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.2024.e4394
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Braz Dent Sci 2024 Oct/Dec;27 (4): e4394
This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in
any medium, provided the original work is properly cited.
Volumetric measurement of sleep bruxism-like indentations on
acrylic surface using intraoral scanner and inlay wax
Medição volumétrica de indentações semelhantes ao bruxismo do sono na superfície de acrílico usando scanner intraoral e
cera para fundição
Thaviporn LIMRACHTAMORN1 , Teekayu Plangkoon JORNS2 , Supanigar RUANGSRI2 , Rajda CHAICHIT3 ,
Jarin PAPHANGKORAKIT2
1 - Thammasat University, Faculty of Dentistry, Pathumthani, Thailand.
2 - Khon Kaen University, Faculty of Dentistry, Department of Oral Biomedical Science, Khon Kaen, Thailand.
3 - Khon Kaen University, Faculty of Dentistry, Department of Preventive Dentistry, Khon Kaen, Thailand.
How to cite: Limrachtamorn T, Jorns TP, Ruangsri S, Chaichit R, Paphangkorakit J. Volumetric measurement of sleep bruxism-like indentations
on acrylic surface using intraoral scanner and inlay wax. Braz Dent Sci. 2024;27(4):e4394. https://doi.org/10.4322/bds.2024.e4394
ABSTRACT
Objective: This in vitro study introduced methods to measure the volume of sleep bruxism-like indentations to
be used in the evaluation of bruxing intensity. Material and Methods: Indentations of different sizes and depths
were created on seven clear heat-cured acrylic blocks. The volume of all indentations was rst measured by a
prolometer as the gold standard, then by scanning the negative replicate of the indentations obtained from
polyvinyl siloxane impressions both with double impression technique (IOSD) and putty silicone only (IOSP),
using an intraoral scanner, and lastly by weighing the blue inlay wax used to ll the indentation. Agreements
between the intraoral scanning and blue inlay wax methods compared to the prolometer were tested using ICC.
Results: ICCs between IOSD, IOSP, inlay wax and the prolometer were 0.963, 0.950, and 0.999 respectively.
The average volumetric error tended to be greater with IOSD (30.51±8.34 %) and IOSP (35.68±10.29 %)
compared to that of blue inlay wax (24.87±10.29 %). Blue inlay wax was apparently superior to IOSD and IOSP
in quantifying small and deep indentations. Conclusion: Both intraoral scanner and blue inlay wax had high
agreement in volumetric measurement of acrylic indentations while the wax method performed the best. These
methods could be used to measure the amount of wear on occlusal splints.
KEYWORDS
Intraoral scanner; Occlusal wear; Occlusal splints; Polyvinyl siloxane; Sleep bruxism.
RESUMO
Objetivo: Este estudo in vitro introduziu métodos para medir o volume de indentações semelhantes às do
bruxismo do sono para serem usadas na avaliação da intensidade do bruxismo. Material e Métodos: Foram
criadas indentações de diferentes tamanhos e profundidades em sete blocos de acrílico transparente curado pelo
calor. O volume de todas as indentações foi medido primeiro com um perlômetro como padrão de ouro, depois
através da digitalização da réplica negativa das indentações obtidas a partir de impressões de polivinil siloxano,
tanto com a técnica do silicone de impressão dupla (DS) como apenas com silicone pesado (SP), utilizando um
escanêr intra-oral e, por último, pesando a cera para fundição azul utilizada para preencher a indentação. As
concordâncias entre os métodos de digitalização intra-oral e de cera para fundição azul, em comparação com o
perlômetro, foram testadas utilizando o Coeciente de Correlação Intraclasse (ICC). Resultados: Os resultados
mostraram que os ICCs entre o DS, o SP, a cera para fundição azul e o perlômetro foram 0.963, 0.950, e 0.999
respetivamente. O erro volumétrico médio tendeu a ser maior com o DS (30.51±8.34%) e o SP (35.68±10.29%)
comparado com o da cera para fundição azul (24.87±10.29%). A cera para fundição azul foi aparentemente
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Braz Dent Sci 2024 Oct/Dec;27 (4): e4394
Limrachtamorn T et al.
