CAD/CAM is an acronym for computer-aided design/computer-aided manufacturing. Used for decades in the manufacturing industry to produce precision tools, parts and automobiles, CAD/CAM technology has been increasingly incorporated into dentistry over the past 20 years.
CAD/CAM technology and metal-free materials are used by dentists and dental laboratories to provide patients with milled ceramic crowns, veneers, onlays, inlays and bridges. Dental CAD/CAM also is used to fabricate abutments for dental implants, used to replace missing teeth.
As the materials and technology available for CAD/CAM dentistry have improved over the years, so too have the restorations that patients can receive from this form of digital dentistry. Today's CAD/CAM restorations are better-fitting, more durable and more natural looking (multi-colored and translucent, similar to natural teeth) than previously machined restorations.
In-Office and Dental Laboratory CAD/CAM Options
Dental CAD/CAM technology is available for dental practices and dental laboratories, enabling dentists and their staff (or a laboratory technician) to design restorations on a computer screen. The CAD/CAM computer displays a 3-D custom image of your prepared tooth or teeth obtained by digitally capturing the preparations with an optical scanner. Alternatively, the 3-D images can be obtained by scanning a traditional model obtained from conventional impressions of the preparations.
The dentist or laboratory technician then uses those 3-D images and CAD software to draw and design the final restoration. The amount of time it takes for a dentist, in-office restoration designer or laboratory technician to design a restoration varies based on skill, experience, and complexity of case and treatment. Some cases could take minutes, while others could require a half-hour or more of design time to ensure quality.
Once the final restoration is designed, the crown, inlay, onlay, veneer or bridge is milled from a single block of ceramic material in a milling chamber. The restoration then can be customized with stains and glazes to create a more natural look, before being fired in an oven (similar to ceramics and pottery), and then finished and polished.
Benefits of CAD/CAM Dentistry
Research suggests that today's milled CAD/CAM restorations are stronger than those milled from earlier materials. They also are less likely to fracture.
One of the advantages of CAD/CAM technology is that if your dentist has the technology in office, same day dentistry may be a treatment option for you. CAD/CAM dental technologies such as CEREC in-office or the E4D Dentist System can be used to make an inlay, onlay, crown or veneer restoration in a single appointment, while you wait.
If your dentist offers in-office CAD/CAM, you do not require traditional impressions, a temporary restoration or a second appointment. You will only receive local anesthetic (be numbed) once for any necessary tooth preparations.
An exception to this process is the all-ceramic bridge, since it is created in a laboratory using the CAD/CAM technology. All-ceramic bridge restorations require a second office visit to insert the bridge. In such cases, a temporary restoration would be necessary.
Another exception is if your dentist prefers to fabricate the CAD/CAM restoration while you are not in the office, making it a two-appointment process. Some dentists prefer this approach in order to dedicate more time to the design and characterization processes involved with creating a CAD/CAM restoration. A temporary also would be required in this instance.
Special Considerations for CAD/CAM Dentistry
CAD/CAM technology is not a replacement for the accuracy and talent provided by a dentist or dental laboratory technician. Dentists must be precise in creating the initial tooth preparation; both dentists and laboratory technicians must be accurate when taking the digital impression and drawing the restoration.
Equally important is the accuracy and skill with which they design a restoration, particularly since the fit of a restoration is critical to preventing future tooth damage. For example, an ill-fitted crown, veneer, inlay or onlay can leave space between the teeth, or between the tooth preparation and the restoration. This could lead to an increased risk of infection or disease.
When to Choose CAD/CAM Dentistry
It is important to note that not every tooth can be treated with a CAD/CAM restoration. Your dentist will determine if a CAD/CAM restoration is among the appropriate treatment options for your condition. Additionally, despite improvements in the esthetics of CAD/CAM materials, patients may find that some CAD/CAM restorations look too opaque and lack natural characterizations.
Depending on the type of restoration that's needed (such as inlays/onlays), your dentist may prefer conventional laboratory fabrication techniques that have a longer and more proven track record for accuracy of fit. Therefore, patients must discuss their particular situation and desires with their dentist, who will make the final treatment decision based on a thorough examination.