For decades, dental implants have offered alternatives to dentures and bridges, improving people's lives by giving them replacement teeth that look a bit more natural. But, despite the advances in prosthetic teeth, not everybody is smiling: placing the implants can be a complicated, expensive, and lengthy process of trial and error for both the dentist and the patient. And, the results aren't always aesthetically pleasing.
Fortunately, Atlantis Components Inc. (Cambridge, MA), a custom dental products company, has begun to change the often-bleak scenario of "false teeth." The company has enabled approximately 1,000 dentists around the country to provide implants that look as natural as real teeth in less time and at a lower cost. A key part of Atlantis' process relies on digital duplication technology from 3D Systems' Geomagic.
From Frustration to Innovation
A dental implant has three main parts: the fixture, which anchors the implant to the jawbone; the crown, which replaces the natural tooth; and the abutment, the part that screws into the fixture and holds the crown in place. Perhaps the most difficult stage of the procedure is fitting the abutment.
"It can be very time-consuming to fit an abutment," says Tom Cole, Atlantis president. "For one thing, the mouth is a difficult place in which to work. And, depending on when the tooth was extracted or lost, there can be difficulties with the quality of bone in which to place the fixture."
Because much of the bone might have shrunk over time, dentists often must angle the fixture in a patient's mouth to anchor it into solid bone. These angles create problems in making the abutment conform to the natural shape of the patient's other teeth. Abutments also can be difficult to seat on the implant the later in the process they are placed, resulting in entrapment of the gums before the crown can be put into place. Once the abutment is placed, numerous radiographs can be required to ensure that it is properly seated, resulting in more time and expense.
Frustrated with existing tooth implant-abutment methods, Dr. Julian Osorio, a Boston prosthodontist, formulated an abutment concept that would fit the exact geometry of the patient's mouth. His goal was to create a process that would make implants accessible to mainstream dentistry. Osorio founded Atlantis Components in 1996, with a product that has changed implant dentistry -- The Atlantis Permanent Healing Abutment.
Building a Better Abutment
To create his product, Dr. Osorio turned to the world of CAD/CAM technology and Geomagic Wrap, which makes it possible to take output from 3D scanners and digitally duplicate the shape, textures, and color of real-world objects, including the cast of a patient's mouth. Geomagic Wrap models can be output directly to CAD software, stereolithography devices, or CNC manufacturing systems. They can also be automatically transformed to highly detailed, but very small, models that can be displayed efficiently on the Web.
"Geomagic allows us to obtain an accurate visualization of the cast of the mouth in the computer. This is very important in ensuring that the abutment has the proper fit," says Cole, who is not only president, but also an engineer who helped develop the Atlantis abutment process. "We're the first company to really make this process easy by taking advantage of computers and dental knowledge to design the abutment using the patient's individual oral geometry."
The Atlantis process begins with scanning a cast of the patient's mouth provided by the dentist. Geomagic Wrap is used to create surfaces from the scanned point cloud data. The surfaces are then imported into CAD software.
"The surface of the teeth is used as reference geometry for accurate modeling of our abutment. Surfacing the dental anatomy in Geomagic Wrap allows us to modify CAD models in context, thus accurately producing an abutment that fits into the patient's mouth with no further adjustments," says Bethany Grant, Atlantis senior development engineer.
The template-based work flow feature of Wrap increases productivity by enabling surface patch layouts to be reused, eliminating the repetitive task of creating new patch layouts for similar models.
"Exact Anatomic Duplicate"
Dr. Joseph Gian-Grasso, a Philadelphia dentist who has been in practice since 1973 and has been placing implants since 1983, has used the Atlantis abutment on about 50 patients in the last year or so. Dr. Gian-Grasso estimates that the Atlantis process saves him between two to six months' time because the impression for the abutment can be made the same day the fixture is placed in the bone. Previously, Dr. Gian-Grasso had to wait for the implant to be integrated with the bone.
"If you've got a busy practice, time is money," Gian-Grasso says. "Most patients really want the process completed expeditiously and expertly. The Atlantis abutment allows us to do that."
In the earlier days of implant dentistry, Gian-Grasso said the abutments he used were more a one-size-fits-all, off-the-shelf type product. "In an ideal circumstance you would have an acceptable result, but with the Atlantis abutment, the result is much more predictable because it is customized to the exact fit of the patient's mouth," he says. "The abutment actually reproduces the exact anatomic duplicate of what a dentist would try to make manually."
A Solution for Mainstream Dentistry
Using Geomagic Wrap with CAD/CAM technology, what once took 10 visits for the implant patient now only takes three to five visits. Dr. Osorio's goal of bringing implant technology to mainstream dentistry has become a reality, and the real winner is the patient, who walks away with a new smile that looks completely natural in far less time than ever before.