3D printing is one of the newest and most versatile forms of rapid prototyping and prosthetic development. 3D printing is an additive method of manufacturing where layers of photopolymer plastic, wax, ceramics, or even living tissue are stacked vertically to create three-dimensional objects from a CAD model. While 3D printing, like that done at places like EIGERlab, has picked up an enthusiast following that uses the technology for consumer applications, there are several medical applications of 3D printing as well.
3D printing has provided an alternate method for creating functional prosthetics. Facial replacements like prosthetic ears or noses can be created without the expensive process of sculpting a wax replica and creating a silicone cast from the replica. Instead, the injured area is digitally photographed, and the photograph is converted to a digital model that a 3D printer can use to create a prosthetic. This reduces the time it takes to produce prosthetics and also allows replacement prosthetics to be created more easily if the original is damaged.
Researchers from Washington State University have even used 3D printers to create temporary replacement bone. When a patient has a fractured bone or skull, a CT scan is taken of the damaged area and the scan results are converted to a CAD model. The temporary replacement is made from a composite of calcium phosphate, silicon and zinc. The bone surrounding the damaged area can grow onto the replacement bone and heal until the replacement dissolves, leaving healthy bone in its place.
Dentistry is one of the most promising fields for the rapid uptake and expansion of 3D printing. Currently the biggest use for 3D printing in dentistry is for practicing invasive procedures. MRI and CT scans can be used to create 3D replicas of patients' jawbones and teeth. These replicas can be used for practice runs by oral surgeons so that they are familiar with a patient's periodontal structure, minimizing the risk of accidental damage during the actual procedure.
3D printing can also be used to create functional dental prosthetics. 3D printing dental crowns and implants will be much cheaper than dental porcelain and ceramic, and will soon be comparable in strength to traditional materials. Oral surgeons are also experimenting with large-scale maxillofacial replacements. Oral surgeons at the Biomedical Research Institute of Hasselt University have succeeded in implanting a 3D printed titanium mandibular implant in an 83-year-old woman
Doctors are experimenting with using 3D printing to supplement complex structures on the inside of the human body. While full 3D printed organs like kidneys, hearts, and lungs cannot yet be created, surgeons are able to supplement damaged organs with 3D printed materials to improve their function. 3D printing these materials is much more affordable than creating them using traditional methods, and they are often more accurately designed since they can be made from the results of body scans that are fed directly to the 3D printer.
Tracheomalacia is a life-threatening condition that has been treated with 3D printing. In this condition, some of the tissue in the trachea is not strong enough to support breathing, periodically collapsing and cutting off the airway. 3D splints can be inserted in the airway to hold it open in the area where it normally collapses.
Surgeons have also implanted artificial heart valves made from 3D printing. Specially designed 3D printers can create heart valves from living tissues. This is especially useful for newborns with congenital heart defects, whose hearts cannot typically support prosthetic valves made from artificial materials.
3D printing will continue to revolutionize the medical field as the technology further develops. Doctors may soon be able to provide full prosthetic limbs and complete organ replacements made from 3D printed materials.