UNIVERSIDADE ESTADUAL PAULISTA
“JÚLIO DE MESQUITA FILHO”
Instituto de Ciência e Tecnologia
Campus de São José dos Campos
ORIGINAL ARTICLE DOI: https://doi.org/10.4322/bds.2025.e4770
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Braz Dent Sci 2025 Apr/Jun; 28 (2): e4770
This is an Open Access article distributed under the terms of the Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/), which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Influence of post-processing filters of tomographic images in the
diagnosis of maladaptation of prosthetic crowns
Influência de filtros de pós-processamento de imagens tomográficas no diagnóstico de desadaptação de coroas protéticas
Lúcia Andrea Contin MOREIRA1 , Luiz Miguel FERREIRA2 , Marcos Paulo MAIA-LIMA2 , Júlia Moreira DUTRA3 ,
Karina Lopes DEVITO4
1 - Universidade Federal de Juiz de Fora, Faculdade de Odontologia, Departamento de Odontologia Restauradora, Programa de
Pós-graduação em Odontologia. Juiz de Fora, MG, Brazil.
2 - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba, Departamento de Diagnóstico Oral, Programa de
Pós-graduação em Estomatopatologia. Piracicaba, SP, Brazil.
3 - Universidade Federal de Juiz de Fora, Faculdade de Odontologia, Programa de Pós-graduação em Odontologia. Juiz de Fora, MG, Brazil.
4 - Universidade Federal de Juiz de Fora, Faculdade de Odontologia, Departamento de Clínica Odontológica. Juiz de Fora, MG, Brazil.
How to cite: Moreira LAC, Ferreira LM, Maia-Lima MP, Dutra JM, DEVITO KL. Inuence of post-processing lters of tomographic images
in the diagnosis of maladaptation of prosthetic crowns. Braz Dent Sci. 2025;28(2):e4770. https://doi.org/10.4322/bds.2025.e4770
ABSTRACT
Objective: This study evaluated the impact of digital lters on enhancing cone beam computed tomography
(CBCT) images for diagnosing marginal maladaptation of prosthetic crowns by specialists and academics.
Material and Methods: CBCT was performed on 12 teeth restored with lithium disilicate ceramic crowns,
duly adapted, and with maladaptations of 0.30 and 0.50 mm. The images were evaluated by three specialists
and three students, regarding the presence of marginal gaps under three conditions of post-processing lters:
“normal,” “sharp,” and “very sharp”. Intra- and inter-examiner reproducibility were assessed using the Kappa
index. Gap detection accuracy was determined using the area under the ROC curve, and the values for each group
of examiners and tested lters were compared using analysis of variance and Tukey’s post-hoc tests. Results:
Intra- and inter-examiner agreement was considered moderate (p ≤ 0.05), with Kappa indices ranging from
0.32 to 0.79 (mean = 0.52 / SD = ± 0.21) and 0.21 to 0.88 (mean = 0.45 / SD = ± 0.13), respectively. There
was no signicant difference between the lters (p = 0.914), but there was a notable difference between the
examiners, with specialists outperforming academics (p = 0.001). Conclusion: Post-processing lters did not
inuence the diagnostic accuracy of marginal maladaptation in restorations based on lithium disilicate ceramics,
as examined by experts and academics. However, there was a signicant difference between the examiners, with
better performance for the specialists.
KEYWORDS
Ceramics; Cone-beam computed tomography; Dental marginal adaptation; Image enhancement; Lithium disilicate.
RESUMO
Objetivo: Este estudo avaliou o impacto de ltros digitais no aprimoramento de imagens de tomograa
computadorizada de feixe cônico (TCFC) para diagnóstico de má adaptação marginal de coroas protéticas
por especialistas e acadêmicos. Material e Métodos: A TCFC foi realizada em 12 dentes restaurados com
coroas de cerâmica de dissilicato de lítio, devidamente adaptadas, e com má adaptação de 0,30 e 0,50 mm.
