Journal of

Clinical Medicine

Article
Digital Protocol to Record Occlusal Analysis in Prosthodontics:
A Pilot Study
Emanuele Risciotti 1,† , Nino Squadrito 2,† , Daniele Montanari 2 , Gaetano Iannello 3 , Ugo Macca 4 , Marco Tallarico 5 ,
Gabriele Cervino 6 and Luca Fiorillo 6,7,8, *

1 Private Practice, 20145 Milan, Italy; risciotti.e@tiscali.it

2 Private Practice, 16121 Genova, Italy; nino.squadrito@libero.it (N.S.); d.montanari19@gmail.com (D.M.)
3 Private Practice, 16036 Genova, Italy; gaetano.iannello@micerium.it
4 Private Practice, 96100 Siracusa, Italy; ugomaccast@gmail.com
5 School of Dentistry, University of Sassari, 07100 Sassari, Italy; me@studiomarcotallarico.it
6 Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina,
98122 Messina, Italy; gabrielecervino@gmail.com
7 Department of Dental Cell Research, Dr. D. Y. Patil Dental College and Hospital, Dr. D. Y. Patil Vidyapeeth,
Sant-Tukaram Nagar, Pimpri, Pune 411018, India
8 Multidisciplinary Department of Medical-Surgical and Odontostomatological Specialties, University of
Campania “Luigi Vanvitelli”, 80121 Naples, Italy
* Correspondence: lfiorillo@unime.it
† These authors contributed equally to this work.

Abstract: Background: Digital technologies enable the accurate replication of occlusion, which is
pivotal for stability in maximum intercuspation and dynamic occlusion. CAD softwares generates
standardized occlusal morphologies requiring significant adjustments. The consideration of individ-
ual mandibular movements during restoration leads to better functional integration. This pilot study
evaluates the efficacy of a novel, fully digital protocol for occlusal analysis recording in prosthodon-
tics. Methods: Patients needing single or multiple metal-free restorations were included. Teeth
underwent horizontal finish line preparation, while restorations on implants were either directly
screwed or used multi-unit abutments. A digital impression (Trios 3 Intraoral Scanner) captured
Citation: Risciotti, E.; Squadrito, N.;
the mouth’s elements. Dynamic occlusion was recorded via Patient Specific Motion (PSM). After
Montanari, D.; Iannello, G.; Macca, U.;
the placement and functionalization of temporary restorations, subsequent scans included various
Tallarico, M.; Cervino, G.; Fiorillo, L.
Digital Protocol to Record Occlusal
elements, and CAD software (Dental system) was used for the restoration design. Restorations were
Analysis in Prosthodontics: A Pilot milled in monolithic zirconia, pressed from CAD/CAM-milled wax, and sintered. Results: An
Study. J. Clin. Med. 2024, 13, 1370. evaluation of 52 restorations in 37 patients indicated high accuracy in restorations manufactured via
https://doi.org/10.3390/ the fully digital workflow. Monolithic zirconia was predominantly used. Subtractive (17.3%) and
jcm13051370 additive (7.7%) occlusal adjustments were mainly chairside. Conclusion: This study underscores the
efficacy of meticulous verification measures and a centric contact system in reducing the need for
Academic Editors: Henk S. Brand and
Takeyasu Maeda
clinical occlusal refinements in prosthetic restorations.

Received: 22 January 2024 Keywords: intraoral scanning; occlusal analysis; CAD/CAM; Patient Specific Motion; prosthetic
Revised: 19 February 2024
rehabilitation
Accepted: 26 February 2024
Published: 28 February 2024

1. Introduction
Copyright: © 2024 by the authors.
Intraoral scanning (IOS) systems have achieved significant reliability in accuracy and
Licensee MDPI, Basel, Switzerland. precision and have had widespread use in dental practice in recent decades [1]. CAD/CAM
This article is an open access article technology made fabricating dental and implant-supported restorations possible through a
distributed under the terms and digital workflow. Digital impressions transfer the intraoral situation to a virtual model and
conditions of the Creative Commons represent the first step of the digital workflow. The accuracy of this procedure is crucial to
Attribution (CC BY) license (https:// transferring the implant position correctly, and it represents the success of the treatment.
creativecommons.org/licenses/by/ If it is performed poorly, it can lead to mechanical and biological complications. Digital
4.0/). impressions can accelerate the data-capturing process and eliminate most drawbacks

