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.e4379
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Braz Dent Sci 2024 July/Sept;27 (3): e4379
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.
Water sorption and color stability of dental composites light-cured
with a broadband LED device and different radiant exposures
Sorção de água e estabilidade da cor de compósitos dentários fotopolimerizados com um dispositivo LED de amplo espectro
e diferentes exposições radiantes
Pedro Henrique MAGÃO1 , Angélica Feltrin dos SANTOS2 , Lourdes Rosa CHIOK OCAÑA3 ,
Fabio Antonio Piola RIZZANTE4 , Adilson Yoshio FURUSE1
1 - Universidade de São Paulo, Faculdade de Odontologia de Bauru. Bauru, SP, Brazil.
2 - Faculdade de Ciências do Tocantins. Araguaína, TO, Brazil.
3 - Universidad Cientíca del Sur. Miraores, Peru.
4 - Medical University of South Carolina, James B. Edwards College of Dental Medicine, Department of Reconstructive and Rehabilitation
Sciences. Charleston, SC, United States of America.
How to cite: Magão PH, Santos AF, Chiok-Ocaña L, Rizzante FAP, Furuse AY. Water sorption and color stability of dental composites light-cured
with a broadband LED device and different radiant exposures. Braz Dent Sci. 2024;27(3):e4379. https://doi.org/10.4322/bds.2024.e4379
ABSTRACT
Objective: This study assessed the properties of four resin-based composites (Charisma Classic, Charisma
Diamond, Filtek Z350XT, and Filtek Bulk Fill) concerning water sorption and color stability under different
radiant exposures of a broadband LED device (Valo Cordless, Ultradent) and immersion solutions. Material
and Methods: Disc-shaped specimens of the composites were prepared and subjected to two different radiant
exposures: 20 J/cm2 at 1000 mW/cm2 for 20 seconds and 16.8 J/cm2 at 1400 mW/cm2 for 12 seconds. Water
sorption (SO) was measured using a precision weighing scale, while color stability (∆E00) was evaluated after
immersion in distilled water, coke soft drink, or beer for 28 days. Factorial ANOVA and Tukey HSD test (α = 5%)
were employed for data analysis. Results: Signicant differences were observed in water sorption (p = 0.000)
among the composites and radiant exposures (p = 0.022). Likewise, color stability (∆E00) exhibited signicant
differences among composites (p = 0.000), radiant exposures (p = 0.000), and immersion solutions (p = 0.000).
Interaction between factors was also signicant (p = 0.000). Conclusion: Radiant exposure signicantly impacts
the properties of resin-based composites, particularly affecting water sorption and color stability. Optimal
performance in clinical settings can be achieved by tailoring polymerization conditions. The study found that
exposure to 20 J/cm2 at 1000 mW/cm2 for 20 seconds resulted in the lower water sorption values, while the
lowest color alteration (∆E00) was observed with 16.8 J/cm2 at 1400 mW/cm2 for 12 seconds.
KEYWORDS
Color; Composite resins; Curing lights; Dental restoration; Esthetics.
RESUMO
Objetivo: Este estudo avaliou as propriedades de quatro compósitos à base de resina (Charisma Classic,
Charisma Diamond, Filtek Z350XT e Filtek Bulk Fill) em relação à sorção de água e estabilidade da cor sob
diferentes exposições radiantes de um dispositivo LED de amplo espectro (Valo Cordless, Ultradent) e soluções
de imersão. Material e Métodos: Foram preparados espécimes em forma de disco dos compósitos e submetidos
a duas exposições radiantes diferentes: 20 J/cm2 a 1000 mW/cm2 durante 20 segundos e 16.8 J/cm2 a 1400
mW/cm2 durante 12 segundos. A sorção de água (SO) foi medida usando uma balança de precisão, enquanto
a estabilidade da cor (∆E00) foi avaliada após imersão em água destilada, refrigerante de cola ou cerveja por 28
dias. Para a análise dos dados, foram utilizados ANOVA fatorial e o teste HSD de Tukey (α = 5%). Resultados:
Foram observadas diferenças signicativas na sorção de água (p = 0.000) entre os compósitos e exposições
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Magão PH et al.
Water sorption and color stability of dental composites light-cured with a broadband LED device and different radiant exposures
Magão PH et al. Water sorption and color stability of dental composites
light-cured with a broadband LED device and different radiant
exposures
INTRODUCTION
The association of aesthetic, mechanical,
handling properties and the low cost makes resin
composites currently be the material of choice
for direct restoration of teeth [1-4]. However,
the stability and longevity of this material are
still a major concern since factors of the oral
environment affect these parameters [5,6].
