So far, Everyone has heard about the benefits of digital dental impression scanning. Digital “impressions” are more comfortable for patients, faster for the dental team and are able to produce highly accurate images that contribute to restorations that sit easily and quickly. I have personally used a digital scanner for six years and have been able to see how each successive generation of technology has improved upon the last. Today, scanners have reached a point where they are more versatile, accurate and productive than ever before.
My current scanner is the 3M True Definition Scanner, which has greatly streamlined the workflow in my office and not just for crown and bridge work. All too often the discussions surrounding scanners are only about crown and bridge applications, which makes sense given how much of the average dentist’s day is devoted to these procedures. But digital scanners have capabilities far beyond crowns and bridges, which can make them even more valuable tools. It is important for professionals to consider not only what they may be comfortable doing with a digital scanner now, but also what additional workflows they may one day want to incorporate into their daily practices.
READ MORE | Joining the digital workflow: The chairside CAD/CAM case
Understanding the “architecture” of a scanner
When considering different scanning systems, dentists should carefully consider how they integrate with other technologies. This integration, or lack thereof, will dictate the workflows the dentist can access. For example, the 3M system has two different connection classes that give the dentist the opportunity to perform many other applications. These include orthodontic treatment, implant dentistry and milling of CAD/CAM restorations.
First, there are “Trusted Connections”, which means that a workflow has been technically and clinically tested and that dentists can expect a high level of integration and smooth communication between technologies. Currently, the 3M scanner has reliable connections with various technologies for mills, implants and orthodontic appliances.
In addition to reliable connections, the 3M scanner also produces “open” STL files, meaning scans can be exported to any system that accepts STL files. This is in contrast to many scanner systems which are “closed”, producing files compatible with only a limited selection of workflows. With an “open” system, dentists have the flexibility to use the scanner for whatever design, material, and manufacturing options they desire, as long as the system can accept STL files. For example, many dentists are currently exploiting these open connections to produce night guards or other devices.
Reviewing a few sample workflows will help demonstrate how my 3M True Definition scanner provides flexible options for a wide variety of restorations and treatments:
Biomet 3i implants
With this workflow, we use the scanner to take a digital impression of the Biomet 3i BellaTek Encode Healing Abutment in place. This therapeutic abutment has codes on the occlusal surface that eliminate the need for impression management. After reviewing the scan for completeness and accuracy, we send it electronically to the BellaTek Production Center. There, a patient-specific abutment is designed and sent to my designated laboratory for review, after which the custom abutment is milled by the Manufacturing Center. The abutment and an SLA model of the abutment, working model, and gauge model are then sent to my lab where the final restoration is designed and completed. The lab then delivers the model, base and restoration to me. For my office, this entire workflow simply involves the initial scan and electronic submission of the files, making this workflow faster, easier, and more efficient than conventional implant impression techniques. I was actually a pilot user of this workflow with the 3M ESPE Lava Chairside COS Oral Scanner Now it works even more smoothly with the reliable connection to the 3M True Definition Scanner.
Invisalign
To create clear Invisalign aligners, we scan the full arch and review the 3D model on the touch screen to ensure the scan is captured accurately. We then send the scans electronically through the trusted link to Invisalign. While the guidelines say to allow 90 minutes for the information to be transmitted, in my experience this sometimes takes as little as 10 minutes. On the Invisalign Doctor site, we simply enter the patient’s information and attach his or her scan to the online prescription. Once I approve the ClinCheck created by Invisalign, the aligners are made and shipped back to me. We really like this workflow and the patients do too. Once again, it’s faster, easier and more efficient.
Control, flexibility and precision
This flexible system of open and trusted connections gives me greater control over the workflows used in my practice and our select labs. Today, I find that almost every lab I work with is fully prepared to handle scans or collaborate on digital workflow with SLA models. Lab technicians tell me they appreciate that SLA models are more durable than stone, so they won’t crack or chip. The models also have very sharp, crisp detail and a better surface finish than previous generations of digitally produced models. These models and open STL files give me the freedom to be innovative and apply my scans to different applications. The 3M system expands my ability to use digital data and does not limit how I can apply it.
In any of the workflows discussed here, accuracy is of course of the utmost importance. I have found that digital scanning provides a level of accuracy that we cannot achieve with conventional impression materials simply because of the nature of the materials and the process. Any conventional material must be mixed, resulting in the risk of bubbles, voids or uneven setting of the material. Additionally, every material on the market has some degree of shrinkage and every model that is poured will have some degree of set expansion. Additionally, conventional impressions must be disinfected, which often happens once in the dental office and again in the lab. Each of these factors can introduce a slight distortion to the procedure with conventional techniques, regardless of the experience of the dentist or laboratory technician.
Instead, a digital scan gives the dentist the ability to instantly see the “impression” on the chairside screen and zoom in to examine every aspect in detail. In addition to being much faster than a conventional impression, this process virtually guarantees that the dentist will send the lab a complete and accurate “impression”. If something doesn’t look right, it can be rescanned in seconds. It is no longer necessary to send an impression to the lab and hopefully it will come out okay.
READ MORE | Why digital impressions?
conclusion
As can be seen from the sample workflows discussed here, digital scanners have evolved far beyond typical crown and bridge applications. Today, a scanner can serve as the entry point to a long list of workflows, and dentists and labs have additional freedom to think of their own applications for STL files. As more reliable connections are added, dentists will have access to even more efficient workflows.
The continued expansion of the capabilities of these systems is great for patients, dentists and labs. Patients have a more comfortable and consistent chairside experience, and dentists and labs gain a tool that helps them work more quickly, efficiently and accurately.
Pamela G. Doray, DMD, MSEd, FAGD, AAACD, she received her DMD and MSE at the University of Pennsylvania. She is currently an assistant professor in both the Department of Restorative Dentistry at the University of Pennsylvania School of Dentistry and the Department of Oral Biomaterials at the University of Texas Dental Clinic at Houston. Dr. Doray is an accredited member of the American Academy of Cosmetic Dentistry, a member of the Academy of Osseointegration, and a member of the Academy of General Dentistry. She serves on the Dental Innovator Council for 3M ESPE and is a speaker-mentor for Biomet 3i. Dr. Doray maintains a private practice focusing on adult restorative, cosmetic and implant dentistry in Philadelphia, Pennsylvania.
