3D Printed Ceramics for Medical Applications
Technical ceramics play a leading role in today’s medical industry and are widely used in a variety of applications, including patient-specific implants, medical devices and surgical instruments. This can range from hip prosthetic femoral heads, dental screws and scaffolds, to microdispensing nozzles, x-ray tubes and pressure sensors, through to an array of complex components for valves, lasers, medical pumps, and electrosurgical assemblies.
When it comes to implanted ceramics, it’s important to note that they are both bioinert (materials which do not initiate a response or interact when introduced to surrounding biological tissue) and bioresorbable (naturally-dissolving materials that can be broken down by the body and so do not require mechanical removal).
Across the broad picture represented by the medical world, technical ceramics offer other critical advantages due to their unique blend of properties, amongst which are:
- Not allergy-causing
- Low heat conductivity
- Easily sterilizable
- Electrically insulating
- High mechanical strength
- Corrosion free
- Highly wear resistant
- No artifacts during x-ray or MRT
Given that the medical industry requires durable, high-performance products with excellent surface quality and reproducible, defect-free parts, we can see how the advent of additive manufacturing (AM) has played a significant role in pushing boundaries and broadening potential.
Regular Ceramics Expo exhibitor Lithoz (Vienna, Austria) is already applying its Lithography-based Ceramic Manufacturing (LCM) concept in this area and can produce customized implants for any purpose, as well as components for medical devices and surgical equipment made out of high-performance ceramic materials.
LCM allows fast and cost-effective design iterations by just editing a CAD file and enables the production of highly complex lattice structures, undercuts and cavities with feature sizes down to 100μm. A batch-oriented production approach offers the possibility of individualized components with additional advantages of mass production.
Lithoz offers its customers a wide range of ceramic based materials especially suited for medical purposes, such as alumina, zirconia, silicon nitride and tricalcium phosphate. Medical device components demanding perfect surface quality and close tolerances can benefit from the AM approach.
One example is an intracardiac catheter pump, used to support the heart to pump blood after heart surgery or an infarction. This novel approach developed by TU Wien and Vienna Medical University, and printed by Lithoz, is made of bioinert alumina. Alumina is particularly suitable because of its mechanical strength, good surface characteristics and thromboresistance.
For the designing process of bioresorbable patient-specific implants, data from computed tomography or magnetic resonance imaging can be used, ensuring optimum implant fit. An example here is a cranial implant in tricalcium phosphate, chosen due to its similarity to the inorganic fraction of the bone tissue.
The geometry of this model is inspired by the cranium, with its two layers of cortical bone on the outer side and highly porous layer of trabecular bone in between. Size and shape of the pores can be varied independently while the interconnectivity of the pores is ensured. The combination of a resorbable material with defined macroporosity enables an ingrowth of bone cells and subsequent vascularization.
Technical ceramics are suitable as permanent patient-specific implants due to their high mechanical strength, high wear resistance, good body-compatibility, low thermal and electrical conductivity and no artifacts on CT/MRI.
Osteosynthesis plates, for instance, can be produced in silicon nitride, which offers very good anti-infective and osseointegrative properties and can be formed using the LCM process with hardly any limitations in design. These plates reduce adaption work during the operation, and thus reduce time in the operation room. This decreases the risk for the patient due to shorter anesthesia.
For scaffolds, LCM enables the fabrication of optimized designs. AM is ideal for producing ceramic scaffolds that mimic the complex spongy structure of bone, allowing them to be both lightweight and strong. Scaffolds allow the ingrowth of bone cells and provide pathways for vascularization, which accelerates the healing process by enabling the transport of nutrients and removal of metabolic waste. LCM can produce both precisely defined and highly reproducible macroporosity and textured surfaces on the microporous structures, which together can improve osteoblast adhesion and coverage.
Are you interested in learning more about Lithoz products and services for medical applications? Get in touch with Dr. Daniel Bomze, their in-house expert for any concern in medical: +43 1 934 66 12 - 219 / [email protected].
Lithoz will exhibit at Ceramics Expo 2018 on Booth 428.