Customized Characterization Made Easy
Inside Dental Technology delivers updates on digital workflows, materials, lab techniques, and innovation in dental technology through expert articles and videos.
July 1, 2014
Volume 5, Issue 7, July 2014
Page(s): p. 70-71
Until now, customized characterization of dentures has been a challenge for dental laboratory professionals regardless of the type of denture being created. With conventional dentures, the characterization is rendered in the mold. However, when the acrylic is injected, the stains can get pushed in the wrong locations on the denture. With hybrid (i.e., screw-retained) dentures, the small mold makes characterization difficult, particularly in tight areas surrounding the implants. When using digital techniques, no molds are used to perform characterization because the denture is created from a milled puck or printed base. The technician can attempt to achieve characterization by painting on the surface, but this will eventually wear off of the denture.
PALA® cre-active® light-curing color-fluid system
5 filled flowable gingiva resins, including a clear resin
6 intense color fluid tints
1 gum (around 80% filled) resin
Signum® connector bonding agent for both heat-cured and cold-cured resins
Signum® insulating gel
Fortunately, the combination of cre-active and Signum—along with creativity and imagination—enables dental laboratory professionals to produce natural-looking, long-lasting customized characterization of all three types of dentures. Below is a step-by-step description of how the author recently used these products to custom-characterize a denture created using Heraeus Kulzer’s Mondial® i anterior and posterior denture teeth and Palapress® vario acrylic.
The first step was to remove approximately 1.0 mm to 1.5 mm of the buccal flange of the acrylic denture base where the tint was to be applied, using carbide burs (Figure 1).
Composite does not bond well to acrylic. Because the light-cure composites such as cre-active that are used to modify denture esthetics don’t naturally bond to acrylic denture bases, a bonding agent is necessary to ensure compatibility between the modifying material and denture base.
Next, the author applied Signum connector to the prepared area with a brush and let it work on the surface for 2 minutes (Figure 2). This is a critical step, as Signum creates a molecular bond between the denture and cre-active materials that will subsequently be added to the denture base to achieve the desired natural-looking results. The author then cured it for 90 seconds (using the new Signum HiLite® power light-curing unit from Heraeus Kulzer).
A small brush was used to apply the cre-active R50 gingiva shade (a flowable filled resin), which is a lighter color than the denture base to represent the root eminence (Figure 3). This shade mimics the natural blanching effect that is created as the root protrudes and displaces blood in the eminence.
The author then applied cre-active’s pink fluid (an intense, unfilled color) to mimic the deep underlying blood, bone, and darker supporting structures in the interproximal areas to create a deep separation in the proximal papilla regions (Figure 4). Please note that this fluid is actually a deeper color than the name “pink” suggests.
The next series of steps plays a key role in the amazingly lifelike characterization that can be achieved with cre-active, which enables the laboratory professional to be creative. First, the author applied cre-active’s red fluid in the peripheral area to represent small capillaries (Figure 5). Next, the author blended the red fluid (Figure 6).
The author then used a scalpel on the red area to create the look of small veins and a very natural-looking texture effect (Figure 7). At this stage, exposure to a curing light for 3 seconds ensures stability in subsequent steps.
To make the lighter R50 eminence look lighter and more lifelike, the author applied cre-active’s polar color fluid (which is blue) to complement the reddish hue of the denture base (Figure 8).
Next, the author finished the papilla with cre-active’s R50 gingiva shade. The contour was finished with cre-active shade 200 (a filled flowable resin), which is similar to the denture base color, features some translucence, and actually contains extremely lifelike micro-fiber veins. This step gave depth to the stains, putting them deep into the buildup (Figure 9).
Having completed the buildup (Figure 10), the author placed the denture in the curing light unit for 90 seconds.
After removing the denture from the curing light unit, the author applied a layer of Signum insulating gel over the entire buildup (Figure 11) and returned the denture to the Signum HiLite power light-curing unit for a final cure of 180 seconds (Figure 12).
Until now, each denture type posed its own challenges for customized characterization. With the combination of PALA cre-active light-curing color-fluid system and Signum connector bonding agent for both heat-cured and cold-cured resins, remarkably lifelike customized characterization is easily achievable for conventional, digital, and hybrid dentures.
Disclaimer: The preceding material was provided by the manufacturer. The statements and opinions contained therein are solely those of the manufacturer and not of the editors, publisher, or the Editorial Board of Inside Dental Technology.
For more information, contact:
Heraeus Kulzer
P 800-431-1785
W www.heraeus-kulzer-us.com
Craig Nelson, AAS, CDT, is Senior Technical Manager of Scientific and Clinical Affairs for Heraeus Kulzer.
