The relationship between the salivary buffer capacity test (CAT21 Buf Test) results and caries status in Mongolian preschool children

Abstract

This study was conducted to investigate the relationship between results of a salivary buffer test (CAT21 Buf Test) and caries status in 507 preschool children, who were 4-6 years old in Ulaanbaatar City, Mongolia. The prevalence of caries in the preschool children was 96.1%, and the mean deft and d teeth were 8.1 and 7.2, respectively. The mean CAT21 Buf Test score was 53.3% for low risk (high buffer capacity) and 46.7% for high risk (low buffer capacity). When salivary buffer score was divided into two groups (high risk, low risk), mean deft differed a significantly between the two groups (ANOVA P<0.001). The high risk group had a mean deft higher than that of the low risk group. These results suggest that the CAT21 Buf Test is useful for clinical application in children. Furthermore, when the CAT21 Buf Test score was higher, a higher correlation was shown with caries status.Key words Dental caries, Salivary buffer test (CAT21 Buf Test). © 2005, The Japanese Society of Pediatric Dentistry. All rights reserved.

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PEDIATRIC DENTAL JOURNAL 15(1): 115–119, 2005
115
Received on October 1, 2004
Accepted on December 28, 2004
The relationship between the salivary buffer capacity test
(CAT21 Buf Test) results and caries status
in Mongolian preschool children
Bazar Oyuntsetseg, Yoshihide Okazaki and Tsutomu Shimono
Department of Behavioral Pediatric Dentistry,
Graduate School of Medicine and Dentistry, Okayama University
2-5-1 Shikata-cho, Okayama 700-8525, JAPAN
Abstract This study was conducted to investigate the relationship between
results of a salivary buffer test (CAT21 Buf Test) and caries status in 507
preschool children, who were 4–6 years old in Ulaanbaatar City, Mongolia.
The prevalence of caries in the preschool children was 96.1%, and the mean
deft and d teeth were 8.1 and 7.2, respectively. The mean CAT21 Buf Test score
was 53.3% for low risk (high buffer capacity) and 46.7% for high risk (low
buffer capacity). When salivary buffer score was divided into two groups
(high risk, low risk), mean deft differed a significantly between the two groups
(ANOVA P⬍0.001). The high risk group had a mean deft higher than that of
the low risk group. These results suggest that the CAT21 Buf Test is useful for
clinical application in children. Furthermore, when the CAT21 Buf Test score
was higher, a higher correlation was shown with caries status.
organism is compelled to react against them. The
most effective reaction is neutralization of the acids
by saliva buffers, in much the same way that the
organism protects itself against internal pH variations
by blood buffering. The relationship between buffer
capacity and caries activity has been of interest to
many researchers21–23). Our knowledge of the functions
of individual bacterial and salivary constituents and
their interactions has increased enormously in recent
years24–26). We now have a better understanding of
their diagnostic importance in the determination
of caries activity27,28). Salivary diagnostics is now
entering the realm of modern dentistry.
The aim of the present study was to investigate
the relationship between the results of the CAT21
Buf Test and caries status in Mongolian preschool
children.
Materials and methods
Subjects of study
Five hundred seven preschool children aged 4–6
Introduction
Saliva is one of the most important host factors,
since it performs many functions that directly or
indirectly affect general oral health and dental
caries
1–6)
. One such function is buffering, and another
is passive host defense against caries7–11). These
protective characteristics of saliva depend mainly
on its mechanical cleansing action the dilution and
neutralization of plaque acid by buffering system,
particularly bicarbonates. The role of saliva in the
process of dental caries is well known12–17). Dreizen
et al. have demonstrated that concentration of saliva
buffers varies in relation to number of caries18).
Stephan demonstrated that the teeth are decalcified
in a medium with a maximum pH of 5.019). These
findings were corroborated by Muracciole et al.20)
Based on these findings, we are of the opinion that
when acids are formed in the mouth, the host
Key words
Dental caries,
Salivary buffer test
(CAT21 Buf Test)

