prior to embedding, but rather stain the scale, we have to go where the material is, and we with polarising microscopy can be obtained by knives. There are a handful of us in the world that surfaces of our thick (e.g., 100 µm) sections. These must take our microscopes with us. A big advantage introducing compensator and/or bandpass cut-off can honestly say, “we are hard tissue biologists”, and stains penetrate 5-10 µm below the surface, and of white light Nipkow disc confocal microscopes is filters or dichroic mirrors. who have the opinion that to throw away more than when imaged above an opaque white diffusing plate, that they do not require a lot of hardware, such as half of a bone or tooth’s mass is not the best starting present an image formed almost exclusively from the a laser source or power supply. We thought that point for obtaining a complete understanding of the stained thickness layer; this image is equivalent to a Confocal microscopy a portable confocal scanning optical microscope Confocal microscopes belong to the family of nature of the tissue. This is all the more important stained 5-10 µm thick decalcified paraffin-embedded (PCSOM) would satisfy if it was packed into two scanning imaging technologies. A small aperture or in light of microscopy techniques we employ and section. pieces of approved check-in luggage for air travel, if describe below to visualise the histocomposition of slit translated across the field of view transmits both it was robust to whatever it is that happens after hard tissues. However, if we wished to image the Polarising microscopy the illuminating beam and the emitted or reflected check in, and if it was adaptable to “field” conditions collagen fabric of say, a bone, in greater detail, we Birefringent materials - like hydoxy apatite with light returning from the object, which, for reasons of and operating on 110 or 220 V. A number of images may decalcify the embedded mineralised section, negative intrinsic birefringence - or stacked the geometry of the system, returns exclusively from below were taken with this system and we briefly leaving only the collagen for providing morphological structures like collagen molecules, microfibrils and the plane of focus of the objective lens. A single describe it here. contrast. fibrils, with water in between which give positive pinhole scanned across the entire field of view takes We used a PCSOM based on the Nipkow disk form birefringence, generate orientation-dependent a bit of time, and thus the image must be built up. technique, described in detail by Petran and contrast in polarising microscopy. Most polarising However, by using many thousands of pinholes on Microscopy Hadravsky (1966) and first commercialised in the A variety of microscopy technologies and techniques microscopes in the world employ a linear polariser a spinning Nipkow disc, the holes interlace in space early 1980s; applications to hard tissue biology are are employed on either intact unprepared bone and filter on the illumination side of the specimen and and integrate in time to produce a real time confocal available in Boyde (1983), and the history and various tooth tissues, or those infiltrated with and embedded a “crossed” linear analyser filter on the imaging image of the entire field of view when spun at video technical achievements in confocal microscopy are into plastic and cut with any one of a number of side of the specimen. Increasing brightness in the rate. summarised in Boyde (1995). We utilise a “single- precision saws. In our laboratories we employ image is associated with the degree to which the Laser confocal microscopes are used almost sided” Nipkow disk design in which the illumination stereo zoom and compound light microscopy, white birefringent components are in the plane of the exclusively for exciting fluorophores and detecting and detection pinholes are the same (Kino, 1995). We light and laser confocal microscopy, real time 3D section. However, the crossed linear polarising filter fluorescence with high spatial resolution in the Z configured our PCSOM to contend with the variety microscopy, and scanning electron microscopy. arrangement renders an artefactual darkness along axis. White light confocal microscopes imaging in of conditions encountered at museums around the 6 ISSUE 49 MARCH 2018 7 world (Bromage, 2003a). An interesting feature of detectors are used to observe SEs having lower Bone tissues the design of our confocal module was the solution energies than the incoming beam and that are 3D human bone tissue applied to suppress internal non-image-related ejected in large numbers from atoms encountered Figure 1 shows a 3D image of a blood vessel channel (top and centre of image) taken by conventional reflections. Linear polarising light filters and a single by the beam on the surface. Their propagation is transmission compound microscopy, that is contained within layers of human bone tissue called lamellae quarter wave plate are employed for this purpose. substantially determined by topographic variability, and imaged by circularly polarised light. 24 2D images taken 3 microns apart were acquired in a through The unintended benefit of this strategy was that and thus SE-SEM is a superior method for visualising focus series, comprising a digital 24-image data set.
