نتایج جستجو برای: enamel

تعداد نتایج: 10227  

2017
Ghislain Thiery Vincent Lazzari Anusha Ramdarshan Franck Guy

Enamel thickness is highly susceptible to natural selection because thick enamel may prevent tooth failure. Consequently, it has been suggested that primates consuming stress-limited food on a regular basis would have thick-enameled molars in comparison to primates consuming soft food. Furthermore, the spatial distribution of enamel over a single tooth crown is not homogeneous, and thick enamel...

2012
E. Kaplova K. Tomankova H. Kolarova P. Krejci

J. O. Turner was the first who described the developmental defect of permanent tooth caused by periapical inflammation of temporary predecessor. This disorder is most common in the upper front teeth and premolars. These disorders are collectively called developmental defects of enamel (DDE). They are visible deviations from the normal translucent enamel resulting from enamel organ dysfunction. ...

2015
Amer Sehic Qalb - E - Saleem Khan Cuong Khuu Minou Nirvani Tor Paaske Utheim

Dental enamel is the only mineralized tissue of epithelial origin in mammals. The exceptional structural complexity and physical properties of tooth enamel seem to be dependent upon the properties of the protein matrix precursor. Proteins involved in enamel biosynthesis guide hydroxyapatite mineral formation, making the tooth enamel the hardest tissue in the vertebrate body. In dentistry, due t...

Journal: :The Anatomical record 1971
H Warshawsky C E Smith

A three-dimensional reconstruction of the rod profiles seen in inner and outer rat incisor enamel was made from serial 1 μ cross sections of a decalcified upper incisor. The enamel rod was found to be an elongated structure which travelled incisally relative to its origin and ran continuously from the dentino-enamel junction to the enamel surface. The rod was divisible into an inner and outer e...

Journal: :Journal of dental research 2003
T Nagano S Oida H Ando K Gomi T Arai M Fukae

Amelogenin, enamelin, sheathlin (ameloblastin/ amelin), enamelysin (MMP-20), and KLK4 (EMSP-1) are the major structural proteins and proteinases in developing tooth enamel. Recently, odontoblasts were reported to express amelogenin, the most abundant enamel protein. In this study, we hypothesized that odontoblasts express all enamel proteins and proteases, and we measured their relative mRNA le...

Journal: :Biology letters 2014
Charles Ziscovici Peter W Lucas Paul J Constantino Timothy G Bromage Adam van Casteren

Dental enamel is prone to damage by chipping with large hard objects at forces that depend on chip size and enamel toughness. Experiments on modern human teeth have suggested that some ante-mortem chips on fossil hominin enamel were produced by bite forces near physiological maxima. Here, we show that equivalent chips in sea otter enamel require even higher forces than human enamel. Increased f...

ژورنال: مجله دندانپزشکی 2010
توسلی حجتی, سارا, نخجوانی, یحیی, پهلوان, ایوب,

Background and Aims: Moisture contamination of etched enamel during application of sealant is the most frequently cited reason for sealant failure. In previous studies, some hydrophilic bonding agents have been shown to bond to etched enamel after salivary contamination. The purpose of this study was to evaluate the enamelsealant interface following the use of primer on the saliva contaminated ...

Journal: :Journal of dentistry 2014
Nathaniel C Lawson Sridhar Janyavula Sarah Syklawer Edward A McLaren John O Burgess

OBJECTIVES To compare the wear and opposing enamel wear of adjusted (A); adjusted and polished (AP); and adjusted and glazed (AG) zirconia and lithium disilicate. METHODS Specimens (n=8) were prepared of lithium disilicate (A, AP, and AG), zirconia (A, AP, and AG), veneering porcelain, and enamel (control). Surface roughness was measured for each ceramic. In vitro wear was conducted in the UA...

Journal: :Journal of human evolution 2008
Anthony J Olejniczak Tanya M Smith Robin N M Feeney Roberto Macchiarelli Arnaud Mazurier Luca Bondioli Antonio Rosas Javier Fortea Marco de la Rasilla Antonio Garcia-Tabernero Jakov Radovcić Matthew M Skinner Michel Toussaint Jean-Jacques Hublin

The thickness of dental enamel is often discussed in paleoanthropological literature, particularly with regard to differences in growth, health, and diet between Neandertals and modern humans. Paleoanthropologists employ enamel thickness in paleodietary and taxonomic studies regarding earlier hominins, but variation in enamel thickness within the genus Homo has not been thoroughly explored desp...

Journal: :Cells, tissues, organs 2009
Carolyn W Gibson Yong Li Bill Daly Cynthia Suggs Zhi-an Yuan Hanson Fong Darrin Simmons Melissa Aragon Ashok B Kulkarni J Timothy Wright

INTRODUCTION The amelogenin proteins secreted by ameloblasts during dental enamel development are required for normal enamel structure. Amelx null (KO) mice have hypoplastic, disorganized enamel similar to that of human patients with mutations in the AMELX gene, and provide a model system for studies of the enamel defect amelogenesis imperfecta. Because many amelogenin proteins are present in d...

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