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15
Padjadjaran Journal of Dentistry 2013;25(1):15-20.
Corresponding author: Anisya Pramesti, Department of Oral Biology Faculty of Dentistry Universitas Padjadjaran
Sekeloa Selatan No.1 Bandung, West Java-Indonesia, Ph./Fax.: +6222-2504985/2532805
Teeth re-whitening eect of strawberry juice on coee
stained teeth
Anissya Pramesti*, Tadeus Arufan Jasrin*, Opik Taok Hidayat**
*Department of Oral Biology Faculty of Dentistry Universitas Padjadjaran
**Department of Conservative Dentistry Faculty of Dentistry Universitas Padjadjaran
ABSTRACT
Many people favor coee. However, regarding health and aesthetic dentistry, coee gives a
negative eect. Tanin in coee causes a brown stain on the tooth surface. Therefore, in aesthetic
dental care, teeth whitening has become popular matter. One of the natural ingredients used for teeth
whitening treatment is strawberry. The purpose of this study was to obtained data regarding the eect of
strawberry juice on the re-whitening process of the coee-stained tooth enamel surface. This study was
a pure experimental in-vitro using Friedman and Wilcoxon Matched Pairs Tests for statistical analysis. The
population of this study was anterior teeth. The samples were maxillary central incisors. The sampling
technique using sample size determination based on the testing formulas of the dierence of two
average data pairs resulted in 11 specimens. The result of the research showed that all coee-stained
teeth sample had an increasing enamel colour index. The samples were then applied with strawberry
juice resulted in a signicant average dierence colour index value indicated by p<0.001. The conclusion
of this research indicated that there was an eect of strawberry juice on the coee-stained teeth re-
whitening process.
Keywords: Strawberry juice, coee stained, teeth whitening.
INTRODUCTION
Coee is one of the most popular beverages
for many people. Coee has become a very
lucrative business. Coee is a type of beverage
derived from the processing and extraction of
the coee beans contains high concentration of
caeine.1 Caeine is a compound resulted from
the alkaloid secondary group metabolism of the
coee plant.2 The role of caeine inside the body
system is to increase the psychomotor function
thus makes the body stay awake and provide
physiological eects by energy increased,3
reduce the risk of cancer, diabetes, gallstones,
and cardiovascular disease.4 However, regarding
aesthetical aspect in dentistry, coee gives a
negative eect. The tannin deposits present
in coee cause brown staining on the buccal,
lingual, labial, and palatal surfaces of teeth.5 This
condition will aect individual appearances and
may decrease condence.
Nowadays, the general population chooses
modern dentistry to improve facial aesthetics,
health, and social success.6 Techniques and
materials available for dentists have also developed
rapidly. This fact supports a better and more
16
Teeth re-whitening eect of strawberry juice on coee stained teeth (Anissya Pramesti et al.)
conservative restoration. Much attention has been
devoted towards aesthetical dentistry aspects and
individual attention on physical appearances.7
The white tooth color associated with
healthiness, young age, and strength. A recent
survey of American women showed that 55% of
women aged 34-55 years old would undergo the
teeth whitening or orthodontic treatment to
create a younger appearance.8 One development
of aesthetic dentistry was the teeth whitening.9
Many manufacturers produce teeth
whitening products. However, these products
containing chemical compounds and often used
publicly without any supervision from the dentist.
On the other hand, much information regarding
non-synthetic materials that have the potential
for teeth whitening. One of them is strawberries.10
Strawberries belong to the herbaceous
fruit plants and belong to the family of Rosaceae.
Strawberries (Fragaria sp.) Is one of many fruits
consumed due to its rosy red color, sweet and sour
taste, and various benets. This fact is based on the
growing number of people consuming strawberries
in both fresh and processed conditions.11
Strawberries have various benets, including
the ability to prevent coronary heart disease
and controlling high blood pressure. Strawberry
is also useful in assisting the absorption of iron
from vegetables consumed. Strawberry contains
only a small amount of sugar, so it is appropriate
to be consumed by people with diabetes.
Also, strawberries can be used to make a more
beautiful and healthy skin and improving brain
power and vision.12 Based on these properties,
we are interested in researching the eectivity of
strawberry juice as the bleaching agent for the
coee stained tooth enamel surface.
METHODS
This research was a purely experimental in-
vitro. The population of this study was anterior
teeth. The sample of this study was maxillary
central incisors. The inclusion criteria were
extracted permanent human teeth without
abnormalities and caries-free. Independent
variable in this study was the strawberry juice
application, and the dependent variable was the
tooth color index.
