Home / Ausgabe 11(2014) / Postprocessing of 3D printed ceramic scaffolds for bone replacement
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Abstracts

Postprocessing of 3D printed ceramic scaffolds for bone replacement

The human body is able to transform synthetic hydroxyapatite (HA) to new body’s own bone material. To sup-port this process the chemistry as well as human biology has to be known well. The present study investigates the biomimetic modification and prevention of thermal degradation of 3D printed HA scaffolds as well as prelimi-nary results of thermal treated HA with targeted contamination. In order to imitate human bone with its combina-tion of inorganic and organic materials a gelatine infiltration of 3D printed open porous scaffolds was performed. Former attempts to increase the compressive strength of infiltrated 3D printed open porous scaffolds [1] could be improved by factor 1.8 up to 23.2MPa with a new infiltration method for gelatine. Acid binders induce an addi-tional thermal degradation of HA during sintering process which could be omitted by using polysaccharides as binders. Printed samples with powder consist of HA and 15 wt.% dextran with a green part mean CS of 5.6MPa was reached. After sintering of HA with targeted contamination a high increase in Vickers hardness and sintering activity could be measured.

Der menschliche Körper ist in der Lage synthetisiertes Hydroxylapatit (HA) in körpereigenes Knochenmaterial umzuwandeln. Diese Umwandlungsprozesse können nur unterstützt werden, wenn die Materialeigenschaften, sowie die biologischen Prozesse dahinter verstanden werden. Bei thermischer Nachbehandlung von 3D gedruckten keramischen Knochenersatzstrukturen findet unter anderem ein Abbau von Hydroxylapatit zu Tricalciumphosphat und Brushit statt. Um diesen Prozess minimieren zu können, wurden verschiedene nicht säurebasierte Bindersysteme getestet. In dieser Studie wird gezeigt, wie sich diese Binder auf die Festigkeit der Grünteile und die thermisch nachbearbeiteten Teile auswirken. Ebenso wird veranschaulicht, wie die Beifügung von Sinteradditiven die Sinteraktivität positiv beeinflussen kann.