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J Appl Oral Sci. 200
ABSTRACT
www.scielo.br/jaos
Color stability, surface roughness and
microhardness of composites submitted to
mouthrinsing action
Marília Salomão Campos Cabrini FESTUCCIA1, Lucas da Fonseca Roberti GARCIA2, Diogo Rodrigues CRUVINEL3,
Fernanda de Carvalho Panzeri PIRES-DE-SOUZA4
1- DDS, Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
2- DDS, MS, PhD, Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
3- DDS, MS, Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
4- DDS, MS, PhD, Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
Corresponding address: Profa. Dra. Fernanda de Carvalho Panzeri Pires-de-Souza - Faculdade de Odontologia de Ribeirão Preto - USP - Departamento
de Materiais Dentários e Prótese - Avenida do Café, s/n - Bairro Monte Alegre - 14040-904 - Ribeirão Preto - SP - Brazil - Phone: +55-16-3602-3973 - Fax:
+55-016-3633-0999 - e-mail: ferpanzeri@usp.br
Objective: The purpose of this study was to evaluate the effect of mouth rinse solutions
on color stability, surface roughness and microhardness of two composite resins.
Material and Methods: Fifty test specimens of each composite (Filtek Z250 and Z350; 3M
microhardness baseline measurements of each specimen were made and specimens (n=10)
were immersed in 5 mouth rinse solutions: G1: distilled water (control), G2: Plax Classic, G3:
Plax alcohol-free; G4: Periogard, and G5: Listerine. Final measurements of color, roughness
and microhardness were performed and the results submitted to statistical analysis (2-way
for Z250 when immersed in Listerine (p<0.05). Z350 showed greater color change when
immersed in Listerine in comparison with Plax alcohol-free (p<0.05). Microhardness of
alcohol-free (p<0.05). Conclusion: Composite changes depended on the material itself
rather than the mouth rinse solution used.
Key words: Composite resins. Oral hygiene. Dental materials. Physical properties.
INTRODUCTION
Color and surface roughness are very important
properties in aesthetics, characterizing a smile21.
Since the introduction of composites in 1960,
efforts have been made to increase the longevity
of composite restorations. Although some progress
has been made, optical properties in this type of
materials need to be improved5.
The color change of composites is multifactorial,
being associated with intrinsic discoloration and
extrinsic staining of the material. Intrinsic factors
involve changes in the chemical stability of resin
matrix and matrix/particles interface, and extrinsic
factors are related to absorption of staining solutions
from exogenous sources related to hygiene habits,
food, and smoking8.
Composite structure and the characteristics
of the inorganic fillers have a direct impact
on composite resin surface smoothness26 and
susceptibility to extrinsic staining24. Several studies
have shown that composite resins are susceptible to
color alteration when exposed to staining solutions,
especially red wine, coffee, cola, tea and whisky2,9.
Furthermore, this property depends on both water
absorption of the composite and its hydrophilic resin
matrix to allow permeation of staining agents, thus
resulting in greater color changes2.
Today, the number of people using mouth rinse
2012;20(2):200-5
J Appl Oral Sci. 201
solutions for anti-microbial control has increased
not only because of professional recommendations,
but also due to the capacity of such materials to
provide cooling sensation and to reduce halitosis7.
Mouth rinse solutions have various components
dyes and alcohol. It is known that composite resins
exposed to ethanol exhibit lower microhardness
values compared to non-exposed materials23.
According to Sarret, et al.22 (2000), alcohol acts
as a plasticizer of the polymeric matrix, making
the material more ductile. In addition, ethanol can
reduce bonding between resin matrix and inorganic
cause staining of resin matrix23.
Thus, the purpose of this study was to evaluate
the effect of mouth rinse solutions on color stability,
surface roughness and microhardness of composite
resins. The null hypothesis stated that mouth
rinse solutions would not promote changes in the
properties of the studied composites.