J. Clin. Med. 2024, 13, 1370. https://doi.org/10.3390/jcm13051370 https://www.mdpi.com/journal/jcm

J. Clin. Med. 2024, 13, 1370 2 of 11

usually found with conventional impressions, thereby decreasing patient discomfort while
improving the predictability of prosthesis design and manufacturing procedures [2].
A recent systematic review demonstrated that the precision and accuracy of the
digital workflow, compared with the conventional technique, favored up to four-unit
restorations [3].
Precision is defined as the ability to take the same measurement value consistently [4].
An intraoral scanner should present high trueness and precision, and it can be evaluated
by superimposing different scans of the same object using the same IOS device [5]. Many
factors might compromise the performance of an IOS and decrease its accuracy. The
aspects related to the equipment, such as the scanning technology, the state of the device,
and the temperature and illumination of the room and the reading area, may affect the
accuracy of the readings. Also, the operator’s skills, experience, and scanning technique
are accuracy-influencing factors. In vivo, the patient’s movements, limited mouth opening,
and oversized tongues may make the scanning procedure difficult. In vitro, the design and
material of the cast and the design of the scan body, as well as its light reflection properties,
can affect the precision of the digital impression [6–8].
Among the benefits of digital technologies is that occlusion can be accurately replicated
using an IOS.
Occlusal design plays a significant role in maintaining and promoting stability in
maximum intercuspation without generating interference in dynamic occlusion [9]. The
digital workflow allows one to send information about the three-dimensional shape of
the prepared tooth and adjacent and antagonist teeth, allowing for further CAD/CAM
(computer-aided design/computer-aided manufacturing) processing of the prosthetic
restoration [10]. However, CAD software generates occlusal morphologies based on stan-
dardized shapes requiring major occlusal adjustments [11,12]. For this purpose, using an
articulator to simulate the movements of a working model is considered an indispensable
aspect for prosthetic restorations [13]. Esposito et al. [14] investigated the reliability of
recording occlusal contacts using an intraoral scanner versus articulating paper, finding sig-
nificant differences in contact numbers except for upper central incisors and first premolars,
with low clinician agreement on occlusions, highlighting the need for a precise method for
recording occlusal contacts. Abbas et al. [15] studied the influence of occlusal reduction
design on the biomechanics of endocrowns in maxillary premolars, revealing that PEKK-
TON endocrowns with anatomical preparations offer optimal restoration, suggesting these
innovative systems could improve the longevity of tooth restorations. Pereira et al. [16]
assessed the accuracy and reproducibility of real versus virtual occlusal contact points
in implant-supported dentures, finding that both methods provided clinically excellent
contact points with no significant difference in reproducibility, indicating intraoral scanners
as a viable tool for occlusion mapping.
It has been demonstrated that the functions performed by a virtual articulator are
comparable to those performed by an analog system [17]. However, to develop movements
compatible with mandibular kinematics, analog models or digital scans must be positioned
appropriately [18]. Analogically, this step is performed using an arbitrary or kinematic
facebow, setting the condylar parameters, respectively, to mean values or according to
pantographic tracings [18]. In a digital environment, models can be aligned using artic-
ulatory scanning with arch-mounted models [19] or by aligning STL models based on
CBCT [20] or face scans [21], or by using jaw motion detection systems such as Arcus
Digma or Zebris (Figure 1) [22], recording the individual parameters to be transferred
to the virtual articulator. Digital technologies have recently been introduced, allowing
mandibular movements to be acquired and reproduced in a virtual environment without
needing to place them in a virtual articulator.
J.J.Clin.
Clin.Med.
Med.2024,
2024,13,
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Figure
Figure1.1.Protrusive movement
Protrusive movement (left) andand
(left) gothic archarch
gothic (right 2). These
(right). are are
These the the
free free
movements of theof
movements
patient. In this phase, verifying the accurate functional movements with the articulation
the patient. In this phase, verifying the accurate functional movements with the articulation paper paper
previously
previouslydetected
detectedon
onthe
thepatient
patientisispossible.
possible.

