Digital manufacturing comprises two important types: one is subtractive manufacturing, which is CAD/CAM and the other type is Additive Manufacturing, which is 3D Printing or rapid prototyping.
Computer-aided designing and computer-aided milling work on the principle of the reduction of excess material from a block or other shape to a desired designed outcome that involves wastage of material. This specific limitation is being addressed by 3D Printing, which adds layer by layer to construct a designed structure. Some of the CAD applications involve radiological or image interpretation and it involves designing any healthcare data and other patient-specific virtual designs and treatment plans. The CAM application includes milling a product from the created design, including dental crowns, bridges, and implant bars, along with the cast (negative replica) for prosthetic manufacturing.
3D Printing technology
It is undoubtedly true that 3D Printing technology has made a revolution in nearly every discipline. This technology has made great strides in the engineering industries. But its usage in medical and dental applications is in no way inferior. The availability of 3D scanners, 3D software and 3D printers has caused a revolution in digital manufacturing, thereby, reducing the time and enhancing the quality of every application. There are nearly 13 different 3D Printing technologies in the world now, and each technology has its pros and cons with a complete range of materials.
The applications are enormous and innovations are happening every day using all of the above technologies. Gartner research says, by 2025, nearly 25% of surgeons will practise on 3D printed models before patient surgery. The CAGR of 3D Printing technology and materials has consistently been more than 20% in the healthcare industry, along with the up tick in the number of patents filed towards healthcare.
Common medical applications
Anatomical models and medical devices
Complex pathologies and fractures are always very difficult to categorise even with the availability of CT/MRI data. It requires a lot of skill and time to visualise the 2D image (DICOM) data into the 3D image in mind to get a proper understanding of the condition. The evolution of 3D Printing technology has been tremendous as it becomes efficient to produce a complete, variable range of patient-specific anatomical models across different disciplines in the healthcare sector. The anatomical models can be 3D printed in various textures ranging from rigid to ultra-soft and also transparent to different colours that could mimic real-life anatomies.
A patient-specific model can be used to get trained and planned and to teach for a given complex surgery before operating on the patient. Medical devices of any form can be 3D printed, and even a customised device for a specific medical condition can also be created. Necessities like ventilators and swabs for oxygen supply and testing have been in huge demand during COVID, and 3D Printing technology helped massively during that phase. Even some emergency medical devices have been designed and created to be used in war zones.
The concept of bio-printing always creates hype. Most people will be excited if they read or hear that human hearts, livers, and kidneys can be 3D printed. These are on the way, but it takes a very long time to get approved for use in humans. The human body has nearly 30 trillion cells and 200 cell types, which are the building blocks of who we are. Imagine recreating these cell types and the way it works. In the bio-fabrication technology, bio-printing utilises cells, proteins and other biomaterials as building blocks for 3D printed biological models, biological systems and therapeutic products.
This technology involves various stages of complexity, and it is highly technique sensitive. But the rapid advancement stimulated the development of novel bio-inks which are used as 3D bio-printable material, stem cell advancements, personalised cancer treatment and for drug discovery. This technology may address some of the prominent issues like demand for organ transplants, animal testing, precision treatment and is devoid of human error.
Customised orthotics and prosthetics
Currently, more than one million limb amputations are carried out globally every year because of accidents, war casualties, metabolic disorders, tumours, and congenital anomalies. When an arm or other extremity is amputated or lost, a prosthetic device or prosthesis is needed to carry out the day-to-day activities to lead an independent life. Advanced scanning expertise can get accurate patient data, while the designing and development process will be done using various tools and a team of experts.
The designed data will create end-use prostheses by combining it with 3D Printing, advanced sensors, and conventional methodologies using a choice of materials based on the requirements. The orthotics and prosthetics created using these advanced technologies will have superior physical, chemical, biological, and aesthetic properties along with reduced turnaround time from days to even hours.
The dental segment has exploited most applications using 3D scanners, 3D software, and 3D Printing technology. The development of materials has been expedited to such a great extent, such that it supports almost all dental applications. Concepts have been developed to scale where a dentist can have his/her complete digital workflow at a very reasonable price. Having the complete digital dental workflow is akin to having every solution required in one’s hands and enabling one to deliver any work to the patients in a few hours instead of waiting for a few days with utmost precision and exemplary finishing. The 3D Printing technology can accomplish dental tasks starting from aligners, appliances, bridges, crowns, dental models, dental implants, dentures, metal copings, removable appliances, surgical guides, wax try-ins and veneers.
