“Ask Away” is a recurring Smile Bulletin column that features questions posed by dentists at live courses and online courses offered by Glidewell Clinical Education. This provides attendees — and Smile Bulletin readers — an opportunity to get useful clinical tips, tricks and guidance from dentists who are experts in their respective fields. Here, Dr. Taylor Manalili answers questions about denture impressions, including digital vs. conventional impressions, her recommended material for the final impression, the accuracy of different border-molding compounds and what to do for patients with a hypersensitive pharyngeal reflex.

What is your preference: taking digital or conventional impressions?

Dr. Taylor Manalili: The intraoral scanning technology has come a long way. If you can manage to capture the hard-to-reach landmarks like the tuberosity, hamular notch and lingual vestibule, an intraoral digital static impression of an edentulous arch is possible. This, however, is still a static impression. When I can, I like to use the intraoral scanner for a preliminary impression to fabricate a custom tray or a record base that will be relined as a definitive impression. However, to capture the vestibular borders I defer back to a conventional method. The conventional method allows me to shape impression material along the border area of a custom impression tray/record base by functional or manual manipulation of the soft tissue to capture the contours and size of the vestibule. If a digital workflow is desired, these border-molded impressions can then be digitized by the lab.

What material do you use for the final denture impression?

TM: Once the custom tray is border molded, I use a low-viscosity, fast-setting vinyl polysiloxane for the definitive impression.

Other than green stick compound, what border-molding compounds do you think are accurate? Can you border mold with a rigid VPS?

TM: Yes, there are other materials that I and others successfully use. I was trained with green stick compound and I find that, in my hands, this is the fastest, cheapest method for me at this time. That being said, other materials that I have successfully used include a syringable heavy body VPS and putty VPS.

How do you take denture impressions on a patient who is an extreme gagger?

TM: These are hard patients in general to fabricate complete dentures for. However, it is especially critical that you capture an accurate definitive impression that will allow for a stable prosthesis to be fabricated. A patient who has trouble with the impression stage may require a little extra attention, ensuring the definitive prosthesis is properly contoured and polished. Read below for some steps that can help alleviate discomfort for patients while still giving you a great denture impression.

How to Take Quality Denture Impressions and Support Patients’ Comfort

1. Determine the location of the sensitivity — Identify exactly where the sensitivity is coming from in order to be more mindful when capturing the denture impression. For most patients, it is the posterior tongue or the soft palate. The utilization of a viscous lidocaine to help numb the mucous membrane can aid in patient tolerance in the more extreme cases.
   
   
2. Do the mandibular impression first — Start with the mandibular impression for those who have a hypersensitive pharyngeal reflex, or gag reflex, as you can generally keep the tray and materials away from these areas. Once the mandibular impression is over, it can make the maxillary impression a little easier for the patient.
   
   
3. Check for defined borders and the appropriate amount of impression material — Take the time to ensure that the borders are properly defined and the tray is not overextended or overfilled with impression material.
   
   
4. Give patients something else to think about — Throughout the process, I find that distraction techniques can help patients shift their thinking toward something other than their discomfort. For example, sometimes I’ll have the patient concentrate on lifting their left leg and then their right.