As imagens foram avaliadas por três especialistas e três estudantes, quanto à presença de falhas marginais sob
três condições de ltros de pós-processamento: “normal”, “nítido” e “muito nítido”. A reprodutibilidade intra e
interexaminador foi avaliada usando o índice Kappa. A precisão da detecção de falhas foi determinada usando
a área sob a curva ROC, e os valores para cada grupo de examinadores e ltros testados foram comparados
usando análise de variância e testes post-hoc de Tukey. Resultados: A concordância intra e interexaminadores
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Influence of post-processing filters of tomographic images in the diagnosis of maladaptation of prosthetic crowns
Moreira LAC et al. Influence of post-processing filters of tomographic images in
the diagnosis of maladaptation of prosthetic crowns
foi considerada moderada (p ≤ 0,05), com índices Kappa variando de 0,32 a 0,79 (média = 0,52 / DP = ± 0,21)
e 0,21 a 0,88 (média = 0,45 / DP = ± 0,13), respectivamente. Não houve diferença signicativa entre os ltros
(p = 0,914), mas houve diferença notável entre os examinadores, com especialistas superando acadêmicos
(p = 0,001). Conclusão: Os ltros de pós-processamento não inuenciaram na acurácia diagnóstica da má
adaptação marginal em restaurações de cerâmicas à base de dissilicato de lítio, conforme examinado por
especialistas e acadêmicos. Entretanto, houve uma diferença signicativa entre os examinadores, com melhor
desempenho para os especialistas.
PALAVRAS-CHAVE
Cerâmicas; Tomograa computadorizada de feixe cônico; Adaptação marginal dentária; Melhoramento de
imagem; Dissilicato de lítio.
with specic parameters of the imaging device
such as the quality of calibration and the size
of the field of view (FOV), can significantly
affect image quality. Inadequate or imprecise
calibration can impair the scanner’s ability to
correctly interpret differences in tissue density,
leading to distortions in the reconstructed image.
This may enhance the formation of artifacts or
obscure anatomical details, thereby increasing
the risk of diagnostic errors [6,11].
When interpreting digital image exams,
the dentist can use computational resources to
enhance the quality of the image in relation to the
original image through the application of digital
enhancement lters [12]. The lters perform the
function of increasing or decreasing the contrast
of the adjacent voxels, which modifies the
images, as it improves the low contrast resolution
and reduces noise, or vice versa, depending on
the lter used [13]. The software of the CBCT
devices themselves allows the application of
post-processing techniques, such as brightness
adjustments, contrast and the use of digital lters,
in order to improve the tomographic images and
perhaps provide more accurate diagnoses [14].
Nevertheless, no studies in the literature
have evaluated this tool with the aid of the
diagnosis of indirect restoration gaps. In addition,
studies evaluating these tools in CBCT exams
are still limited, being mostly restricted to the
eld of Endodontics, due to their accuracy in
detecting second mesiobuccal canals [15] and
diagnosing of endodontic complications [16],
such as root resorptions [17], bone loss [18], and
fractures [12]. Therefore, there is a great demand
for research evaluating the impact of these tools
on image quality and diagnostic accuracy [14].
Given the relevance of the careful evaluation
of the adaptation of indirect restorations and
considering the probable interference of artifacts
INTRODUCTION
The longevity of a restorative treatment
is strongly inuenced by marginal adaptation,
regardless of the type of material used [1]. The
presence of gaps, also known as cracks, failures or
marginal maladaptations, with great discrepancy,
represent a relevant clinical challenge directly
related to the loss of retention, the dissolution of
cement, biolm accumulation and the emergence
of secondary carious lesions, due to the facilitation
of microinltration by bacteria, resulting in the
loss of restorative work [2].
The radiopacity of the restorative material
and the technique used may have an impact
on the radiographic evaluation of marginal
maladaptations [3]. Thus, when imaging tests
are requested to evaluate the marginal adaptation
of indirect restorations, the limitations of two-
dimensional radiographic examinations should
be considered because of the overlapping of the
structures [4]. For this reason, although it is not
the preferred imaging test for the evaluation
of dental restorations, cone-beam computed
tomography (CBCT) has been widely used in
dentistry owing to its high diagnostic potential, as
well as the ability to evaluate three-dimensional
images [5], without overlaps [6], in high spatial
resolution [7] and enable image processing.