Load more

Recommended publications
  • Preparation of Absorption-Resistant Hard Tissue Using Dental Pulp-Derived Cells and Honeycomb Tricalcium Phosphate
    materials Article Preparation of Absorption-Resistant Hard Tissue Using Dental Pulp-Derived Cells and Honeycomb Tricalcium Phosphate Kiyofumi Takabatake 1, Keisuke Nakano 1,* , Hotaka Kawai 1, Yasunori Inada 1, Shintaro Sukegawa 1,2 , Shan Qiusheng 1, Shigeko Fushimi 1, Hidetsugu Tsujigiwa 1,3 and Hitoshi Nagatsuka 1 1 Department of Oral Pathology and Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama University, Okayama 700-8525, Japan; [email protected] (K.T.); [email protected] (H.K.); [email protected] (Y.I.); [email protected] (S.S.); [email protected] (S.Q.); [email protected] (S.F.); [email protected] (H.T.); [email protected] (H.N.) 2 Department of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, Kagawa 760-8557, Japan 3 Department of Life Science, Faculty of Science, Okayama University of Science, Okayama 700-0005, Japan * Correspondence: [email protected] Abstract: In recent years, there has been increasing interest in the treatment of bone defects using undifferentiated mesenchymal stem cells (MSCs) in vivo. Recently, dental pulp has been proposed as a promising source of pluripotent mesenchymal stem cells (MSCs), which can be used in various clinical applications. Dentin is the hard tissue that makes up teeth, and has the same composition and strength as bone. However, unlike bone, dentin is usually not remodeled under physiological conditions. Here, we generated odontoblast-like cells from mouse dental pulp stem cells and combined them with honeycomb tricalcium phosphate (TCP) with a 300 µm hole to create bone-like Citation: Takabatake, K.; Nakano, K.; tissue under the skin of mice.
    [Show full text]
  • Enamel Lamellae ** Thin Leaf Like Structure, Extend from the Enamel Surface to a Considerable Distance in the Enamel Till DEJ , Sometimes Extend Into the Dentin
    Objectives: 1-Understand the Physical and Chemical characteristic features of enamel 2-Recognize the surface and histological structure of enamel. (1) Definition; Enamel is the hardest mineralized tissue in the human body that covers the anatomical crown of teeth. It forms a protective covering of teeth to resist the stresses and forces of mastication. (2) Origin ectodermal in origin from the IEE. Formative cells: Ameloblasts which are lost as the tooth erupts and hence enamel can not renew itself. Oral ectoderm *It is a mineralized epithelial tissue that is totally acellular. Dental *Inert. lamina *Non-vital. *Insensitive. Inner *If wear or Caries, it can’t replaced enamel Or regenerated (can’t renew itself). epithelium *Permeable. *Unique crystalline structure. *Unique matrix protein. (3) Physical properties of enamel: A)Color: Yellowish white to grayish white (according to thickness, degree of translucency, degree of calcification & homogeneity of enamel). B)Thickness: Variable (max. on cusp tips {2-2.5mm.}& kinfe edge at cervical margin). C)Hardness: Hardest calcified tissue in the body due to: [↑↑content of mineral salts & its crystalline arrangement]. Hardness of permanent teeth ˃ deciduous. Hardness at the surface ˃ DEJ. Hardness at cusp & incisal edge ˃ hardness at cervical line. D)Brittleness: Enamel is brittle, especially when looses its elastic foundation of healthy dentin (i.e. undermind enamel). E)Permeability: Enamel can act as semipermeable membrane, permitting complete or partial slow passage of certain ions & dyes. Mainly from the saliva to the outer layer of enamel, but to a lesser degree from the pulp to the inner enamel layer across the dentin. GROUND SECTION DECALCIFIED SECTION Methods of Studying ” hard tissues” HISTOLOGICAL PREPARATION OF TEETH GROUND SECTIONS ENAMEL Show enamel, dentin and bone.
