Additive Manufacturing is an application-driven field, with different printing technologies more suitable for certain types of production than others. A challenging area for any manufacturing process, is food or medical applications that require a certain degree of sterility or biocompatibility. Given the right material and material forming process, there are countless applications that could benefit from materials that are certified Biocompatible per ISO 10993 standards. But what does it actually mean to be ISO-10093 Certified and what can you do with these materials?
What is Biocompatibility?
Biocompatibility is the ever-changing status of knowledge and testing into how biomaterials, in our case 3D printed materials, interact with the body and how those interactions help determine the clinical success of a medical device or accessory to the medical process. Or in a more simple term, testing to make sure the 3D printed materials are safe to use in conjunction with the human body and medical procedures. Biocompatibility is the material’s lack of interaction with living tissue or living system by not being toxic, injurious or physiologically reactive. The goal is to not cause an immune response by a person.
Jacobs Institute Vascular Health Care and Medical Device Development
International Standard Organization (ISO)
The International Standards Organization (ISO) developed ISO 10993 trying to standardize biocompatibility testing. ISO 10993 is a 20-part standard that evaluates the effects of medical device materials on the body. It uses matrices to break medical devices down into three categories: Surface, External Communicating and Implant. These are further broken down into subcategories based on exposure time (limited, prolonged and permanent) as seen in Table 1. ISO 10993 is not a checklist, but more of a guide used to provide the information to get you pointed in the right direction and design a testing program. Luckily for us, most material manufacturers, or printing companies have done a decent amount of this testing.
Materials that hold this certification are capable of being sterilized via industry-standard methods which enables them to be in direct patient contact, in a clean room, and custom implants or prosthetics. This certification helps manage biological risk and ensures that the host response is not negative or harmful.
3D Printing Solutions for Biocompatibility
Now that we’ve reviewed what we ultimately want, we can look at the best approach to get us there. Depending on your biocompatible need and application, there are different additive manufacturing technologies that are a better fit than others. It is for this reason the Stratasys offers different biocompatible materials on three different 3D printing platforms. Below is a breakout of the different technologies and their suggested applications, though they are not limited to these.
- FDM Technology: for larger, more robust parts
- Ultem 1010
- PolyJet Technology: for smaller, hyper-realistic models
- Biocompatible Digital ABS
- P3 Technology: for injection-molded quality in performance grade resins
- MED 412
- MED 413
- Loctite 3843
- BASF UltraCur3D ST45
Each of these technology platforms offers different material options and the ability to create biocompatible prototypes, jigs and fixtures, prosthetics and more.
FDM Biocompatible Materials
ULTEM 1010 – A high-performance FDM thermoplastic and has the highest tensile strength and chemical and heat resistance of any FDM thermoplastic available on the platform to date. It has NSF 51 food contact certification and is biocompatible per ISO 10993 and USP Class VI certification. It can be sterilized using autoclave and other methods, making it appropriate for medical tools such as surgical guides or even as work holding fixtures for sterilization. It has the coefficient of thermal expansion of any FDM material and an HDT of over 420 degrees Fahrenheit, making it suitable for many industrial tooling applications and other parts that require a unique combination of strength and thermal stability.
ABS-M30i – Next on the FDM platform, Stratasys has unlocked the use of ABS in biocompatible applications with ABS-M30i. ABS-M30i blends strength with biocompatibility and sterilization capability. It complies with ISO 10993 and USP Class VI for biocompatible testing and can be sterilized using gamma radiation, hydrogen peroxide gas plasma or EtO methods. Parts made with ABS-M30i have excellent mechanical properties and are well-suited for conceptual modeling, functional prototyping, manufacturing tools, and end-use parts.
PC-ISO – Which is polycarbonate with biocompatibility per ISO 10993 and USP Class VI. The material can be sterilized using EtO and gamma radiation. PC-ISO has high tensile and flexural strength and a high heat deflection temperature. In these categories, its values are 33 percent to 59 percent higher than those of ABS-M30i. Suitable applications may include medical devices and food and drug packaging. It is also 3D printable using an FDM machine.
PolyJet Biocompatible Materials
Stratasys has made biocompatible output possible to almost all of their current PolyJet 3D printers with the launch of Vero ContactClear which is available on the J35, J55 Prime, J850 Pro, J50 Prime, and J826. Other biocompatible materials may not be available on all systems, so be sure to ask your TriMech Sales Representative for the most current list.
Vero ContactClear – A clear biocompatible material, printed with PolyJet technology, with easily removable supports which offer the same mechanical properties as the other Vero resins. As the name suggests, it is transparent and often an alternative to glass, ideal for form and fit testing of see-through tools. Also, available on previous generation machines is MED610 which has very similar clear characteristics. These two materials shine in applications that revolve around the medical and dental fields. Being able to rapidly manufacture biocompatible drill guides, or even perform fit tests for liners or other implants is a great way to reduce procedure and recovery time for patients while allowing manufacturers to reduce their overhead and lead times. These clear rigid materials help enable the development of precision equipment or medical devices that must be sterilizable and have direct interaction with the patient in dermal or mucosal applications.
Vero ContactClear MED610
MED625 – Additionally, Stratasys offers MED625 for PolyJet machines, which is a flexible clear material that also boasts the ISO 10993 Certifications. MED625 features an approximate 50% elongation at break and has a shore hardness of 75A, making it ideal for applications such as orthodontic indirect bonding trays and implant gingival masks. While these two oral applications make sense due to the biocompatibility standards of short-term oral implants, it could be applied to a wide range of applications that require flexibility and biocompatibility.
Biocompatible Digital ABS – A unique ability of PolyJet technology is the ability to combine different materials during the 3D printing process. One such family of materials is Digital ABS. Stratasys also has a biocompatible Digital ABS formula, achievable by combining MED515+ and MED531. By combining these two-component materials during 3D printing, the resulting polymer offers higher heat resistance and impact strength than traditional Vero resins, which can add value in some of the rigorous applications and sensitive environments these parts may be used.
The ability to print tough and durable tools, jigs, and fixtures to support the medical field is mission-critical in the quest to bring cutting-edge technology to market. Stratasys has filled the market need on multiple levels by bringing these types of materials to market on three different technologies. In this article, we have discussed both FDM and PolyJet, and in the next article in this series, we will explore in detail the four different materials that can be printed on the Origin One platform using P3 technology.
Interested to learn more about how 3D printing coincides with the medical industry? Download our guide, Advancing Health Care With 3D Printing.