by Armen Mirzayan, DDS
For more on this topic, go to www.dentaleconomics.com and search using the following key words: Focus on, chairside CAD/CAM, impressions, Dr. Armen Mirzayan.
When chairside CAD/CAM was first introduced to the dental community in 1985, it was slow to catch on. The technology garnered a lot of fanfare, praise, and excitement, but with it came too many questions and unknowns. Moreover, CAD/CAM had a deliriously high price tag. At the time, it was probably the most expensive piece of operatory equipment a dentist could own. So, even if we were able to overcome the initial sticker shock, there were important questions regarding the clinical viability of chairside CAD/CAM that just couldn't be appropriately answered right away. Only with the passage of time (lots of it), along with reams of research and real-world application, would we know for sure if this amazing new technology would be a boom or a bust.
Here we are now, 23 years later, and we've got all the answers we need. The materials are clinically proven, the chairside indirect restoration process is incredibly effective and efficient, and the technology is more advanced, versatile, and capable than ever before. With more and more manufacturers designing systems that provide chairside digital impressions — the basis of chairside CAD/CAM — it is now safe to say that CAD/CAM dentistry has been fully accepted by mainstream dentistry.
Making a good impression
Today, there are several distinct kinds of chairside CAD/CAM available from different manufacturers. There are systems, such as the iTero by Cadent and Lava C.O.S. by 3M ESPE, that allow the dentist to take a chairside digital impression only, which is then sent via the Internet to a fabrication center. While these systems eliminate the conventional material-based impression, they don't eliminate lab intervention or the associated lab fees. The single most beneficial aspect of CAD/CAM dentistry is to deliver a restoration in one appointment! There are also systems that allow the dentist to take a digital impression as well as design and mill the restoration in-office, such as the E4D by D4D Technologies, LLC.
Sirona Dental Systems has just released the CEREC AC Powered by Bluecam, which allows the dentist to take the digital impression chairside, design the restoration, verify it for proper fit and occlusion, and then mill and place it in a single patient appointment. It also offers the option to send digital impressions to a lab for fabrication via the Web portal, www.CERECConnect.com.
It's the only chairside CAD/CAM system that offers a comprehensive range of chairside-fabricated restorations, including inlays, onlays, crowns, veneers, and multi-unit provisionals. It also offers the option to send digital impressions to a lab when necessary, such as for multiple-unit bridges, complex cases, or to handle overflow.
How do CAD/CAM systems factor into today's economy?
In the past, dental CAD/CAM was often thought of as a luxury or niche product only suited for high-esthetic cosmetic dental practices that could afford it while still being profitable. Today, this is simply not true. The beauty of the chairside CAD/CAM is the inherent versatility to provide restorations of proven strength and dependability for everyday “bread-and-butter” restorative needs, such as replacing old amalgams or repairing new cavities with conservative all-ceramic inlays. In a faltering economy, where high-cost elective cosmetic procedures are declining, a chairside CAD/CAM system must be capable of providing daily dentistry for any patient, and it must do so affordably for the patient and with a profit for the dental office.
For most typical bread-and-butter cases, the all-ceramic restoration goes straight from the milling chamber to the mouth with no external characterization (stain and glaze) necessary to blend right in with the patient's natural dentition. A quick pass with a polishing wheel is the typical protocol for producing a restoration that is virtually undetectable.
Patients generally prefer this option, but a significant number of dentists opt to stain and glaze their restorations to rival lab-fabricated restorations. This extra step requires minimal effort, yet affords most practices the opportunity to showcase team members and contribute to the overall internal marketing aspect of the machine.
How the chairside CAD/CAM process means profit in any office
Productivity in the dental office is a direct result of efficiency and effectiveness. The CAD/CAM process lends itself to being efficient, effective, productive, and profitable.
Many of the steps involved in fabricating a restoration are either automated or can be done by a trained assistant, so the doctor does not have to be with the patient the entire time and can be productive elsewhere.
A typical inlay or onlay may take about 45 to 60 minutes to complete from prep to final placement, but the doctor is not with the patient the entire time. For example, after the prep is done, a qualified dental assistant (in states that allow assistants to take final impressions) can take the digital impression and design, mill, and cement the restoration while the dentist sees two or three other patients for hygiene exams, a fourth patient for a CAD/CAM crown prep, and another patient for other simple restorative procedures.
This system is a multitasking workhorse for the multitasking dentist. Monitoring the health of a dental practice by gauging its hourly production has become an industry standard. CAD/CAM maximizes the hourly production by reducing associated costs, increasing efficiency, and delivering effective care to patients who appreciate being finished in one visit.
Bluecam technology: productivity comes to light
The CEREC AC System's acquisition camera, “Bluecam,” uses blue light-emitting diode (LED) technology to capture impression images with unprecedented detail and speed. A half arch can be imaged in 40 seconds, a full arch in about two minutes. The individual images are automatically stitched together as the camera acquires them as it moves along from distal to mesial. This allows for easier quadrant dentistry, in which one restoration is being milled while the next in line is being designed. The learning curve has been dramatically reduced with this new system.
Concerning precision, the shorter the wavelength of light used to acquire the image, the greater the detail. Compared with other chairside CAD/CAM systems available that use red laser light or infrared, the blue light used by the new system is at the shortest — and therefore most precise — end of the visible spectrum.
A short wavelength means the individual waves of light are extremely close to each other — tight and dense — whereas longer wavelengths are stretched farther apart and are, in a sense, “looser” than shorter wavelengths. The more dense and short the wavelength used to acquire an image, the more accurately and precisely it can reproduce that image.
Conclusion
The clinical viability of chairside CAD/CAM is no longer a point of contention in the dental community. All-ceramic indirect chairside restorations are proven to last as long as alloys and direct composites, with wear properties similar to natural enamel. The system, process, and associated restorative materials have been researched extensively, with more than 370 clinical articles published since 1987, and, as the technology advances, more studies are being conducted and articles written. The fact that there are four chairside CAD/CAM systems on the market today for in-operatory use, and more than double that number for laboratory use, proves that CAD/CAM is no longer a niche product; it has fast become a must-have commodity in dentistry.
Profitability also is no longer a deterrent to ownership, as the versatility of chairside CAD/CAM has expanded to include virtually all types of restorations for virtually any indication. Although it's perfectly capable of fulfilling the needs of patients who want “Hollywood smiles” and practices that want to specialize in them, it's not strictly the domain of high-end practices in affluent markets.
Chairside CAD/CAM also is ideally suited for everyday bread-and-butter dentistry, which is the foundation of most successful dental practices today, and a mainstay of profitability in an economic climate that's currently at the lowest levels in history. In times like this, dentists looking for a solution to streamline efficiencies, increase productivity and profit potential, and have fun doing it all are encouraged to consider chairside CAD/CAM as a way to achieve those goals.
Armen Mirzayan, DDS, is in private practice in Los Angeles and is a certified continuing education provider for the state of California and the Academy of General Dentistry. He maintains membership in the American Dental Association, Academy of General Dentistry, Academy of Computerized Dentistry, and American Academy of Cosmetic Dentistry. Reach him at [email protected].