Properties of the resin-based composites
can be influenced by their physic-chemical
composition and by extrinsic factors, such as
the buccal environment and polymerization
conditions [5-7]. The oral environment directly
influences the hydrolytic degradation of the
material through constant changes in temperature
and pH from the presence of chemicals such as
water, saliva, acids. The deterioration begins
with the absorption of water by the material,
which consists of a controlled diffusion process,
causing the chemical degradation of the material,
leading to problems such as detachment of the
particles of the polymer matrix, thus reducing the
wear resistance and decreasing its mechanical
properties [8,9].
In general, the amount of water sorption by
the polymer matrix is inuenced by the degree of
conversion and the degree of hydrophilicity of the
polymer chains [10,11]. On the other hand, the
evaluation of mechanical and physical properties
can provide an indirect measure for predicting
the conversion of monomers in composite
resins [8,10,12]. The absorption of water also
contributes to the hygroscopic expansion and
consequently hygroscopic stress of the material,
which can result in microcracks or even cracks
in the cusps of restored teeth [8].
Color alteration of a resin composite
restoration is caused by intrinsic and extrinsic
factors, such as discoloration of the resin itself
associated with insufficient polymerization,
immersion in liquid, adsorption of food dyes and
heating [13-17]. Dyes present in cola-based soft
drinks, tea, coffee, wine, and juices can alter the
color of teeth and resin composites interfering
with the esthetical properties [13,15,18].
The higher the percentage of unreacted
monomers in the polymer matrix, the greater
the occurrence of the sorption and pigmentation
phenomena in the resin composite [19,20].
Therefore, the success of resin-based
restorations also depends on the polymerization
method and efficiency. For a suitable
polymerization the material must receive
a certain dose of energy for a certain time,
which is called radiant exposure, which is the
product of the irradiance (mW/cm2) by the time
(s). Thus, different combinations of time and
irradiance can lead to significant differences
in material properties within the same radiant
exposure [21,22]. It has been emphasized that
new generations of light emitting diodes (LED)
can reduce the time of irradiation, decreasing
clinical working time without signicant loss of
the mechanical properties [23].
New generations of LED include broadband,
also known as polywave, devices that contains both
blue and violet spectra. These devices have been
developed to offer clinicians multiple irradiances
and exposure times. This is an important issue
since such devices are advertised as having
standard (lower irradiances) and high power/turbo
modes (higher irradiances), while manufacturers
recommend reduced light activation times
(lower radiant exposures) when high power
modes are used. This variability in irradiance and
exposure times necessitates further investigation to
determine whether different radiant exposures can
produce polymers with distinct properties [24].
With the development of new composite resin
radiantes (p = 0.022). Da mesma forma, a estabilidade da cor (∆E00) apresentou diferenças signicativas entre os
compósitos (p = 0.000), as exposições radiantes (p = 0.000) e as soluções de imersão (p = 0.000). A interação
entre fatores também foi signicativa (p = 0.000). Conclusão: A exposição radiante tem um impacto signicativo
nas propriedades dos compósitos à base de resina, afetando particularmente a absorção de água e a estabilidade
da cor. O desempenho ideal em ambientes clínicos pode ser alcançado através da adaptação das condições de
polimerização. O estudo concluiu que a exposição a 20 J/cm2 a 1000 mW/cm2 durante 20 segundos resultou
nos valores mais baixos de sorção de água, enquanto maior estabilidade de cor (∆E00) foi observada com 16,8
J/cm2 a 1400 mW/cm2 durante 12 segundos.
PALAVRAS-CHAVE
Cor; Resinas compostas; Lâmpadas de polimerização dentária, Restauração dentária permanente, Estética.
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Magão PH et al.
Water sorption and color stability of dental composites light-cured with a broadband LED device and different radiant exposures
Magão PH et al. Water sorption and color stability of dental composites
light-cured with a broadband LED device and different radiant
exposures
formulations and photoinitiators, it is essential to
continuously evaluate their behavior under various
polymerization protocols, since, the formation
of the polymer network may vary signicantly,
depending on the radiant exposure and chemycal
composition of the material. Existing studies often
isolate individual properties, whereas our research
aims to explore the combined impact of water
absorption and color stability, both crucial for the
long-term aesthetic and functional performance
of composites.Thus, further studies should be
conducted to evaluate whether this difference in
radiant exposure would produce polymers with
different properties. The objective of this study was
to evaluate the degree of water sorption of resin
composites, cured with two radiant exposures after
7 days of storage in distilled water and the color
stability after 28 days of immersion in staining
solutions. Null hypothesis was that there would
be no differences in the water sorption and color
stability of different resin composites when two
radiant exposures were used.
MATERIAL AND METHODS
Factors analyzed were resin composite in
four levels, and the radiant exposure in two
levels. Quantitative response variables were the
degree of water sorption (SO) in μg/mm3 and
color stability (ΔE00). Four resin composites
were evaluated: Charisma Classic A2 (Heraeus
Kulzer GmbH, Hanau, Germany), Charisma
Diamond A2 (Heraeus Kulzer GmbH, Hanau,
Germany), Filtek Z350XT A2B (3M ESPE, Saint
Paul, USA) and Filtek Bulk Fill A2 (3M ESPE,
Saint Paul, USA). The broadband LED device
utilized was the Valo Cordless (Ultradent,
South Jordan, USA) in two radiant exposures:
20 J/cm2 with the device operating at Standard
Mode, with 1000 mW/cm2, for 20 seconds; and
16.8 J/cm2 with the device operating at High
Power Mode, with 1400 mW/cm2, for 12 seconds.