MATERIAL AND METHODS
Samples preparation
Two direct composite resins (shade A3) currently
indicated for esthetic anterior and posterior
restorations were used in the present study.
Information regarding composite type, composition
and manufacturer is given in Figure 1.
Fifty cylindrical test specimens (12 mm diameter
x 2 mm thick) of each composite were made using
the matrix in 2 increments and light-activated
by a LED device (FLASHlite 1401, Discus Dental,
cm2, wavelength in the range between 460 and 480
nm), for 20 seconds, according to manufacturer’s
recommendations. The specimens were polished
with 320, 600, 1200 and 2000-grit sandpapers. The
thickness of every test specimen was checked with
a digital caliper (Digimess, São Paulo, SP, Brazil).
Next, the test specimens were randomly separated
into 5 groups (n=10) according to the mouth rinse
solution in which they had been immersed (Figure
2): Group 1 - distilled water (control); Group 2 -
Plax classic; Group 3 - Plax alcohol-free; Group
4 - Periogard; and Group 5 - Listerine Cool Mint.
To simulate the use of mouth rinse solutions once
a day during a period of 1 year, the test specimens
were submitted to 12 cycles of 1-min immersion,
then washed in running water and immersed in
distilled water for 29 min at 37°C, during 30 days,
totaling 360 cycles11.
Color stability
Before immersion, color reading of the test
specimens was performed according to the CIE
system, against a white background (Standard
for 45/0°; Gardner Laboratory Inc., Bethesda,
6807, BYK Gardner, Geretsried, Germany). This
LED lamps with 10 different colors arranged in a
circle, which directs a light bundle at 45° with the
back to the equipment, which captures and records
axes refers to the lightness coordinate and its value
ranges from zero (black) to 100 (white). The axis
green axis and the yellow-blue axis, respectively.
negative values indicate a shift to green. Similarly,
and negative values indicate the blue color range.
After immersion in mouth rinse solutions,
specimens color was measured by the
spectrophotometer, as previously described. Based
'E) was
determined using the following equation:
'E=[('2+('2+('2]1/2
Values of '
unacceptable20.
Surface roughness and Knoop microhardness
Surface roughness (Ra) and Knoop microhardness
Commercial
name
Type Monomers Load particles
!"#$"%
Manufacturer
Filtek Z250 Microhybrid Bis-GMA, UDMA,
Bis-EMA
Zirconia/Silica 0.6 µm 3M ESPE Dental Products,
St Paul, MN, USA
Filtek Z350 Nanoparticulate Bis-GMA, Bis-
EMA, UDMA and
TEGDMA
Zirconia/Silica 5-20 nm
with clusters of 0.6-1.4
µm
3M ESPE Dental Products,
St Paul, MN, USA
Bis-GMA: bisphenol A diglycidyl ether dimethacrylate; Bis-EMA: Ethoxylated bisphenol A dimethacrylate,
TEGDMA:Triethylene glycol dimethacrylate; UDMA: urethane dimethacrylate
Figure 1- Tested composites
Color stability, surface roughness and microhardness of composites submitted to mouthrinsing action
2012;20(2):200-5
J Appl Oral Sci. 202
of the test specimens were performed before and
after mouth rinse solution immersion. Surface
roughness was measured with a Rugosimeter
(Mitutoyo SJ-201P, Mitutoyo, Tokyo, Japan), cut-
off - 0.25 mm, Lc parameter - 1.25, speed - 0.1
mm/s. The rugosimeter needle (10 µm diameter)
was positioned over each test specimen, performing
three readings in different locations of the sample
surface, after which, the mean roughness of the
test specimens were obtained. Surface roughness
changes were calculated by the differences between
mean values obtained before and after immersion.
The Knoop microhardness of the test specimens
was measured (Shimadzu device, HMV Shimadzu,
Kyoto, Japan) in three different points, with a 10
N/15 s load. After three readings, the microhardness
mean values of the test specimens were obtained.