Restorations
Restorationsfabricated
fabricatedwith
withknowledge
knowledgeof ofindividual
individualmandibular
mandibularmovements
movementshave have
been
been reported
reported toto have
have better
better functional
functional integration
integration than
than restorations
restorations fabricated
fabricated using
using
medium
mediumarticulator
articulatorsettings
settings(Figure
(Figure1)
1)[23].
[23].
Forthis
For thispurpose,
purpose,thethe3Shape
3Shapesystem,
system,combined
combinedwith withthe
thetrio’s
trio’sscanner,
scanner,allows
allowsfor
for
mandibularmovements
mandibular movementsto tobe
beacquired
acquiredthrough
throughaafunction
functionnamed
namedPatient
PatientSpecific
SpecificMotion
Motion
(PSM),with
(PSM), withthe
thepossibility
possibilityofofreproducing
reproducingititininthe
theCAD
CADenvironment
environmentto toallow
allowforforthe
the
design of ideal prosthetic restorations according to actual mandibular
design of ideal prosthetic restorations according to actual mandibular movements andmovements and
function.This
function. Thispilot
pilotstudy
studyaims
aimstotodemonstrate
demonstrateand andevaluate
evaluatethe
theefficacy
efficacyofofthis
thisdigital
digital
procedurein
procedure inrecording
recordingananocclusal
occlusalanalysis.
analysis.

2.2.Materials
Materialsand
andMethods
Methods
Thepresent
The presentpilot
pilotstudy
studywas
wasdesigned
designedasasaaclinal
clinalaudit
audittotoevaluate
evaluateaanovel,
novel,fully
fullydigital
digital
protocol for recording occlusal analyses through a case series. This study was
protocol for recording occlusal analyses through a case series. This study was conducted conducted
betweenJanuary
between January2023
2023and
andMay
May2023.
2023.Patients
Patientswhowhoneeded
neededaasingle
singleor
orup
uptotoaathree-unit
three-unit
metal-free (zirconia or lithium disilicate) restoration delivered on natural teeth or implants
metal-free (zirconia or lithium disilicate) restoration delivered on natural teeth or implants
were considered eligible for this study. Patients requiring complex occlusal therapy (re-
were considered eligible for this study. Patients requiring complex occlusal therapy (re-
organizational approach in centric relation and/or variation in the vertical dimension of
organizational approach in centric relation and/or variation in the vertical dimension of
occlusion) were excluded. Natural teeth were prepared with a horizontal finish line. At the
occlusion) were excluded. Natural teeth were prepared with a horizontal finish line. At
same time, all the restorations on implants were screwed directly on the implants (single
the same time, all the restorations on implants were screwed directly on the implants
crown) or using a multi-unit abutment (MUA) if splinted. All the restorations were made
(single crown) or using a multi-unit abutment (MUA) if splinted. All the restorations were
starting with an IO scan of the patient’s mouth (Trios 3 Intraoral Scanner, 3Shape A/S,
made starting with an IO scan of the patient’s mouth (Trios 3 Intraoral Scanner, 3Shape
Copenhagen, Denmark). Then, the patient’s mandibular movements (dynamic occlusion)
A/S, Copenhagen, Denmark). Then, the patient’s mandibular movements (dynamic
were recorded using the Patient Specific Motion (PSM) tool (3Shape A/S). All patients
occlusion) were recorded using the Patient Specific Motion (PSM) tool (3Shape A/S). All
were rehabilitated in maximal intercuspidation. According to the Council for International
patients were rehabilitated in maximal intercuspidation. According to the Council for
Organization of Medical Sciences (CIOMS-2016), approval by an ethical committee was not
International Organization
required because of Medical
“the research poses noSciences
more than (CIOMS-2016),
minimal risk to approval by anwith
participants” ethical
this
committee
type of non-invasive intraoral scanning. The patients were selected among patients risk
was not required because “the research poses no more than minimal to
already
participants” with this type of non-invasive intraoral scanning. The patients
candidates for prosthetic rehabilitation, no personal data are shown, and this method were selected
among patients
could not alreadyany
have caused candidates
damage; for prosthetic
in the case of an rehabilitation,
incompatible no personalthe
prosthesis, data are
patient
shown,
would and
havethis method could
continued not have
with their caused prosthetic
temporary any damage; in the case ofbefore
rehabilitation an incompatible
receiving a
prosthesis, the patient
new prosthetic product. would have continued with their temporary prosthetic
rehabilitation before receiving a new prosthetic product.
J. Clin. Med. 2024, 13, x FOR PEER REVIEW 4 of 11
J. Clin. Med. 2024, 13, x FOR PEER REVIEW 4 of 11
J. Clin. Med. 2024, 13, 1370 4 of 11

