The ceramic products produced by 3D printing technology have huge potential in the field of medical technology, which is particularly obvious in many applications. This article focuses on the application of Austrian Lithoz high-precision ceramic 3D printing technology in the medical field.
For many years, ceramics with biocompatibility and biodegradability have been widely used in medical fields such as wound treatment and plastic surgery. Zirconia, alumina, and silicon nitride are representative of high-performance ceramic materials. Due to their excellent mechanical properties, wear resistance, low thermal conductivity and electrical conductivity, and excellent biocompatibility, they are widely used in the production of permanent Implants and other medical devices. Medical departments not only need high-performance ceramics with particularly high mechanical properties, but also biodegradable ceramics with other characteristics.
Tricalcium phosphate and hydroxyapatite belong to the group of biodegradable ceramics, which are used in the production of biodegradable implants because of their similar inorganic composition to bone. Through the degradation of materials during the healing process, cells can be provided with the necessary ions; at the same time, space is created for the cells to grow inward. In an ideal state, the degradation rate of artificial bones is as fast as the growth of regenerated tissues, thereby ensuring that certain mechanical stability is maintained throughout the healing process.
Lithoz's Austria-based manufacturing process (3D printing) is a very effective method for producing highly complex parts. At present, it is receiving more and more attention, especially in the field of medical device manufacturing. Through the "light-curing high-precision ceramic 3D printing (LCM)" process, various ceramics (such as zirconia or hydroxyapatite (HA)) can be made into almost any shape to achieve external (structural form) and internal geometric structures (Hole design).
The LCM process achieves high solids content (high filling density of ceramic particles) through the selective curing of photosensitive ceramic slurry, which is a prerequisite for obtaining dense and defect-free ceramic parts. The printing process follows the layer-by-layer printing principle. The 3D model of the product to be printed is automatically cut into 25 μm thick layers in the lihtoz software. Through selective exposure, the organic matrix is crosslinked to form a composite of polymer and ceramic particles. The polymer acts as a binder between the ceramic particles, thereby shaping them. In thermal post-treatment, the organic matrix is first removed without residue at high temperatures, and the final ceramic component is produced by sintering at temperatures in excess of 1000 ° C.
The LCM process is used to manufacture medical devices. It can relatively easily and conveniently produce personalized implants based on the individual patient's physiological structure. These implants perfectly match the local structure and the implantation positioning is more accurate. Together with imaging technology (such as CT, MRI, etc.), it is possible to quickly manufacture personalized implants that highly match the needs of patients. Unlike injection molding, this technology does not require any molds, and can be economically and easily customized or mass-produced for a part.
In addition to being able to make personalized implants, structures can also be designed to promote or even activate ingrowth of cells. For this purpose, interconnect systems with defined geometries and pore sizes are required to suit the respective cells. The LCM process can achieve a minimum wall thickness of 120 μm and a channel structure of 160 μm. The printing process has the advantages of high accuracy and repeatability.
Applications:
1.Pacemaker pump
Because Lithoz's LCM process produces ceramic parts with advantages such as high precision and high mechanical strength, researchers at the Vienna University of Technology and Vienna Medical University chose the LCM process as the manufacturing method of the pacemaker pump. This project is devoted to the design and production of mechanical heart pumps that use helium powered devices. The heart pump is designed as a temporary cardiac assist pump after a patient's heart surgery. It is combined with an intra-aortic balloon pump to optimize blood supply to coronary arteries to relieve heart pressure during critical healing stages. Because of its excellent biocompatibility, bio-inertia, and high surface finish, the alumina material was selected as the manufacturing material for the pacemaker pump. Through the lithoz LCM printing process, it is very convenient to produce, test, and optimize the design model in a short time.
2.Personalized bone repair
The project at the Kepler University Hospital in Linz is to use lithoz's LCM process to produce personalized bone defect repairs for patients. Bone defect repairs are used to surgically repair fracture sites in order to fix the fracture ends together while fixing the fracture site. Traditional products are made of metallic materials and must be properly bent and adjusted by the surgeon in the operating room. However, combined with CT and other methods, the size of the bone repair component is fully obtained. Through the lithoz's LCM technology, it is possible to quickly, high-precision, and high-quality produce personalized bone repair parts that fit the patient's bone repair site. At the same time, compared with conventional materials (such as titanium alloys), the use of zirconia with high abrasion resistance and the highest elasticity will not cause the problem of particle wear caused by wear of metal repair parts during use.
Degradable implants for bone replacement
Bone replacement after severe trauma or tumor resection remains a major challenge in current medicine. On the one hand, it is necessary to restore the stability and protection of bones as soon as possible, and on the other hand, to achieve good healing of the body's own bone cells. To this end, biodegradable ceramics (such as tricalcium phosphate) are used to produce personalized implants for patients, such as skull implants after severe head injury, scaffolds for bone structures, and the like. This is a joint R & D project by the Austrian Organisation for Regeneration, the Ludwig Boltzmann Experimental Institute, and Clinical Traumatology / AUVA.