For Knoop microhardness calculation, the baseline
mean values were subtracted from those obtained
after immersion.
Statistical analysis
For each property, data obtained were subjected
to two-way ANOVA and the measurements were
compared by the Bonferroni’s test. All statistical
testing was performed at a pre-set alpha of 0.05.
RESULTS
Color stability
The mean values and standard deviations for
1. None of the studied composites exhibited color
change with values above the clinically acceptable
20. With regard to Z250, comparison
of the effects of different mouth rinse solutions
revealed a small color change for specimens
difference compared with the other mouth rinse
solutions (p<0.05). When immersed in Plax Classic
solution, this composite exhibited an intermediate
Commercial name Composition pH Manufacturer
Plax Classic Triclosan, Gantrez, Sodium lauryl sulphate,
phosphate, Sodium saccharine, red dye, ethylic
5.8 Colgate Palmolive Ind. e Com.
Ltda., São Bernardo do
Campo, SP, Brazil
Plax Alcohol-free
Glycerin and Propylene, Sodium methyl taurate,
phosphoric acid, Disodium phosphate, Sodium
saccharine and water
4.96 Colgate Palmolive Ind. e Com.
Ltda., São Bernardo do
Campo, SP, Brazil
Periogard
water, glycerin, ethanol, polysorbate 20, aromatic
sodium saccharine, FD&C blue dye #1
5.0-7.0 Colgate Palmolive Ind. e Com.
Ltda., São Bernardo do
Campo, SP, Brazil
Listerine
Cool Mint
Thymol, eucalyptol, methyl salicylate, menthol,
sodium saccharine, sodium benzoate, green dye
#3
3.7
Paulo, SP, Brazil
Figure 2- Tested mouth rinses
Z250 Z350
Control 1.52 (0.37)a,A 0.96 (0.24)b,AB
Listerine 0.99 (0.29)a,B 1.25 (0.24)a,AC
Plax Classic 1.32 (0.46)a,AB 0.64 (0.23)b,B
Plax alchohol-free 1.42 (0.45)a,A 1.46 (0.30)a,C
Periogard 1.40 (0.71)a,A 0.93 (0.16)b,AB
Table 1-
FESTUCCIA MSCC, GARCIA LFR, CRUVINEL DR, PIRES-DE-SOUZA FCP
2012;20(2):200-5
J Appl Oral Sci. 203
'
With regard to Z350, the highest 'E change was
observed for Plax alcohol-free solution, with
Comparing the composites to each other, it was
for the test specimens immersed in distilled water
(control), with both Plax Classic and Periogard
solutions allowing smaller color changes for Z350.
Surface roughness
The mean values and standard deviations for
surface roughness (Ra) changes are presented
in Table 2. For both composites, the greatest
change in Ra occurred when the samples were
immersed in Listerine solution, with statistically
free (p<0.05). When compared to each other,
difference (p>0.05) regarding any studied mouth
rinse solution.
Knoop microhardness
The mean values and standard deviations for
Knoop microhardness changes are presented in
Table 3. When compared to each other, Z250 and
(p>0.05) regarding any studied mouth rinse
solution. Immersion of Z350 in Plax alcohol-
free solution resulted in greater decrease of
difference in relation to the other mouth rinse
solutions (p<0.05).
DISCUSSION
The variability in our results was consistent
with other studies, which showed that several
factors, including composite resin type, mouth rinse
microhardness of composites28. Therefore, the null
hypothesis could not be accepted.
Color stability can be evaluated both visually
5,8,11. The methodology
used in the present study is according to previous
studies that used spectrophotometry and the CIE
5,11
system was chosen to evaluate color variation ('E)
because it is appropriate for small color changes
determination and have advantages such as
repeatability, sensitivity and objectivity11.
ranging from 1 to 3 are perceptible to the naked
eye18
unacceptable20. Considering these concepts; the
composite resins tested in the present study
demonstrated acceptable color stability when stored
in the different types of mouth rinse solutions
(Table 1).
modulated by its conversion degree and by some
physical properties, such as water sorption2,6.
