3D printed medical device validation refers to the process of confirming and ensuring that medical devices meet and surpass certain quality and safety standards, such as the FDA and ISO13485. Validation is required to ensure 3D printed medical devices are safe for use. The FDA and ISO13485 define validation as establishing evidence for ensuring, meeting, and surpassing certain minimum required quality and safety specifications for the intended uses of each class and application of medical devices (including dental and orthodontic devices).

Validation requires the implementation of quality management systems for ensuring the manufacturing of safe medical devices. Validated medical devices should guarantee each manufactured piece is always of the same quality.

Validation of medical devices must demonstrate their safety and consistency (non variability and unconsistency) upon time before use. The FDA and ISO13485 require medical device manufacturers (not to their raw material 3D resin suppliers) to ensure that proper manufacturing processes and controls are used to guarantee the quality and safety of 3D printed medical devices.

Since 3D printing permits with a minimum investment that any dental lab technician becomes manufacturer of its own medical devices, such as dental and orthodontic devices, special attention needs to be paid to ensure quality, safety and consistent manufacturing of 3D printed medical devices. 

Reliance on "non relevant certifications" of 3D resins as if they would be medical devices are meaningless since 3D resins certifications cannot replace nor ensure the quality and safety of 3D printed medical devices since 3D resins are starting raw materials, not medical devices, which depending on their design and tuning to different printers and postprocessing units and their specifications, may meet or not the quality requirements of each class and application of medical devices.

Unfortunately, most commercial printers do not meet the minimum standards for ensuring consistent and reliable performance (without variability or inconsistency), since they often sufffer from too low light power output (leaving too high concentration of unreacted monomers, leachables, and extractables), a significant light power decay upon time (uncontrolled light power variability which results in variable decreasing quality and safety), as well as non uniform light power distribution across the printing area of the printers (higher light power in the center vs lower power in the borders of the resin tank or printing area resulting in printed parts showing different quality and safety depending on their positioning of the printing area or build platform).

This performance variability of most commercial SLA, DLP and LCD printers, unless properly addressed and prevented, is a source of inconsistency and unreliability affecting negatively on the quality and safety of 3D printed medical devices, since excessive unreacted monomers, leachables, and extractables can leach out, be extracted for example by the saliva of the mouth, and absorbed by the mucosa in dental and orthodontic applications.  

Learn more about biocompatibility of 3D resins:

Conclusions
Validation requires scientific evidence, processes, and protocols for ensuring the manufacturing of consistently produced safe medical devices and for meeting the quality regulatory requirements and specifications of each medical class and its intended use. Validation needs to ensure and verify the safety and quality of 3D printed medical devices.

Due to the effect of the design, the 3D resin, the printer, postprocessing, quality control equipment, and their specifications on the quality and safety of 3D printed medical devices is crucial that medical device manufacturers certify their products; select and tune high quality 3D resins, printing and postprocessing equipment, in accordance with properly designed, implemented, and validated manufacturing practices.

For more info read: 3Dresyns consulting for biomedical devices