Beginner’s Guide to 3D Printing Body Parts

- Materials

Prototype jawbone replacement fitting test

Undergraduate student Matthew Haldon discusses 3D printing for bone cancer victims, sharing work from a group project his team is completing under Dr Andrey Molotnikov.

What are you working on right now?

I’m creating a partial 3D-printed jaw implant for a bone cancer patient, as part of the MTE5886 Additive Manufacturing with Metals group project.

What are some of the challenges involved in 3D printing body parts? How did you address these in your own work?

Our focus was on making the design printable, while also custom tailored to the patient. It also has to be lightweight while filling the jaw line so that it will look natural after surgery.

This project provided a lot of insight into printing biomedical implants. For example, we hoped to use cell growth to promote adhesion between the implant and the bone, however we found out that this strategy is limited because the patient has to undergo chemotherapy six weeks after the implant surgery. This is to ensure that all cancerous cells have been killed, but it also destroys any new bone growth. As a result, bone glue is now used as the main method of adhesion, greatly increasing the risk of fatigue and cracking.

How did you go about printing the jawbones? Any technical difficulties you experienced?

For the prototyping we printed plastic jawbones and implants in PLA with a desktop Fused Disposition Modelling (FDM) printer. The biggest issue we found was finding a way to make accurate cuts into the remaining jawbone for the teeth to set in. For the plastic model we could use metal files and epoxy paste to get a close fit – a surgeon operating on live bone would have to be much more delicate! Rather than change the design, though, our first solution to this problem would be to create several smaller ‘stencil’ parts that can clip over the remaining bone and guide the surgeon in making their cuts.

What possibilities does this type of printing hold for wider use?

3D printing is best suited to the production of specialised, high-impact but low production volume parts, which cannot be manufactured by faster traditional manufacturing techniques. The bone implant we developed is a perfect example of this, as we were able to effortlessly replicate the patient’s jaw shape. This represents a significant growth area for additive manufacturing.

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Beginner's Guide