These exposure times were used according to the
LED device manufacturer’s instructions.
For SO resin composite specimens were
prepared in a metallic mold with dimensions
of 5 mm in diameter and 2 mm in thickness for
each experimental group (n = 10). The material
was placed in a single increment and at the top
of the mold a polyester strip was tted along
with a glass slide for microscopy to press the
resin composite to avoid blistering and remove
any surplus material. Then specimens were
polymerized with a broadband LED device (Valo
Cordless, Ultradent, South Jordan, United States)
following the light-activation protocol according
to the radiant exposure/irradiance level of each
group. The specimens were then individually
stored in a desiccator containing silica gel at
37 °C ± 1°C for 24 hours.
After storage, the specimens were weighed on
a precision weighing scale. Using a digital caliper
(Digmatic Caliper, Mitutoyo Sul Americana, São
Paulo, Brazil) the measurements of the specimen
volume calculated in mm3 were obtained.
Subsequently, the specimens were stored with
5 mL of distilled water at 37 °C ± 1°C for 7 days.
The samples were weighed daily on an analytical
scale until a constant mass (m1) was obtained.
The specimens were then returned to the desiccator
containing silica gel at 37 °C ± 1°C and weighed
daily until a constant mass (m2) was obtained.
The water sorption (SO) values in μg/mm3 were
calculated with the following formula:
SO = m1-m2/v (1)
Where m1 = is the mass after immersion in water,
m2 = is the mass after the second desiccation cycle
and v = is the volume of the specimen in mm3.
As for the color stability, the color was
evaluated according to the CIEDE2000 (ΔE00)
equation after aging in different immersion
solutions. The specimens were manually polished
with a sequence of polishing discs from coarse
to super ne (Sof-Lex, 3M Espe. St. Paul, USA),
placed in ultrasonic water bath for 2 minutes,
then stored into distilled water at 37 °C ± 1°C for
24 hours, after this period they were placed inside
of individual vials containing 5 mL of one of the
solutions: distilled water, Coke soft drink (Coca-
Cola, Atlanta, Georgia, United States) or beer
(Heineken Lager Beer, Amsterdam, Netherlands)
for 28 days with the solution renewed every 2 days.
The color was evaluated with a spectrophotometer
(Easyshade Advance, VITA Zanhnfabrik Bäd
Sackingen, Baden-Württemberg, Germany) on a
at matte white standardized acrylic background,
under standardized illumination. The color
variation (ΔE00) was calculated according to the
following formula:
1/ 2
2
22
00
' ' ' ''
LL CC H H CC H H
L C H CH
E RT
KS KS K S KS K S
∆ ∆ ∆ ∆∆
∆= + + +
(2)
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Braz Dent Sci 2024 July/Sept;27 (3): e4379
Magão PH et al.
Water sorption and color stability of dental composites light-cured with a broadband LED device and different radiant exposures
Magão PH et al. Water sorption and color stability of dental composites
light-cured with a broadband LED device and different radiant
exposures
In which ΔL’, ΔC’ and ΔH’ represent
luminosity, chroma and hue respectively, RT
refers to the interaction between chroma and hue
in the blue region, SL, SC and SH are weighting
functions to adjust total color difference in L*,
a* and b* coordinates and KL, KC and KH are
correction terms for experimental conditions.
SO data were analyzed by Two-way analysis
of variance, while the ∆E00 data were evaluated
through three-way ANOVA, both were submitted
to Tukey’s HSD test, adopting a signicance level
of 5%.
RESULTS
Mean values, standard deviations and
statistical differences among groups analyzed
for SO are shown in Table I. For SO there
were significant differences between resin
composites (p = 0.000) and radiant exposures
(p = 0.022). The interaction effect was not
signicant (p = 0.984). Charisma Diamond with
the radiant exposure of 1000 mW/cm2 showed
the lowest SO values. In general, the experimental
groups that used the resin composite Charisma
Diamond showed the lowest water sorption
values, and when considering all the resin
composites evaluated, the groups that received
radiant exposure of 20 J/cm2 with 1000 mW/cm2,
for 20 seconds showed the lowest water sorption
values.
