The Artificial Intelligence Will See You Now
One of the hottest topics on the scene right now is artificial intelligence. It’s hot, but not necessarily new. Two of my favorite films from my youth were focused on the rise of A.I. and its consequences. Namely, the Terminator and The Matrix franchises. The first of these films was released in 1984…four decades ago. Both franchises showcase “intelligent” machines (or robots if you will) and their hostile relationship with their creator…humanity.
Today’s outlook is far less dramatic but still interesting watching things unfold. One of the major talking points with the continual improvements to A.I. are the tasks that it can perform in the context of disrupting professions. In other words what jobs are going to be deemed obsolete because a computer can do it with greater efficiency. Let’s define greater efficiency as any net improvement in speed and accuracy.
A “machine” will perform tasks without emotion. In some industries that’s good, in some industries that’s not good. Presently looming are self-driving vehicles which will threaten the livelihood of truckers who are only allowed to drive a fixed amount of time per day. A self-driving vehicle can drive non-stop representing a 100% increase in speed of delivery. That’s just one example.
In my world (knock on wood), it would seem that we are more insulated from the creep of A.I. on the large scale. This is largely due to the fact that every dental issue and pathology is unique to the tooth and the person. Not to mention every individual’s oral anatomy in variable making it difficult to program generic applications. This does not mean that A.I. applications are not entering the field of dentistry, and the ones that are showing up are for the time being making life easier for the dental providers without the slightest threat of taking away our jobs.
One such application I use everyday and is the utility that has had the greatest benefit to my practice as a dentist, and that is same-day digital crown design via 3D optical scanning. In order to fully describe this to the lay person let’s discuss the former method of crown fabrication with the method I’m using now and have been since 2015.
What is a Dental Crown?
A contemporary dental crown is a 1.5 to 2mm thick monolithic shell that replaces the outer shell (mostly enamel) of a damaged tooth. Think of it as replacing the roof and siding on an old beat-up house. Also, when I say monolithic it just means the crown is a single material. The two materials that make up 95% of crowns today are Lithium Disilicate and Zirconium. These have replaced the prior industry standard of the porcelain layered over a metal core called a PFM (porcelain fused to metal) in our world.
Why Would a Tooth Need a Crown?
There are several reasons but let’s talk about the 2 main ones. The 1st being that the tooth is structural compromised resulting in decreased functionality or the high potential of decreased functionality in the near future. “Your roof looks like it’s going to cave in, should we fix it before it caves in?” I imagine most of us would answer yes to that question. Common reasons a tooth becomes structurally compromised is large dental decay (cavity) too large for a simple filling (termites have created a lot of rot in your roof). Quite often this decay is secondary to an already existing large filling (we have patched your roof a few times and now it’s time to just re-build the whole thing).
Another reason is that a portion of the tooth will just break off (a tree fell on your roof). This is also very frequently associated with prior dental fillings. For those patients that see their hygienist routinely we can often identify these potential fractures before they happen, and quite often they are preceded by sharp discomfort while chewing. I should also clarify (in case any other dentists are reading), that depending on the extent of the decay or the fracture, a root canal might be required prior to crown therapy.
The 2nd reason is simply aesthetics. In this case the tooth isn’t necessarily functionally compromised but you want to replace the old dingy siding and throw a fresh coat of paint on the trim. This is an elective cosmetic treatment which is easily accomplished with crowns or often times veneers, porcelain shells that only replace the front of the teeth requiring less removal of natural tooth structure.
How is a Tooth Prepared for a Crown?
Each contemporary crown material has its thickness parameters which as I mentioned earlier are 1.5 to 2.0mm. If I, as a dentist, want my patient’s new crown to satisfy its material thickness recommendations and look as natural and aesthetic as possible, then I need to remove a sufficient amount of the peripheral tooth structure. I have specialized diamond coated burs (fine…drill bits) that allow me to remove the exact amount needed for the optimal outcome. If I don’t remove enough the crown will either be weaker than ideal or bulbous looking making it stand out as “fake.” The industry term for that is “over-contoured.” Believe it or not this is a very common problem with new dentists because while 2mm sounds tiny to you (the reader) it looks quite significant through our fancy magnified glasses.
How is the Crown Made?
Alright! We have finally arrived at the fork in the road. Up to this point the process is the same with A.I. and prior to A.I. In the past at this point we would fill up a tray with some very colorful and thick goop called poly-vinyl siloxane (PVS) while simultaneously squirting a very colorful but runnier version directly on the prepared tooth. The tray with the thick goop then goes in the mouth while the patient bites down for approximately 2 minutes. This goop is very good at picking up the shape of the tooth if done correctly.
That impression is then sent off to a dental lab technician who creates a stone model and sculpts by hand the new crown via the lost wax technique. Google it if you want to know more about the process. This typically requires 2 to 4 weeks while the patient has a crudely fabricated temporary crown in place that often falls off before the final crown is done. This method is dying and on life support, largely because the new process is far more convenient and efficient. Remember, faster and more accurate with the assistance of A.I.
The new and improved (and vastly superior method while being way more convenient for the both dentist and patient) method replaces the very colorful Willy Wonka goop with a digital optical scan of the prepared tooth and a few neighboring teeth in either direction, a digital optical scan of the opposing teeth (the ones that bite into the teeth in the first scan), and a digital optical scan of the teeth while in a firm bite.
Once this trio of scans is captured the software (A.I.) will trace the outline of the preparation, what we would call the margin. The dentist has the ability to modify the outline if needed and then the software (A.I.) will create a new tooth with the data and information it has been provided with. A new tooth that will function in the space created for it. We call this new tooth the “proposal and just like with the outline, the dentist has a robust digital toolkit that allows for further modification and customization of the proposal. I personally do quite a bit of modification but with every software update the proposals are getting better and better requiring less and less human input (scary).
Once the dentist is satisfied with the design, they simply click the mouse a couple times and the software communicates with a CNC Milling unit outfitted with precision diamond bits that fabricates the exact crown out of a solid block of the selected material. This process takes anywhere from 8 to 12 minutes depending on the size of the crown.
When it is done milling the crown is in its blue state (because it’s a light blue prior to being sintered in the furnace) and can be placed in the patient’s mouth and further modified by hand if needed. Finally, the dentist will glaze and color the crown for optimal natural aesthetics with the goal to match the existing teeth in the patient’s mouth and place the crown in the furnace. Once crystallized the highly aesthetic, strong, and precisely accurate crown is bonded onto the prepared tooth.
I can’t overstate how awesome this advanced technology makes day to day routine dentistry for me and my patients. When I dove in in 2015, I was considered an early adopter but now 8 years later the old Willy Wonka approach is the exception to the rule. As stated earlier this “A.I.” doesn’t threaten my profession, it makes it better and easier. The single appointment crown is just one example but A.I. is also aiding us in precision implant planning and placement, 3D printing and prosthetic design, etc. I’m optimistic and excited for what the future has in store for me as a dentist.
Thanks for making it to the end of my dental ramblings and I hope you make the most of our unbeatable northwest Montana summer. Wherever the sunshine takes be sure to take your SMILE.
Read The Artificial Intelligence Will See You Now by Dr. John F. Miller, DDS, in 406 Woman magazine.