Crowning Achievement

Technology gives tooth restoration a new twist


Good news in technology is invariably accompanied by bad news somewhere in the marketplace.

Computers, for example, were good news to everyone except to those in the typewriter industry.

CDs were good news to everyone except to those in the vinyl record industry.

And so it follows that the new machine standing in Dr. Chris Winterholler's dental office will be good news to everyone except to those in the dental lab industry, who Winterholler predicts will be flat out of jobs as the CEREC 2's technology develops.

But as it is now, the CEREC 2 is one impressive box of computer circuitry and precision tools that turns a complex two-and-a-half week, 160-step dental process restoring damaged teeth into a single-step, less-than-60-minute job.

In the past, restoration began with your friendly family dentist grinding your tooth down and shoving wads of a clay-like substance in your mouth to create a mold; the mold would be sent to a lab while your dentist created a temporary filling for the cavity; the technician would create a replica of the damaged tooth, bake it in porcelain and send it back to the dentist, who would have to drill out your temporary filling; and if any adjustments needed to be made, the tooth would have to travel back and forth until all flaws were corrected, while you traveled back and forth to the dentist's office.

"Very labor-intensive and time consuming," Winterholler said.

Tooth time

But that was then and this is now.

With the CEREC 2, the damaged tooth is covered with a thin layer of reflective white powder that makes it visible, without shadows, to an electronic camera about the size of a hammer handle.

A three-dimensional optical impression of the tooth is then digitally scanned onto a computer screen, and it is from this image that the restoration is designed.

Once the computer is done with its creative thinking, the new cap is milled out from a solid ceramic block in 15 minutes. And the cap is milled so precisely that it snaps right on to the damaged tooth.

And if any adjustments need to be made to the artificial tooth, it doesn't need to be sent back to a lab.

"I do it right here," Winterholler said. "Those delays are completely eliminated."

There are only five dental offices in all of Arizona that have a CEREC 2, Winterholler said, and his was the second.

Created and perfected by a German electrical company, the machine takes advantage of military technology that's been around for 10 years.

"I've repaired about 5,500 teeth since I bought CEREC 2 in November," Winterholler said, "and, as for its convenience for me and my patients, it just can't be beat. More of my time is freed up because I can complete a crown in one visit instead of two or three, and for the patient, there is only that one visit and no added cost."

Generally, the crowns produced by the CEREC 2 require a few more adjustments than those that would come back from a lab, Winterholler said, "But it's not any more adjustments than the lab man used to do before he shipped it back to me. This machine actually puts more of the control in my hands, rather than the lab man's."

Once a patient's tooth is optically imaged, Winterholler stores the data on a conventional floppy disc.

Tooth repair on the go

"If the crown breaks when you're off on vacation somewhere, I can e-mail the data file to the other dentist if he has one of these machines, and he will instantly be able to reproduce the crown," he said.

Not that Winterholler expects it to break.

"The dental porcelain used by this system is of an extremely consistent quality. It's manufactured in Europe under controlled conditions whereas hand-fabricated laboratories are all at different elevations, the conditions are all different, the lab techs have varying levels of experience.

"Also, if you're making porcelain in a dental lab, you're mixing it with water and packing it and sculpting it and baking it and you're going to get bubbles inside or other imperfections.

"Each one of these crowns, on the other hand, is as perfect as all the others. And this dental material almost mimics your tooth structure; it gives you about 95 percent of the strength of the original tooth.

"It is," Winterholler concludes, "a real breakthrough."

Of course, breakthroughs in computer technology are a daily occurrence. What will Winterholler do when the CEREC 2 becomes outdated?

"That's already happened," he said. "That's why, next week, we'll be getting the CEREC 3. It's even better and faster."

Commenting has been disabled for this item.