116 Oyuntsetseg, B., Okazaki, Y. and Shimono, T.
years old, in Ulaanbaatar City, Mongolia, were
randomly selected.
Methods
a. Dental examination
Dental examination was conducted by one dentist
under natural light with the aid of a dental mirror
and probe. The results were designated using the
“deft” system (decayed (d), extracted (e), filled (f),
teeth (t)) according to WHO standard criteria.
b. Salivary buffer capacity test
(CAT21 Buf Test, Morita Co., Japan)
Since sample collection could not be restricted to
a specific time of day, collection was randomly
between performed 9:00 a.m and 12:00 p.m (noon)
at a kindergarten. There was no of any sex or group
(caries and control) in any given hour within the
collection period. The majority of collections were
performed from two to four hours after intake of
food or beverage (minimum of one hour). All
procedures were completed by one investigator.
The children were given a simple explanation of
the nature and reasons for the test before collecting
saliva samples. Each child chewed on a pellet
(unflavored gum, CAT21 Buf Test, Morita Co.,
Japan) for three minutes. Their stimulated whole
saliva was then collected before dental examination.
All samples were analyzed immediately after
collection. One ml of saliva was added to the buffer
test ampoule (Figure 1), covered and mixed. The
resulting color was compared with the color chart
and divided into two groups. The color chart has a
pH scale ranging from 4.0–6.5. A yellow or orange
color result signifies high risk group (low buffer
capacity, pH4.0–5.5), and red or purple, a low risk
group (high buffer capacity, pH 5.8–6.5) (Figure 2).
All data were analyzed using the SPSS (Statistical
Package for the Social Sciences) software. Statistical
significance of differences was determined using
non-parametric partial correlation analysis and
ANOVA.
Results
Prevalence of caries in the subjects was 96.1%. The
meanⳲSE for decayed teeth (dt) and def-teeth were
7.21Ⳳ0.18 and 8.13Ⳳ0.19, respectively. The mean
value for extracted teeth (et) was 0.26Ⳳ0.03 and
filled teeth (ft) was 0.62Ⳳ0.05.
Results of the CAT21 Buf Test (Figure 3) were
as follows: 53.3% (n⳱270) of the subjects had
CAT21 Buf Test scores of low risk (high buffer
capacity), and 46.7% (n⳱237) had high risk (low
buffer capacity). Figure 4 shows the correlation
between CAT21 Buf Test scores and decayed teeth
(dt): low risk group with mean dt 6.80Ⳳ0.24 and
high risk group with mean dt 7.68Ⳳ0.26. It can,
therefore be concluded that the mean dt will increase
with decrease of the salivary buffer capacity. A
statistically significant correlation was detected
between decayed teeth and buffering capacity of
saliva (ANOVA P⬍0.001). The high risk group
Fig. 1 CAT21 Buf Test Kit
Fig. 2 CAT21 Buf Test colorimetric scale
1ml
indicator
line
test
ampoule
collection
cup
chewing
pellet
pipette
6.5 4.06.2 6.0 5.8 5.5 5.2 5.0 4.8 4.5
High buffer capacity
(red or purple)
Low buffer capacity
(yellow or orange)
Fig. 3 Distribution of CAT21 Buf Test scores in preschool
children

