Volume 8, Issue 8, August – 2023 International Journal of Innovative Science and Research Technology

ISSN No:-2456-2165

Evaluation of the Degree Conversion of Dental

Composite Nanoparticles as an Effect on the
Variation of Initial Temperature Treatment
Subhaini Jakfar 1*, Sri Fitriyani 1, Evita Mutiara Peron 1, Diana Setya Ningsih 1, Iin Sundari 1, Viona Diansari 1, Basri A. Gani 2
1
Dental Material Department of Dentistry Faculty, Universitas Syiah Kuala (USK), Darussalam, Banda Aceh, Indonesia, 23111
2
Oral Biology Department of Dentistry Faculty, Universitas Syiah Kuala (USK), Darussalam, Banda Aceh, Indonesia, 23111

Abstract:- The degree of conversion in photo-activated As a result, it could reduce the longevity of the restoration [5,
resin composites can be affected by temperature. A new 6].
type of composite, called nanoparticle resin composite,
has been developed for dentistry. This study aimed to The degree of conversion of the composite resins is
investigate how temperature variation of the nanoparticle related to the conversion of monomer carbon-carbon double
Ceram-XTM Duo resin composite before polymerization bonds to polymeric carbon-carbon single bonds [7]. Lovell, et
affects the degree of conversion. The study used 30 al. reported that increased conversion would result in
cylindrical specimens, each 6mm in diameter and 3mm in increased surface hardness, flexural strength, flexural
thickness, divided into three treatment groups: 5°C, 25°C, modulus, fracture resistance, diametral strength, and
and 60°C. Each group contained five polymerized wearability [8]. Many factors can affect the value of the
specimens and five unpolymerized specimens. The degree degree of conversion, namely the color and thickness of the
of conversion was measured using FTIR with 45 scans, a resin, type of filer, type and quality of the light source, curing
resolution of 4 [1/cm], and an analyzed wavelength of time, the distance between the light source and the resin
500-4000 [1/cm]. Statistical analysis was performed using surface, and the temperature of the composite resin [9, 10].
the One-Way ANOVA test and Tukey. The results
showed that temperature significantly influenced the Daronch, et al., in their research, stated that the degree of
degree of conversion. The highest degree of conversion conversion of the hybrid composite resin under heated
was observed at 60°C, with a value of 21.38%, compared conditions (60˚C) was higher when compared to the condition
to 14.94% at 5°C and 7.24% at 25°C. In conclusion, this of the composite resin at room temperature (22˚C) and cold
study demonstrates that temperature variation before temperatures (3˚C) [11]. Cold temperatures ranged from 3 -
polymerization impacts the degree of conversion of dental 5˚C (the average temperature in the refrigerator), room
nano particle resin composites. temperature, and hot temperatures between 40-60˚C are
chosen to maintain the effectiveness of heat because when
Keywords:- Temperature; Degree of Conversion; removing the composite from the syringe, filling it into the
Nanoparticle Resin Composite. cavity, contouring, and the light-curing procedure will
consume the time and simultaneously lower the temperature.
I. INTRODUCTION Meanwhile, temperatures of more than 60˚C are not
recommended because of the potential to cause injury to the
The use of composite resins as restorative materials in pulp. Thus, Kincses, et al. stated the effect of temperature on
dentistry is increasing rapidly; that composite resin has better degree conversion of composite, which is the temperature
physical, mechanical, and esthetic properties when compared would reduce the system's viscosity, increase the mobility of
to other filling materials those are previously discovered, such radicals, and produce additional polymerization [12].
as silicate or acrylic resin [1]. Currently, composite resin can
be applied for several purposes, such as restoration of anterior The development of dental materials in recent years has
and posterior teeth caused by the caries process, adjustment of produced dental composites with filter particle sizes in nano
occlusion, cementation for indirect restorations, and bonding units ranging from 0.1–100 nm [13, 14]. Changes in the size
of orthodontic brackets [2]. of the filer result in improved mechanical properties that are
better when compared to the previous type of composite, so
However, some dentist practitioners claim that the they can also be applied to posterior teeth. Nanoparticle
composite resins have several weaknesses, including being composites have a high level of translucency, resistance to
able to experience volume reduction (shrinkage) during polishing similar to microfiler composites, and wearability
polymerization, which is followed by the emergence of stress comparable to some hybrid composites [15]. Therefore, this
on the bond between the tooth and the restoration [3, 4]. This research was conducted to evaluate the effect of variations in
stress can break the bonding or cause deflection around the the initial temperature treatments of the nanoparticle
tooth structure. The magnitude of this stress contraction is composite resin on the conversion degree.
related to the restoration configuration, for example, the
degree of conversion of composites and their conversion rate.

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Volume 8, Issue 8, August – 2023 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
II. MATERIAL AND METHODS

A. Material
The material used for this study was Ceram-XTM Duo
nanoparticle composite resin (Dentsply Products Germany)
for posterior tooth restorations with the composite color used
D3.

