Efficient, Accurate, and Affordable Digital Scanning

Figure 1. Fractured lingual cusp on tooth No. 15.
Figure 2. The temporary crown fractured after several years in service. Note: Tooth No. 14 was restored with a zirconia crown (Lava [3M ESPE]) in the time since the photo in Figure 1 was taken.
Figure 3. The preparation, as seen after removal of the top cord.
Figure 4. The area was lightly powdered prior to scanning.

By now, we have all heard about digital impression systems. In addition, we have been told about the benefits of greater accuracy, reduced retakes and remakes, and greater patient comfort. Some dentists have adopted these systems and are already realizing these benefits, but many are still waiting on the sidelines.

What are dentists’ reasons for waiting? For some, it’s a hesitancy to be an early adopter and the risks in having to work through technology refinements. For others, it’s the perception that their current impression-taking method is adequate enough to justify complacency. However, for many dentists, one of the primary reasons that they have not adopted a digital impression system is cost. With price tags of $20,000 and higher, digital impression systems have been a significant investment that not all practices have been willing (or able) to make.

The following case will demonstrate the use of a new and more affordable scanning system (True Definition Scanner [3M ESPE]) used in the treatment of a fractured second molar.

CASE REPORT
Diagnosis and Treatment Planning

The patient was a middle-aged man who had been with the practice for more than 10 years. A number of issues were identified at his initial visit, including the need for repairs of several broken teeth, 3 root canals, and 10 crowns. The patient was not experiencing pain with these issues and thus was able to work through the treatment recommendations over a number of years, according to priority. Figure 1 shows an image of tooth No. 15 (taken in 2007), after the tooth had fractured. Because it was not painful, the patient opted to treat the tooth with a long-term provisional, continuing on with planned restorations to other teeth in the interim. A permanently cemented prefabricated temporary restoration (Protemp Crown [3M ESPE]) was used to provisionalize the tooth until it could be treated with a definitive solution (Figure 2).

After several years in service, the temporary crown fractured (in the fall of 2012). The patient’s treatment had progressed to a point that he was ready to address tooth No. 15.

Figure 5. A digital image (True Definition Scanner [3M ESPE]), clearly showing the entire preparation margin.
Figure 6. A digital image demonstrating the 3-dimensional view of the preparation.
Figures 7 and 8. The definitive zirconia crown (Lava).

Treatment Protocol
The patient was anesthetized with 2% Lidocaine (1:100,000 epinephrine). The tooth was cleaned using a prophy cup with plain pumice, and then flossed. The temporary crown was removed. Next, epinephrine-impregnated cord (Gingi-Pak 1) was packed into the sulcus, followed by an additional cord (Siltrax AS 10) soaked in a solution of buffered aluminum chloride (Hemodent [Premier]). Packing 2 cords, as outlined here, allowed for better control of the tissue and the minimization of any bleeding.

The tooth preparation was then done, and the top cord was removed (Figure 3). The first cord was left in place and the preparation was lightly powdered (Figure 4). The tooth was then scanned and the digital impression (Figures 5 and 6) and prescription were sent to the dental laboratory team for the creation of a zirconia crown (Lava [3M ESPE]).

The tooth was provisionalized again (Protemp Crown [3M ESPE), using a temporary cement (RelyX Temp Zinc Oxide [3M ESPE]). The patient returned for the crown delivery appointment and the temporary was removed, revealing healthy tissue around the tooth at the subgingival margin. The crown was tried-in to confirm fit, and then it was cemented with a self-adhesive resin cement (RelyX Unicem 2 [3M ESPE]) (Figures 7 and 8).

Currently, all that remains in the patient’s original restorative plan is the replacement of an old filling on an anterior tooth. During the past 11 years, this patient has experienced the evolution in both impression-taking technology and restorative materials. We were able to keep the shade of his crowns consistent throughout the years, while adding greater speed and comfort to the process.

