As an orthodontist, there is nothing more frustrating than finishing up a case, only to have the patient return later due to tooth movement. While you want to do everything possible for your patients, refining just one tooth can take time from your day that should be spent working with patients who are actively in treatment.
To combat this problem, I now use digital impressions during the debanding and retention process. As I near the end of treatment for my patients, I forego the usual two-appointment approach for debanding and retaining, and instead simplify the routine through a single disband visit where I then deliver the retainer to the patient.
In addition to eliminating the need for a second appointment, I also utilize a unique retainer removal program in my practice. When my patients have their braces removed, we automatically provide them with a primary and backup retainer. If the primary retainer breaks or is lost, the patient can simply switch to the backup and order a new primary retainer from our office. Since we have a digital impression, the new retainer can be made without the patient returning to our office.
Technology plays an important role in streamlining debanding and retention, allowing you to deliver maximum results to your patients. Below, I will outline the steps I take with my intraoral scanner and the lab.
Step One: Taking a Digital Scan
Once I determine the patient’s braces are ready to be removed, I take a digital impression with an intraoral scanner, upload the files to my lab, and schedule the final appointment. This process is advantageous to my patients for a number of reasons. First, it eliminates the need for an additional appointment to take the conventional impression and send the model off to fabricate the retainer. Patients are busier than ever, and the fewer appointments required, the better.
The second benefit—and this is huge—is that patients find intraoral scans to be much more comfortable than traditional impressions. Most patients aren’t fans of impression materials in the first place. Intraoral scanning is a superior technique for anyone with a severe gag reflex because the user can easily and immediately remove the handpiece if needed, allowing the patient to regain composure. And, if you choose an intraoral scanner with different tip sizes (large and small), you can better accommodate both adults and children.
Intraoral scanners are also impressive to patients on their own. My patients always express how amazed they are with the technology in my practice, and my staff and I enjoy having the reputation of being “high-tech.”
For even more of a “WOW!” factor, I can also project the scan onto a large LCD screen so patients and their parents can watch the process in real time.
Step Two: Fabricating the Retainers
After taking the digital scan, I send my open-format stereolithography (STL) files to the laboratory. The particular lab I work with, Specialty Appliances, located in Cumming, Ga, uses advanced software to digitally remove the braces from my virtual models, allowing them to print extremely accurate 3D models for retainer fabrication.
The reason I send the scan to the lab right away—even when the patient’s braces are still on—is to get the patient into the retainer as soon as possible and reduce the risk of tooth movement. In this way, I can provide the best care to my patient from the moment the braces come off.
One of my first concerns about switching from traditional to digital impressions was accuracy. While most accuracy studies involve restorative or prosthetic cases, some of these studies have found that crowns fabricated from digital impressions are more accurate than those made from conventional impressions; in addition, they are easier to seat.1 One in vitro study found that the accuracy of digital impressions were equal or better than that of conventional impressions.2
To see the results for myself, my staff and I created a spreadsheet to compare the results of appliances made from both stone and printed digital models after incorporating my intraoral scanner (Carestream Dental’s CS 3500) into my practice. After analyzing the data, it was apparent that the scanner delivered more accurate results and created better-fitting appliances than the alginate impressions and stone models. And, the CS 3500 exceeds the minimum image quality required by orthodontic laboratories.
The reason for the increase in accuracy is that digital impressions allow us to eliminate many of the steps involved with traditional impressions; thus, enabling us to avoid the associated problems. With digital impressions, there is no risk of distorted impressions or problems with the stone model.
Step Three: Removing the Braces and Seating the Retainer
Once the retainer is fabricated and the patient is ready for a debanding appointment, all that remains is removing the patient’s braces and seating the retainer—without the need for a return visit. By eliminating a second appointment, the patient can immediately enter a retention program, so the potential for tooth movement is eliminated.
Orthodontic treatment is quite an investment for many patients (or their parents), and naturally, they want to ensure it is protected. For this reason, we offer a retainer program to serve as a warranty for our patients’ teeth. Thanks to digital impressions, we have the ability to fabricate a lost or broken retainer immediately.
Using a Retainer Removal Program
With traditional stone models, you could only make one retainer at a time. But with an intraoral scan, you can make as many as you want from the acrylic model. This gives you the ability to not only make two retainers after finishing a treatment—a primary and a backup—but it also allows you to archive all of your virtual models.
The ability to store models digitally has changed everything about how we retain patients. Traditionally, if a patient loses or breaks his or her retainer, and is unable to come in right away, he or she has to make an appointment to get a new impression taken. By the time the patient comes in for this visit, the teeth have moved and must be reset— a headache for both the patient and the orthodontist.
Fortunately, with digital impressions, orthodontists can put ownership on the patients (and in that same vein, parents can put ownership on their child). Since patients have a backup retainer, they no longer have an excuse if their primary retainer breaks. As long as the patient wears the backup retainer every night—and doesn’t have any new dental work done—the retainer always fits.
The new retainer removal program requires less work for your practice: the patient calls, your staff orders a new retainer, and then puts the newly fabricated retainer in the mail. The process is so streamlined, you don’t even have to see the patient in person.
When you switch to digital impressions for retainers you have to make sure to price these services in a way that reflects obvious value and makes patients feel like the choice is obvious. For example, we charge $125 for a single retainer created from a stone model. However, for digital impressions, we charge $250 for two retainers (the primary and backup), as well as the virtual model archive. If patients lose one of their two retainers, we then charge $50 for a replacement.
As you can see, digital impressions have a number of potential clinical applications in orthodontics. For my practice specifically, using an intraoral scanner has helped me streamline the deband/retainer process and improve patient retention by having the ability to readily fabricate replacements. OP
Robert Waugh, DMD, MS, graduated from Georgia Regents University in 1987 with both a DMD and a Masters in Oral Biology, before going on to earn his orthodontic certification and a second Masters degree at Baylor College of Dentistry in 1989. Waugh has served as president of the Georgia Association of Orthodontists and is a member of the International and American Colleges of Dentists.
1. Henkel GL. A comparison of fixed prostheses generated from conventional vs digitally scanned dental impressions. Compend Contin Educ Dent. 2007:28(8):422-431.
2. Ender A, Mehl A. Full arch scans: conventional versus digital impressions—an in-vitro study. Int J Comput Dent. 2011;14(1):11-21.