Using Intraoral Scanning to Fabricate Complete Dentures:
First Experiences
Brian J. Goodacre, DDS, MSD1/Charles J. Goodacre, DDS, MSD2
The newest impression techniques use intraoral scanners to capture both the hard and
soft tissues. However, with edentulous patients, the accuracy of an intraoral scanner
to capture an acceptable impression for the fabrication of a complete denture needs
to be evaluated. Therefore, the purpose of this report of two patient treatments is
to describe a technique that used intraoral scanning to record mucosal morphology
and fabricate computer-aided design/computer-assisted manufacture (CAD/CAM)
complete dentures. Int J Prosthodont 2018;31:166–170. doi: 10.11607/ijp.5624
Impressions are a critical step in complete denture
fabrication, as their accuracy allows denture bases
to exhibit both retention and stability. Historically,
Computer-aided design and computer-assisted
manufacturing (CAD/CAM) of complete dentures
has made it possible to fabricate denture bases with
multiple impression techniques have been proposed improved adaptation,10 leading to improved retention
in the literature, including the functional impression compared to conventional processing techniques.11
technique,1 the mucostatic impression technique,2 While the manufacturing process itself has embraced
and the selective pressure technique.3 In addition, digital technology, the clinical procedures have re-
modifications have been made to these techniques mained analog. However, a limited number of ar-
over the years with the use of different impression ticles have been recently published in which digital
materials.4,5 impressions were taken of edentulous arches.6.8,9,12
The newest impression technique eliminates im- One such paper reported on a technique whereby
pression materials by using intraoral scanning of both pressure-indicating paste (PIP) mixed with zinc oxide
the teeth and soft tissue, but concerns have been eugenol was proposed as a means of improving ac-
expressed regarding its use for digitizing edentulous curacy when scanning edentulous ridges intraorally.12
jaws due to inaccuracies.6 As with other technologic These articles point out the need for more information
advancements, the process needs to be evaluated regarding the ability of intraoral scanners to capture
clinically to determine if it has potential use in com- edentulous ridge mucosa as an alternative to conven-
plete denture prosthodontics. tional impression procedures. Therefore, the purpose
The use of intraoral scanners in dentistry was doc- of this report of two patient treatments was to de-
umented as early as the 1980s.7 There are currently scribe the use of intraoral scanning for the fabrication
many brands of intraoral scanners that can be used of CAD/CAM complete dentures.
to make digital impressions of dentate arches for the
fabrication of both direct and indirect restorations. A Clinical and Technical Procedures
report was published in which an intraoral scanner
was successfully used to make a digital impression As described below, the technique used with both
of a partially dentate maxilla for the fabrication of a patients involved intraoral scanning of the edentulous
removable partial denture framework,8 and intraoral arches combined with use of the Wagner EZ Guide
scanners have been used in edentulous arches to re- process (AvaDent Global Dental Science LLC). The
cord the positions of implant scan bodies for the fabri- EZ Guide process involves three appointments and
cation of complete-arch implant restorations in vitro.9 includes use of a Wagner Try-In (WTI) at the second
appointment. After desired esthetic customization to
tooth positions and vertical dimension at the second
1Graduate Student in Prosthodontics and Implant Dentistry, Loma Linda appointment, the denture is fabricated.
University School of Dentistry, Loma Linda, California, USA. The first intraoral scanning was performed on a pa-
2Distinguished Professor, Loma Linda University School of Dentistry,
tient with an edentulous maxilla. The use of different
Loma Linda, California, USA.
surface additives was tested to see if they improved the
Correspondence to: Brian J. Goodacre, Loma Linda School of Dentistry, scanner’s ability to capture the soft tissue. The second
Graduate Prosthodontic Clinic, 11092 Anderson Street,
patient was edentulous in both the maxilla and man-
Loma Linda, CA, 92350, USA. Email: bgoodacre@llu.edu
dible, and scanning was used for both arches to de-
©2018 by Quintessence Publishing Co Inc. scribe the technique and determine what challenges
166 The International Journal of Prosthodontics
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Goodacre and Goodacre
might be encountered when
using intraoral scanning to
record the morphology of an
edentulous mandible.
Patient No. 1
Five different digital impres-
a b c
sions were made of the first
patient’s edentulous max-
illa using an intraoral scan-
ner (Trios 3, 3Shape A/G).