    [Show full text]
  • Collagen Fibres Are Not Required for Initial Matrix Mineralization by Bone Cells
    Cells and Materials Volume 6 Number 1 Numbers 1-3 Article 23 1996 Collagen Fibres are Not Required for Initial Matrix Mineralization by Bone Cells M. M. Hosseini University of Toronto S. A. F. Peel University of Toronto J. E. Davies University of Toronto Follow this and additional works at: https://digitalcommons.usu.edu/cellsandmaterials Part of the Biomedical Engineering and Bioengineering Commons Recommended Citation Hosseini, M. M.; Peel, S. A. F.; and Davies, J. E. (1996) "Collagen Fibres are Not Required for Initial Matrix Mineralization by Bone Cells," Cells and Materials: Vol. 6 : No. 1 , Article 23. Available at: https://digitalcommons.usu.edu/cellsandmaterials/vol6/iss1/23 This Article is brought to you for free and open access by the Western Dairy Center at DigitalCommons@USU. It has been accepted for inclusion in Cells and Materials by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. Cells and Materials Vol. 6, No. 1-3, 1996 (Pages 233-250) 1051-6794/96$5.00+ .25 Scanning Microscopy International, Chicago (AMF O'Hare), IL 60666 USA COLLAGEN FIBRES ARE NOT REQUIRED FOR INITIAL MATRIX MINERALIZATION BY BONE CELLS M.M. Hosseini, S.A.F. Peel and J.E. Davies• Centre for Biomaterials, University of Toronto, 170 College Street, Toronto, Ontario, Canada, M5S 3E3 (Received for publication June 25, 1996 and in revised form December 27, 1996) Abstract Introduction Passaged primary cultures of young adult rat bone We have recently shown that differentiating osteo­ marrow cells were maintained in medium containing genic cell s, derived from explants of young adult rat combinations of the supplements dexamethasone, ascor­ bone marrow, elaborate an interfacial matrix with the bic acid and Na-{3-glycerophosphate.
    [Show full text]
  • Jci.Org Volume 124 Number 12 December 2014 5219 Brief Report the Journal of Clinical Investigation
    The Journal of Clinical Investigation BRIEF REPORT Hair keratin mutations in tooth enamel increase dental decay risk Olivier Duverger,1 Takahiro Ohara,1 John R. Shaffer,2 Danielle Donahue,3 Patricia Zerfas,4 Andrew Dullnig,5 Christopher Crecelius,5 Elia Beniash,6,7 Mary L. Marazita,2,6,8 and Maria I. Morasso1 1Laboratory of Skin Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, Maryland, USA. 2Department of Human Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. 3Mouse Imaging Facility, National Institute of Neurological Disorders and Stroke (NINDS), NIH, Bethesda, Maryland, USA. 4Office of Research Services, Division of Veterinary Resources, NIH, Bethesda, Maryland, USA. 5National Capital Consortium Oral and Maxillofacial Surgery, Walter Reed National Military Medical Center, Bethesda, Maryland, USA. 6Department of Oral Biology, 7Center for Craniofacial Regeneration, and 8Center for Craniofacial and Dental Genetics, and Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. Tooth enamel is the hardest substance in the human body and has a unique combination of hardness and fracture toughness that protects teeth from dental caries, the most common chronic disease worldwide. In addition to a high mineral content, tooth enamel comprises organic material that is important for mechanical performance and influences the initiation and progression of caries; however, the protein composition of tooth enamel has not been fully characterized. Here, we determined that epithelial hair keratins, which are crucial for maintaining the integrity of the sheaths that support the hair shaft, are expressed in the enamel organ and are essential organic components of mature enamel. Using genetic and intraoral examination data from 386 children and 706 adults, we found that individuals harboring known hair disorder–associated polymorphisms in the gene encoding keratin 75 (KRT75), KRT75A161T and KRT75E337K, are prone to increased dental caries.
    [Show full text]
  • The Role of Bone Marrow-Derived Cells During Ectopic Bone
    Int. J. Med. Sci. 2018, Vol. 15 748 Ivyspring International Publisher International Journal of Medical Sciences 2018; 15(8): 748- 757. doi: 10.7150/ijms.24605 Research Paper The Role of Bone Marrow-Derived Cells during Ectopic Bone Formation of Mouse Femoral Muscle in GFP Mouse Bone Marrow Transplantation Model Kiyofumi Takabatake1, Hidetsugu Tsujigiwa2, Yu Song1, Hiroyuki Matsuda1, Hotaka Kawai1, Masae Fujii1, Mei Hamada1, Keisuke Nakano1, Toshiyuki Kawakami3, Hitoshi Nagatsuka1 1. Department of Oral Pathology and Medicine Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama University, Okayama, Japan; 2. Department of life science, Faculty of Science, Okayama University of Science, Okayama, Japan; 3. Hard Tissue Pathology Unit, Matsumoto Dental University Graduate School of Oral Medicine, Shiojiri, Japan. Corresponding author: Kiyofumi Takabatake, Department of Oral Pathology and Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-Cho, Okayama 700-8558, Japan. Phone: (+81) 86-2351-6651; Fax: (+81) 86-235-6654; E-mail: [email protected] ama-u.ac.jp © Ivyspring International Publisher. This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) license (https://creativecommons.org/licenses/by-nc/4.0/). See http://ivyspring.com/terms for full terms and conditions. Received: 2017.12.27; Accepted: 2018.04.12; Published: 2018.05.22 Abstract Multipotential ability of bone marrow-derived cells has been clarified, and their involvement in repair and maintenance of various tissues has been reported. However, the role of bone marrow-derived cells in osteogenesis remains unknown. In the present study, bone marrow-derived cells during ectopic bone formation of mouse femoral muscle were traced using a GFP bone marrow transplantation model.