2.1. Clinical Steps

2.1. Clinical Steps
2.1. Clinical
EligibleStepspatients underwent an initial scanning of the elements to be rehabilitated. In
Eligible patients underwent an initial scanning of the elements to be rehabilitated. In
a second appointment, temporary an
Eligible patients underwent restorations were applied
initial scanning of the and madeto
elements functional on both
be rehabilitated.
a second appointment, temporary restorations were applied and made functional on both
teeth and implants. After four to six weeks of function, all
In a second appointment, temporary restorations were applied and made functional the patients received the fol-
on
teeth and implants. After four to six weeks of function, all the patients received the fol-
lowing scans: working arch with functionalized temporary restoration,
both teeth and implants. After four to six weeks of function, all the patients received definitive abut-
lowing scans: working arch with functionalized temporary restoration, definitive abut-
ment or scan body,
the following scans:antagonist,
working arch right andfunctionalized
with left occlusionstemporary
(scan bite),restoration,
and PSM. Before car-
definitive
ment or scan body, antagonist, right and left occlusions (scan bite), and PSM. Before car-
rying
abutment out orthescan
scans,
body,the excursiveright
antagonist, occlusal contacts
and left (protrusion
occlusions and and
(scan bite), laterality) were
PSM. Before
rying out the scans, the excursive occlusal contacts (protrusion and laterality) were
marked
carryingusingout thea 21scans,
µ redthearticulating
excursivepaper (Accufilm
occlusal contacts II red). In contrast,
(protrusion andcontacts
laterality)in max-
were
marked using a 21 µ red articulating paper (Accufilm II red). In contrast, contacts in max-
imum
marked intercuspidation
using a 21 µ red were marked with
articulating 21 µ(Accufilm
paper black articulating
II red). paper (Accufilm
In contrast, II black)
contacts in
imum intercuspidation were marked with 21 µ black articulating paper (Accufilm II black)
so that clinical evidence of these areas was acquired during
maximum intercuspidation were marked with 21 µ black articulating paper (Accufilm the color scanning phase to
so that clinical evidence of these areas was acquired during the color scanning phase to
allow for so
II black) contact verification
that clinical during
evidence of the CAD
these phases
areas was of makingduring
acquired the restorations. After the
the color scanning
allow for contact verification during the CAD phases of making the restorations. After the
phase
first to allow
scan, for contact
the interim verification
restoration during theand
was removed, CAD thephases
secondofscanmaking the restorations.
was taken at the im-
first scan,
After the interim
the first scan, therestoration
interim was removed, and the second scan was taken at the im-
plant level (scan body) or naturalrestoration was removed,
tooth (double-cord and the
technique). second
Subsequently, scan antagonist
was taken
plant level
at theocclusion(scan
implant level body) or natural tooth (double-cord technique). Subsequently, antagonist
and were (scan body)Finally,
recorded. or natural tooth (double-cord
a dynamic occlusion was technique).
scanned Subsequently,
and recorded
and occlusion were recorded. Finally, a dynamic occlusion was scanned and recorded
during the digital impression procedure in the PSM scan step. After that, allscanned
antagonist and occlusion were recorded. Finally, a dynamic occlusion was scans wereand
during
recorded the digital
during impression
the digital procedure
impression in the
procedure PSM
in thescan
PSM step.
scan After
step. that,
After all scans
that, all were
scans
sent to the laboratory via the “Communicate” intra-net system in the proprietary 3ox for-
sent to
were thetolaboratory
sent the via the
laboratory via“Communicate”
the “Communicate” intra-net system
intra-net in theinproprietary
system the proprietary 3ox for-
3ox
mat (3Shape A/S).
mat (3Shape A/S).
format (3Shape A/S).
2.2. Laboratory Steps
2.2. Laboratory Steps
All the scans were imported into CAD software (Dental system). The accuracy of the
All the scans were imported into CAD The accuracy of the
intermaxillary relationships was verified at software
the sagittal (Dental
view,system).
corresponding to the areas
intermaxillary relationships
relationships was
was verified
verified at
at the sagittal
sagittal view, corresponding to the areas
clinically marked with the articulation paper, to verify the absence of encroachments or
clinically marked with the articulation paper, to verify the absence of encroachments or
spacings, both in maximum intercuspidation and in excursive movements (Figures 2–4).
intercuspidation and
spacings, both in maximum intercuspidation and in in excursive
excursive movements
movements (Figures
(Figures 2–4).
2–4).

Figure 2. Checking
Checking the
the occlusion
occlusion and
and the mandibular movements.
Figure
Figure 2.
2. Checking the occlusion and the
the mandibular
mandibular movements.
movements.

Figure 3. Sagittal view corresponding to the marked area.