The first scan was made with
no additives to the soft tis-
sue (Fig 1a), the second scan
used four radiopaque adhe-
sive markers (Spee-D-Mar, d e
PDC Healthcare) (Fig 1b)
placed around the palate, Fig 1 Comparison of intraoral scanning using different tissue additives. (a) No additive.
the third scan used scan- (b) Adhesive radiopaque markers. (c) Intraoral scanning spray. (d) Minimal PIP application.
(e) Maximal PIP application.
ning spray (High Definition
Scanning Spray, 3M) lightly
sprayed on the soft tissue (Fig
1c), the fourth scan used a
minimal amount of PIP (Mizzy,
Keystone Industries) (Fig 1d),
and the fifth scan used a max-
imal amount of PIP (Fig 1e).
Each digital impression was
exported as an STL file and
sent to Global Dental Science Fig 2 Esthetic try-in. Fig 3 Patient smile with prosthesis.
for fabrication of a CAD/CAM
milled denture base.
At the second appoint- The retention and stability were surprisingly satisfactory given the estimation
ment, each of the five denture of border extensions obtained from the intraoral scan. Minor changes were
bases was clinically evaluated made to the tooth positions, and an interocclusal record was made between
for adaptation and retention. the maxillary WTI and the mandibular natural teeth. The overall esthetic out-
Clinically, no discernable dif- come of the definitive maxillary complete denture is shown in Fig 3.
ference was seen between the The completed denture was judged to be esthetically appropriate and ex-
five denture bases. Therefore, hibited good retention and stability. Instructions were provided to the patient
the decision was made not to regarding postplacement appointments and care.
apply any additive to the tis-
sue surface for the maxillary Patient No. 2
scans. There is very limited
information with regard to the At the initial appointment for the second patient, an evaluation was per-
mandibular arch, so it was formed of the vestibular depth, frenal attachments, and border extensions of
decided to apply a minimal the edentulous arches. The clinical scanning procedure was performed using
amount of PIP to the mandibu- two people, one to scan the arch and the other to retract the lips, cheek, and
lar ridge crest. tongue. Special care must be taken to retract the soft tissues to positions that
The WTI was then fabri- simulate the border extensions of a complete denture while avoiding excess
cated based on the maxillary stretching. Retraction can be accomplished using a finger (Fig 4) or a surgical
scan with no additives to the retractor (Fig 5), allowing visually appropriate border extensions during scan-
soft tissue, and the stabil- ning. While the lips and cheeks were retracted, an intraoral scanner (Trios 3,
ity and estimated tooth posi- 3Shape A/G) was used to record the crest of the maxillary edentulous ridge,
tions were evaluated (Fig 2). then the palate, and finally the vestibule.
Volume 31, Number 2, 2018 167
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Intraoral Scanning for Complete Denture Fabrication
Fig 4 Finger retraction of cheeks to deter- Fig 5 Intraoral scanning with cheeks re- Fig 6 Measurement of lip at rest using
mine vestibular depth. tracted using Brånemark retractor. Massad lip ruler.
The desired tooth form and
shade were selected, and the dis-
tance from the incisive papilla to
the lip at rest was measured using
the Massad Lip Ruler (Nobilium
CMP Industries LLC). The incisive
papilla-to-lip distance was used to
determine the location of the in-
cisal edge of the maxillary central
incisors (Fig 6). This incisal edge
a b
position information, along with
the STL file of both the maxilla
and mandible, were sent to Global
Dental Science for fabrication of
a WTI. Based on the incisal edge
position of the maxillary incisors,
the location of the incisive papilla,
and other anatomical landmarks,
a WTI was fabricated that located
the teeth based on anatomical
average locations and provided a
trial denture, which was then re-
c d fined clinically.
Fig 7 (a) Color digital impression of maxillary arch. (b) Solid-color digital impression of The collected information and
maxillary arch. (c) Color digital impression of mandibular arch. (d) Solid-color digital impression the digital impressions of the max-
of mandibular arch.
illa and mandible in a standard
tessellation language (STL) file
format were sent to Global Dental
Science for fabrication of the max-
The intraoral scan of the mandible was expected to be more difficult, so illary and mandibular WTIs (Fig 7).