B. Methods
Temperature variations were conducted in the following
ways: cold temperature at 5˚C obtained using a refrigerator,
room temperature at 25˚C obtained from an air conditioner,
and hot temperature at 60˚C obtained using an incubator. For
non-polymerized specimens, the composite paste will be
directly tested using FTIR. The composite paste was put into
the mold using a plastic instrument with bulk technique, then
the surface of the mold was flattened. Furthermore, the
surface of the composite material was coated with a mylar
strip, and on top of it was placed a microscope slide and given
Fig 1. The Degree of Conversion in an average of
a load of 1 kg for 20 seconds. The composite was irradiated
Nanoparticle Composite Resin at different temperature,
with Litex 692 LED Curing Light with a light intensity of 700
significance levels were indicated as *** (p <0.001)
mW/cm2 and an irradiation time of 40 seconds. Each
temperature group consists of 10 specimens, so the total
IV. DISCUSSION
number of specimens is 30. After one hour, the specimens
were removed from the mold, washed with a mild detergent,
The finding informs that the maximum degree of
and rinsed with water. Then the specimen was put into a
conversion was obtained at the highest temperature of 60˚C,
plastic vial containing 3 ml of water as the immersion medium
while the lowest degree of conversion was obtained at 25˚C.
and stored in an incubator at 37 ± 1˚C for 24 hours.
Room temperature shows a lower conversion degree value
when compared to cold temperatures of 5˚C. Our findings
CD% =(1-(Caliphatic/Caromatic)/(Ualiphatic/Uaromatic)) x 100% (1)
were slightly different from the statement of Daronch et al.
that the higher the temperature will produce a higher degree of
The abbreviation "CD" refers to the conversion degree.
conversion [11]. The degree of conversion in heated
The absorption peaks of 1638 cm-1 before and after
composite resin has a higher value when compared to room
polymerization corresponds to Ualiphatic and Caliphatic,
temperature and cold temperatures where high temperatures
respectively. Similarly, the absorption peaks of 1608 cm-1
can increase molecular mobility, and reduce system viscosity;
before and after polymerization correspond to Uaromatic and
thus, more monomers will be converted [16].
Caromatic, respectively.
Increasing the temperature (60˚C) will increase the
The results are expressed as means  S.D which were
mobility of molecules due to decreased viscosity and delay
analyzed by one-way ANOVA, followed by a Tukey multiple
the control of diffusion propagation and termination so that
comparison test, the significant levels were indicated as *p <
the system will achieve high conversion before vitrification.
0.05, **p < 0.01, and ***p < 0.001.
Thus, when the temperature of the composite is increased,
more crosslinks will be formed, and at the same time, will
III. RESULTS
improve the mechanical and physical properties of the
composite. The high temperature will increase the degree of
The initial temperature treatment of the composite resin
conversion on the upper and lower surfaces of the composite
was 25˚C, resulting in a conversion degree of 7.24%. The
resin restoration [17, 18]. Mechanical properties such as
degree of conversion increased to 21.38% at a temperature of
composite hardness is correlated with the degree of
60˚C and then decreased to 14.94% at a temperature of 5˚C.
conversion. The higher the hardness value of a material, the
Based on the results of statistical tests using ANOVA
higher the degree of conversion achieved.
followed by the Tukey test, it can be concluded that the initial
temperature of the composite resin affects the degree of
Composite resin at cold temperatures (5˚C) showed
conversion, with the highest peak degree of conversion
higher conversion than at room temperature (25˚C). Osterack
obtained at a temperature of 60˚C.
et al., in their research on the effect of temperature on the
hardness of composite resin, stated that the hardness value of
composite resin at cold temperatures was higher than at room
temperature. It could occur because the composite at cold
temperatures is only slightly affected by the heat generated by
the light source, thereby reducing the stress during
polymerization. It is different for composite resins at room
temperature, where polymerization occurs more quickly due

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Volume 8, Issue 8, August – 2023 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
to the considerable influence of heat generated by the light presence of the (-NH-) group, which also increases the
source, which traps monomer molecules between polymer viscosity. However, this aliphatic molecule has a higher
chains and hinders the formation of polymer networks. polymer chain mobility than Bis-GMA [22].

According to Lovell, et al., cooled composite resin will Another matrix monomer contained in Ceram-XTM Duo
increase the viscosity of the material and will decrease the composite resin is methacrylate-modified polysiloxane. This
mobility of the monomer [8]. Dall'Magro, et al., in their matrix is here to replace the use of TEGDMA, which is
research, also stated that although the mobility of the considered to have drawbacks, one of which is minimizing the
monomer decreased at cold temperatures, the hardness value polymerization shrinkage that occurs. When combined with
of the material did not change, which is a degree of glass filler or other reactive monomers, this matrix will also
conversion obtained would not decrease either [19]. make a composite resin restoration with excellent physical
and mechanical properties. Polysiloxane forms a covalent
The degree of conversion obtained in this study is not so block bonded by silicon atoms during photo-polymerization,
high compared to the average degree of conversion achieved and an inorganic-organic network (polymer mixture) will be
in general. The composite material component in the form of developed. Polysiloxane has the same structure as silicate
a combination of monomers is believed to influence the glass or ceramics, so the composite resin also becomes more
degree of conversion. The combined monomer matrices in the translucent and has excellent optical properties [23, 24].
Ceram-XTM Duo composite resin consist of Bis-GMA,
UDMA, and methacrylate modified polysiloxane. The V. CONCLUSION
structure of each matrix monomer is shown in Figure 2.
There is an influence on the conversion degree of the
initial temperature treatment of dental nanoparticle composite
resin before polymerization. Thus, to get the optimum degree
of conversion, dentists could pre-warming of the composite
resin before polymerization at 60˚C.

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