Figure 3. Sagittal
After view
that, the corresponding to theproject
aesthetic–functional marked area.
Figure 3. Sagittal view corresponding to the markedofarea.
definitive restorations was carried out by
reproducing an ideal anatomical wax-up according to the Geometric Functional Anatomy
(AFG) technique, replacing the use of a caliper with a 3D grid that provided anatomical ref-
erences. After a careful verification of the occlusal morphology and functional movements,
the occlusal contacts in MI were reinforced with the individual morphing tool, using a
radius with a 0.48 mm diameter and a level of influence with a thickness of 25 µ using the
“additive wax knife tool” (Figure 5).
J. Clin. Med.
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Figure 4. Marked contacts.

After that, the aesthetic–functional project of definitive restorations was carried out
by reproducing an ideal anatomical wax-up according to the Geometric Functional Anat-
omy (AFG) technique, replacing the use of a caliper with a 3D grid that provided anatom-
ical references. After a careful verification of the occlusal morphology and functional
movements, the occlusal contacts in MI were reinforced with the individual morphing
tool, using a radius with a 0.48 mm diameter and a level of influence with a thickness of
25 µ using the “additive wax knife tool” (Figure 5).
Figure 4. Marked contacts.

Figure 4. Marked contacts.

After that, the aesthetic–functional project of definitive restorations was carried out
by reproducing an ideal anatomical wax-up according to the Geometric Functional Anat-
omy (AFG) technique, replacing the use of a caliper with a 3D grid that provided anatom-
ical references. After a careful verification of the occlusal morphology and functional
movements, the occlusal contacts in MI were reinforced with the individual morphing
tool, using a radius with a 0.48 mm diameter and a level of influence with a thickness of
25 µ using the “additive wax knife tool” (Figure 5).

Reinforcedocclusal
Figure5.5.Reinforced
Figure occlusalcontact
contactpoints
pointsusing
usingan
anadditive
additiveknife
knifetool.
tool.

Definitive restorations
Definitive restorations were
weremilled
milledininmonolithic zirconia
monolithic 850,850,
zirconia using cutting
using toolstools
cutting with
a 0.2 mm diameter, and subsequently sintered according to the manufacturer’s
with a 0.2 mm diameter, and subsequently sintered according to the manufacturer’s rec- recommen-
dations. The lithium
ommendations. disilicate
The lithium restorations
disilicate were pressed
restorations starting
were pressed from CAD/CAM-milled
starting from CAD/CAM-
wax and finally sintered according to the manufacturer’s recommendations (Table 1).
milled wax and finally sintered according to the manufacturer’s recommendations (Table
1).
Table 1. CAD parameters.
Table 1. CAD parameters.
Level of Occlusal Occlusal
Dental Radius Prototype
Software Influence Adjustments Adjustment during Occlusion
Units (CAD) Occlusal Models
(CAD)
Figure 5. Reinforced
Level of occlusal in MI
contact points
Occlusal Lateral
using an Movements
additive knife tool.
Radius Adjustment Prototype
52 Units3Shape
Dental 1 DA 25
Software µ
Influence0.48 mm Accufilm 21 µ
Adjustments Accufilm 21 µ MI
Occlusion No
Definitive (CAD) during Lateral Models
(CAD) restorations were in milled
MI in monolithic zirconia 850, using cutting tools
with a 0.2 mm diameter, and subsequently sintered Movements
according to the manufacturer’s rec-
Finally, all the restorations were finished
ommendations. The lithium disilicate restorations were and polished,
pressed maintaining
starting fromthe reinforced
CAD/CAM-
52 3Shape points
1 DAunder
25 µ protection.
0.48 mm AfterAccufilm 21 µ theAccufilm
sintering, 21 µ and occlusal
interproximal MI No were
contacts
milled wax and finally sintered according to the manufacturer’s recommendations (Table
marked with a pencil to avoid contact with the bur and polishing rubbers. All the phases
1).
wereFinally,
performed fully
all the digitally, without
restorations the need
were finished andtopolished,
create any master models.
maintaining The CAD
the reinforced
parameters
points
Table under
1. CAD are reported in Table 2.
protection. After sintering, the interproximal and occlusal contacts were
parameters.