Volumetric measurement of sleep bruxism-like indentations on acrylic surface using intraoral scanner and inlay wax
Limrachtamorn T et al. Volumetric measurement of sleep bruxism-like indentations on
acrylic surface using intraoral scanner and inlay wax
INTRODUCTION
Sleep bruxism is dened as the repetitive
contraction of jaw muscles characterized by
clenching or grinding of teeth and/ or by bracing
or thrusting of the mandible [1]. This can result
in masticatory muscle hypertrophy, cracked teeth,
failed restorative materials, tooth sensitivity,
toothache, loss of periodontal support [2]. In
addition, sleep bruxism might be related to
temporomandibular disorders (TMD) [3,4].
One of the most common treatments for
sleep bruxism is the prescription of flat plane
stabilization occlusal splint [5]. The main goal
of the splint is to protect the teeth from damage
caused by clenching or grinding [2,6,7]. It is
generally recommended that occlusal splint
patients should be scheduled to be returned for
evaluation within 2-7 days after the delivery visit.
During the follow-up visit, the bruxing wear on the
occlusal splint should be examined so the sleep
bruxism activity could be monitored. Routinely,
dentists are only able to examine the positions
and approximate changes of the wear but not its
magnitude. This makes it difcult to accurately
monitor the efcacy of occlusal splint treatment.
A prolometer has been used as the gold
standard in quantifying the amount of worn
surface [8] and surface roughness [9] but it is
impractical for clinical use. Digital impression
using intraoral scanners has gained increased
popularity and tended to be preferred by both
practitioners and patients in terms of comfort,
total working time [10] and accuracy [11].
The accuracy of intraoral scanning was found
to be not significantly different from that of
conventional impression when the marginal
gap of the fabricated crown was examined [12].
When different types of intraoral scanners were
tested against various conventional impression
materials in real patients, the precision of
the dental arch obtained from the intraoral
scanners fell between vinysiloxanether (highest
precision) and alginate (lowest precision),
the older scanning systems (
e.g
. Lava COS®,
Cadent iTero®) being less accurate than the
modern ones (
e.g.
3Shape TRIOS®) [13]. The
authors suggested using intraoral scanners for
single-unit restorations up to 4-unit xed partial
dentures rather than whole arch rehabilitation.
Among seven digital impression systems tested,
TRIOS 3® was shown to have the best balance
of speed and accuracy due to its good trueness
and precision for complete arch scanning [14].
Recently, intraoral scanner has been introduced
to quantify wear volume on tooth surfaces in
both laboratory and clinical studies. For example,
Kumar
et al
[15]. measured the amount of
tooth loss from enamel samples by scanning
their surface before and after immersion in
citric acid and found that the intraoral scanner
was able to detect early tooth wear but the
accuracy was low. O’toole
et al
. compared the
volumetric loss of tooth surface over 3 years
on dental stone duplicated with conventional
silicone impression between the intraoral
scanner and profilometer, analyzed with the
gold-standard software, and demonstrated that
the values measured with both instruments were
signicantly different [16]. Mitrirattanakul
et al
.
used an intraoral scanner (iTero Element® 2) to
detect the loss of tooth surface in vitro and found
that the overall sensitivity was 98% compared to
micro-CT image with the accuracy of 97% [17].
In another study, intraoral scanning of an
alveolar bone-defect model revealed acceptable
precision compared to the gravimetric method
based on the Archimedes’ principle in which
silicone impression was used to ll the defect and
its volume was derived by dividing its mass by
the density [18]. Regarding the above ndings,
the present study aimed to introduce practical
methods to quantify the volume of indentations
on acrylic surface using the intraoral scanner
and blue inlay wax and compare the accuracy
between these methods and the prolometer. The
ndings could help clinicians to more accurately
monitor the level of sleep bruxism in splint-
wearing patients.
superior ao DS e ao SP na quanticação de indentações pequenas e profundas. Conclusão: Tanto o scanner
intra-oral como a cera para fundição azul apresentaram uma elevada concordância na medição volumétrica das
indentações acrílicas, enquanto o método da cera teve o melhor desempenho. Estes métodos podem ser utilizados
para medir a quantidade de desgaste em placas oclusais.
