Crowns are amazing restorations—if you break your front tooth horseback riding or decay weakens a molar, a crown covers the damage and reinforces tooth structure in a way that looks natural. Whenever it’s time to get one, however, very few of us leap with joy. Many of us fail to appreciate just how far today’s gleaming crowns have come.
In 200 A.D., the Etruscans, who lived in central Italy just north of Rome in what is now Tuscany, made crowns consisting of animal or human teeth held together by bands made of gold soldered together. Other cultures that used cosmetic dentistry included the ancient Egyptians, who hammered seashells into their gums as tooth replacements.
During the 18th century, dentistry was actually performed by barbers and blacksmiths. Barbers routinely performed, along with shaving and cutting hair, tooth extractions usually without anesthetics. In fact, the all-familiar barber’s pole advertised a haircut and “dental surgery.” Paul Revere, America’s most famous messenger, was a highly skilled silversmith and placed advertisements in a Boston newspaper offering his services as a dentist able to make crowns and bridges.
During this time, crowns were made crudely from cow bone, ivory tusks or human teeth (sometimes robbed from corpses buried in graveyards) and were installed using metal or wooden posts. Because the ill-fitting crowns never quite fit, they encouraged bacteria, decay and infection.
Happily, much progress was made in the early 20th century. Novocaine was invented, dentistry’s first modern anesthetic, and the “lost-wax” technique was adapted for dentistry by W. H. Taggart. Using the techniques of ancient jewelers, Taggart discovered that warm wax could be used to create an impression of a tooth. The impression could be filled with heated materials such as gold or metals that when cooled became artificial teeth implanted into the mouth.
In some ways, Taggart’s basic principle remains the same. You may be familiar with this scene: Your dentist gives you a tray of often bad-tasting putty and tells you to bite down for a few minutes. Then, a temporary crown is made for you and cemented in lightly while your impression is mailed off to a lab and processed. Weeks later, you return to the dentist who cements the final crown into place.
Dr. Brian Valle of Valle Functional and Cosmetic Dentistry explains that, thanks to advanced digital technology, uncomfortable impressions are no longer necessary. The fitting, fabrication and installation of a crown has evolved from a messy process taking weeks into a smooth generally two-step procedure taking as little as days. It is a special kind of art involving close teamwork between dentist and an accomplished lab, he notes.
Here’s what happens in his office. First he designs and prepares the tooth needing treatment to ensure the new crown will fit precisely next to the adjacent teeth. This is where skill is needed, says Valle. “It is an art. There must be precise shaping of the tooth for proper fit and function for the crown to be successful.”
Then, with a digital wand—a hand piece equipped with a tiny camera—he scans your teeth and sends 3-dimensional images and measurements immediately to a lab via a computer. With this chairside digital oral scanner, “I can scan a tooth and in five minutes the lab I use on the West Coast can receive the information and begin making it immediately,” he explains.
The advantages are many: “You don’t have a mess with impression material, the patient is more comfortable, and a scan is usually quicker and much more accurate. Since we use a lab out on the West Coast, traditionally the case would take three days to get there. Now, with the touch of a button, the lab receives the case in minutes.”
The artistry continues in the lab. Using sophisticated software and precise measurements, technicians manipulate 3-D imagery of the patient’s tooth and entire jaw, noting occlusion (bite), location, and the shade of tooth. They program a computerized milling machine to carve the crown from one block of material, usually a ceramic composite or zirconium, a high-grade porcelain. “In one step, they have everything they need to design the crown, for the right shape, size, color and bite,” says Valle.
Once the tooth emerges, it is examined, hand sculpted to the doctor’s specific instructions and then painted by a technician who layers on shades of enamel using a very small brush. Staining, color and surface texture are applied to mimic the patient’s natural teeth. The finished masterpiece is mailed back to Dr. Valle, who cements the crown into place.
“Today’s digital tools and computer-operated milling machines dramatically improve the art and ensure a precision difficult to achieve using traditional methods,” says Valle, who opened his private practice in Millersville in 1989. Communication between the dentist and lab cannot be underestimated. That’s why Dr. Valle uses a lab in Seattle, Washington, which he visits often while helping other dentists advance their skills at the Kois Center, where he is a mentor. Meanwhile, he is constantly scanning the horizon for new and better technology. So, the next time you find yourself reclining in the dentist’s chair (invented in 1878) count yourself lucky—maybe, you get to experience and appreciate the “art of the crown.”