3D printing in medical field introduces personalized treatments and improves quality of patient cares. Additive manufacturing is now utilized by medical professionals to develop new surgical guides, orthopedic implants, and prosthetics as well as the customized replicas of tissues, bones and organs.
Credit: Tom Claes on Unsplash
Table of Contents
What is 3D Printing?
3D printing is a process of creating a physical object from a three-dimensional digital file. The objects are built by laying down successive layers of raw materials such as metals, plastics, and ceramics.
Credit: Tom Claes on Unsplash
Since objects are made by addition of material, 3D printing is also known as additive manufacturing (AM).
The trend of using 3D printing in different industries has risen due to the rapid development of technology. In 2019, the global 3D printing market grew to over $10.4 billion, and was predicted to double in size every 3 years with the annual growth varying between 18.2% and 27.2%, forecasted by 3D Hubs.
Global 3D printing market size and prediction. Source: Autonomous Manufacturing
3D printing technique has been applied to many different industries:
Medicine
Patient-specific cranioplasty implant made by 3D printing. Credit: 3D Natives
At a rapidly growing rate, 3D printing in medical field is recognized as one of the highest potential markets in the future. 3D printing is now used to develop new surgical guides, orthopedic implants, and prosthetics as well as the customized replicas of bones, organs, and blood vessels.
Architecture
Architecture model made by 3D printing. Credit: 3DCompare.com
3D printing offers a fast, easy and economical alternative to produce highly detailed concept models that help architects and clients to visualize the design. The models can be simply produced by 3D CAD, BIM or other design software that architects typically use.
Jewelry
3D printing can reproduce complex features which are difficult to hand carve. Credit: Formlabs
Not only does 3D printing allow more design freedom, it also simplifies the steps and reduces production time over traditional handcrafted method. More and more jewelry designers now prefer to 3D model and print their designs over conventional ones.
3D printing is also widely applied in the following industries:
Art/ Sculpture/ Design
Automotive
Fashion
Aerospace
Education
Benefits of 3D Printing in Medical Field
Personalized Healthcare
Shapeshift production process for customized wearables. Credit: 3D Natives
With recent technology and material advance, 3D printing allows for the design and print of more complex designs and material options than conventional manufacturing method. Healthcare professionals can now easily create customized medical tools and implants that are perfectly adapted to a patient’s anatomy, or a specific surgery.
The better fit of prosthetics and implants can drastically reduce the chance of infection, provide pain-free functions and speed up the recovery process.
Fast Design and Production
Traditional prosthetics and implants can take weeks to design and manufacture, especially if they are custom made for a patient.
With 3D printing techniques, healthcare professionals can design and print the object in-house on a professional 3D printer within a few days (and sometimes even less), which is much faster than molded or machine parts.
This could significantly reduce patients’ waiting time and lower the chances of complications that may occur as a result of delayed or unavailable medical devices.
Increase Cost Efficient
3D printing provides patients with affordable tailor-made prostheses and implants that are so expensive in traditional manufacturing processes. There is also no need to make any specialized tooling, jigs or fixtures, and there are no minimum volume requirements.
The entire process – from scanning, to 3D modeling and printing – can be performed simply by a single person and an inexpensive desktop 3D printer, saving time, labor, and money.
Medical Applications of 3D Printing
Dental Products
Dentures made by 3D printing. Credit: Formlabs
3D printing is ideal for customized dental treatments like dentures, surgical guides dental implants, and orthodontic appliances such as braces and aligners, that perfectly match a patient’s anatomy.
Instead of relying on laboratories to mold and create tools, dentists and orthodontists can now prepare, scan, and print the implants/ tools with 3D printer on-site, saving time and money.
Custom-made Prosthetics
3D Printed leg prosthetics. Credit: 3D Printing Industry
Prostheses created using traditional manufacturing methods are expensive and may not necessarily built to specifications, resulting in patient discomfort or pain. If a patient does need a custom prosthesis, it will be even more expensive and time-consuming.
Using 3D printing, medical professionals can speed up the production process significantly, at the same time, create much affordable prostheses that closely tailored to patient’s exact need.
Bioprinting Tissues and Organoids
Bioprinted heart (left), ear (top right) and corneas (bottom right). Credit: 3D Natives
Rather than using metals or plastics, bioprinting use living cells, also known as bio-ink, to create artificial living tissues.
While bioprinting cannot yet be used to 3D print body parts, this technology is already being used to fabricate relatively simple artificial tissues and structures such as cartilage, cornea, skin, bone and blood vessels. This could provide a better way of studying certain diseases and testing new drugs and therapies.
In 2019, a team of Israeli researchers bioprinted a miniature human heart with cells, blood vessels, ventricles and cavities.
In the near future, bioprinting will be able to produce organs and tissues eligible for transplantation and regenerative surgery.
Surgical Instruments
Surgical instruments including forceps, scalpel handles and hemostats can be 3D printed on-site by surgeons. Credit: RapidMade
Complexity of each operation varies; and the hands of every surgeons are different. So why should surgeons be confined to standardized surgical instruments?
3D printing provides an inexpensive and timely alternative for surgeons to customize surgical tools specific to their needs and operations. With tools that will better fit the unique situation, surgeons can work with increased precision and efficiency.
Related article: 7 Stunning Use Cases For 3D Printing In Medical Field
How does 3D printing work?
There are three most established types of 3D printing: Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), and Stereolithography (SLA). Each method has its unique benefits and is suitable for different applications.
Fused Deposition Modeling (FDM)
PLA and ABS made by 3D printing through FDM. Credit: Makeblock
Fused Deposition Modeling (FDM), also known as fused filament fabrication (FFF), is the simplest and most cost-effective 3D printing technology. In this process, thermoplastic material is melted and laid onto the build platform layer-by-layer, until the formation of the object is finished.
