Alaadien Khalyfa ♦ Sebastian Vogt ♦ Jurgen Weisser ♦ Gabriele Grimm
Annett Rechtenbach ♦ Wolfgang Meyer ♦ Matthias Schnabelrauch
Received: 25 October 2005 / Accepted: 9 January 2006 / Published online: 11 January 2007 / Springer Science+Business Media, LLC 2007
Abstract: A key requirement for three-dimensional printing (3-DP) of medical implants is the availability of printable and biocompatible powder-binder systems. In this study we developed a powder mixture compris- ing tetracalcium phosphate (TTCP) as reactive com- ponent and b-tricalcium phosphate (b-TCP) or calcium sulfate as biodegradable fillers, which can be printed with an aqueous citric acid solution. The potential of this material combination was demonstrated printing various devices with intersecting channels and filigree structures. Two post-processing procedures, a sintering and a polymer infiltration process were established to substantially improve the mechanical properties of the printed devices. Preliminary examinations on relevant application properties including in vitro cytocompati- bility testing indicate that the new powder-binder system represents an efficient approach to patient specific ceramic bone substitutes and scaffolds for bone tissue engineering.
Calcium phosphate based ceramics are widely used in medicine as bone substitutes, implants, and coatings on dental and orthopaedic prostheses [1–3]. Because of their chemical and structural similarities to the inor- ganic phase of human bone, hydroxyapatite (HA) and other calcium phosphates like a- or b-tricalcium phosphate (a- or b-TCP) show an excellent biocom- patibility. Most of the relevant application properties of these materials including their biological influence on tissues and especially their biodegradation behav- iour are determined by their special chemical compo- sition, morphology and surface topology. Therefore, a proper material design offers numerous possibilities for the use of calcium phosphate materials in hard tissue replacement and regeneration.