A New Era Is Upon Us
Early clinical studies support viability of additive materials for definitive prosthetics
Adoption rates for 3D printing in dentistry have taken off in recent years as the cost of the technology has decreased dramatically. We are entering a new era, so it is a fun and exciting time. Printed devices such as night guards and surgical guides have become widely utilized, and definitive prosthetics are becoming viable options as well. The primary questions for definitive prosthetics have involved whether printed materials can be esthetic, whether they can hold up in the mouth, and whether they can be produced reliably at scale. The early studies involving wear resistance are promising, but more research remains to be done.
How do printed materials differ from other materials used by dental laboratories?
Some of the new hybrid nano-ceramic materials actually are displaying better wear resistance than products used in the analog world, such as conventional denture teeth. However, we know porosity issues come with 3D printing—at least in the current era of the single-resin, single-light-source printing process—so hygiene becomes even more important. Our clinicians must be calibrated with us on the expectations for these products. If you spend a lot of time characterizing a denture for a patient who is a smoker, it probably will not last long in the mouth because bacteria get into those cracks and they propagate. With the proper care, however, we are reaching a point where we can trust these materials to hold up well over time, and the esthetics and function are strong.
How important are instructions for use (IFUs) for any printed materials?
Just as using materials from a manufacturer who has carefully validated them with the hardware is important, utilizing the exact processes that the manufacturers have specified—including cleaning and curing—is critical to ensure that we get standardized results. The FDA released its first guidelines for 3D printed medical devices in 2017 and has pending documentation expected to be released early this year that will focus on regulating at the point of care. Currently, a clinician can purchase a $500 printer off Amazon and use a high-end dental resin in it; good results can be achieved with extensive knowledge and fine-tuning, but without that, it can result in fractures, color changes, and poor fit with materials that otherwise are very reliable, so that will no longer be considered compliant under the new regulations. We need to ensure that we are utilizing a known recipe that keeps the patient safe and provides a known result.
Is multi-material printing a realistic possibility in the future?
The dental industry's knowledge of light and resin has helped push the additive manufacturing industry as a whole to provide better material solutions, but we still will always be handcuffed to one material at a time with the current technology. That is super limiting, especially for the denture application, where we always need to print a minimum of two parts. I view a world where we can print a denture base and a denture tooth at the same time via a jetting technology, allowing us to use different shades simultaneously. Jetting offers a number of advantages, but it has required a a non-viscous material to pass through the small nozzles properly; current DLP resins are very viscous, and making them less viscous sacrifices quality and can increase toxicity. There have been recent breakthroughs on the chemistry side, however, and jetting will play a very big role in definitive dental prosthetics as we look to the future.
My whole mission pertaining to 3D printing in dentistry is to provide high-quality products at a more affordable price to the patient. We are giving people more access to care. We need to keep the patient first.
About the Author
Chris Kabot is Vice President of Research and Development for Affordable Care.