    [Show full text]
  • Pulp Canal Obliteration After Traumatic Injuries in Permanent Teeth – Scientific Fact Or Fiction?
    CRITICAL REVIEW Endodontic Therapy Pulp canal obliteration after traumatic injuries in permanent teeth – scientific fact or fiction? Juliana Vilela BASTOS(a) Abstract: Pulp canal obliteration (PCO) is a frequent finding associated (b) Maria Ilma de Souza CÔRTES with pulpal revascularization after luxation injuries of young permanent teeth. The underlying mechanisms of PCO are still unclear, (a) Universidade Federal de Minas Gerais - and no experimental scientific evidence is available, except the results UFMG, School of Dentistry, Department of Restorative Dentistry, Belo Horizonte, MG, of a single histopathological study. The lack of sound knowledge Brazil. concerning this process gives rise to controversies, including the (b) Pontifícia Universidade Católica de Minas most suitable denomination. More than a mere semantic question, Gerais – PUC-MG, Department of Dentistry, the denomination is an important issue, because it reflects the nature Belo Horizonte, MG, Brazil. of this process, and directly impacts the treatment plan decision. The hypothesis that accelerated dentin deposition is related to the loss of neural control over odontoblastic secretory activity is well accepted, but demands further supportive studies. PCO is seen radiographically as a rapid narrowing of pulp canal space, whereas common clinical features are yellow crown discoloration and a lower or non-response to sensibility tests. Late development of pulp necrosis and periapical disease are rare complications after PCO, rendering prophylactic endodontic intervention
    [Show full text]
  • RANKL/OPG Ratio Regulates Odontoclastogenesis in Damaged
    www.nature.com/scientificreports OPEN RANKL/OPG ratio regulates odontoclastogenesis in damaged dental pulp Daisuke Nishida1, Atsushi Arai2, Lijuan Zhao3, Mengyu Yang3, Yuko Nakamichi3, Kanji Horibe4, Akihiro Hosoya5, Yasuhiro Kobayashi3, Nobuyuki Udagawa6* & Toshihide Mizoguchi1,6* Bone-resorbing osteoclasts are regulated by the relative ratio of the diferentiation factor, receptor activator NF-kappa B ligand (RANKL) and its decoy receptor, osteoprotegerin (OPG). Dental tissue- localized-resorbing cells called odontoclasts have regulatory factors considered as identical to those of osteoclasts; however, it is still unclear whether the RANKL/OPG ratio is a key factor for odontoclast regulation in dental pulp. Here, we showed that odontoclast regulators, macrophage colony-stimulating factor-1, RANKL, and OPG were detectable in mouse pulp of molars, but OPG was dominantly expressed. High OPG expression was expected to have a negative regulatory efect on odontoclastogenesis; however, odontoclasts were not detected in the dental pulp of OPG-defcient (KO) mice. In contrast, damage induced odontoclast-like cells were seen in wild-type pulp tissues, with their number signifcantly increased in OPG-KO mice. Relative ratio of RANKL/OPG in the damaged pulp was signifcantly higher than in undamaged control pulp. Pulp damages enhanced hypoxia inducible factor-1α and -2α, reported to increase RANKL or decrease OPG. These results reveal that the relative ratio of RANKL/OPG is signifcant to pulpal odontoclastogenesis, and that OPG expression is not required for maintenance of pulp homeostasis, but protects pulp from odontoclastogenesis caused by damages. Osteoclasts are monocyte/macrophage-derived multinucleated bone-resorbing cells 1–3. Bone tissue is continu- ously resorbed by osteoclasts, and is subsequently replenished by osteoblasts4.