Water sorption of composite resins depends on the
resinous matrix composition. It has been reported
that water uptake in Bis-GMA based composite
Z250 Z350
Control 44.94 (0.34)a,A 27.60 (0.28)a,A
Listerine 78.46 (0.56)a,AB 61.99 (0.53)a,AB
Plax Classic 38.28 (0.18)a,A 13.36 (0.18)a,A
Plax alcohol-free -4.22 (0.20)a,AC -10.76 (0.27)a,AC
Periogard 64.43 (0.46)a,AB 58.22 (0.34)a,AB
Table 2- Means (standard deviations) for Ra
Z250 Z350
Control 7.30 (0.17)a,A 22.28 (0.18)a,A
Listerine -14.88 (0.10)a,A 1.20 (0.27)a,A
Plax Classic -6.98 (0.08)a,A 15.83 (0.40)a,A
Plax alcohol-free -5.03 (0.23)a,A -25.73 (0.19)a,B
Periogard -0.24 (0.18)a,A 14.80 (0.24)a,A
Table 3-
Color stability, surface roughness and microhardness of composites submitted to mouthrinsing action
2012;20(2):200-5
J Appl Oral Sci. 204
resins increased from 3 to 6%, as the proportion of
TEGDMA increased from 0 to 1%13. UDMA seems to
be more stain resistant than Bis-GMA15, and under
normal curing conditions, UDMA based composite
resins presented lower water sorption and higher
color stability than other dimethacrylates in their
resin matrix15,20, which could be observed in the
present study.
Moreover, it is important that the composite
in the polymer network to minimize the formation
composites. This is especially important regarding
the performance of composites in aqueous
environments, such as mouth rinse solutions,
matrix interface may increase the water sorption
of composites25.
Nanocomposites correspond to a class of
new materials with nanoscale inorganic filler
particles dispersed within the resinous matrix27.
In comparison with microhybrid composites, these
materials have been reported to have improved
properties, such as, elasticity modulus, mechanical
strength and color stability. Furthermore, these
improvements are achieved at low concentrations
generally require high loadings within the range of
60%11,19. This is an important factor in aesthetic
maintenance of non-particulate composites, since
light, which in turn, provides the opacity of the
particle size the greater the light spread, and
consequently, the greater the opacity16. The opacity
of composites increases as the difference between
particles also increases16. In addition, the smaller
absorbed by the polymer network, which results in
lower degradation of the interface matrix/particle,
and consequently, lower color change10. The Z250
to 20 nm, which could explain the greater color
stability for Z35029. Also, according to Kawaguchi,
et al.14 (1994), microhybrid composites present a
various sizes of their particles, which contributed
According to Villalta, et al.30 (2006), the low
pH and alcohol concentration of solutions affect
the surface roughness of composite resins and
cause staining. Nevertheless, the composite
regarding color stability, surface roughness and
microhardness values when the composite was
immersed in the alcohol-free mouth rinse solution
(Plax alcohol-free), thus contradicting the results
of a previous study30. However, Miranda, et al.17
(2011) demonstrated that despite the absence
of alcohol, Plax alcohol-free has phosphoric acid
in its composition, which might alter the polymer
matrix of composites by catalysis of the ester
groups present in the dimethacrylate monomers.
The hydrolysis of the ester groups forms alcohol
and carboxylic acid molecules, which accelerate
polymer network degradation by the decrease of pH
inside the composite matrix10,17. The degradation of
the polymer network leads to a phenomenon called
“plasticization”, which decreases microhardness
values in composites10.
According to the methodology used in the
present study, the negative values regarding
microhardness represent a smoothening of the
resin matrix, and positive values, hardening.