For ∆E00 there were signicant differences
between resin composites (p = 0.000), radiant
exposures (p = 0.000), and immersion solutions
(p = 0.000). All interaction effects were found
to be significant (p < 0.05). Mean values,
standard deviations and statistical differences
are shown in Table II and Figure 1. The lowest
ΔE00 values were observed by the experimental
groups containing the resin composite Charisma
Classic that received the radiant exposure of
16.8 J/cm2 with 1400 mW/cm2, for 12 seconds
after immersion in beer, followed by the same
material polymerized using the radiant exposure
of 20 J/cm2 with 1000 mW/cm2, for 20 seconds
after immersion in the same solution. Further
analysis shows that when all resin composites and
immersion solutions are considered, groups that
received the radiant exposure of 16.8 J/cm2, with
1400 mW/cm2, for 12 seconds showed greater
color stability with lower ∆E00 values. When
all resin composites and radiant exposures are
considered the immersion solution that was least
pigmenting was distilled water, followed by beer
and Coke soft drink.
DISCUSSION
The null hypothesis that there would be no
difference in the SO and color stability values in
the different resin composite types as a function
of radiant exposures was rejected because
signicant differences were found in SO and color
stability tests.
However, the ndings of the current study
do not support the previous research where
different power densities of LED light did not
affect the degree of conversion of composite
resins and the microleakage values of restorations
in small Class II cavities [25]. However, both
pieces of evidence demonstrate the relevance of
better understanding the behavior of light-cured
materials in extreme environments such as the
mouth.
The degree of conversion is a very
important feature of resin-based materials,
Table I - Mean values, standard deviations, and statistical differences of water sorption (in μg/mm3). Different superscript letters for each
column means statistically significant differences (p < 0.05)
Resin Composite Radiant Exposure Water sorption
(µg/mm3)
Charisma Classic 1000 mW/cm214.8 (1.9)ab
1400 mW/cm217.1 (4.2)b
Charisma Diamond 1000 mW/cm211.1 (2.9)a
1400 mW/cm212.5 (4.4)ab
Filtek Bulk Fill 1000 mW/cm215.6 (4.1)ab
1400 mW/cm217.8 (4.4)b
Filtek Z350 XT 1000 mW/cm215.6 (2.5)ab
1400 mW/cm217.6 (5.0)b
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Magão PH et al.
Water sorption and color stability of dental composites light-cured with a broadband LED device and different radiant exposures
Magão PH et al. Water sorption and color stability of dental composites
light-cured with a broadband LED device and different radiant
exposures
Table II - Mean values and standard deviations of ∆E00. Different superscript letters mean statistically significant differences (p < 0.05)
Resin material Immersion solution Radiant exposure ΔE00
Charisma Classic
Distilled water 1000 mW/cm21.0 (0.4)a
1400 mW/cm21.5 (0.5)a
Beer 1000 mW/cm20.6 (0.2)a
1400 mW/cm20.5 (0.0)a
Coke 1000 mW/cm21.5 (0.1)a
1400 mW/cm20.9 (0.1)a
Charisma Diamond
Distilled water 1000 mW/cm22.4 (0.2)a
1400 mW/cm21.2 (0.3)a
Beer 1000 mW/cm21.0 (0.2)a
1400 mW/cm20.9 (0.3)a
Coke 1000 mW/cm21.3 (0.4)a
1400 mW/cm23.7 (0.6)a
Filtek Bulk Fill
Distilled water 1000 mW/cm29.2 (0.8)b
1400 mW/cm211.1 (0.6)bc
Beer 1000 mW/cm213.4 (0.8)bc
1400 mW/cm22.7 (1.6)a
Coke 1000 mW/cm211.7 (0.5)bc
1400 mW/cm212.0 (0.4)bc
Filtek Z350 XT
Distilled water 1000 mW/cm22.4 (1.0)a
1400 mW/cm29.6 (5.3)b
Beer 1000 mW/cm215.0 (2.0)c
1400 mW/cm212.9 (1.1)bc
Coke 1000 mW/cm219.2 (1.0)d
1400 mW/cm21.8 (0.5)a
Figure 1 - Mean values of ∆E00 error bars represent the 95% confidence interval.
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Magão PH et al.
Water sorption and color stability of dental composites light-cured with a broadband LED device and different radiant exposures
Magão PH et al. Water sorption and color stability of dental composites
light-cured with a broadband LED device and different radiant
exposures
as it is significantly correlated with several
other important characteristics of the material,
such as mechanical properties, polymerization
shrinkage stress, wear resistance and elution of
monomers [8,13,14,20]. Therefore, the degree
of conversion of the resin-based materials can
vary from 40% to 75% depending mainly on the
material and the photopolymerization conditions
and is often measured to evaluate the efciency
of the polymerization and the most common
method is by spectroscopy techniques that infer
the amount of remaining double bonds, such
as the Fourier transform infrared spectroscopy
(FTIR) method [26,27].
However, it is known that the greater the
number of unreacted monomers in the polymer
matrix, the greater the solubility of the resin
composite [19].