117
PREVENTION OF DENTAL CARIES
had the highest mean extracted teeth (et) (Figure 5).
Figure 6 shows the correlation between CAT21 Buf
Test scores and the filled teeth (ft). No significant
difference was observed between “e” and “f” teeth
and buffering capacity of saliva. Figure 7 shows the
correlation between CAT21 Buf Test scores and
deft. The mean deft was 7.65Ⳳ0.26 (SE) among
subjects with CAT21 Buf Test scores of low risk,
and 8.68Ⳳ0.28 (SE) for those with high risk. It can,
therefore be concluded that deft will increases with
increase in CAT21 Buf Test scores. Also it means
that high risk group (low buffer capacity) had a high
deft. A significant difference was found between
deft and buffering capacity of saliva (ANOVA
P⬍0.001).
Discussion
Better understanding and analysis of caries activity
in preschool children are helpful to the prevention
and treatment of caries. Newbrun has stated that the
only salivary factor which correlates with certainty
with the development of dental caries is buffering
capacity29). We compared the caries status of 507
children aged 4–6 years with CAT21 Buf Test
scores. This is the first such report in Mongolia. Our
results serve as reference and should be valuable for
the prevention and treatment of caries in preschool
children. In this study, significant differences were
found between CAT21 Buf Test scores and respect
to dt and deft. Based on the above results, it can be
ascertained that the CAT21 Buf Test is effective in
predicting caries activity. Okazaki et al.24) investigated
CAT21 Buf Test scores which showed a significant
correlation with dt (ANOVA P⬍0.05). The present
results confirm this finding. In present study, the
caries status was found to be higher, and 46.7% of
the children were found to have low buffer capacity.
Similar results have been reported for Japanese
preschool children27).
Many investigators have attempted to correlate
dental caries activity with salivary buffer capac-
ity8,15–18,22,28). Buffer effect varies among individuals,
and low or extremely low buffer capacity has been
Fig. 7 Correlation between CAT21 Buf Test scores and deft
Fig. 4 Correlation between CAT21 Buf Test scores and d teeth
Fig. 5 Correlation between CAT21 Buf Test scores and e teeth
Fig. 6 Correlation between CAT21 Buf Test scores and f teeth

118
reported to correlate with increased dental caries10).
We can compare an unbuffered system to a system
buffered with saliva or blood. When a very small
quantity of hydrochloric acid is added drop by drop
into distilled water, and the pH decreases quickly.
However, when added it is saliva or blood, the pH
remains stable. This demonstrating that body fluid
exhibits a defense reaction and buffering action
system when subjected to environmental influences.
Thus, salivary buffer capacity tests are able to
predict caries activity. The CAT21 Buf Test ampoule
has a dry powder reagent (lactic acidⳭpH indicators)
which is activated when 1.0ml distilled water is
added and the pH becomes 2.5. In this case study,
saliva is added to the mixture. If the pH of lactic
acid is 2.5, one needs to add 100 ml distilled water
to raise the pH to 4.5 (yellow color, low buffer
capacity). Consequently, a pH of 5.2 (orange color,
medium buffer capacity), 6.0 (red color, high buffer
capacity), and 6.5 (purple red color, high buffer
capacity) would require the addition of 510, 3,200,
and 10,000 ml of distilled water, respectively. In
other words, to raise the pH back to 6.0, we need
saliva in an amount equivalent tooth 3,200 times
more water.
The findings of this study, indicate that low
salivary buffer capacity is associated with a higher
mean deft (Figure 7). There is evidence in the
literature suggesting that the buffer capacity of
saliva is one of the best indicators of caries
susceptibility, since it reveals the degree of host
response8,24,28). Individuals with high buffer capacity
are often quite resistant to the process of caries
because high host response can compensate for
active caries habits3,9,20). In other studies, CAT21 Buf
Test score has been found to be a good predictor of
caries activity based on the high correlation between
prevalence of caries and activity
22,24,26–28)
. Our finding
with respect to buffer capacity also agree with those
of other studies8,9,19). Some investigators have reported
that the buffer test is useful for clinical application
among preschool and schoolchildren16,17,26–28). Some
investigators have suggested using an inert material
such as paraffin wax or rubber bands for chewing with
standard weight (1–5 g, M.Pⳮ42°C) at a constant
rate (about 70 chews/minute). A metronome is
usually used for mechanical stimulation8,9,14,20). In
the CAT21 Buf Test, a chewing pellet is used. It is
a spherical, unflavored gum 10mm in diameter and
0.8 g in weight. This chewing method is effective in
schoolchildren, and particularly suitable in preschool
children. We know for certain whether an enamel
surface is carious or not, but we do not know
whether the process of caries is in progress or
arrested whether the lesion is merely a sign of
caries in the past. The predictive value of certain
salivary tests can help to reduce such uncertainties
in clinical dental practice. Salivary buffer capacity
is very important in the development of caries with
respect to attacking and defensive factors. This study
ascertained the correlation between caries status
and salivary buffer capacity, and showed that a low
buffer capacity is associated with a high deft. The
CAT21 Buf Test appears to be a clinically useful
method for improving our ability to predict the
progression of caries in children at an earlier stage.
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