Its list of indications in dentistry is
extensive, being traditionally used in the areas of
implantology, endodontics, maxillofacial surgery
and orthodontics [8]. Currently, the use of CBCT
for other purposes has been investigated, which
includes the identication of dental caries and
marginal maladaptations of restorations [4,9,10].
Although it is not the purpose of using this test,
CBCT images obtained for other causes may be
useful for the evaluation of dental conditions [9].
However, the presence of high-density
materials in rehabilitative components, along
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Influence of post-processing filters of tomographic images in the diagnosis of maladaptation of prosthetic crowns
Moreira LAC et al. Influence of post-processing filters of tomographic images in
the diagnosis of maladaptation of prosthetic crowns
generated by the restorative material in the
quality of tomographic images, causing possible
interference in the diagnosis of marginal gaps,
this study aimed to evaluate the influence of
digital lters for post-processing of CBCT images
in the diagnosis of marginal maladaptation of
prosthetic crowns by specialists and academics.
The hypotheses tested were: 1) The use of CBCT
image enhancement lters improves the diagnosis
of marginal maladaptation of prosthetic crowns;
and 2) There is a signicant difference in the
accuracy of gap detection between students and
experienced specialists.
MATERIAL AND METHODS
The present study had an in vitro analytical
experimental design and was conducted
after approval by the Human Research Ethics
Committee of the Federal University of Juiz de
Fora (Juiz de Fora, Minas Gerais, Brazil) under
opinion number 4.814.944.
Sample preparation
A total of 14 healthy lower teeth (13 molars
and one premolar) were obtained from the
Human Teeth Bank of the School of Dentistry
of the Federal University of Juiz de Fora, being
that one molar and one premolar were used
only to create proximal contact with the teeth
of the sample. Molars with caries, fractures,
restorations, and vestibulo-lingual and mesio-
distal dimensions that were not similar or varied
by more than 10% were excluded.
The 12 teeth of the sample were submitted
to preparations for total crown by a single
prosthodontist, who performed occlusal wear of
2 mm and axial wear of 1.2 mm. All preparations
had expulsive walls and rounded angles to
facilitate accommodation of the prosthetic piece.
Subsequently, the teeth were sent to a
prosthesis laboratory, where they underwent
digital scanning (Scanner 3Shape; Copenhagen,
Denmark) and through the CAD-CAM system
(Ceramill Motion 2, Amann Girrbach, Koblach,
Austria) the crowns were planned virtually
and organic polymer standards for CAD/CAM
(Incadcam, Curitiba/PR) were milled. After
the necessary laboratory steps, according to
the manufacturer’s recommendations, lithium
disilicate ceramic crowns were fabricated using
injection technology (IPS e.max Press LT A1;
batch number Z04946; Ivoclar, Vivadent; Schaan,
Liechtenstein). Disadaptations were intentionally
made in the proximal mesial and distal faces;
eight faces had marginal maladaptation of 300 μm
(0.3 mm), eight had maladaptation of 500 μm
(0.5 mm), and eight faces presented adequate
marginal adaptation (Figure 1), whose distribution
between the teeth can be seen in the Table I.
The gaps in the vestibular and lingual
surfaces were not simulated, considering that the
maladaptations in these regions are more easily
identied in the clinical examination [4].
The crowns were not cemented to the teeth,
but only positioned in place, as in previous studies
[4,10,19], because the presence of cement could
mask the simulated marginal maladaptations.
Thus, for the accommodation of the crown, a
settling force of 2 Kgf was standardized on the
occlusal surface of the crown, perpendicular to
the long axis of the tooth.
For the xation of the teeth and simulation
of the human tomographic bone density, an
articial edentulous mandible made of barium
(Nacional Ossos, Jaú, SP, Brazil) was used, where
alveoli were made to insert the study teeth.
The density of the gums and facial soft
tissues was simulated with the aid of utility wax
(Technew, Rio de Janeiro, Brazil), positioned
on the vestibular and lingual surface of the
mandible, with a thickness of 15 mm [20].
In addition, a structure produced in wax was
positioned to simulate the tongue in the central
region of the mandible [21].