In the present study, the radiant exposures
evaluated are the ones recommended by the LED
manufacturer for curing the nal layer of the resin
composite restorations. The light-activation with
different radiant exposures, however, is not in
agreement with the concept of reciprocity, or the
Exposure Law of Reciprocity was not followed.
According to this idea, the same radiant energy (in
Joules) reaching the surface of a resin composite
(i.e., radiant exposure measured in J/cm2) would
have the same effect on the material’s properties
despite the irradiance (in mW/cm2) and exposure
time (in seconds) combinations. It has been
suggested that such an equivalence is material-
and property-dependent [22].
The large variations in the sorption values
of the different materials can be explained by the
difference in the composition of each material.
In general, when the weight percentage of the
filler particles increases, the polymer matrix
decreases with the consequent decrease of water
sorption [6,8-10] and different polymers have
different tendencies to absorb different amounts
of water, based on their microstructure and
molecular aspects [28].
The water sorption behavior of resin
composites is primarily determined by the
hydrophilicity of the monomers in their
formulation. This hydrophilicity is inuenced by
the presence of hydrophilic functional groups—
such as hydroxyl, ether, or amine groups—within
the monomer’s chemical structure. Monomers like
triethylene glycol dimethacrylate (TEGDMA) have
a higher tendency to absorb water due to their
polar nature and ability to form hydrogen bonds
with water molecules. In contrast, monomers
like bisphenol A-glycidyl methacrylate (Bis-
GMA) exhibit lower water uptake because their
less polar aromatic structures reduce water
affinity [8,15,20] It should be noted that the
ISO 4049 standard which establishes methods
and criteria for evaluating this property was not
strictly followed in this study either in terms of
the size of the specimen to be evaluated or the
period of accommodation in the dissector at room
temperature, to reduce the amount of material
required and to lower the initial barriers to
starting the project. While the standard provides a
useful framework for generating widely accepted
evidence, the methodology was adjusted to
better align with the specific objectives and
practical considerations of our study. Although
this approach may introduce some differences
compared to standardized results, it is expected
to still provide valuable insights relevant to our
research goals. Resins primarily composed of
hydrophobic monomers can still show increased
water sorption if they include more hydrophilic
monomers or additives designed to improve
handling and ow characteristics [8-10]. Studies
comparing bulk-ll composites with conventional
composites indicate that bulk-ll resins typically
have similar or slightly higher water sorption,
depending on their specific formulations and
curing protocols. This aligns with our ndings,
which showed no statistically significant
differences in water sorption between bulk-ll
resins and other composite resins evaluated [7].
Even if a material’s composition ensures
good mechanical properties, incorrect
polymerization can lead to material failure.
It is important to consider that the emission and
absorption properties of photoinitiators can vary
signicantly [7], and the mechanical properties
of resin materials are directly correlated with
the types of photoinitiators used and the power
density of light activation [12,29] In this study,
we standardized the light exposure times based
on the manufacturer’s recommendations for
the broadband LED device rather than using
the curing times suggested by each material’s
manufacturer. This approach allowed us to
compare the performance of different materials
under consistent light exposure conditions, as the
recommended curing times for various materials
can differ widely. By following the LED device’s
specications, we aimed to provide a uniform
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Magão PH et al.
Water sorption and color stability of dental composites light-cured with a broadband LED device and different radiant exposures
Magão PH et al. Water sorption and color stability of dental composites
light-cured with a broadband LED device and different radiant
exposures
baseline for evaluating material responses under
similar photoactivation conditions.
This study evaluated the color stability
of dental composites, which is influenced by
water absorption and other physical-mechanical
properties. Composites with lower water
absorption are generally more resistant to
discoloration because water can cause the
leaching of unreacted monomers, pigments,
and other components, leading to changes
in optical properties [4,5,15,18]. The study
observed varying degrees of color change
among different materials after immersion in
distilled water, carbonated soft drinks, and beer,
highlighting the effects of humidity, acidity,
and pigmented beverages on dental aesthetics.
These findings are consistent with previous
studies that have identied uid absorption and
matrix degradation as key factors contributing
to color change in dental composites [12,23].
This is further demonstrated by the signicant
color alterations observed in Filtek Z350 XT after
28 days of exposure to staining solutions [20].
A spectrophotometer was used to measure
color across different evaluation periods, selected
for its precision and versatility in accommodating
a wide range of experimental designs in research
on resin composites for dental applications.
The data obtained from spectrophotometry can
be effectively translated into clinically relevant
information and can detect color variations that
are imperceptible to the human eye [29,30].
In addition to evaluating color changes, the
study also assessed perceptibility and acceptability
thresholds, which consider non-uniformities
in human color perception. Although there is
some disagreement in the literature regarding
the perceptibility threshold for acceptable color
change, this study referenced the thresholds of
ΔE00 for perceptibility at 0.8 and acceptability
at 1.8 [31] of the 24 experimental groups
evaluated, 21 exhibited perceptible color
changes, and 13 showed color changes that
were both perceptible and unacceptable after
28 days of immersion in staining solutions.