Table 2. Distribution of the restorations. Occlusal

Level of Occlusal
Radius Adjustment Prototype
Dental Units Software Influence Adjustments Single Multiple
Occlusion
(CAD) during Lateral Models
(CAD) Teeth in MI 32 3 (3 units)
Movements
Implants 8 1 (3 units)
52 3Shape 1 DA 25 µ 0.48 mm Accufilm 21 µ Accufilm 21 µ
40 MI No
4 (12 dental units)

Finally,
Once inallthe
thedental
restorations
office, were finishedcheck
an intraoral and polished, maintainingcontacts
of the interproximal the reinforced
and the
points under protection. After sintering, the interproximal and occlusal
internal fit of the restorations was performed using a fit checker. After that,contacts were
the occlusal
J. Clin. Med. 2024, 13, 1370 6 of 11

contacts were checked in the same way as previously described, using 21 µ red articulating
paper (Accufilm II red), while the contacts in maximum intercuspidation were marked
with 21 µ black articulating paper (Accufilm II black). Moreover, 8 µ Shimstock (company)
paper was used to check all the contacts.
Occlusal verification was carried out before cementation or for the implants after
the verification of passivity and tightening the screws. The present research recorded
and analyzed the number and type of occlusal adjustments. Periapical radiographs were
obtained if needed.

3. Results
A total of 52 new restorations and not remakes, delivered on 37 patients, were evalu-
ated. All the restorations were made in MI using lithium disilicate or monolithic zirconia.
All the restorations were made starting from an intraoral digital impression and patient-
specific motion acquisition, according to a fully digital workflow.
On thirty-three patients, definitive restorations were made in monolithic zirconia,
while lithium disilicate was used in the other four. A total of forty single crowns were
delivered; of these, eight were delivered on implants and bonded on T-base abutments.
A total of 12 restorations were multiple. Of these, three bridges of three units each were
delivered on natural teeth, and only one was delivered on implants (Table 2). Restorations
were applied on incisors and premolar and molar teeth. All multi-unit rehabilitations were
performed on premolar–molar teeth.
A total of nine subtractive occlusal finishings (17.3%) and four addictive occlusal
finishings (7.7%) were performed. All the subtractive occlusal adjustments were made
chairside, while all the four addictive occlusal finishings were made in the laboratory. In
this case, the crowns were delivered in later appointments (Table 3).

Table 3. Number and type of finishings.

Subtractive Addictive Dinamic

Restorations No Finishing
Finishing Finishing Finishing
39–75% 9–17.3% 4–7.7% 7–13%
30 single teeth, 2 3-unit teeth, 2 single teeth, 2 single teeth,
supported supported supported supported
52 6 single implants, 1 3-unit implant,
supported 2 single supported
1 3-unit implant,
implants,
1 3-unit implant, supported 2 single-implants,
supported
supported supported

• Study participants: 52 restorations were evaluated across 37 patients.

• Materials used: restorations primarily used monolithic zirconia.
• Occlusal adjustments: 17.3% of the cases required subtractive occlusal finishing, and
7.7% required additive finishing.
• Finishing techniques: subtractive occlusal adjustments were performed chairside,
whereas all additive occlusal finishings were executed in the laboratory.
These results highlight the efficacy and precision of the fully digital workflow in pros-
thetic dental restorations, emphasizing the reduced need for post-production adjustments.

4. Discussion
The present study was designed as a clinical audit to evaluate the efficacy of a novel,
fully digital protocol for recording occlusal analyses. The preliminary results encourage
the presented protocol, improving the final accuracy of the restorations and reducing the
need for finishing. This study compares the new digital method with traditional methods.
An occlusal analysis in prosthodontics traditionally involves physical impressions and
manual adjustments to replicate patient-specific occlusal dynamics. This process can be
J. Clin. Med. 2024, 13, 1370 7 of 11