PALAVRAS-CHAVE
Escâner intra-oral; Desgaste oclusal; Placas oclusais; Polivinilsiloxano; Bruxismo do sono.
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Limrachtamorn T et al.
Volumetric measurement of sleep bruxism-like indentations on acrylic surface using intraoral scanner and inlay wax
Limrachtamorn T et al. Volumetric measurement of sleep bruxism-like indentations on
acrylic surface using intraoral scanner and inlay wax
MATERIAL AND METHODS
Preparation of indentations
Circular and linear indentations of different
sizes and depth were created on clear heat-cured
acrylic blocks (labelled A to G) (Meliodent®,
Kulzer, Germany), ten of each. Blocks A and
B represented shallow (approximately 0.5 mm
deep) and deep (approximately 1 mm deep)
circular indentations whereas blocks F and G
represented shallow (approximately 0.5 mm
deep) and deep (approximately 1 mm deep)
linear indentations. Blocks C, D and E represented
shallow linear indentations with different lengths
(approximately 2, 3, and 4 mm long) (Figure 1).
All indentations were created using a round steel
bur No.014 with a micromotor vertically stabilized
on a xed stand. Although the drilling method
was standardized, it was not possible to create
all indentations with exactly same dimensions.
However, the sizes of nal indentations in the
same group were similar and could be grouped in
each of the above categories. The average actual
dimensions of all indentations in each acrylic
block determined by the prolometer were shown
in Table I.
Volumetric assessment
Prolometer
Each indentation was scanned with a
prolometer (Optical Surface Proler Contour
GT, Bruker, MA, USA). The x and y axes of
the prolometer was gradually titled to ensure
that the whole top surface of the acrylic block
showed brightest fringes. The measurement type
was set as VSI, the back scan was set between
5-10 μm and the threshold was set at 5%. If the
indentation was larger than the scanning eld,
being 1.3 x 1.5 mm2 (width x length), more
than one scan was performed and all scanned
photos were connected via reference points so
that the first part of the indentation was not
re-measured. Finally, the surface area and depth
of the indentation were obtained using Vision
64 Map software (Bruker, MA, USA) and the
indentation’s volume was calculated.
Figure 1 - Examples of the indentations in blocks A to G used in the present study sized to the same scale.
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Braz Dent Sci 2024 Oct/Dec;27 (4): e4394
Limrachtamorn T et al.
Volumetric measurement of sleep bruxism-like indentations on acrylic surface using intraoral scanner and inlay wax
Limrachtamorn T et al. Volumetric measurement of sleep bruxism-like indentations on
acrylic surface using intraoral scanner and inlay wax
Intraoral scanner method
In the beginning, the indentation was directly
scanned using an intraoral scanner (TRIOS 4®,
3Shape Global, Denmark) but the resulting quality
was not acceptable due to the transparency of
the acrylic. Hence, the indirect method was used.
The indentation was rst duplicated with double
impression technique using polyvinyl siloxane
light body (Provil® Novo Light, Kulzer, Japan)
and putty-type polyvinyl siloxane (Provil® Novo
Putty Soft, Kulzer, Japan) and then scanned with
the intraoral scanner (IOSD). Secondly, the same
indentation was duplicated using putty-type
polyvinyl siloxane alone and scanned (IOSP).
Small amount of the impression material was rst
injected into the indentation and the remaining
material was then loaded onto a at acrylic plate
and pressed against the indentations with a force
of approximately 40-50 N. The scanner’s probe
was kept within 5-mm distance from the surface
of the impression and moved slowly. A click sound
must be heard before proceeding to the next
area. The 3-D scanned image was subsequently
converted to a steriolithograph file (stl) and
imported to a 3-D mesh modelling software
(Meshmixer®, Autodesk, CA, USA) to calculate
the volume of the indentation (Figure 2).
