The value of a digitally focused
“reference denture” technique
In dental prosthetic treatment therapy,
the best way to begin is with the end in mind.
The first of several hurdles you may
face when addressing a removable prosthodontics
case is lack of knowledge, experience
or vetted resources that provide reliable
information or training. Often, clinicians
in this situation have no information at all,
and patients have difficulty providing useful,
repeatable information to move the case
forward. Of course, clinicians experience fear
of the unknown as well; many dental health
professionals shy away from conducting
removable prosthodontics treatment because
of all these elements. In many cases, they
simply lack confidence in their ability to
deliver a truly optimal product that meets
and exceeds their patients’ expectations.
This is a reasonable and predictable
reaction; indeed, it would not be prudent
to venture into a field of care in which a
clinician or technician is not confident.
As a clinician, attempting to re-create
an existing prosthesis with precision and predictability, and to effectively repeat an
original, potentially decades-old outcome
that the patient finds agreeable can be
difficult. This task is challenging in both
analog and digital workflows, but from
the cases I have studied and undertaken, it
can be a more predictable experience using
digital denture technology.
Another significant challenge: reproducing
what feels “normal” to the patient.
While some edentulous patients will need
or want to replace a prosthesis they have
been using for as few as five years, many
will visit your office wearing a decades-old
device. In my practice, I have replaced several
prostheses my patients had been wearing for
more than 30 years!
In my experience, many denture wearers
use their prostheses for longer than they
should in an ideal scenario. They avoid
change because they fear a new denture
might not be as comfortable or aesthetically
pleasing as their current device, to which
they have become accustomed.
Most people reading this article will be
more familiar with the analog approach.
That makes sense: It is the approach we
are all schooled in and trained on and
have been practicing since we entered the
industry. Regardless of whether you are
just starting out in your career or you’re a
seasoned professional who feels your current
workflow is adequate, you should continually
ask yourself: But is there a better way?
Traditionally, reproducing a hand-crafted
denture is arduous; using the traditional
(analog) processes, it is difficult to duplicate
an existing prosthetic exactly or at the very
least, within normal limits. As any dental
professional knows, unfortunately, an analog
denture relies heavily on the hand-eye
coordination and motor dexterity of the
person fabricating it—which means dentures
are exposed to significant potentialities for
Today, with digital dentures, reproducing
a prosthetic a patient finds agreeable is
eminently achievable. Together, sophisticated
scanning technology and design software
allow us to re-create a patient’s current
denture with a very high degree of fidelity.
We can also modify a device’s aesthetic
dimensions while improving the fit, which
is often precisely what patients want.
In simple terms, modern digital dentures
replace error-prone plaster molds with precise
computerized files. Using this technology,
properly trained dental professionals can scan
impressions of a patient’s mouth, transform
them into 3D renderings on a computer
screen, and start a precise computer-aided
manufacturing process at the push of a
The workflow highlighted in the accompanying
case is known as the reference
denture technique. We begin by using
a patient’s existing denture as our initial
reference record, then we fabricate a final
definitive prosthesis according to these
initial specifications. We duplicate these
prosthetics and use them as closed-mouth
functional impression trays and as a formality
of “wax rims” with teeth—all in the same
appointment! This can also be done in the
patient’s existing denture; however, it may
render some challenges.
In my practice, I currently use sophisticated
scanning, 3D-printing and milling
technology to re-create reference dentures.
My workflow begins with a full 360-degree
scan of the patient’s existing denture, which
allows me to create a duplicate of it to be
used to take impressions. I also have the
capacity to 3D-print a prototype of the new
proposed final denture, which is known as
a functional try-in. The clinician can use
this sophisticated prototype to evaluate the
The Ivotion Digital Denture system from
Ivoclar Vivadent, which I use, is fabricated
using CAD/CAM technology and high-quality
proven materials in conjunction with a
sophisticated five-axis milling machine. The
result is a perfectly realized denture that
corresponds exactly to the measurements
provided. The finished product is completely
uniform and absolutely seamless in all aspects.
These dentures are precision-milled out of a
solid disc of Ivoclar’s high-quality PMMA
acrylic denture base material. Because the
raw materials are essentially “preshrunk,”
there is zero volumetric polymerization
This methodology provides both the
clinician and the digital technician all
the necessary data required to fabricate a
removable prosthesis. Never before have we
been able to digitize all this information,
empowering us to position the teeth in an
anatomically correct arrangement to improve
fi t, form, function, aesthetics and phonetics.