These ndings emphasize the need for materials
with greater resistance to discoloration and a
deeper understanding of how photoactivation
protocols can inuence the physical and chemical
properties critical to their clinical application.
In conclusion, the polymerization of dental
composite resins is a crucial factor in the success
and longevity of dental restorations. This process
is inuenced by several variables, including light-
curing protocols and, specically, the radiant
exposure [21,22,26,32].
High irradiance with shorter exposure times
accelerates the polymerization process, resulting
in a rapid increase in cross-link formation.
However, this rapid process can limit the time
available for the material to relax, leading
to shrinkage stresses [33,34]. Consequently,
microvoids and internal stresses may form,
creating structural weaknesses within the
composite. These defects can serve as pathways
for water ingress, increasing water sorption
and potentially causing discoloration over
time [35,36].
These findings suggest that the curing
protocol directly affects the kinetics of the
polymerization reaction, potentially leading to
incomplete monomer conversion, the formation
of suboptimal cross-links, and the development
of internal defects within the composite structure.
The impact of polymerization and degree of
conversion on water sorption is evident in the
results of this study, where increased radiant
exposure combined with reduced curing times
elevated water sorption levels, making the material
more susceptible to hydrolytic degradation. From
a practical and clinical perspective, protocols
that excessively increase radiant exposure while
reducing curing times, although efficient in
appearance, may compromise the structural and
physical properties of composite resin.
For future studies, we recommend not only
determining the degree of water sorption but
also directly measuring the degree of conversion.
Studies that consider multiple causal variables
provide signicant insights into the factors that
affect the clinical performance and longevity of
dental materials.
CONCLUSION
It can be concluded that both the type of resin
composite and the radiant exposure signicantly
inuence water sorption (SO) and color stability
(ΔE00) of the materials tested. The light-curing
protocol of 16.8 J/cm2 at 1400 mW/cm2 for
12 seconds provided the best color stability, while
20 J/cm2 at 1000 mW/cm2 for 20 seconds was most
effective in reducing water sorption. Therefore,
the optimal light-curing protocol depends on
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Magão PH et al.
Water sorption and color stability of dental composites light-cured with a broadband LED device and different radiant exposures
Magão PH et al. Water sorption and color stability of dental composites
light-cured with a broadband LED device and different radiant
exposures
whether the primary goal is minimizing color
change or water sorption. The combination of the
appropriate resin composite and radiant exposure
is most effective in minimizing water sorption
and color change. The immersion solution
also signicantly impacted color stability, with
distilled water causing the least discoloration,
followed by beer and Coke soft drink.
Author’s Contributions
PHM, LCO, AYF: Conceptualization,
Methodology. PHM, AFS, FAPR, AYF: Writing
– Review & Editing, Formal analysis. PHM,
AFS, LCO, AYF: Data Curation. PHM, AYF:
Investigation, Funding Acquisition, Project
Administration. LCO: Resources. AFS: Writing
– Original Draft Preparation, Investigation,
Supervision.
Conict of Interest
The authors have no proprietary, nancial,
or other personal interest of any nature or kind
in any product, service, and/or company that is
presented in this article.
Funding
This work was supported by the Fundacao
de Amparo a Pesquisa do Estado de Sao Paulo –
FAPESP (grants numbers: 2022/11613-2, 2022/11632-
7, and 2023/12518-6) and by the Coordenacao de
Aperfeiçoamento de Pessoal de Nivel Superior
– CAPES (Finance Code 001).
Regulatory Statement
Not applicable.
REFERENCES
1. Favoreto MW, Carneiro TS, Bernardi LG, Ñaupari-Villasante R,
Matos TP, Kunz PM, et al. A new preheating thermoviscous
composite for restoration of non-carious cervical lesions: a
6-month randomized clinical trial. Braz Dent Sci. 2022;25(4):e3575.
http://doi.org/10.4322/bds.2022.e3575.
2. Ibrahim HA, Abdalla AI, El-Sayed HY. Clinical study of different
composite resin systems in Class I cavities (an 18-month
randomized clinical trial). Braz Dent Sci. 2023;26(3):e3737.
http://doi.org/10.4322/bds.2023.e3737.
3. Magão PH, Fernandes PHM, Borges AFS, Furuse AY. Correção
anatômica e fechamento de diastemas com procedimentos
diretos baseados em proporção áurea. RSBO. 2023;20(1):238-44.
http://doi.org/10.21726/rsbo.v20i1.2022.
4. Furuse AY, Santana LOC, Rizzante FAP, Ishikiriama SK,
Bombonatti JF, Correr GM, et al. Delayed light activation
improves color stability of dual-cured resin cements. J
Prosthodont. 2018;27(5):449-55. http://doi.org/10.1111/
jopr.12509. PMid:27455118.
