Vergleichende Untersuchungen zur Radioaktivität von

Vergleichende Untersuchungen zur Radioaktivität von Knochenzementen und
der darin enthaltenen Röntgenkontrastmittel
Studies to compare radioactivity of bone cements and their ingredient X-ray
contrast media
Ch. Hopf, B. Glöbel, Th. Hopf
Rofo. 1990 May;152(5):601-2.
Orthopädische Universitätsklinik Mainz (Leiter: Prof. Dr. med. J. Heine), Abteilung
Medizintechnik und Strahlenschutz der Universitätskliniken des Saarlandes (Leiter: Prof. Dr.
med. Dr. rer. nat. B. Glöbel) und Orthopädische Universitäts- und Poliklinik Homburg/Saar
(Direktor: Prof. Dr. med. H. Mittelmeier)
Zusammenfassung
Verschiedene Knochenzemente und Röntgenkontrastmittel, die darin Verwendung finden,
wurden hinsichtlich ihrer radioaktiven Strahlung in einem Gammaspektrometer untersucht.
Alle gemessenen Knochenzemente (Implast®, Palacos R® und Sulfix-6®) zeigten einen
gewissen Grad von Radioaktivität. Als Strahlenquelle in diesen Knochenzementen ist das als
Röntgenkontrastmittel zugesetzte Zirkondioxid verantwortlich. Die Untersuchung der
Zirkondioxide verschiedener Hersteller ergab teilweise hohe Emissionswerte, während das
gleichfalls als Kontrastmittel benutzte Bariumsulfat keine Radioaktivität zeigte. Es ist davon
auszugehen, daß bei den verwendeten Knochenzementen sowie dem vorwiegenden Einsatz
der Zemente bei Patienten mit einem Alter von über 60 Jahren keine strahleninduzierten
Schäden entstehen. In Anbetracht der Tatsache, daß diese Knochenzemente dazu bestimmt
sind, jahrzehntelang im Körper zu verbleiben, sollten die Hersteller sobald wie möglich das
radioaktive Zirkondioxid durch strahlenfreies oder durch Bariumsulfat ersetzen.
Summary
Various PMMA bone cements/containing zirconium oxide (ZrO2) as an X-ray contrast
medium and zirconium oxides of several manufacturers were tested for their radioactivity by
means of a gamma spectrometer. All the bone cements tested (Implast®, Palacos R®, and
Sulfix-6®) showed a certain degree of radioactivity. The radiation source in the bone cement
is the added zirconium oxide, which is polluted by radioactive elements. The examination of
various zirconium oxides showed some high radioactive emissions. The risk of
radiogeninduced cancer seems to be small, because the cements are normally implanted in
humans older than 60 years. In view of the fact that these X-ray contrast media remain in the
body for decades as components of the bone cement, the radioactive zirconium oxides
should be replaced by high-purity radiation-free zirconium oxide or barium sulphate as soon
as possible.
Radioactivity in zirconium oxide powders used in industrial applications.
Lischinsky J, Vigliani MA, Allard DJ.
Applied Consultants, Inc., Woburn, MA 01801.
Health Phys. 1991 Jun;60(6):859-62.
Abstract
Recent work involving the decommissioning of a former ceramic manufacturing facility
licensed by the Nuclear Regulatory Commission for activities involving depleted uranium
oxide has uncovered the presence of unexpected high levels of natural radioactivity in nonlicensed zirconium oxide powders also used in the same facility. A comparison between the
levels of source material found in samples of this material and the current regulatory
guidance for licensed activities and decommissioning has been conducted. It has been
determined that the radioactivity in the zirconium oxide is of a high enough magnitude to
raise health physics concerns in the areas of licensing and regulatory compliance,
decontamination criteria, and worker health and safety. An examination of these areas has
been conducted and the implications associated with our findings are presented.
[Radioactive burden resulting from zirconia implants]
[Article in German]
Fischer-Brandies E, Pratzel H, Wendt T.
Dtsch Zahnarztl Z. 1991 Oct;46(10):688-90.
Klinik und Poliklinik für Kieferchirurgie der Universität München.
Abstract
Due to its mechanical properties circonia is an interesting implantation material. However, it
may contain a certain amount of radioactive isotopes. The measurement of alpha-emission
reveals varying amounts of radiation. As a result, a declaration of radioactivity should be
required for circonia implants and only circonia with low emission levels should be used for
implantation purposes.
New Y-TZP powders for medical grade zirconia.
Burger W, Richter HG, Piconi C, Vatteroni R, Cittadini A, Boccalari M.
J Mater Sci Mater Med. 1997 Feb;8(2):113-8.
Cerasiv GmbH, P.O.Box 1149 Plochingen, Germany.
Abstract
There is interest in using zirconia for biomedical applications as ball heads for total hip
prostheses. Two potential types are under discussion: partially stabilized zirconia (PSZ) and
tetragonal zirconia polycrystals (TZP) materials. Because of its enhanced material properties,
TZP stabilized with yttria is favourable. To eliminate high amounts of natural radioactive
impurities, the precursors are purified. The kind of precursor and purification method
determine the powder impurity level. The disadvantage of Y-TZP is that the hydrothermal
decomposition reaction method is that it depends very strongly on the grain size and the
distribution of the stabilizing yttria within the zirconia grains. Thermodynamical and kinetic
investigations on high purity coprecipitated and yttria-coated zirconia powders show different
behaviours. Y-TZP materials based on yttria-coated zirconia powders show excellent
mechanical strength of more than 1000 MPa, a Weibull modulus of up to 20 a! nd a fracture
toughness of 9 MPa radical m. The material properties of Y-TZP ceramics based on
coprecipitated powders and prepared under the same conditions are less attractive. It is
expected that materials based on yttria-coated zirconia will show enhanced properties
compared to materials derived from coprecipitated powders. Therefore Y-TZP materials
derived from yttria-coated powders are very attractive as medical grade zirconia.