Data obtained from the results of the color
change measurements then analyzed statistically
using the Friedman and Wilcoxon matched
pairs signed-rank test.13 The data used was the
data score, then the Wilcoxon test was used to
determine dierences between observation
groups.13 The Friedman Test was used to compare
the average dierence in more than two groups of
paired data.
RESULTS
The research conducted on the eects of
strawberry juice as the bleaching agent of coee
stained tooth enamel surface was performed
towards as much as 11 anterior mandibular central
incisor specimens. The study was conducted
through three stages of the working procedure
such as follows: specimen control; coee staining
or discolouring of specimens; and application of
strawberry juice towards the specimens. For the
Table 1. Comparison of tooth enamel surface colour index from each treatment
No. Procedure Mean Standard Deviation Median Range
1 Original Color 6.36 3.139 63 – 10
2Discoloration by coee 8.91 3.448 66 - 13
3Strawberry juice application Day 1-1 6.09 3.3 63 - 10
4Strawberry juice application Day 1-2 4.64 1.567 63 - 6
5Strawberry juice application Day 2-1 3.91 1.758 31 - 6
6Strawberry juice application Day 2-2 2.15 0.934 31 - 3
7Strawberry juice application Day 3-1 2.45 0.934 31 - 3
8 Strawberry juice application Day 3-2 2.09 1.044 31 - 3
9Strawberry juice application Day 4-1 2.09 1.044 3 1 - 3
10 Strawberry juice application Day 4-2 2.09 1.044 31 - 3
Notes : X2 (Friedman) = 86.377; p<0.001
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Padjadjaran Journal of Dentistry 2013;25(1):15-20.
control specimens, the procedure was performed
by immersing the eleven specimens in articial
saliva for 24 hours, then the discolouration
procedure was performed by immersing the
specimen in the coee solution for 48 hours.
For the treatment specimens, the procedure
was performed by applying the strawberry
juice towards the specimens for 4 days. Both
procedures were performed twice daily. The
study was conducted by observing discolouration
of the tooth enamel on the labial surface
each day, which assessed using a shade guide.
The results from the comparison test of the
tooth enamel surface color index and its original
color, after discolouring process and after applied
with strawberry juice, were presented in Table 1.
From the collected data, the average statistical
measure, standard deviation, and the median
value were calculated. The Wilcoxon Matched-
Pairs Signed Test was used to determine the
dierences between the observations, and the
results were presented in Table 2.
Figure 1. Average of tooth enamel surface colour index decrease in all specimens
Tabel 2. Comparison of the colour index between all specimens after application
No Inter Group Comparison Z (Mann-Whitney) P-value
1 Original colour with Coee-stained 2.007 0.004
2Original colour with Strawberry juice application 1–1 0.272 0.785
3Original colour with Strawberry juice application 1–2 2.121 0.034
4Coee-stained with Strawberry juice application 1-1 2.007 0.004
5Coee-stained with Strawberry juice application 1-2 2.059 0.004
6Strawberry juice application 1-1 with Strawberry juice application 1-2 2.00 0.046
7Strawberry juice application 1-2 with Strawberry juice application 2-1 0.046 0.102
8 Strawberry juice application 1-2 with Strawberry juice application 2-2 1.633 0.006
9Strawberry juice application 2-1 with Strawberry juice application 2-2 2.762 0.023
10 Strawberry juice application 2-1 with Strawberry juice application 3-1 2.271 0.023
11 Strawberry juice application 2-2 with Strawberry juice application 3-1 2.271 1.0
12 Strawberry juice application 2-2 with Strawberry juice application 3-2 0 0.157
13 Strawberry juice application 2-2 with Strawberry juice application 4-1 1.414 0.157
14 Strawberry juice application 2-2 with Strawberry juice application 4-2 1.414 0.157
15 Strawberry juice application 3-1 with Strawberry juice application 3-2 1.414 0.157
16 Strawberry juice application 3-1 with Strawberry juice application 4-1 1.414 0.157
17 Strawberry juice application 3-2 with Strawberry juice application 4-1 1.414 1.0
18 Strawberry juice application 4-1 with Strawberry juice application 4-2 0 1.0
Notes: signicant in p<0.05; very signicant in p<0.001
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Teeth re-whitening eect of strawberry juice on coee stained teeth (Anissya Pramesti et al.)
Based on Table 1 and Figure 1 can be seen
that from the total of 11 specimens that have
been discolored by the coee solution, there was
an increase in the tooth enamel surface color
index. For the result in the treatment group, from
the total specimen that has been discolored by
the coee solution, there was a decrease in the
average of the colour index value after being
applied with strawberry juice. However, a decrease
in the colour index values was only up to the third
day of treatment and did not change signicantly
on the fourth day of treatment and after.