5. Tohidkhah S, Jin J, Zhang A, Aregawi W, Morvaridi-Farimani R,
Daisey EE,etal. Post-failure analysis of model resin-composite
restorations subjected to different chemomechanical challenges.
Dent Mater. 2024;40(6):889-96. http://doi.org/10.1016/j.
dental.2024.04.005. PMid:38692997.
6. Drummond JL. Degradation, fatigue and failure of resin dental
composite materials. J Dent Res. 2008;87(8):710-9. http://doi.
org/10.1177/154405910808700802. PMid:18650540.
7. Boeira PO, de Azevedo Kinalski M, Santos MBF, De Moraes RR,
Lima GS. Polywave and monowave light-curing units effects
on polymerization efficiency of different photoinitiators. Braz
Dent Sci. 2021;24(4):1-9. https://doi.org/10.14295/bds.2021.
v24i4.2661
8. Alshali RZ, Salim NA, Satterthwaite JD, Silikas N. Long-term
sorption and solubility of bulk-fill and conventional resin-
composites in water and artificial saliva. J Dent. 2015;43(12):1511-
8. http://doi.org/10.1016/j.jdent.2015.10.001. PMid:26455541.
9. Zidan AZ, Mansouri SA. Effect of water sorption and solubility
on color stability of bulk-fill resin composite. J Contemp
Dent Pract. 2018;19(9):1129-34. http://doi.org/10.5005/
jp-journals-10024-2393. PMid:30287716.
10. Gajewski VES, Pfeifer CS, Fróes-Salgado NRG, Boaro LCC, Braga
RR. Monomers used in resin composites: degree of conversion,
mechanical properties and water sorption/solubility. Braz
Dent J. 2012;23(5):508-14. http://doi.org/10.1590/S0103-
64402012000500007. PMid:23306226.
11. Ito S, Hashimoto M, Wadgaonkar B, Svizero N, Carvalho RM, Yiu
C,etal. Effects of resin hydrophilicity on water sorption and
changes in modulus of elasticity. Biomaterials. 2005;26(33):6449-
59. http://doi.org/10.1016/j.biomaterials.2005.04.052.
PMid:15949841.
12. Souza MBA, Briso ALF, Ramos FSS, De Oliveira Reis B, Dos Santos
PH, Fagundes TC. Influence of different types of light curing units
and photoinitiators in microhardness and color of composite
resins after immersion in wine. Braz Dent Sci. 2019;22(3):371-7.
http://doi.org/10.14295/bds.2019.v22i3.1754.
13. Khazaal G, Daou M, Mahdi SS, Ahmed Z, Maalouf E, Batteni
G,etal. In vitro evaluation of the color stability and surface
roughness of a new composite flow. J Clin Exp Dent.
2023;15(1):e43-50. http://doi.org/10.4317/jced.60005.
PMid:36755675.
14. Choi JW, Lee MJ, Oh SH, Kim KM. Changes in the physical
properties and color stability of aesthetic restorative materials
caused by various beverages. Dent Mater J. 2019;38(1):33-40.
http://doi.org/10.4012/dmj.2017-247. PMid:30298856.
15. Paolone G, Formiga S, De Palma F, Abbruzzese L, Chirico L,
Scolavino S,etal. Color stability of resin-based composites:
staining procedures with liquids-A narrative review. J Esthet
Restor Dent. 2022;34(6):865-87. http://doi.org/10.1111/
jerd.12912. PMid:35396818.
16. Mazzitelli C, Paolone G, Sabbagh J, Scotti N, Vichi A. Color
stability of resin cements after water aging. Polymers (Basel).
2023;15(3):655. http://doi.org/10.3390/polym15030655.
PMid:36771956.
17. Meleka N, El-Banna A, El-Korashy D. Color stability and degree
of conversion of amine-free dual cured resin cement used with
two different translucencies of lithium disilicate ceramics. Braz
Dent Sci. 2023;26(2):e3614. http://doi.org/10.4322/bds.2023.
e3614.
9
Braz Dent Sci 2024 July/Sept;27 (3): e4379
Magão PH et al.
Water sorption and color stability of dental composites light-cured with a broadband LED device and different radiant exposures
Magão PH et al. Water sorption and color stability of dental composites
light-cured with a broadband LED device and different radiant
exposures
18. Tonetto MR, Santezi Neto C, Felício CM. Effect of staining agents
on color change of composites. RSBO Online. 2012;9(3):266-71.
http://doi.org/10.21726/rsbo.v9i3.999.
19. Sideridou I, Tserki V, Papanastasiou G. Study of water
sorption, solubility and modulus of elasticity of light-
cured dimethacrylate-based dental resins. Biomaterials.
2003;24(4):655-65. http://doi.org/10.1016/S0142-
9612(02)00380-0. PMid:12437960.
20. Silva MF, Dias MF, Lins-Filho PC, Silva CHV, Guimarães RP. Color
stability of Bulk-Fill composite restorations. J Clin Exp Dent.
