idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Grafik: idw-Logo

idw - Informationsdienst
Wissenschaft

Science Video Project
idw-Abo

idw-News App:

AppStore

Google Play Store



Instanz:
Teilen: 
05.01.2012 10:41

Nanocrystals Make Dentures Shine

Dr. Ute Schönfelder Stabsstelle Kommunikation/Pressestelle
Friedrich-Schiller-Universität Jena

    Chemists of Jena University develop novel glass ceramics for dentistry

    The hardest substance in the human body is moved by its strongest muscles: When we heartily bite into an apple or a schnitzel, enormous strengths are working on the surface of our teeth. “What the natural tooth enamel has to endure also goes for dentures, inlays or bridges“, glass chemist Prof. Dr. Christian Rüssel of the Friedrich Schiller University Jena (Germany) says. After all, these are worn as much as healthy teeth. Ceramic materials used so far are not very suitable for bridges, as their strengths are mostly not high enough. Now Prof. Rüssel and his colleagues of the Otto-Schott-Institute for Glass Chemistry succeeded in producing a new kind of glass ceramic with a nanocrystalline structure, which seems to be well suited to be used in dentistry due to their high strength and its optical characteristics. The glass chemists of Jena University recently published their research results in the online-edition of the science magazine “Journal of Biomedical Materials Research“ (doi: 10.1002/jbm.b.31972).

    Glass-ceramics on the basis of magnesium-, aluminium-, and silicon oxide are distinguished by their enormous strength. “We achieve a strength five times higher than with comparable denture ceramics available today”, Prof. Rüssel explains. The Jena glass chemists have been working for a while on high density ceramics, but so far only for utilisation in other fields, for instance as the basis of new efficient computer hard drives. “In combination with new optical characteristics an additional field of application is opening up for these materials in dentistry“, Prof. Rüssel is convinced.

    Materials, to be considered as dentures are not supposed to be optically different from natural teeth. At the same time not only the right colour shade is important. “The enamel is partly translucent, which the ceramic is also supposed to be“, Prof. Rüssel says.

    To achieve these characteristics, the glass-ceramics are produced according to an exactly specified temperature scheme: First of all the basic materials are melted at about 1.500 °C, then cooled down and finely cut up. Then the glass is melted again and cooled down again. Finally, nanocrystals are generated by controlled heating to about 1,000 °C. “This procedure determines the crystallisation crucial for the strength of the product“, the glass chemist Rüssel explains. But this was a technical tightrope walk. Because a too strongly crystallised material disperses the light, becomes opaque and looks like plaster. The secret of the Jena glass ceramic lies in its consistence of nanocrystals. The size of these is at most 100 nanometers in general. “They are too small to strongly disperse light and therefore the ceramic looks translucent, like a natural tooth“, Prof. Rüssel says.

    A lot of developing work is necessary until the materials from the Jena Otto-Schott-Institute will be able to be used as dentures. But the groundwork is done. Prof. Rüssel is sure of it.

    Original Publication:
    Dittmer M, Rüssel C.: Colorless and high strength MgO/Al2O3/SiO2 glass-ceramic dental material using zirconia as nucleating agent. J Biomed Mater Res B Appl Biomater. 2011 Nov 21. doi: 10.1002/jbm.b.31972

    Contact:
    Prof. Dr. Christian Rüssel
    Otto-Schott-Institute for Glass Chemistry
    Friedrich Schiller University Jena
    Fraunhoferstr. 6, D-07743 Jena
    Phone: ++49 3641 / 948501
    Email: Christian.Ruessel[at]uni-jena.de


    Weitere Informationen:

    http://www.uni-jena.de


    Bilder

    The glass-ceramics are produced according to an exactly specified temperature scheme.
    The glass-ceramics are produced according to an exactly specified temperature scheme.
    Photo: Jan-Peter Kasper/FSU
    None

    Prof. Dr. Christian Rüssel, Head of the Otto-Schott-Institute.
    Prof. Dr. Christian Rüssel, Head of the Otto-Schott-Institute.
    Photo: Anne Günther/FSU
    None


    Merkmale dieser Pressemitteilung:
    Journalisten, Wissenschaftler
    Chemie, Medizin, Werkstoffwissenschaften
    überregional
    Forschungsergebnisse, Wissenschaftliche Publikationen
    Englisch


     

    Hilfe

    Die Suche / Erweiterte Suche im idw-Archiv
    Verknüpfungen

    Sie können Suchbegriffe mit und, oder und / oder nicht verknüpfen, z. B. Philo nicht logie.

    Klammern

    Verknüpfungen können Sie mit Klammern voneinander trennen, z. B. (Philo nicht logie) oder (Psycho und logie).

    Wortgruppen

    Zusammenhängende Worte werden als Wortgruppe gesucht, wenn Sie sie in Anführungsstriche setzen, z. B. „Bundesrepublik Deutschland“.

    Auswahlkriterien

    Die Erweiterte Suche können Sie auch nutzen, ohne Suchbegriffe einzugeben. Sie orientiert sich dann an den Kriterien, die Sie ausgewählt haben (z. B. nach dem Land oder dem Sachgebiet).

    Haben Sie in einer Kategorie kein Kriterium ausgewählt, wird die gesamte Kategorie durchsucht (z.B. alle Sachgebiete oder alle Länder).