Digital dentures in a few
hours offer a safer option
for a patient who
can’t risk visiting the
practice several times
by Dr. Nadim Z. Baba
Seniors living in long-term assisted-living care facilities and nursing homes are a
particularly vulnerable population when it comes to receiving proper oral care.1 The
aging population in the United States is living longer2 and retaining more of their
natural teeth than previous generations.3 As these seniors transition from independent
to dependent living, their oral needs often go unaddressed, resulting in tooth loss, poor
oral hygiene and oral disease.4 Good oral health significantly affects general health,
especially in older adults, because the ability to chew and consume food affects the
quality of their diet and, as a consequence, their overall health. The oral health of
residents in long-term care facilities is often not perceived as a priority by caretakers,
which delays assessment and treatment.4
In recent years, the ability to properly treat geriatric adults has been exacerbated
by the pandemic, because this older population is more susceptible to infection and
compromised by existing age-associated health conditions.5 For this most vulnerable
patient demographic, treatments that require multiple appointments and long
appointment times increase the risk of COVID-19 infection for both the patient and
the dental care professional. Treatment options that limit the number of in-practice
visits are optimal for treating these patients.
Clinical report
A 94-year-old patient who lives in a long-term assisted-living facility with his wife
was referred to the practice by his daughter, a longtime patient of the dental practice.
The chief complaint was that he had difficulty eating because of the degradation of his
teeth. The daughter requested her father be fitted with dentures to restore his chewing
ability, aesthetics and self-esteem, but she also wanted a solution that did not require
multiple practice visits, because taking him from the assisted-living facility was a
difficult process and increased his chances of exposure to the coronavirus.
Because of the patient’s age and vulnerability
if exposed to COVID-19, he was
scheduled for a Saturday appointment, when
no other patients or staff would be present.
Upon initial examination, it was obvious
he had been mostly edentulous for many
years: The mandibular arch was edentulous
and only four tooth roots remained in the
maxillary arch (Fig. 1). The treatment plan
that would best fit this patient with a long-term
and aesthetic solution without multiple
visits to the practice was an immediate CAD/CAM-milled monolithic denture.
Fig. 1
Several methods can be used to obtain
clinical records for the digital denture
workflow. Because this patient presented
with no existing dentures, it was decided to
use conventional definitive impressions to
accurately capture his anatomy and muscles
that would be involved in holding a denture
in his mouth.
Appropriately sized heat-moldable
disposable impression trays (Accudent XD,
Ivoclar, Fig. 2) were used to make the definitive
maxillary and mandibular impressions.
Adhesive was applied to the flanges of the
maxillary impression tray before border
molding, using heavy-body polyvinyl
siloxane, or PVS (Virtual XD Heavy
Body, Ivoclar, Figs. 3 and 4). Once the
border molding procedure was completed,
additional adhesive material was painted
on the remaining parts of the tray and a
definitive impression was made a using
light-body wash PVS impression material
(Virtual XD Light Body, Fig. 5). The
impression-taking protocol was repeated
for the mandibular arch (Figs. 6–8).
Fig. 5
Condensing the timeline
At this point in the record-taking
process, clinicians would normally send
the impressions to the laboratory to pour
working casts and fabricate wax rims, which
would be “tried in” at the patient’s second
visit to verify phonetics, aesthetics, occlusal
vertical dimension (OVD), occlusion and
retention. Because of the unique nature of
this case, I chose to complete these steps
in the office while the patient was waiting.
Maxillary and mandibular stone casts
and wax rims were created using conventional
protocols (Fig. 9). The wax rims were inserted
into the patient’s mouth to perform any
needed corrections to the midline, position
of the teeth, centric relation (CR) or OVD.
A bite registration (Virtual CADBite, Ivoclar)
was completed to record the relationship
between the maxilla and mandible (Fig. 10)
and to provide information that would be
critical for initial placement of the denture
teeth—incisal length, labial position and
occlusal plane, as well as vertical dimension
and centric occlusion.