In the accompanying case, I’ve shared
my process and workflow, which I hope
you’ll take into consideration to implement
the reference denture technique in your
In all aspects of dentistry, a virtually
limitless number of roads lead to a finite set
of final destinations. In many instances, we
all end up at the same place, but it’s how we
get there that really matters. Only a humble
oral health professional can appropriately
understand that the success of our cases is
often not determined by our professional
opinion alone; rather, it has a lot to do with
the individual patients who instill their trust
in us as dental professionals, expecting we
will provide them a service that will improve
their quality of life. And isn’t this why we
entered this profession in the first place?
Digital denture technology has created
an opportunity for clinicians to be more
effective, efficient and predictable with the
way we can treat patients with removable
prosthetics. Following my example, you
should be more confident about providing
removable prosthodontics therapy for your
patients, starting today.
Figs. 1–3: Patient presents with fractured teeth and an overclosed vertical dimension. Patient
reports some difficulty in the past few months with ability to function.
Figs. 4 and 5: The Conmetior VDO Gauge is ergonomically designed based on golden proportion
principles to fit the anatomy of the human face, providing accuracy and consistency.
Fig. 6: Step 1: Measure the distance between
the center of the eye and the commissure of the
lips using the two straight, extended markers.
Fig. 7: Step 2: Tighten the bolt to lock that
measurement into place.
Fig. 8: Step 3: Using the other side of the gauge, place
the friendly rounded edge just under the nose and
under the chin. As you can see here, there is a space
between the chin and the curve; therefore the patient
is currently overclosed. Close the gauge until it touches
the patient’s chin to determine the existing situation,
measuring the difference between the patient’s current
vertical dimension of occlusion (VDO) and new proposed
Figs. 9 and 10: Step 4: Have the patient exercise various ways of capturing their position of
vertical dimension of rest (VDR). Confirm back with the initial VDO difference. This information
is then sent to the digital denture laboratory to create a 3D-printed monoblock of these scans.
Figs. 11 and 12: The patient’s existing dentures are scanned 360 degrees, using iOS
technology 3Shape Trios 4, creating an exact duplication. These files are then printed by the
laboratory or in-office printing solutions.
Fig. 13: Closed-mouth functional final
impressions are conducted within the 360
dentures. This allows the clinician to make
various modifications to the intaglio surface
and peripheral borders as well as occlusion.
Closed-mouth functional final impressions
create a high precision result because of
the material being dispersed through the
dental arches under the patient’s functional
forces (tissue compression) as well as their
neuromuscular and functional activity.
Figs. 14 and 15: The functional impressions are conducted utilizing Virtual VPS monophase
material (Ivoclar Vivadent) for the maxillary peripheral borders as well as the entire intaglio
and borders for the mandibular arch. Light-body material is used to take the final wash
impressions in both arches. Lastly, after taking the CR record, a thin bead of monophase is
used to capture a “post dam” in the impression surface.
Fig. 16: The records are then digitized with 3Shape
Trios 4. The scan of the upper impression surface,
facial and occlusal surface, lower intaglio surface
facial and occlusal, and occlusion are sent to the
digital denture laboratory.
Figs. 17 and 18: The digitized reference denture
scans are imported into sophisticated digital denture
design software (3Shape). The advantages of this
software and workflow are the ability to visualize
the patient’s existing situation within the new
proposed tooth arrangements, and the ability to truly
evaluate positioning of the dental arch in the proper
anatomical and physiological position to maximize fit,
form, function, aesthetics and phonetics. These are
then 3D-printed to create monoblock try-ins.
Fig. 19: These 3D-printed monoblock (monolithic,
monochromatic) try-in dentures are utilized to evaluate fit,
form, function, aesthetics and phonetics, and also to increase
patient confidence of the final restoration.
Figs. 20–23: The representation of the final prosthesis is mirrored by the monoblock tryins.
This process allows clinicians to evaluate and verify the fit, form, function, aesthetics,
phonetics and centric relation, and communicate to the dental lab any changes required.
In this case, we noted the midline required movement to the patient’s right by 2mm. These
changes were communicated and the finalization process will commence.
Fig. 24: The changes of moving the midline are made back in the
software and the digital removeable prosthesis is ready to be
finalized with the monolithic Ivotion (Ivoclar Vivadent) denture.
Fig. 25: The dentures are milled in the PrograMill
PM7 in one seamless, uninterrupted milling
process to provide a high-quality, digitally
precise removable prosthesis.
Figs. 26–28: The dentures are characterized and
Figs. 29–30: Final results.
Figs. 31 and 32: Before and after.
Eric D. Kukucka, DD, is a
practicing denturist and an
alpha and beta tester for
major industry development
in digital denture
technology. The president
of The Denture Center in
Windsor, Ontario, Kukucka
is a key opinion leader for
Ivoclar Vivadent, 3Shape
and Nobel Biocare, and a member of the 3Shape
Advisory Board in Copenhagen, Denmark. He has given
more than 52 keynote presentations in five countries
and two languages, and has written more than 23
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