Preference Soft Denture Liner: A Denture Liner for the Future
Inside Dental Technology delivers updates on digital workflows, materials, lab techniques, and innovation in dental technology through expert articles and videos.
October 1, 2015
Volume 6, Issue 10, October 2015
Page(s): p. 60
By Craig A. Pickett, RG, CDT, TE
The changing patient demographic indicates an increasing need to serve those for whom a fixed restoration is not an option. Whip Mix has introduced the Preference Soft Denture Liner (Figure 1) to help those patients for whom a traditional hard denture surface and current soft options are not the answer.
Preference Soft Denture Liner is a medical/dental RTV silicone material that meets patient needs for extended length of service, reduced bacterial and fungal growth, and ease of cleaning procedures. However, utilizing silicones changes the working paradigm for the dentist, technologist, and patient. This shift in procedure must be addressed so that acceptance of the new method is understood and its value recognized.
A patient presented with thin tissue and bony tori undercuts, which made the acceptance and success of a hard-surface denture less than ideal. The current denture was prepared and impressions taken for a reline. The impression was poured with stone, and sufficient stone was left for a landing area near the borders (Figure 2). Once the stone had dried and the border areas had been ground, a series of depressions in the stone were cut in a balancing pattern (Figure 3). Cold-cure acrylic was used to create “feet” in the depressions and legs that extended to the flange of the denture for each balanced area, and it was cured (Figure 4).
The denture then was removed from the stone cast and the impression material removed from the denture. The internal surface of the denture and flash around the legs and feet was reduced to allow a minimum of 2-mm thickness of reline material (maximum averages under 1.5 cm but could be longer). The denture was sandblasted with 25-micron aluminum dioxide to include the border area and over onto the flange (Figure 5). The sandblasted parts of the denture were cleaned with acetone (100%) and dried. Preference Primer (Whip Mix, whipmix.com) was applied to all surfaces to which the reline material should adhere, and allowed to dry for 15 minutes (Figure 6). At this point, the casts were cleaned and de-greased with dishwashing soap, rinsed clean, and then soaked in water for 15 minutes. This eliminates air from the cast and provides a damp tissue surface to act as a release agent and activation for the silicone. After the 15 minutes passed for the primer and the cast soak, the excess surface water was gently blown from the cast.
The Preference Soft Denture Liner material was applied by expressing approximately 1 ounce of material (for a full upper) from the tube onto a glass slab (any suitable disposable surface is sufficient). Do not touch with bare fingers the denture surface to be covered. With a cotton swab, a portion of material was picked up and scrubbed onto the surfaces to be covered by the liner (Figure 7). When complete, a cement spatula was used to spread the remainder of the reline material into the interior surface of the denture. Express more liner into the vestibule area of the cast and be certain that there are no trapped air pockets. Do not spread liner over the post dam area of the model. The denture was replaced onto the cast, with the technician moving it from front to back and locating the “feet” into their depressions. It was pressed to seat without flexing the denture or feet (Figure 8).
The seated denture and model were placed into the Preference Pressure Pot (Whip Mix), and the technician installed the lid and pressurized to 80 psi. The case remained at this pressure for the next 14 hours. Once the time had elapsed, the case was removed and separated from the cast. The excess silicone flash was removed using a scalpel blade (Figure 9). The material was finished by moving from soft to hard using the fiber wheels provided in the starter kit (Figure 10), and the remaining acrylic was polished (Figure 11). The liner was adjusted internally using a cross-cut bur and then polished using the red fiber wheel (Figure 12) and delivered to the patient.
Most current soft reline materials have faced difficulty meeting patient expectations for life expectancies, bacterial issues, and remaining soft. Preference Soft Denture Liner will help the patient see the results they expect.
Technicians and dentists must be aware that they can neither shorten the cure time nor reduce the required pressure to achieve the expected results.
Craig A. Pickett, RG, CDT, TE, is the Technical Support Manager for Whip Mix in Louisville, Kentucky.