Blue inlay wax method
The original acrylic block was rst weighed
as the baseline value using a 4-digit digital scale
(ALT 100-5AM, Kern, Germany). The indentation
was then lled with blue inlay wax (Blue inlay
casting wax: regular- type II, class I, Kerr,
Switzerland) and the excess wax was scraped off
at the surface level with a dental roach carver.
The acrylic block was re-weighed after the wax
was added. The difference of the weight of the
acrylic block before and after filling with the
inlay wax was calculated and the volume of
the indentation was determined by dividing its
weight by the density. The density of the blue
inlay wax was separately derived by weighing
a wax cube sized 5 x 5 x 5 mm3 (volume of 125
mm3) made inside a stainless steel crucible. After
completing the rst indentation, the wax was
thoroughly rinsed off using 50 °C water using
a micro brush applicator. The acrylic block was
then cleaned with a piece of paper towel and
air-dried before repeating the whole procedure
for the next indentation.
Tests for intra-examiner and inter-examiner
reliability
Reliability tests were performed for the
intraoral scanner and blue inlay wax methods
within the same examiner and between two
examiners, both being dentists. Six out of 10
indentations in each acrylic block were randomly
selected for re-measurements, representing 60%
of the total indentations.
Statistical analysis
The average volume and standard deviation
(SD) of each indentation measured by all methods
as well as the corresponding volumetric error
compared to the prolometer were described.
The agreement of the volumetric values between
IOSD, IOSP, blue inlay wax methods and the
profilometer was determined by intraclass
correlation coefcients (ICC). In addition, any
difference in the overall volumetric error between
IOSD, IOSP and blue inlay wax methods was
analyzed using Friedman test and post-hoc
pairwise comparisons. Intra- and inter-examiner
reliability of the intraoral scanner and blue inlay
wax techniques were also determined by ICC.
RESULTS
The average volume of the indentations in
each acrylic block measured by the prolometer,
Table I - The average actual dimensions (± SD) of all indentations in each acrylic block measured by the profilometer
Block Average diameter (mm) Average width (mm) Average length (mm) Average depth (mm)
A 1.3748 ± 0.0688 - - 0.2937 ± 0.0403
B 1.6581 ± 0.0518 - - 0.8030 ± 0.0461
C - 1.4315 ± 0.0656 2.4437 ± 0.1076 0.2875 ± 0.0242
D - 1.4537 ± 0.0811 3.2073 ± 0.1278 0.2378 ± 0.0264
E - 1.4554 ± 0.2054 4.2393 ± 0.2791 0.2214 ± 0.0359
F - 1.3214 ± 0.1487 5.1117 ± 0.2557 0.2235 ± 0.0503
G - 2.0286 ± 0.4933 5.0440 ± 0.0702 0.5055 ± 0.0914
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Braz Dent Sci 2024 Oct/Dec;27 (4): e4394
Limrachtamorn T et al.
Volumetric measurement of sleep bruxism-like indentations on acrylic surface using intraoral scanner and inlay wax
Limrachtamorn T et al. Volumetric measurement of sleep bruxism-like indentations on
acrylic surface using intraoral scanner and inlay wax
IOSD, IOSP, and blue inlay wax methods, along
with corresponding ICCs and volumetric errors
compared to those obtained from the prolometer
were shown in Table II. The intra-examiner
reliability of IOSP (ICC = 0.999) was smaller than
that of ISOD and the inlay wax (ICC = 1.000).
The inter-examiner reliability of all methods was
excellent (ICCs = 0.999).
ICCs ranged from 0.878 (block A) - 0.983
(block F) with IOSD, 0.850 (block A) - 0.976
(block F) with IOSP, and 0.965 (block C) - 1.000
(block G) with blue inlay wax (Figure 3). When
all data were pooled, blue inlay wax had higher
ICC (0.999) than IOSD and IOSP (0.963 and
0.950 respectively).