Precision medicine and drug printing
Most of us know that each individual has different fingerprints. If the fingerprint itself is different for everyone, imagine the pharmacokinetics (what the body does to a drug) and pharmacodynamics (what the drug does to a body) for every person. The absorption, distribution, metabolism, and excretion for every person will be different, and so the drug dosage and form needs to be customised according to a person’s need and condition. Factors like age, sex, ethnicity, diet, and disease, along with drug interaction, will affect the efficiency of the drug.
Precision medicine starts with the complete genetic profiling of an individual. Through this profiling, we can identify what sort of disease a person can expect in their future, and they can start measures to prevent it. Giving the right drug at the right dosage to the right individual is the key here. Different combinations of active ingredients and excipients can be customised as droplets, and they can be solidified along with multiple dosages using various 3D Printing techniques.
Reconstructive surgeries can be extremely challenging, even for the most experienced surgeons. The reason is the complex anatomy and uniqueness of each defect. So, conventionally available standard-size implants won’t suit all, and they will need corrections during an operation. Patient-specific implants (PSI) are emerging rapidly as a clinically established treatment option for a variable degree of conditions to match the individual’s anatomy. This PSI can be used in various bone deformities, including injuries due to accidents, war casualties, tumours, aesthetic requirements, functional improvisation and congenital anomalies. Post-COVID, a lot of patients have been affected by mucormycosis, and PSI has been the best available option for that condition. PSI has a range of enhanced properties with absolute fit along with reduced operation time and quicker recovery.
Other advanced technologies
Augmented Reality (AR), Artificial Intelligence (AI) and Virtual Reality (VR) are being developed for educational and training purposes in lockstep with 3D technology. Smart materials and sensors are bringing unimaginable advancements in diagnostic and monitoring aspects of healthcare. The combination of AR, VR, smart materials and sensors, along with 3D Printing will bring innovations that are beyond our imagination in the field of healthcare.
Challenges with 3D Printing
There is a great disparity when it comes to using 3D Printing technology in different parts of the world. Developed countries like the USA, Canada, Australia, and certain countries in Europe have started to use a complete digital platform for their diagnostic, education, and surgical planning purposes. Developing countries like India and China are gradually adapting to the technology, whereas most African countries, which are under-developed have not adapted much to it. The healthcare budget and financial constraints seem to have a direct impact on the acceptance of advanced technologies. If the government and insurance providers lend support, there could be a significant increase in the use of these technologies.
People with design and software expertise in healthcare are rare. Engineering products can be designed on CAD and a few other software, where courses are widely offered and are easy to learn. But for healthcare, there are limited training centres, and it is only just catching up over the last couple of years. In some cases, people purchase 3D printers without having the requisite knowledge about the associated software, post-processing equipment and how they can be effectively leveraged. A person with general medical and dental knowledge along with software and design experience would be ideal in this modern world of technology-assisted health care.
The costs of 3D Printing technology alone is not an issue – it is a one-time investment. But the printing material and maintenance costs are the cause for worry especially in developing countries as the competing conventional labs and treatment costs are much lesser when compared to other developed countries.
Regulations with 3D Printing
There are several regulatory issues or risks that manufacturers of 3D Printing devices encounter that are not going to affect traditional manufacturers. These regulations will scrutinise every step involved in the following activities:
Medical data collection, quality of the data, data format conversion, standardisation of the software, 3D printer type, calibration methods and values, material choice, build type, post-processing, environmental measures and sterilisation.
In traditional manufacturing, there are protocols to ensure low error rates. But in 3D Printing, all the above-said things cannot be checked by individuals who have their own 3D Printing facility at home or in their clinic. It is hard to track the efficacy of the technology and the authenticity of the materials used. It will take some time to create a universal protocol that can be followed by every country and facility to stick to manufacturing best practices. Nevertheless, digital manufacturing, or Additive Manufacturing, already has deep roots in healthcare, and one can only expect more innovations to keep coming while it resolves issues that cannot be easily treated by conventional means.