Table I - Division of teeth according to the marginal maladaptations
produced
Tooth Mesial Face Distal Face
1 Adapted Adapted
2 Gap 0.3 mm Gap 0.3 mm
3 Gap 0.5 mm Gap 0.5 mm
4 Adapted Adapted
5 Gap 0.3 mm Gap 0.3 mm
6 Gap 0.5 mm Gap 0.5 mm
7 Gap 0.5 mm Adapted
8 Adapted Gap 0.3 mm
9 Gap 0.3 mm Gap 0.5 mm
10 Gap 0.5 mm Adapted
11 Adapted Gap 0.3 mm
12 Gap 0.3 mm Gap 0.5 mm
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Moreira LAC et al. Influence of post-processing filters of tomographic images in
the diagnosis of maladaptation of prosthetic crowns
The teeth and their respective crowns were
inserted into the alveoli and xed with the aid of
useful wax. Each restored tooth was positioned
between two healthy teeth, a premolar in the
mesial position and a molar located in the
distal position, to simulate the point of contact
(Figure 2). The healthy teeth were always the
same and did not have their positions changed,
only the restored teeth were changed.
Image acquisition and export
The correctly positioned restored teeth were
subjected to CBCT examinations at the Dental
Radiology Clinic of the School of Dentistry of
the Federal University of Juiz de Fora using
the I-Cat® Next Generation device (Imaging
Sciences International, Hateld, PA, USA), with
the following acquisition protocol: 120 kV, 5 mA,
and 360° of rotation, FOV of 4 x 16 cm, and voxel
of 0.20 mm. The CT scans were then exported in
DICOM (Digital Imaging and Communications in
Medicine) format to a storage unit.
Image preparation
The I-Cat® Vision software (Imaging Sciences
International, Hateld, PA, USA, version 1.8.1.10)
was used to reconstruct the images. The restored
tooth was aligned (its long axis was positioned
perpendicular to the axial plane), and ve sagittal
images were generated in the vestibulo-lingual
direction, with equidistant distances of 0.4 mm, for
each proximal face, with the objective of covering
the entire length of the gap, which was projected
with a width of 2 mm. The protocol was performed
using three digital lters to enhance CBCT images:
“normal” lter (without lter application), “sharp”
and “very sharp”, as can be seen in Figure 3.
After the acquisition of the cuts, the images
were exported individually from the software
in TIFF format (Tag Image File Format) with
a resolution of 96 dpi (dots per inch) without
compression, so that there was no loss of
resolution, totaling 360 images (12 teeth
x 2 proximal faces x 5 cuts x 3 lters).
All images were standardized with a size
of 4.5 cm high by 6 cm wide, evidencing the
mid-coronary section of the teeth, resembling
periapical radiography. Then, a slide show
was created using Microsoft® PowerPoint®
2016 MSO software (Version 2305 Build
16.0.16501.20074), with five sequential cuts
of each proximal face of each tooth and with a
lter applied per slide on a black background,
resulting in 72 templates (12 teeth x 2 proximal
faces x 3 filters), which were randomized so
that the evaluators did not identify the teeth.
In addition, each slide contained an arrow
indicating the vestibulo-lingual orientation of the
Figure 1 - Lithium disilicate crowns with integral margin (A), marginal maladaptation of 0.3 mm (B) and 0.5 mm (C).
Figure 2 - Phantom of clinical simulation of the jaw.
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sections, a numbering so that the evaluators could
orient themselves in lling out the evaluation
worksheet, and the indication of which proximal
face (mesial or distal) should be analyzed.
Image evaluation
Three nal-year dental students and three
specialists in restorative dentistry with more than
ve years of experience were selected to blindly
evaluate the CBCT images (they were unaware
of the applied lters and gap locations), using
the same Samsung monitor (Seoul, Korea do
Sul) 18.5 inches, LED, with a screen resolution
of 1366 × 768 pixels and 32-bit color depth,
in a quiet room with low lighting, to improve
observation conditions. All images were coded
and randomized to avoid identication, and the
use of image manipulation tools, except for zoom,
was not authorized.