All volumetric values obtained from IOSD,
IOSP, and blue inlay wax were smaller than those
from the prolometer. The average volumetric
error of IOSD ranged from 24.88 ± 13.31% (block
G) to 41.23 ± 6.62% (block A) with the pooled
error of 30.51 ± 8.34%. The average volumetric
error of IOSP ranged from 29.12 ± 11.87% (block
G) to 47.71 ± 4.88% (block A) with the pooled
error of 35.68 ± 10.29%. The average volumetric
error of blue inlay wax ranged from 9.71 ± 3.24%
(block G) to 37.98 ± 4.54% (block C) with the
pooled error of 24.87 ± 10.29%. Overall, the
volumetric error of the three measuring methods
was signicantly different (
p
< 0.001), the error
of the blue inlay being the least whereas that of
IOSD was smaller than IOSP (Table II).
DISCUSSION
The present study has demonstrated that
using prolometer as the gold standard, blue
inlay wax could be used in quantifying the
indented surface of the clear acrylic with high
accuracy, regardless of the size, shape, and
depth of indentations. In addition, the indirect
intraoral scanning methods, could also be used
with less, but still acceptable accuracy (ICCs
greater than 0.8).
An optical profilometer was used as our
standard since it can measure surface irregularities
with high precision. Silicone impression material
was used to duplicate the indentations since it
is commonly used in xed prosthodontic works
for its good duplicability and stability. Putty type
silicone impression alone was tested and explored
in the present study because the impression
technique was simple. Blue inlay wax was used in
the present study because it is commonly used in
dental laboratories due to its good thermoplastic
properties, being solid at room temperature but
uniformly softened without decomposition to
form mobile liquid when warmed to 40-50 oC.
It exhibits excellent adaptability to model or die
surfaces and can be removed from the prepared
tooth with minimal distortion. Blue inlay wax
also has good contrast in color with clear acrylic
resin, and is easily carved after softening.
Figure 2 - Examples of silicone impression obtained from double-impression technique (A, C) and corresponding scanned images using
Meshmixer® (B, D). (The label of the acrylic block was shown in each picture).
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Braz Dent Sci 2024 Oct/Dec;27 (4): e4394
Limrachtamorn T et al.
Volumetric measurement of sleep bruxism-like indentations on acrylic surface using intraoral scanner and inlay wax
Limrachtamorn T et al. Volumetric measurement of sleep bruxism-like indentations on
acrylic surface using intraoral scanner and inlay wax
The volumetric values obtained from the
profilometer were always greater than those
obtained from the indirect intraoral scanning
and blue inlay wax methods. This could be due
to the high sensitivity of the profilometer in
detecting the edges of the indentation, resulting
in increased boundaries and the subsequent
volume. Hsu et al. [8] studied the conformity
between the prolometer and a laser scanner in
measuring the volume of surface indentations on a
ceramic disk and found that the volume obtained
from the prolometer could be both larger and
smaller than those obtained from a laser scanner,
depending on the type of material being scanned.
Table II - Average volume (± SD) of indentations in acrylic blocks A to G measured by the profilometer, intraoral scanner with double impression
technique (IOSD), intraoral scanner with putty silicone only (IOSP) and blue inlay wax methods and their ICCs and volumetric errors compared
to those of the profilometer
Block
Average volume (mm3) ICCs*Volumetric error** (%)
p-value
Profilometer IOSD IOSP Wax IOSD IOSP Wax IOSD IOSP Wax
A0.4279 0.2448 0.2215 0.2855 0.878 0.850 0.967 41.23 47.71 33.44
<0.001***
± 0.1073 ± 0.0647 ± 0.0505 ± 0.0760 ± 6.62 ± 4.88 ± 2.33
B1.7250 1.2023 0.9706 1.4861 0.954 0.926 0.987 30.40 43.95 13.99
± 0.1596 ± 0.1406 ± 0.1536 ± 0.1699 ± 3.29 ± 5.30 ± 2.83
C0.8551 0.5610 0.5205 0.5328 0.918 0.886 0.965 34.27 39.17 37.98
± 0.1154 ± 0.0741 ± 0.0929 ± 0.0985 ± 3.32 ± 6.05 ± 4.54
D1.0014 0.7141 0.7142 0.7322 0.956 0.923 0.967 29.03 29.25 26.91
± 0.1480 ± 0.1482 ± 0.1791 ± 0.1175 ± 5.74 ± 8.39 ± 3.12
E1.2987 0.9534 0.9190 0.9642 0.979 0.958 0.984 27.01 29.97 26.15