2020;12(11):e1086-90. http://doi.org/10.4317/jced.57579.
PMid:33262876.
21. Watts DC. Let there be More Light! Dent Mater Off Publ Acad
Dent Mater. 2015;31(4):315-6. PMid:25773189.
22. Peutzfeldt A, Asmussen E. Resin composite properties and
energy density of light cure. J Dent Res. 2005;84(7):659-62.
http://doi.org/10.1177/154405910508400715. PMid:15972597.
23. Shiozawa M, Takahashi H, Asakawa Y, Iwasaki N. Color stability
of adhesive resin cements after immersion in coffee. Clin Oral
Investig. 2015;19(2):309-17. http://doi.org/10.1007/s00784-014-
1272-8. PMid:24950608.
24. Algamaiah H, Alshabib A, Algomaiah M, Yang J, Watts DC.
Diversity of short-term DC outcomes in bulk-fill RBCs subjected
to a 3 s high-irradiance protocol. Dent Mater. 2024. In press.
http://doi.org/10.1016/j.dental.2024.08.008. PMid:39227233.
25. Demir K, Bayraktar Y. Evaluation of microleakage and degree of
conversion of three composite resins polymerized at different
power densities. Braz Dent Sci. 2020;23(2):10. http://doi.
org/10.14295/bds.2020.v23i2.1948.
26. Santos GB, Medeiros IS, Fellows CE, Muench A, Braga RR.
Composite depth of cure obtained with QTH and LED units
assessed by microhardness and micro-Raman spectroscopy.
Oper Dent. 2007;32(1):79-83. http://doi.org/10.2341/06-26.
PMid:17288333.
27. International Organization for Standardization. ISO 4049:2019
- Dentistry — Polymer-based restorative materials [Internet].
2019 [cited 2023 June 26]. Available from: https://www.iso.
org/standard/67596.html
28. Ortengren U, Wellendorf H, Karlsson S, Ruyter IE. Water
sorption and solubility of dental composites and identification
of monomers released in an aqueous environment. J Oral
Rehabil. 2001;28(12):1106-15. http://doi.org/10.1046/j.1365-
2842.2001.00802.x. PMid:11874509.
29. Klotz AL, Habibi Y, Corcodel N, Rammelsberg P, Hassel
AJ, Zenthöfer A. Laboratory and clinical reliability of two
spectrophotometers. J Esthet Restor Dent. 2022;34(2):369-73.
http://doi.org/10.1111/jerd.12452. PMid:30593733.
30. Klotz AL, Habibi Y, Hassel AJ, Rammelsberg P, Zenthöfer A. How
reliable and accurate is the shade determination of premolars
by spectrophotometry? Clin Oral Investig. 2020;24(4):1439-44.
http://doi.org/10.1007/s00784-019-03162-x. PMid:31838595.
31. Paravina RD, Ghinea R, Herrera LJ, Bona AD, Igiel C, Linninger
M,etal. Color difference thresholds in dentistry. J Esthet Restor
Dent. 2015;27(Suppl 1):S1-9. http://doi.org/10.1111/jerd.12149.
PMid:25886208.
32. Musanje L, Darvell BW. Polymerization of resin composite
restorative materials: exposure reciprocity. Dent Mater.
2003;19(6):531-41. http://doi.org/10.1016/S0109-
5641(02)00101-X. PMid:12837402.
33. Pfeifer CS, Ferracane JL, Sakaguchi RL, Braga RR.
Factors Affecting Photopolymerization Stress in Dental
Composites. J Dent Res. 2008;87(11):1043-7. http://doi.
org/10.1177/154405910808701114. PMid:18946012.
34. Szczesio-Wlodarczyk A, Garoushi S, Vallittu P, Bociong K, Lassila
L. Polymerization shrinkage stress of contemporary dental
composites: comparison of two measurement methods. Dent
Mater J. 2024;43(2):155-63. http://doi.org/10.4012/dmj.2023-
192. PMid:38296513.
35. Benkeser SM, Karlin S, Rohr N. Effect of curing mode of
resin composite cements on water sorption, color stability,
and biaxial flexural strength. Dent Mater Off Publ Acad
Dent Mater. 2024;40(6):897-906. http://doi.org/10.1016/j.
dental.2024.04.004. PMid:38702210.
36. Bociong K, Szczesio A, Sokolowski K, Domarecka M, Sokolowski
J, Krasowski M, et al. The influence of water sorption of
dental light-cured composites on shrinkage stress. Materials
(Basel). 2017;10(10):1142. http://doi.org/10.3390/ma10101142.
PMid:28956844.
Pedro Henrique Magão
(Corresponding address)
Universidade de São Paulo, Faculdade de Odontologia de Bauru, Bauru,
SP, Brasil.
Email: pedro.magao@usp.br
Date submitted: 2024 May 17
Accept submission: 2024 Sept 25