Independently, examiners evaluated the
proximal faces of each tooth in the presence of gaps
in the restored teeth. They were given a spreadsheet
where they assigned a rating scale of ve scores:
(I) gap denitely absent; (II) gap probably absent;
(III) uncertainty about the absence or presence
of a gap; and (IV) gap probably present; (V) gap
denitely present.
To measure the reproducibility of the method,
all images were evaluated at two different times
under the same parameters, with an interval of
one week between them.
Statistical analysis
To evaluate the intra and inter-examiner
agreements, the Kappa indices were calculated,
considering for analysis the following
interpretation: 0: no agreement; 0.01 to 0.20:
weak agreement; 0.21 to 0.40: regular agreement;
0.41 to 0.60: moderate agreement; 0.61 to
0.80: strong agreement; 0.81 to 0.99: almost
perfect agreement and 1: perfect agreement [22].
To evaluate the accuracy of the detection of
marginal gaps in CBCT images modied by post-
processing lters, the areas under the receiver
operating characteristic (ROC) curves were
obtained for each group of examiners (specialists
and academics).
Figure 3 - Examples of CBCT images of teeth with adapted and maladapted prosthetic crowns subjected to post-processing filters.
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Moreira LAC et al. Influence of post-processing filters of tomographic images in
the diagnosis of maladaptation of prosthetic crowns
Kolmogorov-Smirnov and Levene tests
were applied to evaluate the normality and
homogeneity of the data, respectively. An
analysis of variance, two-factor ANOVA,
with Tukey’s post-hoc, was used to compare
the accuracy values (area under the ROC
curve), considering the independent variables
“examiner” and “lter”.
The SPSS program (Statistical Package
for the Social Sciences, version 21.0, Chicago,
USA) was used to perform statistical tests, with
a signicance level of 5% (p ≤ 0.05).
RESULTS
The results of the concordances were all
signicant (p ≤ 0.05), with Kappa indices ranging
from 0.32 to 0.79 (mean = 0.52 / SD = ± 0.21)
for the intra-examiner agreement, and from
0.21 to 0.88 (mean = 0.45 / SD = ± 0.13) for
the inter-examiner agreement, being considered
moderate concordances [22].
The areas under the ROC curves were
obtained to evaluate the accuracy of the tested
lters (Table II). No signicant difference was
observed between the filters (p = 0.914);
however, there was a significant difference
between the examiners, and the specialists had
higher success rates than the students in the
dentistry course (p = 0.001). Figure 4 shows
the ROC curves of the two groups of examiners
for the three lters tested.
DISCUSSION
Although not every unsatisfactory restoration
gives rise to an injury, the proper marginal
adjustment of dental restorations and crowns is a
way to prevent the onset of periodontal diseases
and recurrent caries lesions. Thus, the diagnosis of
marginal maladaptations that exceed acceptable
clinical limits is important for maintaining the
health of the teeth and surrounding tissues,
thereby ensuring clinical success [3,19,23,24].
The margins of a restoration or crown can be
evaluated using clinical methods, such as visual
inspection and tactile exploration (with dental
floss or an explorer), in addition to imaging
tests, as well as imaging techniques, such as
radiography and CBCT. However, it is still a
challenging diagnostic task, especially when the
endings are in the interproximal or subgingival
region of the teeth [4,25]. Therefore, imaging
tests should be used to evaluate the interproximal
surfaces more effectively [26]. A micro-CT device
Table II - Comparison between the accuracy values (area under
the ROC curves) for the three filters tested in the CBCT diagnosis
of marginal gaps was performed by two groups of examiners
(specialists and academics of the dentistry course)
Examiners
Filter
Normal
Mean (SD)
Sharp
Mean (SD)
Very Sharp
Mean (SD)
Specialists 0.938 (0.03) 0.950 (0.03) 0.949 (0.03)
Academics 0.828 (0.11) 0.811 (0.13) 0.781 (0.21)
Figure 4 - ROC curves referring to the tomographic diagnosis of gaps for the three filters tested by specialists and academics from the
dentistry course.
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was used to measure the marginal discrepancy of
restorations in the study by Mosharraf et al. [19].
