Improving Communication in Impression Taking

Thomas Trinkner, DDS (TT): A vast majority of people would say yes. This has opened up a fairly big world of design and communication. Conversely, many ceramists who are very artistic and meticulous about their products will argue that the accuracy of digital impressions is not yet sufficient. Like with any other tool, it depends on the ability of the person using it. Personally, I use digital scanning for same-day cases that I plan to mill in-house, and I take conventional impressions for more complex cases.

(ID): For those practices that are not digitally scanning, is the hesitation primarily regarding accuracy?

(TT): No. I believe it is a combination of the cost and, perhaps, the fear of learning a new modality. I anticipate further adoption, but for a recent dental school graduate, the financial burden associated with owning a scanner is quite cumbersome.

(ID): For the more than half of practicing dentists who do not use digital impressions, have there been significant improvements in physical impression materials?

(TT): There have been improvements. Personally, I still prefer polyether, which I have been using for more than 25 years, because it is hydrophilic. I place a high priority on accuracy. Manufacturers advertise impression materials that require less time, but I do not value efficiency as much as accuracy. However, for dentists who utilize a different workflow, today's newer materials can save around 2 to 3 minutes on each impression.

(ID): What are some common errors you see in impressions, and how can they be avoided?

(TT): Many of the errors that are made involve the accommodation of tissue that is not quite healthy enough following the removal of old restorations. In many cases, I try to avoid using retraction cord. I like to be at the margins or slightly supragingival because ceramists today can create great emergence profiles with modern materials. Oftentimes, when inflammation and irritation are present after removing old restorations, I just walk away from the patient for 10 to 15 minutes. The tissue recovers, becoming quiet and pink again, and then I can take a quality impression without packing cord or using a laser.

(ID): Would you offer any tips for optimizing communications with the laboratory to minimize remakes?

(TT): Communication is vital. Good dentistry is really based on a sound dentist-ceramist relationship. You need to grow with each other and share your mistakes, documenting as much as possible. When I see a problem with one of my impressions, I either take a photograph of it or make the laboratory aware of it verbally. For almost every case that I treat, my photographs go directly to the laboratory, and if I see something that I need to discuss with the laboratory, I do it on the day of the preparation, so it is not forgotten or overlooked.

(ID): Conversely, how important is it that your laboratory is comfortable enough in your relationship to alert you to problems with your impressions, rather than just trying to make the best out of a bad situation?

(TT): That is definitely important. My ceramist will tell me if there is a problem, such as the presence of distortion in the impression, and then ask me how I want to handle the situation. In this way, not only does he convey the information to me, but he also provides a visual of the laboratory's workflow. Having a good laboratory that can serve as a resource in this manner is very important. A good laboratory will tell you that an impression is compromised if they do not feel comfortable with it.

(ID): Regardless of the modality, the success of an impression is largely related to the retraction of soft tissues. How can effective retraction be consistently achieved?

(TT): With so many great materials available to provide restorations, the days of needing to be at the gingival or subgingival level are in the past. We do not need to be aggressive in our preparations. The more enamel that is available to bond to, the better off we are. The kinder you are to the tissue at the start, the better the impression. The better the seating of the final restoration, the better the long-term success of the case. It really all comes back to healthy tissue and how you handle it.

Thomas Trinkner, DDS
Accredited Member
American Academy of Cosmetic Dentistry
Private Practice
Columbia, South Carolina