Despite the great decrease in the composite
microhardness (-25.73), the surface roughness
improved when compared to the pre-immersion
values, except when the composite was immersed
in the Plax alcohol-free solution. The same result
in surface roughness was found after immersion
into the same mouth rinse solution. It is worth
emphasizing, however, that there exists a critical
value regarding surface roughness change (Ra
µm). According to Bollen, et al.3 (1997), a greater
caries. Another critical value for Ra is 0.3 µm, which
can be detected when the patient’s lips or tongue
enters in contact with the restorative material,
causing discomfort3. None of the studied composites
showed values for surface roughness change above
the critical limits, irrespective of the type of mouth
rinse solution used.
Asmussen1 (1984) reported that mouth rinse
solutions with high alcohol content might soften
the composite resin, especially Bis-GMA-based
composites. However, Gürgan, et al.12 (1997)
showed that regardless of the alcohol concentration,
both alcohol-containing and alcohol-free mouth rinse
solutions could affect the properties of composite
resins. Immersed of Z350 in Listerine, the mouth
rinse solution with the highest alcohol concentration
(30%), resulted in decrease in microhardness
the other mouth rinse solutions. As for Z250, the
results were the opposite; there was an increase
in the microhardness values when immersed in
Listerine and a decrease when immersed in Plax
difference. These results suggest that changes in
the microhardness of composites do not depend on
mouth rinse’s ethanol concentration12.
FESTUCCIA MSCC, GARCIA LFR, CRUVINEL DR, PIRES-DE-SOUZA FCP
2012;20(2):200-5
J Appl Oral Sci. 205
to color stability. Z350 showed significant
changes when immersed in Listerine and Plax
alcohol-free solutions, both having entirely
different concentrations of ethanol12. However,
this fact could be explained, once again, by the
presence of phosphoric acid in Plax alcohol-free
composition. Studies have reported the release of
by-products from polymer network degradation,
methacrylate molecules, which are capable of
promoting color change in composites4,10,17.
On the other hand, Z250 had greater color
change when immersed in Listerine compared to
the other solutions, unlike Celik, et al.4 (2008), who
found no color change in the composites immersed
in the same mouth rinse solution, despite the high
ethanol concentration.
Clinically, the effect of mouth rinse solutions on
factors that were not replicated in this in vitro
study. Among these factors, saliva could dilute or
buffer pH of mouth rinse solutions, thus reducing
the effect of resinous matrix plasticization10 and
forming a pellicle that could have a protective
effect on the composite surface, thus, decreasing
material staining4. Based on such factors, further
in vivo studies are needed to determine the effects
of mouth rinse solutions on these properties of
composites.
CONCLUSIONS
The results of the present study allow us
to conclude that the changes observed in the
composites depended on the material itself rather
than the mouth rinse solution used.
REFERENCES
1- Asmussen E. Softening of BISGMA-based polymers by ethanol
and by organic acids of plaque. Scand J Dent Res. 1984;92:257-61.
restorative materials. J Dent. 2005;33:389-98.
3- Bollen CM, Lambrechts P, Quirynen M. Comparison of surface
roughness of oral hard materials to the threshold surface
roughness for bacterial plaque retention: a review of the literature.
Dent Mater. 1997;13:258-69.
4- Celik C, Yuzugullu B, Erkut S, Yamanel K. Effects of mouth rinses
on color stability of resin composites. Eur J Dent. 2008;2:247-53.
5- Cruvinel DR, Garcia LF, Consani S, Pires-de-Souza FCP.
Composites associated with pulp-protection material: color-
2010;4:6-11.
6- De Gee AJ, ten Harkel-Hagenaar E, Davidson CL. Color dye for
Dent. 1984;52:626-31.
7- DeVore LR. Antimicrobial mouthrinses: impact on dental
hygiene. J Am Dent Assoc. 1994;2:23S-28S.
8- Dietschi D, Campanile G, Holz J, Meyer JM. Comparison of the
color stability of ten new-generation composites: an in vitro study.
