83-Year-Old Woman Gets New 3D-Printed Titanium Jaw 121
arnodf writes "The University of Hasselt (in Belgium) announced today (Google translation of Dutch original) that Belgian and Dutch scientists have successfully replaced an 83-year-old woman's lower jaw with a 3D-printed model. According to the researchers, 'It is the first custom-made implant in the world to replace an entire lower jaw. ... The 3D printer prints titanium powder layer by layer, while a computer controlled laser ensures that the correct particles are fused together. Using 3D printing technology, less materials are needed and the production time is much shorter than traditional manufacturing. The artificial jaw is slightly heavier than a natural jaw, but the patient can easily get used to it."
Re:Why not stainless steel? (Score:5, Informative)
Titanium is stronger than most stainless steels and is 2/3 of the density. Also nickle is a component of stainless steel and can cause problems in the body. Titanium is inert in the body.
Re:Why not stainless steel? (Score:5, Informative)
Some people also naturally have considerable sensitivity to nickel outside the body too. Some people get terrible hives, rashes, and even permanent burns when wearing cheap jewelry (ie: silver plated jewelry which is made of nickel/rhodium alloys). Given such a damaging reaction when exposed to damp skin, having this inside the body could be dangerous.
Good question. Cheers!
Re:almost true (Score:5, Informative)
Pure Titanium is pretty weak with a Yield of around 20ksi. But the most common type is Grade 5 which when heat treated is good to about 150ksi yield. Most 300 series stainless especially 316 which is pretty much the most inert one is good to about 40ksi. You can get some insane Maraging steels that go to 350ksi. But working with those is a pain. The only times I've used it I had to wire EDM it.
Re:How do they attach muscle/tendons to titanium? (Score:5, Informative)
There some more information in the university's press release [uhasselt.be] which, handily, is also available in English translation [uhasselt.be] :
"The implant was coated with plasma sprayed artificial bone (hydroxy-apatite bone substitute compound) by Cambioceramics, Leiden, The Netherlands. Some anatomical parts, such as the condylar heads and the rims for the mandibular nerves were polished."
So I assume they attach the tendons to the faux-bone.
Re:Why not stainless steel? (Score:5, Informative)
Titanium interacts better with bone and the body tends to tolerate it well (most artificial joints are made of titanium), is lighter that steel, and has superb sintering properties. In fact nanograin titanium oxide (a ceramic) when shaped and sintered is transparent, as light as aluminum, stronger than steel, and far more flexible than either. It is extremely heat resistant and you could in fact build a very impressive engine block out of it... and be able to tune you motor by adjust combustion until your ignition color went blue (indicating complete optimal combustion.)
You could print a very high quality bone replacement and put synthetic bone inside and out to support marrow, a blood supply and attachment points on the outside for muscle and tendon. In fact you could build anchor points for carbon fiber to replace portions of tendon, and the tendon would naturally grow into the fiber over time. With the work being done on 3D printing, Its almost certain that we'll eventually just print up actual replacement organs and tissues from our own stem cells and with a little Extracellular Matrix to make it all grow together, no scars, no complications. We truly live in amazing times!
Re:almost true (Score:5, Informative)
I'm a mechanical engineer and I have to agree. Material selection is much more complicated than it seems. Let's take a typical aluminum parts I design.
If it is a high strength part machined from a block I'd use AL 7075-T6 since it's very strong and machines well. The T6 is an artificial aging that makes it stronger.
Sheet metal with tight bends 5052-O since other Aluminum will crack. The O means it is annealed so it's soft enough to bend cleanly.
Welded parts I'd use 6061-T6 since it's strong and welds nicely. The only problem is when you weld aluminum you anneal the area around the weld and the strength can drop from 36ksi yield to about 8ksi yield. If you really need the strength you can artificially age the part after you weld it but then the part typically warps and you have to straighten it back.
And once you have your part you have another problem with Aluminum. It's really soft. So it's easy to scratch and you can't get the surface clean because it keeps oxidizing and will rub off and make your hand black. So you can anodize it. There is a regular and a hard coat anodize if the part will be subject to wear.
These are just a few of the material selections you need to make. And this is just aluminum.