    [Show full text]
  • Enamel Spindles
    LECTURE V 1 Learning Objective • At the end of this lecture, the students will be able to know about the; Ultrastructure of Enamel Rods Enamel Cuticle Enamel Lamellae Enamel Tufts Dentinoenamel Junction (DEJ) Enamel Spindles 2 ENAMEL CUTICLE • Primary enamel cuticle or the Nasmyth’s membrane • A typical basal lamina under electron microscope • Probably visible with the light microscope - wavy course • Apparently secreted by the ameloblasts 3 Enamel Cuticle Cont’d… • Function of the enamel cuticle • Afibrillar cementum • Pellicle 4 ENAMEL LAMELLAE • Thin, leaf-like structures • May extend to, and sometimes penetrate into, the dentin • Consist of organic material with little mineral content • May be confused with cracks 5 Enamel Lamellae Cont’d… • Types of Lamellae Type A: composed of poorly calcified rod segments Type B: consisting of degenerated cells Type C: filled with organic matter, presumably originating from saliva • Lamellae can be observed better in horizontal sections 6 Enamel Lamellae Cont’d… • Lamellae may develop in planes of tension Where rods cross such a plane, a short segment of the rod may not fully calcify • If the disturbance is more severe, a crack may develop Unerupted tooth: filled by surrounding cells After eruption: filled by organic substances from the oral cavity 7 ENAMEL TUFTS • Arise at the dentinoenamel junction and reach into the enamel to about one fifth to one third of its thickness • Resemble tufts of grass - erroneous • Does not spring from a single small area but is a narrow, ribbon-like structure
    [Show full text]
  • Conservation and Variation in Enamel Protein Distribution During Vertebrate Tooth Development PAUL G
    JOURNAL OF EXPERIMENTAL ZOOLOGY (MOL DEV EVOL) 294:91–106 (2002) Conservation and Variation in Enamel Protein Distribution During Vertebrate Tooth Development PAUL G. SATCHELL,1 XOCHITL ANDERTON,1 OKHEE H. RYU,2 XIANGHONG LUAN,1,7 ADAM J. ORTEGA,3 RENE OPAMEN,1 BRETT J. BERMAN,4,6 DAVID E. WITHERSPOON,1 JAMES L. GUTMANN,1 AKIRA YAMANE,5 MARGERITA ZEICHNER-DAVID,6 2 6 JAMES P. SIMMER, CHARLES F. SHULER, AND THOMAS G.H. DIEKWISCH1,6,7* 1Baylor College of Dentistry/Texas A&M University System, Dallas, Texas 2Department of Pediatric Dentistry, The University of Texas Health Sciences Center at San Antonio, Texas 3Harvard School of Dental Medicine, Harvard University, Boston, Massachusetts 4The Department of Medicine, The University of California, San Diego, California 5Department of Pharmacology, School of Dental Medicine, Tsurumi University, Japan 6Center for Craniofacial Molecular Biology, University of Southern California School of Dentistry, Los Angeles, California 7Allan G. Brodie Laboratory for Craniofacial Genetics, University of Illinois College of Dentistry, Chicago, Illinois ABSTRACT Vertebrate enamel formation is a unique synthesis of the function of highly specialized enamel proteins and their effect on the growth and organization of apatite crystals. Among tetrapods, the physical structure of enamel is highly conserved, while there is a greater variety of enameloid tooth coverings in fish. In the present study, we postulated that in enamel microstructures of similar organization, the principle components of the enamel protein matrix would have to be highly conserved. In order to identify the enamel proteins that might be most highly conserved and thus potentially most essential to the process of mammalian enamel formation, we used immunoscreening with enamel protein antibodies as a means to assay for degrees of homology to mammalian enamel proteins.