When it comes to restorations performed
using lithium dissilicate (Li2Si2O5)-based ceramics,
a material that has been the subject of many
clinical and laboratory studies evaluating marginal
adaptation [23,27,28], fracture resistance [28,29],
biocompatibility [30] and patient satisfaction [27,28],
these have acceptable radiopacity and did not affect
the diagnostic capacity in the CBCT exam for the
detection of proximal caries [31]. Furthermore,
Aglarci et al. [32] pointed out that CBCT could
be used to detect caries under xed crowns after
cementation, as a highly validated post-treatment
diagnostic technique.
CBCT images can be manipulated using tools
available in various software programs. Given the
existing scientic gap regarding how these tools
affect image quality and diagnostic accuracy [14],
this study aimed to evaluate the influence of
digital CBCT image enhancement lters on the
diagnosis of marginal maladaptation in lithium
disilicate-based ceramic restorations.
To increase or decrease specic characteristics
of the image, digital filters use mathematical
algorithms [17], with the purpose of visually
improving and making the aspects of the original
image more visible, generating more diagnostic
information [33]. This function can allow the
increase or decrease of the contrast of the
adjacent voxels, which modies the images, as it
improves the density and contrast characteristics
and reduces the noise, varying according to the
filter used [13,14]. Thus, for the clinician to
decide in which situations to use the lters, it is
crucial to understand how these algorithms work
and their specicities [34].
In this sense, the hypothesis of this study
that there would be signicant differences in the
use of filters for the identification of marginal
maladaptations was rejected (p = 0.914),
corroborating other studies [12,15,16,35] that
also did not find an improvement in accuracy
during other diagnostic tasks when applying digital
filters. In addition, no studies in the scientific
literature have evaluated the inuence of lters
on the diagnosis of marginal maladaptation of
prosthetic crowns, especially those of lithium
disilicate ceramic. Studies that presented the same
results as ours analyzed the use of lters for the
diagnosis of endodontic complications, such as
fractured les, deviated pins, perforations, external
root resorptions [16], vertical root fractures [12,35]
and detection of the second mesiobuccal canal [15].
Another variable analyzed in this study was
the ability of the two groups of evaluators to
diagnose marginal gaps. According to the results,
the hypothesis that specialists would perform
better than students was conrmed (p < 0.01).
Unlike the other studies [17,36,37], ours was
the only study that performed this comparison,
and the others only selected specialists in dental
radiology to evaluate CBCT examinations. The
present study selected specialists in dentistry,
that is, professionals who perform this type
of clinical procedure in their daily lives. Only
Sousa et al. [18] included in their research design
a dental student to perform the evaluations of
CBCT images together with a radiology specialist.
The inter-rater agreement was better than
the intra-examiner agreement for the detection of
maladaptation in indirect restorations. However,
the means of the Kappa index were within
an acceptable limit, according to Landis and
Koch [22], and were classified as moderate
concordances. This may indicate that each
evaluator was more or less consistent in
differentiating between the presence and absence
of gaps. Similarly, Doriguêtto et al. [9] declared
agreement ranging from regular to moderate
when evaluating marginal gaps in teeth restored
with pure ceramics and metal-ceramic crowns.
In line with Verner et al. [16], when
comparing the results of the present study with
those of other studies, some factors should be
considered because of methodological differences.
The main differences concerned the types of
imaging protocols, structures evaluated (marginal
gaps, pathological bone lesions, dental resorption,
root fractures, or endodontic complications),
types of samples (in vivo or vitro), and evaluation
methodologies (evaluators, software, and lters).
In this logic, the most used tomograph in the
investigations of this theme was the same equipment
of this study: the I-Cat9 [14,16-18,34-36,38,39].
Another important factor in image acquisition
protocols is FOV and voxel sizes [11]. According
to Mouzinho-Machado et al. [15], a smaller
voxel size (80 μm) increases diagnostic accuracy.
However, like other studies [34-36,38], we used
a single voxel size (0.2 mm). Regarding the
exposure area, we used a wide FOV (4 x 16 cm),
as in Costa et al. [38], simulating a patient who
needs to scan the entire lower arch.