 

DISCUSSION
Digital Scanning Made More Affordable

Like many technologies, as time has passed, the technical aspects of digital scanners have improved and the costs have decreased. The latest digital impression systems are equipped with smaller wands and better displays, as well as more open connections to mills, dental laboratories, and milling materials. Most importantly, the cost has been lowered dramatically. This is best exemplified by the new scanner presented herein (True Definition Scanner), which is being marketed with a suggested retail price of $11,995 and monthly data plans starting at $199. This price reduction removes the significant financial barrier that has prevented many practices from adopting digital scanning technology. With that barrier removed, many dentists will find their only remaining objections relate to the following: Will adopting digital scanning disrupt their familiar and comfortable workflow? Will it require extensive training for doctor and/or team?

Using this newly introduced scanner as an example, we can explore these questions.

Implementation, Accuracy, and Options
First, the technology is easy to implement. The small scanning wand is similar in size and feel to an operative handpiece. Dentists will find they can comfortably and quickly capture scans from a seated position. In the author’s experience, this is one of the best features of the system. The clinician can sit down next to the patient just like any other procedure and capture the impression. The scan progresses quickly and without breaks, and the process flows easily from one step to the next. The scanning process is fast initially, and with more practice it becomes second nature, increasing the speed even more. Additionally, the cart itself is small and easy to move between operatories, making it simple to use in multiroom offices.

In addition to speed, the accuracy of digital scans is one of the top reasons that digital technology is so attractive. Unlike a traditional impression—which may only reveal its inaccuracies when the dentist tries to seat a completed crown—a digital scan gives the user immediate preparation feedback on the chairside monitor. The clinician can clearly see when all of the necessary information has been completely captured. This improved ability to quickly ensure the accuracy of an impression results in lower retake and remake rates, contributing to savings in materials and time as well as a better patient experience. Data shows that the True Definition Scanner excels in this capacity, providing consistently accurate scans.1 Additionally, the wand has no moving parts and never needs calibration, so there are fewer worries about having downtime with the system.

Lastly, a new feature of the digital workflow for these devices is increased flexibility and openness for use with a variety of in-office systems and/or outside laboratories. The True Definition Scanner utilizes the 3M Connection Center, which is a secure cloud-based platform on which dentists can share open STL files with their laboratory partners. The scanner is also capable of making a chairside connection to the E4D (D4D Technologies) milling system, giving dentists the ability to create same-day restorations in their offices. With these capabilities, clinicians have more material and workflow options, enabling them to use the scanners in the way that fits their practices best.

CLOSING COMMENTS
As is evidenced in this case, incorporating digital impressions into your practice results in incredibly accurate restorations and increased patient comfort (a major benefit of adopting this technology). As these systems become more popular, and the awareness of the technology grows among the general public, patients will begin to understand that there is an alternative to the unpleasant physical impression techniques that they have experienced in the past, and they will seek out offices that provide a digital alternative.

Being able to offer an impression taking experience that is not only comfortable, but actually high-tech, and interesting is a valuable marketing tool for offices now—and something that will come to be expected by patients in the near future. We have all seen how patients are becoming more aware of the new dental technologies available to them, and more discerning about seeking out providers whose practices are perceived as modern and up-to-date. With an affordable digital scanner available, clinicians can adopt this patient-friendly technology now to stay ahead of the curve. With that frame of mind, and the financial costs now lowered significantly, digital scanning is in reach for practices that have previously ruled it out.

Over the coming months and years, more and more dentists will adopt this technology and experience the significant improvements it brings to productivity, accuracy, and patient comfort.


Reference

  1. van der Meer WJ, Andriessen FS, Wismeijer D, et al. Application of intra-oral dental scanners in the digital workflow of implantology. PLoS One. 2012;7:e43312. Additional measurements conducted by ACTA (Academic Center for Dentistry Amsterdam); Wicher J. van der Meer, et. al. (2012). Publication pending.

Dr. Erickson is a 1980 graduate of the University of Minnesota and has completed the Continuum at the Pankey Institute for Advanced Dental Education. For the past 32 years he has been in private practice in St. Paul, Minn, and is a clinical adjunct assistant professor at the general practice residency Program at the University of Minnesota Dental School. Dr. Erickson is an ADA member, past trustee of the Minnesota Dental Association, and past president of the Saint Paul District Dental Society. He is a consultant and clinical researcher for 3M ESPE Dental in the areas of digital impressioning and provisional materials/techniques. He can be reached at (651) 484-4193 or at erick135@umn.edu.

Disclosure: Dr. Erickson is a consultant to 3M ESPE.