Fig. 9
Fig. 10
In a conventional case, the dentist would
send the bite registration to the lab for design
of the denture teeth and request 3D-printed
try-in dentures, which would help ensure
the midline was correct and the patient
approved of the aesthetics and phonetics of
the planned prostheses before the laboratory
milled the final dentures. It must be noted
that in this scenario, depending on the degree
of changes needed for an optimal fit, the
technology to print multiple try-in dentures
is not cost-prohibitive and makes the option
of multiple try-in dentures feasible.
Because this case was unique in that
the final prosthetic had to be completed in
a single visit, the maxillary and mandibular
definitive casts as well as the labial/buccal
surfaces of the wax rim bite registration
were scanned in the in-house laboratory and
the scans uploaded into the CAD software
program (Fig. 11) for virtual articulation
of the wax rims (3Shape Ivotion, 3Shape),
virtual setup of the denture teeth and CAD
design of the complete dentures (Figs. 12–14).
Fig. 11
Milling the definitive prostheses
The subtractive manufacturing digital
denture system used for this case (Ivotion,
Ivoclar) offers two types of definitive complete-
denture protocols.
One protocol is a denture base milled
from a prepolymerized block of polymethyl
methacrylate (Ivobase CAD, Ivoclar) along
with milled denture teeth from a block of
dual cross-linked material (SR Vivodent
CAD, Ivoclar). The milled denture teeth are
then bonded into the milled recesses using a special PMMA bond material (Ivobase CAD Bond, Ivoclar). The dentures are
then finished and polished and sent to the
prescribing dentist for placement.
The second protocol is a monolithic
denture milled from a bicolor disk (Ivotion).
One half of the disc is the denture base
material made of high-impact optimized
PMMA while the other half is the tooth
material made of highly cross-linked PMMA
with no filler (Fig. 15). After the virtual
design of the dentures on the CAD software
(3Shape), the bicolor disk is milled through
a single, uninterrupted milling process, then
finished, polished and sent to the prescribing
dentist for placement.
Fig. 15
For this patient, a milled prosthetic
option that did not require manually bonding
the milled denture teeth to the base was
chosen. The unique geometry of the bicolor
milling disc allows for a single milling
process (PrograMill PM7, Ivoclar) to produce
a definitive monolithic denture (Fig. 16).
The economic advantages include having
to use only one disc, uninterrupted milling
procedure, less milling time overall and
fewer chairside adjustments. In addition, the
strength of the denture is enhanced because
the homogeneous chemical fusion of the teeth
and base materials are uniquely processed
without a bonding interface; therefore, the
dentures are physically monolithic, producing
dimensionally accurate final dentures with
high-quality aesthetics that require only
minimal clean-up and finishing.
Fig. 16
Definitive denture placement
While the dentures were being milled,
the patient’s four remaining tooth roots
were extracted. Once the milling process
was completed, the final dentures were
manually polished (Fig. 17) and inserted
into the patient’s mouth (Figs. 18 and 19).
The placement and postplacement
adjustments of CAD/CAM-created complete
dentures are similar to the placement of
conventional dentures; however, the degree
of adjustment required to insert digitally
processed dentures and the follow-up postinsertion
appointments are significantly
minimized, compared with traditional
clinical workflow and manufacturing.6 Traditional
procedures and materials (Fit Checker,
GC America) or pressure-indicating paste
(PIP, Keystone Industries) are suggested to
identify and adjust the fit of the intaglio
surfaces of the dentures to the intraoral
mucosa. For this case, occlusal contacts were
verified and adjustments made intraorally.
If considered needed, a clinical remount
procedure can be performed depending on
the degree of occlusal adjustment required.
Conclusion
Although this unique case required
in-practice completion of the digitally
manufactured case, all of the steps leading
up to the milling process and final delivery
are conventional protocols that dentists
would normally complete for denture
processing.