Furthermore, based on the Friedman’s
Chi-Square test results obtained the X2=71.113,
p<0.001. These data indicated that the comparison
of the average dierence between more than two
specimen groups was very signicant. Thus seen
that the treatment was eectively decreasing the
average color index level for all the study samples.
According to Table 2, the comparison
between the initial object group and the group
being discoloured with coee solution showed
a signicant dierence (p<0.05). Comparison
between coee-stained specimen groups with
the group already being applied with strawberry
juice also showed signicant dierences on the
rst day of treatment. Furthermore, a signicant
dierence was also observed in the comparison
between the group of strawberry juice application
on the rst day with the group of second-day
strawberry application.
DISCUSSION
From the results of this study can be
inferred that strawberry juice was able to act as
the bleaching agent for the coee-stained tooth
enamel surfaces. Discolouration of the tooth
enamel surfaces is evident of increasing colour
index value after immersed in the coee solution.
By the statement of Kerr5 that the tannin deposits
presence in coee causes brown staining on the
buccal, lingual, labial, and palatal surfaces of
the teeth. Coee-stained tooth enamel surfaces
discolouration is an exogenous color change. This
is consistent with the statement of Osborn and
Ten Cate14 which suggested that tooth enamel has
an ultramicroscopic slit and has semipermeable
properties that can absorb the color from the
outside like some food and beverage colouring
(coee, tea, soft drinks, etc.).
The tooth-whitening eect of fruit juice
can be characterized by the results of this study
which show the average tooth enamel surface
color index from all specimens were decreasing
signicantly after immersed in strawberry juice.
This result was consistent with Williams’s15
statement which suggested that example of the
natural tooth-whitening procedure was performed
by consuming some fruit that has the ability to
whiten teeth. Goldstein and Garber16 suggested
that teeth-whitening occurred by the strong
oxidizing properties of the bleaching agent. This
oxidizing agent has free radicals with unpaired
electrons thus make the bleached substance
received the electron and oxidized.
Research conducted by Ayub17 stated
that strawberries contain various vitamins and
minerals, and also ellagic acid. Strawberries
had an acid pH degree, ranged from 3-4. Ellagic
acid is built by many OH clusters, according to
Gunawan’s18 research stated that the OH cluster
formed the ellagic acid structure has the potential
of becoming a strong oxidizing agent as well as
hydrogen peroxide as the tooth-whitener.
The results of this study were consistent
with the research conducted by Carrel19 suggested
that strawberries consumption can help removing
Figure 2. Decrease in colour index score after application
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Padjadjaran Journal of Dentistry 2013;25(1):15-20.
tooth discolouration caused by wine, soda, and
coee. The natural ingredients tooth-whitening
eect takes place when consumed in the proper
time, concentration, and period.
More research on the use of strawberry juice
for teeth whitening is still needed. Consumption
of strawberry juice provides a bleaching eect
due to its acidic properties, working as a strong
oxidizing agent on the enamel surface of the
tooth. Thus the side eects caused by the acidic
property of the strawberries can be minimized
and safer to use in the future.
According to Winston and Bhaskar,20 if an
acidic material with the pH value less than equal
to the critical value met the enamel surface, it
will decreased the enamel surface pH value, then
shed the phosphate (PO43-) and calcium (Ca2+)
from the enamel surface. The acidity decrease on
the enamel surface caused by an acidic material,
such as fruit juice, resulted in unsaturation
of important ions, PO43- and Ca2+, which are
minerals of the tooth. This condition leads to
enamel dissolution.
In this study, when the tooth enamel surface
was applied with an acidic material under the
critical pH value of the enamel repeatedly, the
enamel surface pH value was decreasing into the
lower value, thus made the mineral dissolution
continue. The same result also found in Larsen’s21
research suggested that saturated properties of
calcium and phosphate at the low pH value prevent
remineralization. As the pH value increases again,
remineralization will begin. The saturated nature
of saliva was expected to stimulate the process
of hydroxyapatite remineralization on the tooth
enamel surface. Saliva protein compounds also
play a role in maintaining this balance.
The use of articial saliva in in-vitro
studies simulates similar chemical conditions in
the oral cavity. This treatment was consistent
with the study conducted by Leung and Darvell22
suggested that the development of articial
saliva was essential for more valid and controlled
experiment as the standardization of the object’s
concentration for application.
CONCLUSION
The conclusion of this research indicated
that there was an eect of strawberry juice on
the coee-stained teeth re-whitening process.
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