time-consuming and less precise, often requiring several adjustments to achieve ideal
occlusion. Using wax for an occlusal analysis in prosthodontics has several disadvantages.
Wax impressions can be less accurate due to distortion or deformation during handling or
storage. The process is also time-consuming, requiring manual adjustments and remolding
to achieve the correct occlusion. Additionally, wax impressions only sometimes effectively
replicate the dynamic aspects of a patient’s bite, leading to inaccuracies in the occlusal
assessment. This traditional method relies heavily on the clinician’s skill and experience,
which can lead to outcome variability. The traditional method of conducting an occlusal
analysis using a facebow involves transferring the spatial orientation of the maxillary arch
and occlusal plane to a dental articulator [24,25]. This technique ensures the articulator
replicates the patient’s jaw movements and occlusal relationships. The facebow records
the relationship between the maxillary arch and a reference point, usually the axis of the
temporomandibular joint. The data collected allow for the accurate mounting of casts
on the articulator, which is essential for fabricating prostheses or orthodontic appliances
that accurately match the patient’s natural occlusion and jaw movements. This method,
while accurate, can be time-consuming and relies heavily on clinician skills. In contrast,
the new digital method employs intraoral scanning systems, providing greater accuracy
and efficiency. It captures precise digital impressions of the mouth, allowing for a more
accurate replication of occlusion. This method integrates digital technologies to record
mandibular movements and design prosthetic restorations that closely mimic natural
dental movements, potentially leading to better functional integration and reducing the
need for manual adjustments [24,26]. The digital method offers advantages over tradi-
tional techniques, including improved precision, reduced treatment time, and enhanced
patient comfort. However, the effectiveness of this method depends on the accuracy of
the digital tools and the operator’s expertise. Yue et al. [23] developed a 3D digital smile
design technique using virtual articulation for esthetic dentistry. This approach utilized
a digital facebow and a virtual articulator to analyze occlusal data and jaw movements,
ensuring stable occlusion and smooth jaw patterns. The technique facilitated the design of
new prostheses, maintaining stable occlusion and patient satisfaction over 9 months. Sun
et al. [24] presented a fully digital workflow for fabricating occlusal stabilization splints.
This method used CAD/CAM systems and a digital facebow based on optical sensor tech-
nology. The study highlighted the workflow’s clinical feasibility, accuracy, and efficiency
compared to traditional methods, demonstrating the potential for improved production
and patient care. Chou et al. [25] developed a personalized virtual dental articulator using
computed tomography (CT) data and motion tracking. This tool mathematically modeled
jaw movements for dental restoration design, replacing traditional facebow transfers. The
articulator’s effectiveness was validated by comparing simulation data with actual jaw
movement measurements.
Jeong et al. [26] evaluated the accuracy of semi-adjustable articulator contacts com-
pared to intraoral contacts during eccentric mandibular movements. Their study revealed
variations in concordance affected by time and whether contacts were on working or
nonworking sides. They concluded that while initial eccentric tooth contacts on the ar-
ticulator were reliable, occlusal adjustments might be necessary post delivery. Prakash
et al. [27] conducted a systematic review assessing the utility of the facebow in complete
denture fabrication. The review compared facebow use against simplified techniques using
anatomical landmarks and found similar clinical efficiency and patient acceptability results.
The review called for more research for conclusive results on changing clinical practices.
Kubrak et al. [28] compared edentulous patients treated traditionally and using a face-bow
and a Quick Master articulator. The study aimed to establish a simple method for occlusal
recording and compare the treatment outcomes of using an articulator and traditional
methods in fabricating complete dentures. The study involved 60 patients, with clinical
examinations and patient surveys conducted post treatment. The findings suggested that
using an articulator in denture fabrication resulted in more physiologic and balanced
occlusion, shorter adaptation periods, and positive patient feedback.
J. Clin. Med. 2024, 13, 1370 8 of 11

Linsen et al. [29] highlighted the significance of registration techniques on condyle dis-
placement and electromyographic activity, illustrating the intricate biomechanics involved
in stomatognathic health and the precision required in dental prosthetics. Resende et al. [30]
emphasized the role of operator experience, scanner type, and scan size in the accuracy of
3D dental scans, shedding light on the importance of technical expertise and equipment
in achieving optimal prosthetic outcomes. Li et al. [31] contributed to this understanding
by focusing on the design of occlusal wear facets in fixed dental prostheses, indicating the
necessity for personalized approaches in dental restoration to mimic natural mandibular
movements. Abdulateef et al. [32] discussed the clinical accuracy and reproducibility of
virtual interocclusal records, stressing the potential of digital technologies in enhancing
the precision of dental measurements and fittings. Cicciù et al. [33] explored the strength
parameters in the “Toronto” osseous prosthesis system, providing valuable insights into
dental implant’ mechanical properties and durability. In a later study, Cicciù et al. [34]
delved into prosthetic and mechanical parameters affecting the facial bone under the load of
different dental implant shapes, further emphasizing the need for a nuanced understanding
of biomechanical interactions in implant dentistry. Finally, Resende et al. [30] reiterated the
influence of operator experience, scanner type, and scan size on 3D scans, reinforcing the
multifaceted nature of factors impacting the precision and reliability of digital impressions
in prosthetic dentistry. These studies underscore the multidimensional considerations
essential in designing, implementing, and evaluating dental prosthetics and implants.
The need to elaborate occlusal surfaces in the CAD phase that are in harmony with the
clinical situation is evident due to the need to produce monolithic restorations that allow
for minimal intraoral correction. During scan acquisition, accuracy is related to several
factors, such as the device’s or software’s technical characteristics, and is dependent on
operator experience. An essential issue in CAD manufacturing is the precision fitting of
the scan acquired. The PMS system is efficient and valuable if the prosthesis is made to
the required vertical dimension, with the upper and lower scans assembled correctly. By
this, Jae-Min Seo proposes checking the accuracy of scan fitting using scan acquisition with
articulation card markers, a technique integrated into our study [31]. However, compared
to the procedure described by Jae-Min Seo, there is no adjustment of the position through
a post-elaboration modification. We are conscious of the various problems that can occur
during bite detection checks, such as occlusal interpenetration or mandibular distancing,
as noted by Abdulateef et al. [32].
Saraa Abdulateef shows frequent compenetration of fitting, with the possibility of
under-occluded artefacts. This phenomenon seems related to the compressibility of the
periodontal ligament in MI. For this reason, our study decided to begin the observation by
detecting clinical contact areas [31] and following artefacts with a slight increase of 25 µ in
an area of 0.48 mm in the occlusal contact zones.
The investigation showed that the prosthesis was correct in 77% of cases, with 12.5%
requiring subtractive modifications and 10% requiring additive modifications, with a
minimum incidence of 3% corrections in excursive areas. This differs from Li’s research,
which does not identify the effectiveness of PMS use. In Li’s study [31], the amount of
occlusal correction of the tooth surface was assessed by comparing overlapping scans of
crowns placed before and after the occlusal adjustment one month later; the authors report
both qualitative and quantitative data and conclude that there are no statistically significant
differences between PSM fabrication and standard fabrication; however, the use of PSM
showed a lower error. There is no indication in Li’s article regarding the necessary control
of the fitting of the scans, as we carried out in our audit by comparing the occlusal contacts
detected at the time of scanning with the articulation chart and the digitally acquired
contacts; this may have influenced the degree of occlusal adjustment required in their work
to achieve correct occlusal integration at maximum intercuspation, which is independent
of whether or not the PMS was used [31]. The PMS is effective in decreasing potential
contacts during the excursion phase. It does not correct possible errors due to the fitting
J. Clin. Med. 2024, 13, 1370 9 of 11