Digital dentures offer clinicians many
advantages over conventionally fabricated
dentures.7,8 Among them:
- The ability to efficiently and
effectively treat patients who have
difficulty commuting to the practice
for multiple appointments.
- The ability to record clinical
information (impressions,
interocclusal records, and tooth
selection) in a single, one- to
two-hour appointment, depending on
the clinician’s experience.
- The ability to place and seat the
dentures in the second appointment.
- The ability to reduce clinical chair
time, which is more cost effective and
decreases practice overhead.
- The ability to archive digitally
obtained 3D images and record-taking
data in the event the patient
should need a replacement denture.
- And the prepolymerized acrylic
resin used for the fabrication of the
denture base provides a superior
fit and strength compared with
conventionally processed bases.
Learn more
about dentures
for older
patients
and
earn CE credit
Dr. Arnold Liebman’s online
CE course explains how to
make aesthetic dentures for
older patients even if they
have medical issues, no lower
ridge or other challenges. To
take the course for a chance
to earn 1.5 CE credits, click here.
References
1. Porter, J., Ntouva, A., Read, A., Murdoch, M., Ola, D., and
Tsakos, G. “The Impact of Oral Health on the Quality of Life
of Nursing Home Residents.” Health Qual Life Outcomes.
2015;13:102.
2. Medina, Lauren, Sabo, Shannon, and Vespa, Jonathan.
“Living Longer: Historical and Projected Life Expectancy in
the United States, 1960 to 2060 Population Estimates and
Projections.” U.S. Census Bureau, US Department of Commerce.
https://www.census.gov/library/publications/2020/
demo/p25-1145.html, accessed Feb. 7, 2022.
3. CDC. Public Health and Aging: Retention of Natural Teeth
Among Older Adults—United States, 2002. https://www.
cdc.gov/mmwr/preview/mmwrhtml/mm5250a3.htm, accessed
Feb. 7, 2022
4. Badewy, Rana, Singh,Kharkirat, Quinone, Carlos, and
Singhal, Sonica. “Impact of Poor Oral Health on Community-
Dwelling Seniors: A Scoping Review.” Health Service
Insights, Vol. 14: 1–19. Accessed Feb. 7, 2022.
5. CDC. COVID-19 Risks and Vaccine Information for Older
Adults. www.cdc.gov. Accessed Feb. 7, 2022.
6. Smith, P.B., Perry, J., and Elza, W. “Economic and Clinical
Impact of Digitally Produced Dentures.” J Prosthodont
2021;30(S2):108–112.
7. Janeva, N.M., Kovacevska, G., Elencevski, S., Panchevska,
S., Mijoska, A., and Lazarevska, B. “Advantages of CAD/
CAM Versus Conventional Complete Dentures—A Review.”
Open Access Maced J Med Sci. 2018 Aug 4;6(8):1498–1502.
8. Baba, N.Z., Goodacre, B.J., Goodacre, C.J., Müller, F., and
Wagner, S. “CAD/CAM Complete Denture Systems and
Physical Properties: A Review of the Literature.” J Prosthodont
2021;30(S2):113-–124.
Dr. Nadim Z. Baba received his DMD
from the Université de Montréal in 1996,
completed a certificate in advanced graduate
studies in prosthodontics, and earned a
master’s degree in restorative sciences in
prosthodontics from the Boston University
School of Dentistry in 1999.
Baba is a professor in the advanced education program in implant
dentistry at Loma Linda University School of Dentistry, an adjunct
professor at the University of Texas Health Science Center School
of Dentistry in the comprehensive dentistry department, and
maintains a part-time private practice in Glendale and Long Beach,
California. He is the past president of the American College of
Prosthodontists (ACP), a diplomate of the American Board of
Prosthodontics and a fellow of the ACP and the Academy
of Prosthodontics.
The author of numerous articles and an international lecturer,
Baba also has published the book "Contemporary Restoration
of Endodontically Treated Teeth: Evidence-Based Diagnosis and
Treatment Planning."