PIP was applied to the crest of the ridge to potentially provide landmarks At the second appointment, the
that would enhance the scanning. However, the PIP did not prove to be WTI trial dentures were placed in
beneficial. The mandibular scanning was started at the crest of the ridge, the mouth, and the adaptation,
including as much of the retromolar pad as possible, and then moved as well as the border extensions,
to the facial vestibule. Using an instrument—in this case an intraoral was evaluated using PIP. The re-
mirror—the tongue was displaced medially while the intraoral scanner tention and stability of the maxil-
recorded as much of the lingual vestibule as possible. It was not pos- lary trial denture was judged to be
sible to record all the desired border extensions in the mandible due to very good. Even the mandibular
the presence of movable mucosa extending close to the residual ridge WTI fit the edentulous ridge well,
crest, resulting in soft tissue movement during the scanning that halted but lacked ideal border exten-
the scanning process. Therefore, a decision was made to proceed with sions. Therefore, the mandibular
fabrication of WTIs based on the extent of the scanning that was possible WTI was modified using conven-
and then make a traditional reline impression inside the mandibular WTI tional border molding and im-
at the second appointment. pression techniques, as would
168 The International Journal of Prosthodontics
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Goodacre and Goodacre
Fig 8 Border-molded mandibular impres- Fig 9 Esthetic try-in. Fig 10 Maxillary and mandibular Wagner
sion using Wagner Try-in as custom tray. Try-In with interocclusal record.
Fig 11 Digital preview showing tooth Fig 12 Final prosthesis. Fig 13 Patient smile, with prosthesis.
arrangement according to sent records.
be performed during a reline impression (Fig 8). The Even though the mandibular arch was not success-
esthetics and occlusal vertical dimension were evalu- fully scanned in its entirety, the scanning was per-
ated, and refinements were made in the maxillary formed relatively quickly and did produce an accurate
anterior tooth positions (Fig 9). A centric relation re- base for the trial denture. The subsequent border
cord was obtained, and the WTIs, along with the in- molding and reline impression were judged to require
terocclusal record, were sent back to Global Dental less clinical time than making a traditional impression
Science for fabrication of the definitive dentures (Fig in a custom tray, thereby having an advantage. On
10). Using the records, the desired tooth arrangement average, the maxillary scan required about 2 minutes
was determined (Fig 11) and the prosthesis fabricated while the mandibular scan required 5 minutes due to
(Fig 12). multiple attempts; the mandibular scan was not com-
During the third appointment, the definitive den- pletely adequate in terms of border extensions.
tures were placed in the mouth and the adaptation The dentures for both patients demonstrated good
evaluated using PIP. Minor adjustments were made retention and stability and only required minimal ad-
and the occlusion refined. The esthetic results were justments at the time of placement and during post-
evaluated (Fig 13) and determined to be appropriate, placement appointments. The authors were somewhat
as were the retention and stability. surprised and were satisfied with the positions of the
maxillary anterior teeth based on the anatomical av-
Discussion erages used with the Wagner EZ Guide process. At
the second appointment, the esthetic tooth positions
This technique determined that an intraoral scanner were evaluated and only required minor adjustments,
can be used to fabricate maxillary complete dentures. after which an interocclusal record was made at the
While it was not possible to accurately record all the desired occlusal vertical dimension for fabrication of
borders of the mandibular denture, sufficient data the definitive prostheses. The benefit of fabricating
were recorded to produce a stable trial denture base the denture over three appointments is the ability to
that was modified to the desired border extensions evaluate and customize the tooth positions prior to
using a conventional reline impression technique. definitive denture fabrication. As needed, the second
Further experimentation is needed to determine how appointment can also be used to record any deficient
this process can be accomplished solely with a digital borders resulting from the scanning using a reline im-
impression of the mandibular arch. pression in the WTI.
Volume 31, Number 2, 2018 169
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Intraoral Scanning for Complete Denture Fabrication
While the use of intraoral scanning was not able to Conclusions
completely capture the mandibular denture borders,
its use in the maxillary edentulous arch was judged The two patient treatments in this report demonstrate
to be rather straightforward. One challenge relates to that intraoral scanning can be used in conjunction
digitally determining the depth of the posterior palatal with the Avadent WTI to effectively fabricate complete
seal in the area of the pterygomaxillary fissures and dentures in three appointments. The addition of the
across the posterior area of the denture. These depths WTI allows both clinician and patient validation prior
need to be palpated intraorally and the information to definitive denture fabrication.
sent so a seal can be established in the virtual cast for
fabrication of the definitive dentures. Acknowledgments
A potential benefit discovered during the scanning
of the edentulous arches was the ability of an intraoral Charles J. Goodacre is a consultant for Global Dental Science, LLC,
scanner to capture what could be described as a true the manufacturers of AvaDent digital dentures. No conflict of in-
terest is reported for the remaining author.
mucostatic impression. Mucostatic impressions have
been advocated in edentulous patients with hyper-
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170 The International Journal of Prosthodontics
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