of the scans. For this reason, it is beneficial to check the fitting of the scans by analyzing
marks reproduced using the articulation table.

Limitations
The main limitation of this study includes the lack of a control group and the relatively
small number of patients treated. A sample size calculation was not possible due to the
novelty of the approach. This limited the study’s capacity to comprehensively compare the
new fully digital protocol with traditional methods and generalize the findings. The results,
therefore, are preliminary and suggest a need for further research with larger sample sizes
and control groups for a more robust evaluation of the protocol’s efficacy. Extending
the protocol to larger-span bridges could be feasible too, but it would require additional
research and validation to ensure accuracy and effectiveness. The specific characteristics of
larger spans, such as increased complexity and the potential for more significant occlusal
forces, would need to be considered in future studies.

5. Conclusions
In conclusion, this clinical audit introduces a pioneering digital protocol for recording
occlusal analyses in prosthodontic rehabilitation. By integrating intraoral scanning systems
with CAD software and leveraging the Patient Specific Motion (PSM) tool, we achieve
precise occlusal replication and functional integration, surpassing traditional methods
in efficiency and accuracy. This study’s innovative approach minimizes the need for
manual occlusal adjustments, demonstrating the potential of digital technologies to enhance
prosthetic outcomes significantly. However, this study’s limitations include the absence
of a control group, a relatively small patient sample, and the application of the protocol
within a specific clinical context, which may restrict the generalization of the findings. The
reliance on advanced digital tools also underscores the necessity of operator expertise,
emphasizing the importance of comprehensive training in successfully implementing the
protocol. Future research should aim to validate these findings through larger, controlled
studies, explore the protocol’s applicability across a broader range of dental restorations,
and investigate the integration of emerging technologies to refine the occlusal analysis and
rehabilitation processes further. This research trajectory promises to elevate the standards
of prosthodontic care and expand the boundaries of digital dentistry.

Author Contributions: Conceptualization, M.T. and D.M.; methodology, D.M.; software, N.S.;
validation, N.S., M.T. and G.C.; formal analysis, G.C.; investigation, G.C.; resources, G.I.; data curation,
G.I.; writing—original draft preparation, U.M.; writing—review and editing, L.F.; visualization, G.I.;
supervision, L.F.; project administration, E.R. and G.C. All authors have read and agreed to the
published version of the manuscript.
Funding: This research received no external funding.
Institutional Review Board Statement: Ethical review and approval were waived for this study due
to the nature of the rehabilitation.
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.
Data Availability Statement: Data are available in the manuscript and are reproductible.
Conflicts of Interest: The authors declare no conflicts of interest.

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