by Jack Ringer, DDS
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For most patients, having an impression taken ranks among the most disliked of dental procedures. As we’ve likely all witnessed, the bad taste of most impression materials and the discomfort of the procedure itself are often enough to make patients gag. For the dentist or assistant taking the impression, the patient’s distress makes for an uncomfortable procedure, and the three to four minutes that it takes for the material to set can pass by very slowly.
Recently, however, a new tool has made it possible to eliminate much of the discomfort in the impressioning procedure, giving dentists with this technology an opportunity to set their practices apart in the eyes of patients. Digital impression systems, which use intraoral wands to capture digital images of the patients’ teeth, offer a much more tolerable method of capturing impressions.
Additionally, the images captured by a digital scan are as accurate or more accurate than traditional impressions. The combination of greater patient comfort and greater accuracy of the final restoration is a powerful incentive for dentists to look more closely at the technology. Furthermore, the greater efficiency made possible by these devices can have an important impact on a practice’s bottom line.
By their very nature, traditional impressions are susceptible to inaccuracies. Any one of the numerous steps involved in the process of creating a restoration using a traditional impression can introduce an error, either because of the human element or a material defect.
Impression materials can be influenced by the way they are mixed, the temperature at which they are stored, or the manufacturing lot in which they are produced.
Additionally, the technique used by the practitioner can lead to inaccuracies, as can the techniques and materials used in the laboratory. While techniques have evolved over the years to compensate for some of these issues, the human element and materials involved in the procedure make impressioning a very delicate process.
Digital impressioning devices remove much of the guesswork and unpredictability from the impressioning process. The device used in my practice, the 3M™ ESPE™ Lava™ Chairside Oral Scanner C.O.S., has a chairside monitor on which the impression image is displayed as it is captured, allowing dentists to review impressions in real time and ensure they are complete before sending them to the laboratory.
Unique to the Lava C.O.S. device is that it utilizes 3-D live video captures, unlike the other systems, which rely on point-and-click capture. Live video capture is highly advantageous because there is no piecing together of data to create the final impressions as there is with point-and-click technology, which renders a more accurate result.
On the laboratory side, the restoration is designed digitally and the model is created in an automated stereolithography process, removing many of the steps at which inaccuracies are traditionally introduced. For users of digital impressioning devices, reducing the potential for human error in the restoration process has produced highly accurate results.
The new efficiencies made possible by digital impressioning devices eliminate much of the labor and guesswork associated with traditional impressions. The time-savings can be considerable, both during the impression appointment and delivery. The steps of tray selection, material dispensing, setting of the material, and disinfecting and shipping the impression are eliminated.
While taking the digital impression, the ability to see the image as it is being captured and review it carefully before sending it to the lab virtually eliminates the need for a retake. The scan of the operative arch, opposing dentition, and bite can be completed in just a few minutes. As software systems for these devices become more sophisticated, the time needed to capture a full scan will likely be decreased even further.
After the digital impression is captured, the dentist can submit the information electronically to the laboratory, with instructions to create a traditional PFM or a compatible CAD/CAM restoration. The steps involved in model-making are eliminated for the laboratory, and the automatically produced resin models provide technicians with a highly accurate and durable basis for their work.
The result of this increased accuracy is a superbly fitting restoration, which significantly reduces the time needed for adjustments at delivery, and brings down users’ remake rates considerably. In fact, 3M ESPE recently began offering a guarantee for new doctors using its Lava C.O.S. — the company will reimburse case fees and compensate the lab if a restoration created with the device does not fit.
Marketing your high-tech practice
Having an impression taken with a digital system can actually be an interesting, positive experience. Patients who have had traditional impressions taken in the past are relieved not to have a mess in their mouths.
Many are very interested in the technology and in watching the chairside monitor as the scan is captured. The ability to see impressions live on the screen is an eye-opening, interactive experience, as opposed to the unpleasant wait for a traditional material to set.
The device can become an important tool in marketing your practice and attracting new patients. I have incorporated messaging about the digital scanning device on my practice’s Web site and in other marketing material to let patients know we have this remarkable capability.
In my practice, the device fits well with other patient-friendly technologies, including lasers, electronic anesthesia, air abrasion, and digital radiography. As a proponent for technology, I have worked to create an atmosphere that projects this philosophy to patients and tells them we have invested in tools to make them more comfortable and help us perform better dentistry. This atmosphere is an important tool in distinguishing a dental practice, and helps keep referrals coming.
Increased efficiency and the bottom line
As with any new piece of dental technology, dentists need to carefully consider the economics of their situations before making an investment in a digital scanner. However, digital scanning devices offer a number of cost-saving benefits that can serve to offset the initial price tag.
First, they drastically reduce the need for traditional impression material, which in my practice is a cost of approximately $30 per impression. While my experiences with traditional impression material are likely no worse than a typical dentist’s, the added efficiency of making digital impressions has been obvious.
Previously, it was not unusual for me to examine an impression tray after removing it from a patient’s mouth and decide that the impression had to be redone. Alternately, many of us likely receive occasional calls from our labs asking us to retake an impression.
The dentist’s ability to judge the quality of a traditional impression is limited by the fact that it is a “negative” of the dentition. A digital scan gives dentists the ability to see the “positive” image, and to magnify and examine it carefully before submission to the lab. If an area is missed in the initial digital scan, the Lava C.O.S. allows the user to “patch” the scan without having to retake the entire impression.
In addition to the reduced material cost from the elimination of retakes, the time savings from digital impressions can be translated into greater productivity. Research has shown that with use of the Lava C.O.S., seating times for single-unit crowns are reduced by an average of 41%.
In my experience, the bite and contacts of restorations made with a digital scan are highly accurate, and few adjustments, if any, are necessary. The incidence of remakes in my practice has also been greatly reduced, which correlates with data showing that Lava C.O.S. users report a remake rate due to marginal fit up to 80% below the industry average.
The Lava C.O.S. is currently indicated for single-unit crowns, multiple and adjacent units, bridges, inlays and onlays, veneers, and seated implant abutments. While not yet indicated for every type of restoration, the capabilities of these devices are growing, and I expect that my use of traditional impression material will decrease even more in the future.
Just as digital radiography has replaced traditional X-rays, I predict that analog impressions will eventually be replaced as well. At this point, dentists who adopt digital impressions have an opportunity to market their practices based on this capability and grow a pool of loyal patients. Over a period of years, the accumulated savings from reduced material costs and a growing patient base can make an investment in a digital impressioning system a very smart move.
Dr. Jack Ringer, an accredited member of the American Academy of Cosmetic Dentistry, has been in private practice for more than 25 years in Anaheim Hills, Calif., and has been teaching contemporary esthetic dentistry at various teaching institutions for the past 14 years. You may reach him at firstname.lastname@example.org or www.dentalcosmetics.com.