Examples of applications:
Medical prostheses
Jigs
Fixtures
Examples of materials:
Acrylonitrile butadiene styrene (ABS), a tough and durable material
Polylactic acid (PLA), a biodegradable material
Stereolithography (SLA)
UDMA hearing aids 3D printed through SLA. Credit: Hubs
Stereolithography (SLA) printed parts have the highest resolution and accuracy, the clearest details, and the smoothest surface among the plastic 3D printing technologies. A UV laser beam hardens the photo-polymer resin in layers and each layer is solidified and built on top of next until the object is formed.
Examples of applications:
Surgical rehearsal models
Surgical guides
Orthopedic applications
Examples of materials:
Urethane dimethacrylate (UDMA) resins, high resolution
Methacrylate resins, thermal and chemical resistant
Selective Laser Sintering (SLS)
Custom implant 3D printed with SLS to replace diseased bone. Credit: Insider on Youtube
In SLS 3D printing, a high-power laser beam fuses the powdered materials layer-by-layer in order to form an object. Since SLS requires no support, designs with complex geometries can be easily produced. All remaining powder can be collected and reused.
Examples of applications:
Tissue engineering scaffold
3d printed medicine
Implants
Examples of materials:
Nylon, a strong and durable material that resists to most physical and chemical conditions
Process and Materials Used for Plastic 3D Printing
Source: Formlabs
Metal 3D Printing
Powder used in metal 3D printing. Credit: Business Wire
Apart from plastic 3D printing processes, metal 3D printing, including Metal FDM, Selective Laser Melting (SLM) and Direct Metal Laser Sintering (DMLS), is another popular choice. Titanium is used commonly in metal 3D printing as it is lightweight, strong, hard and highly resistant to heat, oxidation, and acid.
How to Choose the Right 3D Printing Material for Medical Applications?
To select a desirable material for your medical 3D printing project, you should:
1. Define your purpose – Surgical planning? Prosthetics? Implantation?
2. Identify the requirements – Hard? Chemical Resistant? Biocompatible? Biodegradable?
3. Choose the right materials that fit your requirements
Recommendations of 3D printing materials for different requirements
Source: Formlab, IJSRP, Conserve Energy Future, ScienceDirect, Wiki, ResearchGate, Fabbaloo, Reading Plastic
Although properties are the main consideration when choosing the most suitable 3D printing materials, prices may also a considering factor.
Here is the price of materials mentioned above:
Source: All3DP
Regulations for Medical 3D Printing
US FDA
FDA building. Credit: Bloomberg
The US Food and Drug Administration (FDA) does not regulate the 3D printers; instead, FDA regulates the medical products made via 3D printing.
Medical devices, the most common type of product using 3D printing at this time – are classified into one of the three classes by the risks associated with the device. They are, simply, Class I, II, and III. The higher numbered class, the greater the regulatory control.
Classification is determined not only by the potential risks posed to patient and/or the user, but also the type and intended use of the product.
Medacta received FDA 510(k) clearance in 2021 for its Mpact® 3D Metal Hip Implants using DMLS technology. The product was proved to be substantially equivalent to the predicated devices and was classified as a Class II device. Credit: Medacta
For technical considerations specific to 3D printed devices, you may refer to the FDA’s guidance. The guidance provides manufacturers with recommendations for 3D printed devices from the design stage to process validation and testing activities of finished devices.
In December 2021, the Centre for Devices and Radiological Health (CDRH) within FDA published a discussion paper and began seeking public input on 3D printing of medical devices at point-of-care (PoC) centres like hospitals and doctors’ offices. The paper provides extensive information on FDA’s current regulation of devices and 3D printing technologies, and proposes potential PoC manufacturing scenarios for future policy development.
EU MDR
Credit: Christian Lue on Unsplash
In May 2021, the new European regulation for medical devices (MDR) has come into effect and replaced the previously applicable EU directives 93/42/EEC Medical Device Directive (MDD) and 90/385/EEC Active Implantable Medical Devices Directive (AIMDD).
Following the new regulation, 3D printed devices are no long considered as custom-made medical devices under the CE mark. They are regulated in the EU in a similar way to standardized devices according to their risk classification.
Similar to FDA, EU MDR classifies medical devices by the risk inherent in their use. The classes are Class I (low risk), IIA, IIB, and III (high risk). Implantable devices are considered Class IIB and Class III, depending on the time of implantation and if the device will create modifications or release drugs. All medical devices are subjected to conformity assessment before being placed on the market.
Source: Saint-Gobain
China NMPA
The National Medical Products Administration (NMPA) has issued a guideline on the regulation and registration of 3D printed devices in 2018. Since then, the NMPA has released several guidelines for different 3D printed devices including 3D printed spine fusion cage, acetabular cup and spinal implants.
How to Get Started with Medical 3D Printing?
It is obvious that the trend of using 3D printing in medical field will keep growing, and it is time for us to utilize it to improve patient care.
To start with medical 3D printing, there are usually two ways:
1. Grab a ready-to-print design from models sharing websites like Thingiverse:
Thingiverse is the world's largest platform with millions of free downloadable 3D models.
OR
2. Customize an existing design using a 3D modeling software like Tinkercad:
Tinkercad is free, easy-to-use online platform for 3D design.
If you find it is too complicated to start everything on your own, you can consider consulting with experienced companies. Novus provides medical grade 3D printing filament and 3D printing services for hospitals, researchers and vets.
Contact our expert advisors today at info@novusls.com for a free consultation.