Additive Manufacturing

Dental Industry

The reclining chair, overhead-mounted drill and X-ray machine have long been essential fixtures in any dental clinic. As with other professional sectors of the economy, dentistry is rapidly transitioning to a digitized business model. Soon, it is likely that digital scanners and 3D printers will become just as indispensable to dental professionals as the equipment they’ve traditionally used.

The demand is certainly significant. For instance, according to the American Academy of Implant Dentistry (AAID), the United States dental implant and the prosthetic market are expected to generate $6.4 billion in annual revenue in 2018. In large part, this is because the AAID estimates that 35 million Americans have no natural teeth remaining in one or both jaws.

3D printing in dentistry will improve results for patients while simultaneously shifting production from overseas dental labs back to local facilities. Facing serious foreign competition, the number of dental labs in the United States declined from 7,863 in 2004 to 6,584 in 2015, according to the National Association of Dental Laboratories.

3D Printing in dentistry is a perfect fit

The evolution of additive manufacturing (AM) in dentistry and orthodontics is certainly understandable. Much like a precision-made orthodontic appliance and a patient’s mouth, 3D printing and dentistry are a perfect fit. In fact, orthodontics already uses popular AM processes like vat polymerization, material jetting and material extrusion (fused filament deposition).

Dentistry requires customized crowns, implants, dentures and appliances, and 3D printing’s strength lies in the production of high-resolution, one-of-a-kind objects. During the overall transition to digital dental services, some dentists invested in milling machines capable of quickly producing crowns for patients. Today, that subtractive technique is increasingly challenged by additive manufacturing (AM) processes.

Digitally scanning, combined with 3D printing, also promises to reduce some of the anxiety associated with the dental experience. Those trays filled with a gooey alginate triggered the gag reflex in many an uncomfortable patient. Now, however, it is possible to take a contactless 3D scan of a patient’s mouth as a prelude to crown, bridge and denture fabrication. Dental clinics with on-site 3D printers are well-positioned to provide dental solutions to their patients in minutes or hours rather than days or weeks.

Applications in dentistry and orthodontics

AM processes are already employed to produce everything from dental implant drill guides to frameworks and copings.

With the 2017 FDA approval of a material used to 3D print denture bases, it is now possible for dentists and dental labs to offer 3D-printed full denture solutions. The bases are printed in four different shades using digital light processing (DLP) technology, which employs micromirrors to precisely focus light in a vat of liquid polymer, a single micro-thin layer at a time. The light cures (hardens) the polymer to form a high-resolution object.

The fabrication of 3D-printed dental crowns used to be labor-intensive, with CNC milling a key part of the process. Today, 3D printing of crowns features resolutions down to 10 microns, allowing for smooth surfaces with minimal post-processing. Using selective laser sintering, electron beam melting (EBM) or direct metal laser melting (DMLM) machines, it is possible to print crowns from cobalt-chrome and other alloys. In-house production of 3D-printed braces reduces the number of visits required during a lengthy period that often spans 18 to 24 months or more.

Those prone to grinding their teeth at night are often fitted with a flexible night guard. Using 3D printing in dentistry, it is possible for clinics to fabricate these indispensable mouth appliances on-site in less than an hour. Similarly, it is possible to quickly print clear aligners and acrylic retainers using AM processes.

3D printing in dentistry is also poised to take on serious reconstructive challenges. Just as titanium cranial implants have been used in reconstructive surgery for trauma and cancer victims, it is possible to use 3D printing in mandibular reconstruction and lower arch implant rehabilitation.

In addition, laws require dentists to maintain dental records, including traditional gypsum models, for many years. Over time, storage requirements can become quite daunting. Digital files and hard models printed on-demand may help dental professionals meet compliance requirements.

There is substantial potential for 3D printing to bring comprehensive change to the dentistry profession. An article in the British Dental Journal asserts that, “The congruence of scanning, visualization, CAD, milling and 3D-printing technologies, along with the profession’s innate curiosity and creativity, makes this an exceptionally exciting time to be in dentistry.”