In vitro evaluation of the mutagenic and carcinogenic power of high purity
zirconia ceramic.
Covacci V, Bruzzese N, Maccauro G, Andreassi C, Ricci GA, Piconi C, Marmo E, Burger W,
Cittadini A.
Biomaterials. 1999 Feb;20(4):371-6.
Giovanni XXIII Cancer Research Center, Institute of General Pathology, Catholic University,
School of Medicine, Rome, Italy. [email protected]
Abstract
Tetragonal zirconia polycrystal (TZP) is a new interesting ceramic for the manufacture of
medical devices. Its wide use in orthopedic and odontoiatric implants was limited till now by
the high chemical and radiochemical impurities of the raw materials. Purification processes
now available allow to obtain high purity ceramic grade powders suitable for TZP ceramics
manufacture, even if their possible mutagenic and transforming effects are still unclear. The
aim of this work is to study in vitro the mutagenic and oncogenic effects of a new zirconia
ceramic stabilized by yttria (Y-TZP). This ceramic was sintered from high purity powders
obtained by a process developed under a project carried out within the Brite EuRam
programme. For comparison, ceramics made from unpurified zirconia powder were also
tested. Fibroblasts irradiated by a linear accelerator were used as positive control. The
results obtained show that Y-TZP ceramic does not elicit either mutagenic or transforming
effect on C3H/10T(1/2) (10T(1/2)) cells and demonstrate that ceramic from high purity
powders can be considered suitable for biomedical applications from the point of view of the
effects of its radioactive impurity content.
An overview of zirconia ceramics: basic properties and clinical applications.
Manicone PF, Rossi Iommetti P, Raffaelli L.
J Dent. 2007 Nov;35(11):819-26. Epub 2007 Sep 6.
Catholic University of Sacred Heart, Institute of Clinical Dentistry, Largo F.Vito 1, 00168
Rome, Italy.
Abstract
Zirconia (ZrO2) is a ceramic material with adequate mechanical properties for manufacturing
of medical devices. Zirconia stabilized with Y2O3 has the best properties for these
applications. When a stress occurs on a ZrO2 surface, a crystalline modification opposes the
propagation of cracks. Compression resistance of ZrO2 is about 2000 MPa. Orthopedic
research led to this material being proposed for the manufacture of hip head prostheses.
Prior to this, zirconia biocompatibility had been studied in vivo; no adverse responses were
reported following the insertion of ZrO2 samples into bone or muscle. In vitro
experimentation showed absence of mutations and good viability of cells cultured on this
material. Zirconia cores for fixed partial dentures (FPD) on anterior and posterior teeth and
on implants are now available. Clinical evaluation of abutments and periodontal tissue must
be performed prior to their use. Zirconia opacity is very useful in adverse clinical situations,
for example, for masking of dischromic abutment teeth. Radiopacity can aid evaluation
during radiographic controls. Zirconia frameworks are realized by using computer-aided
design/manufacturing (CAD/CAM) technology. Cementation of Zr-ceramic restorations can
be performed with adhesive luting. Mechanical properties of zirconium oxide FPDs have
proved superior to those of other metal-free restorations. Clinical evaluations, which have
been ongoing for 3 years, indicate a good success rate for zirconia FPDs. Zirconia implant
abutments can also be used to improve the aesthetic outcome of implant-supported
rehabilitations. Newly proposed zirconia implants seem to have good biological and
mechanical properties; further studies are needed to validate their application.
Radiation risk estimation based on activity measurements of zirconium oxide
implants.
Porstendörfer J, Reineking A, Willert HC.
J Biomed Mater Res. 1996 Dec;32(4):663-7.
Isotope Laboratory for Biological and Medical Research, Georg-August-University,
Göttingen, Germany.
Abstract
Implants made form zirconium dioxide exhibit higher specific radionuclide activities of the
uranium-radium and thorium series than metallic and aluminum implants. This study presents
data on activity measurements performed on different samples of ZrO2 raw material
(powder) and on the ceramic joint heads belonging to it to formulate a correlation between
the specific radionuclide activities of the uranium-radium and thorium series in the raw
material, the flux density of the alpha particle leaving the implant surface, and the annual
dose of the tissue surrounding the implant. Based on this experimental study, an equation for
defining the limits of the specific activities in raw material is proposed, taking into account the
long-lived radionuclides (key nuclides) of the uranium-radium and thorium series weighted
with their relative dose contributions from alpha emitters.
Strahlenexposition durch zirkonoxidhaltige Werkstoffe.
Zimmermann M., Fischer-Brandies E., Winkler R., Roos H.:
Wehrmed Wschr, 42: 4-8, 1998.
Î Leider kein Abstract erhältlich.
Untersuchung des Einwachsverhaltens von Zirkoniumdioxid-Implantaten in die
Kieferknochenstruktur – Eine experimentelle Studie am Miniaturschwein
Gudehus H T
Inauguraldissertation München 2006
http://edoc.ub.uni-muenchen.de/6017/1/Gudehus_Timm.pdf
Î Auf Seite 37/38 wird auf das Thema eingegangen.