The news of a 3D printer-created lower jaw made of titanium powder has been populating the twitter-verse.  While this is probably a first time attempt to actually implant something like this in a human body, 3D printer companies like EOS and others have been working on developing 3D printed implantable medical parts for several years. Layerwise, a specialized metal-parts manufacturer in Belgium, built this particular jaw.
This example just proves how quickly this research is progressing. A couple of years ago, I met with EOS management and we discussed their research in developing parts that human bone could graft to for recovery from severe breaks or head trauma. Even then, the technology, i.e. the 3D printer, was capable. But FDA or other medical oversight approval and testing still needed to be done. Now, obviously, we’ve progressed to that stage.
However, because we don’t have the right printable human tissue materials (yet), I still think it will be a while before we actually 3D print our own replacement kidneys.