± 0.2102 ± 0.1970 ± 0.2247 ± 0.1954 ± 5.01 ± 8.59 ± 4.43
F1.3414 0.9880 0.9548 1.0383 0.983 0.976 0.993 26.75 29.27 23.42
± 0.3470 ± 0.2948 ± 0.2951 ± 0.3088 ± 4.68 ± 5.92 ± 4.21
G5.0829 3.7036 3.4801 4.6413 0.900 0.875 1.000 24.88 29.12 9.71
± 2.0036 ± 1.4141 ± 1.1907 ± 1.9735 ± 13.31 ± 11.87 ± 3.24
Pooled 0.963 0.950 0.999 30.51 35.68 24.87
± 8.34 ± 10.29 ± 10.29
*ICCs were determined with respect to values from the profilometer. ** Although the values measured by the profilometer were always larger
than those measured by other methods, the minus signs were omitted for simplicity.*** Significant difference in volumetric errors between
three measuring methods (Friedman test) in which the blue inlay wax method was different from both IOSD and IOSP whereas IOSD was
different from IOSP (pairwise comparisons).
Figure 3 - Bar graphs showing interclass correlation coefficients (ICCs) between volumetric measurement obtained from IOSD, IOSP, blue inlay
wax methods and the profilometer. A horizontal line was drawn at ICC of 0.9 to indicate the cut-off for the excellent agreement.
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Braz Dent Sci 2024 Oct/Dec;27 (4): e4394
Limrachtamorn T et al.
Volumetric measurement of sleep bruxism-like indentations on acrylic surface using intraoral scanner and inlay wax
Limrachtamorn T et al. Volumetric measurement of sleep bruxism-like indentations on
acrylic surface using intraoral scanner and inlay wax
On a ceramic disk, the profilometer provided
larger values with the overall volume difference
of 25.32%, whereas on the silicone impression
replicate, the prolometer gave smaller values
with the means difference of 77.5%.
ICC was used to test the agreement between
our measurement methods since it took into
account both magnitude and correlation of
two data sets. ICCs were mostly in accordance
with percentage volumetric errors. The blue
inlay wax method tended to have highest ICCs.
Duplicating the indentation with polyvinyl
siloxane impression material could produce some
error. Hsu et al. [8] showed a volumetric difference
of 6.1% between the original indentation and
its replicated impression. The error could be
further increased by the scanning procedure.
Hsu
et al
. also demonstrated decreased accuracy
of a laser scanner when impression replicates
of the indentations (approximate depths of
70-260 μ) were scanned (average volumetric
error of 77.5%), compared with the original
indented surface (average volumetric error of
23.5%). The average volumetric errors in the
present study using the intraoral scanner were
smaller (30.51% with IOSD, 35.68% with IOSP).
However, the high ICCs with respect to gold
standard indicated that all three methods could
be used in assessing relatively small changes in
the volume of surface indentations.
IOSD and IOSP produced similar ICCs and
volumetric errors although IOSD seemed to
be slightly more accurate than IOSP. This was
expected since the double impression technique
has been conventionally used in duplicating the
fine details of tooth crown prepared in fixed
prosthodontic work. Considering the small
percentage error between both methods, it was
proposed that IOSP could also be used to quantify
the amount of wear, with fewer steps.
Types of indentation apparently affected
the accuracy of the intraoral scanning methods
whereas less effect was seen with blue inlay wax.
Intraoral scanners especially IOSP had ICCs lower
than 0.9 (the cut-off for excellent agreement) in
small circular (block A), small linear (block C)
and deep linear (block G) indentations, whereas
the blue inlay wax method seemed to be superior
to IOSD and IOSP for these indentations. Smaller
volumetric errors and higher ICCs were also noted
with blue inlay wax for deep circular indentations
(block B) although all methods showed ICCs
greater than 0.9. The effect of indentations’
length could be roughly determined by comparing
ICCs between blocks C, D, and E in which the size
and depth of the indentations were similar, but
the length was different. The ICCs were gradually
increased from block C to block E, suggesting that
the volume of longer linear indentations tended
to be more accurately measured than that of the
shorter ones.
