Trends in Dentistry: Digital Imperative

Thomas J. Balshi, DDS, PhD, FACP, is a board-certified prosthodontist widely known for his contributions to implant dentistry. His four-decade career includes degrees from Temple University School of Dentistry, the University of Toronto, and the Institute for Applied Biotechnology in Gothenburg, Sweden. IDT's Editor-in-Chief, Pam Johnson, put this pioneer-turned-expert to the question about the new and exciting development of digital dentures.

IDT: The emergence of digitally designed and manufactured dentures is still in its infancy. What factors do you believe will positively impact the momentum of adoption by clinicians?

Tom Balshi, DDS, PhD, FACP:There is no doubt that the profession is moving in this direction. In fact there are projections that the digital denture market will experience exponential growth over the next few years with the numbers of dentures produced via digitally empowered production processes doubling in that timeframe. For clinicians the attraction of this process is the reduction in the number of patient visits from five appointments to as few as two, as well as the precision of the final prosthesis. The result is a savings in chairtime and greater patient satisfaction, since the precision of the final prosthesis results in fewer follow-up appointments to make adjustments for sore spots.

IDT: Isn't the precision of the final denture reliant on accurate record taking, a problem that the dental profession has historically struggled to achieve?

Balshi: Yes. There is no doubt that the record-taking step is most critical for the digital denture process to work correctly and accurately. If the clinician does not take good impressions or if the bite registrations are flimsy, then the end result will reflect those weaknesses. However, the threshold of errors that can occur should be caught by the laboratory, which becomes the filter for the system. The laboratory will identify any deficits in the record-taking process and bounce those back to the clinician. This safeguards the process and offers the laboratory the opportunity to get further involved with the client in helping him or her with the impression- and record-taking steps to achieve a successful outcome. In the end, it's forcing clinicians to do a better job.

IDT: What are the advantages of the system for clinicians who adopt the digital denture concept?

Balshi: Of all the digital modalities on the market for the clinical side of dentistry, digital dentures will be the easiest to integrate into the practice. There is nothing to buy in terms of capital equipment and they can use the same analog record-taking processes they learned in dental school.

One of the big advantages to the digital process is the bio-functional try-in. It is milled from a monolithic block of white material in different tooth shades and is a clinical preview of the final denture. Patients can actually wear the try-in denture to test-drive its fit and function—ie, their ability to chew and speak—as well as get feedback from family and friends on the esthetics of the proposed final denture.

Another major advantage of the digital process is the value of the digital record. That digital file of the patient's impression, bite, and vertical dimension of occlusion, and the approved design of the final denture can be used to create an exact copy of the patient's denture with the push of a button. If the patient loses the denture or breaks it somehow, the clinician doesn't have to bring the patient in and create new records and start the process from scratch. Another plus with the digital process is that the dentist can offer the patient a backup denture at the time of delivery for much less than the original for a win-win insurance policy against loss or breakage.

IDT: What are some of the advances in the digital denture concept that we may see in the near future?

Balshi: As was shown at the International Digital Denture Symposium in October by prosthodontist Dr. Charles Goodacre and his son Dr. Brian Goodacre, there is research ongoing to test the potential of using digital impression-taking devices to capture the fully or partially edentulous arch. The ability to capture the underlying soft tissue with intraoral scanning technology will improve as the scanners and software get better and better. The same type of technological revolution that occurred with the cell phone will happen with scanning technology. In the end it may be a digital technology that we are not aware of right now.

Being able to morph the CAD design and the virtual representation of the final denture with an image of the patient will be the next step. We are working on how to do that now and we should see that development in the next couple of years. You can overlay the denture smile design with the 3D image of the patient and do soft tissue mapping to see what type of lip support the denture will provide and be able to demonstrate the effects of moving the teeth forward or back and what will happen to the position of the lips in profile.

Another exciting aspect of this technology as it evolves is the ability to actually recreate the natural tooth form of the patient. If a patient presents with old crown and bridgework or even natural teeth and loves his or her smile, but is faced with tooth extraction due to severe periodontal disease, we can replicate the exact form, shape, and length of the natural or crowned teeth in the denture. You can take an intraoral scan of the existing teeth, or take an impression, and exactly replicate those teeth in the denture once digitized. That is a powerful tool for patient case acceptance.

IDT: Many project that the future of digital denture production lies with 3D printing technology. What are your thoughts on 3D printing overtaking milling of the final denture?

Balshi: 3D printing will probably overtake milling for the manufacture of the final denture somewhere in the future. The technology already has its foot in the door with the printing of custom impression trays and denture bases. And already we've seen two companies with FDA approval of long-term denture materials for this market. It will take 5 to 10 years for 3D printing to get to a level of sophistication for the manufacture of dentures.

IDT: What about advances in material development? Where will that lead us?

Balshi: What we have now is a material that is eight times stronger than the traditional acrylic used to manufacture removable prosthetics. And by milling a monolithic denture puck with white tooth material incorporated within that puck, we have completely eliminated denture tooth pop-off.  I believe the monolithic concept will definitely take over the digital denture market and individual denture teeth will become an interesting story in prosthodontic history.

Although we are at a very satisfactory point with the materials that are on the market for digital denture manufacture, are we at the end point? Probably not. There is always the opportunity to develop new materials or take existing materials from the industry and reformulate them to fit the digital denture process. Look at what has happened to the ceramic market. That tells you material development is always ongoing.

IDT: What signals do you see that the digital denture concept is more than a trend?

Balshi: The fact that dental schools such as University of Connecticut, Rutgers, Nova Southeastern, Maryland, Loma Linda, and many others are now incorporating the digital denture concept at both the undergraduate level and in their residency programs sends a clear signal that the digital denture concept has moved past the trend stage.

In addition, government agencies such as the Veterans Administration have incorporated digital dentures into their patient treatment systems, as has the US military. These are all good indicators that digital dentures, especially the monolithic fully milled products, are becoming the backbone of removable prosthodontics.