Dent Mater. 1994;10:353-62.
of resin composites after immersion in different drinks. Dent Mater
J. 2006;25:371-6.
10- Ferracane JL. Hygroscopic and hydrolytic effects in dental
polymer networks. Dent Mater. 2006;22:211-22.
11- Gürdal P, Akdeniz BG, Hakan Sen B. The effects of mouthrinses
on microhardness and colour stability of aesthetic restorative
materials. J Oral Rehabil. 2002;29:895-901.
12- Gürgan S, Önen A, Köprülü H. In vitro effects of alcohol-
containing and alcohol-free mouthrinses on microhardness of some
restorative materials. J Oral Rehabil. 1997;24:244-6.
13- Kalachandra S, Turner DT. Water sorption of polymethacrylate
networks: bis-GMA/TEGDM copolymers. J Biomed Mater Res.
1987;21:329-38.
14- Kawaguchi M, Fukushima T, Miyazaki T. The relationship
activated resin composites. J Dent Res. 1994;73:516-21.
15- Khokhar ZA, Razzoog ME, Yaman P. Color stability of restorative
resins. Quintessence Int. 1991;22:733-7.
Dent Mater. 2008;24:1243-7.
17- Miranda DA, Bertoldo CE, Aguiar FH, Lima DA, Lovadino JR.
Effects of mouthwashes on Knoop hardness and surface roughness
of dental composites after different immersion times. Braz Oral
Res. 2011;25:168-73.
18- Noie F, O’Keefe KL, Powers JM. Color stability of resin cements
after accelerated aging. Int J Prosthodont. 1995;8:51-5.
19- Rong MZ, Zhang MQ, Pan SL, Friedrich K. Interfacial effects
in polypropylene-silica nanocomposites. J Appl Polym Sci.
2004;92:1771-81.
20- Ruyter IE, Nilner K, Moller B. Color stability of dental
composite resin materials for crown and bridge veneers. Dent
Mater. 1987;3:246-51.
21- Samra AP, Pereira SK, Delgado LC, Borges CP. Color stability
evaluation of aesthetic restorative materials. Braz Oral Res.
2008;22:205-10.
22- Sarret DC, Coletti DP, Peluso AR. The effect of alcoholic
beverages on composite wear. Dent Mater. 2000;16:62-7.
23- Schneider LF, Moraes RR, Cavalcante LM, Sinhoreti MA,
Correr-Sobrinho L, Consani S. Cross-link density evaluation
through softening tests: effect of ethanol concentration. Dent
Mater. 2008;24:199-203.
24- Shintani H, Satou J, Satou N, Hayashihara H, Inoue T. Effects
of various methods on staining and accumulation of Streptococcus
mutans HS-6 on composite resins. Dent Mater. 1985;1:225-7.
25- Skrtic D, Antonucci JM, McDonough WG, Liu DW. Effect
of chemical structure and composition of the resin phase on
mechanical strength and vinyl conversion of amorphous calcium
phosphate-based composites. J Biomed Mater Res A. 2004,68:763-
72.
26- Tjan AH, Chan CA. The polishability of posterior composites.
J Prosthet Dent. 1989;61:138-46.
27- Ure D, Harris J. Nanotechnology in dentistry: reduction to
practice. Dent Update. 2003;30:10-5.
28- Venturini D, Cenci MS, Demarco FF, Camacho GB, Powers JM.
Effect of polishing techniques and time on surface roughness,
hardness and microleakage of resin composite restorations. Oper
Dent. 2006;31:11-7.
29- Vichi A, Ferrari M, Davidson CL. Color and opacity variations in
three different resin-based composite products after water aging.
Dent Mater. 2004;20:530-4.
30- Villalta P, Lu H, Okte Z, Garcia-Godoy F, Powers JM. Effects of
staining and bleaching on color change of dental composite resins.
J Prosthet Dent. 2006;95:137-42.
Color stability, surface roughness and microhardness of composites submitted to mouthrinsing action
2012;20(2):200-5