    [Show full text]
  • Diagnosis of Occlusal Tooth Wear Using 3D Imaging of Optical Coherence Tomography Ex Vivo
    sensors Article Diagnosis of Occlusal Tooth Wear Using 3D Imaging of Optical Coherence Tomography Ex Vivo Misa Kashiwa 1, Yasushi Shimada 1,2,* , Alireza Sadr 1,3 , Masahiro Yoshiyama 2, Yasunori Sumi 4 and Junji Tagami 1 1 Department of Cariology and Operative Dentistry Department, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; [email protected] (M.K.); [email protected] (A.S.); [email protected] (J.T.) 2 Department of Operative Dentistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan; [email protected] 3 Biomimetics Biomaterials Biophotonics Biomechanics & Technology Laboratory, Department of Restorative Dentistry, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195-7456, USA 4 Center of Advanced Medicine for Dental and Oral Diseases, Department for Advanced Dental Research, National Center for Geriatrics and Gerontology, Aichi 474-8511, Japan; [email protected] * Correspondence: [email protected]; Tel.: +81-86-235-6671 Received: 21 September 2020; Accepted: 21 October 2020; Published: 23 October 2020 Abstract: The aim of this study was to assess the utility of 3D imaging of optical coherence tomography (OCT) for the diagnosis of occlusal tooth wear ex vivo. Sixty-three extracted human molars with or without visible tooth wear were collected to take digital intraoral radiography and 3D OCT images. The degree of tooth wear was evaluated by 12 examiners and scored using 4-rank scale: 1—slight enamel wear; 2—distinct enamel wear; 3—tooth wear with slight dentin exposure; 4—tooth wear with distinct involvement of dentin.
    [Show full text]
  • Fabrication and Characterisation of a Novel Biomimetic Anisotropic Ceramic/Polymer- Infiltrated Composite Material
    Al-Jawoosh, S., Ireland, A., & Su, B. (2018). Fabrication and characterisation of a novel biomimetic anisotropic ceramic/polymer- infiltrated composite material. Dental Materials, 34(7), 994-1002. https://doi.org/10.1016/j.dental.2018.03.008 Peer reviewed version Link to published version (if available): 10.1016/j.dental.2018.03.008 Link to publication record in Explore Bristol Research PDF-document This is the author accepted manuscript (AAM). The final published version (version of record) is available online via Elsevier at https://www.sciencedirect.com/science/article/pii/S0109564117310357?via%3Dihub. Please refer to any applicable terms of use of the publisher. University of Bristol - Explore Bristol Research General rights This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/red/research-policy/pure/user-guides/ebr-terms/ Fabrication and characterisation of a novel biomimetic anisotropic ceramic/polymer-infiltrated composite material Abstract Objective. To fabricate and characterise a novel biomimetic composite material consisting of aligned porous ceramic preforms infiltrated with polymer. Method. Freeze-casting was used to fabricate and control the microstructure and porosity of ceramic preforms which were subsequently infiltrated with 40-50% by volume UDMA-TEGDMA polymer. The composite materials were then subjected to characterisation, namely density, compression, three-point bend, hardness and fracture toughness testing. Samples were also subjected to scanning electron microscopy and computerized tomography (Micro-CT). Results. Three-dimensional aligned honeycomb-like ceramic structure were produced and full interpenetration of the polymer phase was observed using micro-CT.
    [Show full text]
  • Biomechanical Analysis of Hard Tissue Responses and Injuries with Finite Element Full Human Body Model
    BIOMECHANICAL ANALYSIS OF HARD TISSUE RESPONSES AND INJURIES WITH FINITE ELEMENT FULL HUMAN BODY MODEL Jay Zhijian Zhao, Gopal Narwani TK Holdings Inc. United States Paper Number 07-0354 ABSTRACT for an average adult male reported earlier [1], was one such tool for injury analyses of the thorax, This paper summarizes the development activities on abdomen and shoulder of a belted occupant. the finite element full human body model, improving However, this model was not fully biofidelic and upon last 19th ESV publication (ESV 05-0399). The thus needed to be further developed. updated Takata Human Model for an average adult male has anatomical details of skeleton and major A biofidelic full human body model requires two soft tissues in all the body parts—head, neck, essential elements: the anatomical structures and the shoulder, thorax, abdomen, pelvis, lower and upper material characterization of human. All the human extremities. The arteries and veins as well as sciatic (hard and soft) tissues of which injuries were nerves in pelvis, thigh and tibia regions were also observed in field should be modeled in the modeled. The model’s responses of all the body parts anthropometrical details and their physical material were validated against published or in-house PMHS properties should be investigated. test data of twenty tissue material tests and forty- seven pendulum, drop or sled tests under frontal, side As an applicable occupant injury assessment tool the and oblique and rear impacts. A method similar to human model was required to be fully validated for those defined in the ISO-TR9790 lateral biofidelity its biofidelity.
    [Show full text]