New developments in the production of absorbable bone substitutes might accelerate the deployment of the 3-D printing technology in the medical field.
3-D printing has already established itself in many areas of medicine. Germany-based EOS, for example, uses the technology to develop of anatomic models or to produce implants with lattice structures like they are needed to fix bone fractures. Furthermore it allows the production of individualized drilling templates, helping the surgeon to perform the operation just like he had planned it on the computer.
„In these fields“, explains Stefanie Kochbeck, Business Development Manager Medical at EOS, „there is still a lot of potential.“ And the technology to unearth this potential already exists. “If you take a look at the structure of a bone – highly complex and very light – our technology is capable of rebuilding exactly this structure.” And Kochbeck continues: “For instance special software is able to create rough surfaces that will accelerate the osseointegration”, which is the direct structural and functional connection between living bone and the surface of a load-bearing artificial implant.
And there are relatively new developments in the production of absorbable bone substitutes, disintegrating at the same speed the body needs to replace it with its own bone tissue. First research projects are under way, says Kochbeck: “This can become a thrilling field of research for us in the next years.” At ‚Fraunhofer Institut für Lasertechnik‘ (ILT) in Aachen; Germany, they are reporting first positive test results. The absorbable artificial bones stimulate the regeneration of the body. One of the features are tiny canals pervading the artificial structure with distances of just a few hundred micrometers between them. The porous canals create a lattice structure which the adjacent bones can grow into. “Its basic structure consists of the synthetic polylactide, or PLA for short. The stored granules from tricalcium phosphate (TCP) ensure rigidity and stimulate the bone‘s natural healing process”, says Simon Höges, project lead at ILT. But the material can only be applied in places where it will not be subject to severe stress: Thus, the »Resobone« implants will primarily replace missing facial, maxillary and cranial bones. Currently, they are able to close fissures of up to 25 square centimeters in size.
For Kochbeck additive manufacturing, traditionally used mainly for fast prototyping, shows clear signs of developing itself into a method for producing (mini)series of final goods. Besides rising technology requirements in terms of assembly quality, quality assurance in the building process, process security and productivity she expects a steady rise in the material portfolio. “Depending on which new materials will show up, whole new areas of application could develop.”
By Ute Eppinger.