The present study had some limitations.
First, the study was conducted in vitro. Although
the dimension of the indentations (especially
blocks A-D) mimicked those seen in sleep bruxing
patients in our orofacial pain clinic and those
previously described [19], the results might
not be accurately applied to the indentations
with sharp-angled base as well as other types of
wear which could be observed in real bruxers.
Secondly, the smallest indentation in the present
study was approximately 1.3 mm wide and 0.2
mm deep whilst the actual brux indentations
could be even smaller. For such indentations, the
accuracy was likely to be reduced with indirect
intraoral scanning methods.
Under the above limitations, we have
demonstrated that both indirect intraoral
scanning and blue inlay wax methods could be
used to quantify the volume of indentations on
clear acrylic surface with acceptable agreement
compared to the prolometer, suggesting that
they could be used to accurately study the
relative change in the volumes. The blue inlay
wax method, on the other hand, seemed to have
both higher agreement and accuracy. However, in
clinical practice, waxing might require more chair
time and could be difcult to be applied in shallow
and irregular indentations. It was presumed that
intraoral scanning of silicone impressions might
be more practical but only when the analyzing
method was further simplied.
CONCLUSION
Within the limitation of this
in vitro
experimental design, there was generally excellent
agreement in the volumetric measurement
of indentations on the acrylic surface using
indirect intraoral scanning methods, either with
putty silicone impression alone or the double-
impression technique, and the blue inlay wax
method compared to the profilometer. The
techniques could be used to quantify volumetric
changes in bruxing wear on an occlusal splint
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Braz Dent Sci 2024 Oct/Dec;27 (4): e4394
Limrachtamorn T et al.
Volumetric measurement of sleep bruxism-like indentations on acrylic surface using intraoral scanner and inlay wax
Limrachtamorn T et al. Volumetric measurement of sleep bruxism-like indentations on
acrylic surface using intraoral scanner and inlay wax
so its efficacy could be evaluated. Blue inlay
wax had the highest agreement for all types of
indentations. Further study is needed in order to
verify the clinical application of the techniques.
Acknowledgements
The authors would like to thank Khon Kaen
University for funding the research, and the staff
in Synchrotron Light Research Institute, Thailand
for technical assistance in the analysis with the
prolometer.
Author’s Contributions
TL: Conceptualization, Methodology, Data
Curation, Formal Analysis, Writing- Original Draft
Preparation. TPJ: Methodology, Formal Analysis,
Writing - Review & Editing. SR: Methodology,
Formal Analysis, Writing - Review & Editing. RC:
Methodology, Formal Analysis, Writing - Review
& Editing. JP: Conceptualization, Methodology,
Formal Analysis, Supervision, Writing - Review
& Editing.
Conict of Interest
The authors have no conicts of interest to
declare.
Funding
The study has no external funding.
Regulatory Statement
This study did not utilize hazardous
substances, animal or human subjects. As a
result, adherence to specic regulatory laws or
guidelines concerning occupational health, safety,
or environmental protection was not required. All
appropriate steps were taken to uphold ethical
research standards and ensure laboratory safety.
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9
Braz Dent Sci 2024 Oct/Dec;27 (4): e4394
Volumetric measurement of sleep bruxism-like indentations on
acrylic surface using intraoral scanner and inlay wax
Limrachtamorn T et al.
Volumetric measurement of sleep bruxism-like indentations on acrylic surface using intraoral scanner and inlay wax
Limrachtamorn T et al. Volumetric measurement of sleep bruxism-like indentations on
acrylic surface using intraoral scanner and inlay wax
Date submitted 2024 June 04
Accept submission: 2024 Dec 01
Jarin Paphangkorakit
(Corresponding address)
Khon Kaen University, Faculty of Dentistry, Department of Oral Biomedical Science,
Khon Kaen, Thailand.
Email: jarin@kku.ac.th