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The evaluation methodologies of the studies
are also heterogeneous, and the main software
of choice for image analysis are OnDemand,
XoranCat, and i-CAT Vision [12,36,37]. It is worth
mentioning that the XoranCat program provides
a greater number of filters when compared to
OnDemand, for example. The researchers that
applied the i-CAT Vision post-processing lters
selected the “Normal”, “Sharp” and “Very Sharp”
lters, as well as our study [12,18,39]. The “Very
Sharp” lter obtained a better performance when
compared to the other two, which justifies its
use for clinical activities [39]. In our study, none
of the three filters influenced the diagnosis of
marginal gaps, and Martin e Silva et al. [12],
found no signicant difference in the accuracy of
the diagnosis of vertical root fractures when the
post-processing lters were varied.
Similar to other in vitro studies [15,39],
this study has limitations regarding the clinical
information, signs, symptoms, and intrinsic
characteristics of the patient, such as changes in
tissue thickness and density, which could help or
hinder the process of diagnosing gaps. Another
limitation was the impossibility of allowing
the evaluators to freely manipulate the CBCT
examinations since they could identify the lters
and teeth used, implying bias. However, some
studies have shown that the le format of digital
radiographs does not inuence the diagnosis of
internal and external root resorption [40], vertical
root fracture [41] and proximal caries lesions [42].
Thus, it is understood that the way this study was
conducted did not have negative effects on the
quality of the images or on the diagnostic accuracy,
although there are no studies in the literature
that evaluate the influence of the file format
on CBCT images. Furthermore, although this
format limitation could potentially inuence the
evaluation, it was intentionally controlled in this
study and constitutes a necessary methodological
restriction to meet the experimental design and
proposed objectives.
Knowing that the quality of the CBCT image
can be affected by the acquisition factors used:
kilovoltage (kV), milliamperage (mA), voxel, and
FOV size [6,11], this study had another limiting
factor, since it restricted the use of only one
tomograph with unique exposure settings, thus
reducing the possibility of comparing the results
obtained with those described in the literature,
which used different CBCT equipment and varied
exposure protocols. Studies that have used image
enhancement lters from other software programs
may also yield different results. Therefore, further
investigations should be conducted for different
diagnostic tasks by applying other digital lters
or image enhancement algorithms in the post-
processing phase of CT scans.
CONCLUSION
In the exposure protocol evaluated, the
application of post-processing lters to CBCT images
did not affect the diagnostic accuracy for detecting
marginal maladaptation in indirect lithium disilicate
ceramic restorations. Therefore, the use of lters
can be guided by the professional’s preference. It is
worth noting, however, that a signicant difference
was observed between examiners, with specialists
demonstrating superior performance.
Author’s Contributions
LACM: Methodology, Investigation, Data
Curation, Writing – Original Draft Preparation,
Writing – Review & Editing. LMF: Methodology,
Investigation, Data Curation, Writing – Original
Draft Preparation, Writing – Review & Editing.
MPML: Methodology, Investigation, Data
Curation, Writing – Original Draft Preparation,
Writing – Review & Editing. JMD: Contribution
of the author: Methodology, Investigation, Data
Curation, Writing – Original Draft Preparation,
Writing – Review & Editing. KLD: Methodology,
Investigation, Writing – Original Draft Preparation,
Writing – Review & Editing.
Conict of Interest
No conicts of interest declared concerning
the publication of this article.
Funding
This research did not receive any specic
grant from funding agencies in the public,
commercial, or non-prot sectors.
Regulatory Statement
This study protocol was reviewed and
approved by the Human Research Ethics
Committee of the Federal University of Juiz
de Fora (Juiz de Fora, Minas Gerais, Brazil),
approval number 4.814.944.
9
Braz Dent Sci 2025 Apr/Jun;28 (2): e4770
Moreira LAC et al.
Influence of post-processing filters of tomographic images in the diagnosis of maladaptation of prosthetic crowns
Moreira LAC et al. Influence of post-processing filters of tomographic images in
the diagnosis of maladaptation of prosthetic crowns
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Date submitted: 2025 Apr 13
Accept submission: 2025 May 07
Karina Lopes Devito
(Corresponding address)
Universidade Federal de Juiz de Fora, Faculdade de Odontologia, Departamento de
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