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Unstimulated salivary flow rate, pH and buffer capacity of saliva in healthy volunteers



To assess the salivary flow rate, pH, and buffer capacity of healthy volunteers, and their relationships with age, gender, obesity, smoking, and alcohol consumption, and to establish the lower-end value of normal salivary flow (oligosialia). A prospective study was conducted in 159 healthy volunteers (age > 18 years, absence of medical conditions that could decrease salivary flow). Unstimulated whole saliva was collected during ten minutes, and salivary flow rate (ml/min), pH, and bicarbonate concentration (mmol/l) were measured using a Radiometer ABL 520. The 5 percentile of salivary flow rate and bicarbonate concentration was considered the lower limit of normality. Median salivary flow rate was 0.48 ml/min (range: 0.1-2 ml/min). Age younger than 44 years was associated with higher flow rates (OR 2.10). Compared with women, men presented a higher flow rate (OR 3.19) and buffer capacity (OR 2.81). Bicarbonate concentration correlated with salivary flow rate. The lower-end values of normal flow rate and bicarbonate concentration were 0.15 ml/min and 1.800 mmol/l, respectively. The presence of obesity, smoking, and alcohol consumption did not influence salivary parameters. In healthy volunteers, salivary flow rate depends on age and gender, and correlates with buffer capacity. Obesity, smoking, and alcohol use do not influence salivary secretion.
Objectives: to assess the salivary flow rate, pH, and buffer ca-
pacity of healthy volunteers, and their relationships with age, gen-
der, obesity, smoking, and alcohol consumption, and to establish
the lower-end value of normal salivary flow (oligosialia).
Methods: a prospective study was conducted in 159 healthy
volunteers (age > 18 years, absence of medical conditions that
could decrease salivary flow). Unstimulated whole saliva was collect-
ed during ten minutes, and salivary flow rate (ml/min), pH, and bi-
carbonate concentration (mmol/l) were measured using a Radiome-
ter ABL 520. The 5 percentile of salivary flow rate and bicarbonate
concentration was considered the lower limit of normality.
Results: median salivary flow rate was 0.48 ml/min (range:
0.1-2 ml/min). Age younger than 44 years was associated with
higher flow rates (OR 2.10). Compared with women, men present-
ed a higher flow rate (OR 3.19) and buffer capacity (OR 2.81). Bi-
carbonate concentration correlated with salivary flow rate. The
lower-end values of normal flow rate and bicarbonate concentra-
tion were 0.15 ml/min and 1.800 mmol/l, respectively. The pres
ence of obesity, smoking, and alcohol consumption did not influ-
ence salivary parameters.
Conclusions: in healthy volunteers, salivary flow rate depends
on age and gender, and correlates with buffer capacity. Obesity,
smoking, and alcohol use do not influence salivary secretion.
Key words: Saliva. Salivary flow rate. Salivary buffer capacity.
Fenoll-Palomares C, Muñoz-Montagud JV, Sanchiz V, Her
reros B, Hernández V, Mínguez M, Benages A. Unstimulated
salivary flow rate, pH, and buffer capacity of saliva in healthy
volunteers. Rev Esp Enferm Dig 2004; 96: 773-783.
Saliva plays a critical role in oral homeostasis, as it
modulates the ecosystem within the oral cavity (1). Lu-
brication of the alimentary bolus, protection against
virus, bacteria and fungi, buffer capacity, protection and
repair of the oral mucosa, and dental remineralization are
some of the functions of saliva (2-4). Taking this into ac-
count, quantitative and/or qualitative alterations in sali-
vary secretion may lead to local (caries, oral mucositis,
candidiasis, oral infections, chewing disorders) or extra-
oral (dysphagia, halitosis, weight loss) adverse effects (5-
Xerostomia or “dry mouth” is usually the clinical ex-
pression of decreased salivary secretion; however, it may
occur without a low salivary flow rate (8).
Xerostomia is a common condition (9) that leads pa-
tients to visit many specialist clinics (gastroentrologists,
dentists, internal medicine doctors), as it may develop in
many local and systemic diseases (Sjögren’s syndrome,
diabetes mellitus, drug exposures, radiation to the head or
neck) (10-13); nevertheless, in older patients xerostomia
may develop in the absence of any disease (14-15), which
may be explained by an ageing-related decrease in sali
vary secretion.
It has been suggested that ageing leads to a decrease in
salivary flow rate as a consequence of parenchymal atrophy
(16-21). Alternatively, some authors showed that healthy
old people had a normal salivary flow rate with a great
functional reserve, mainly in the parotid glands (22-26).
The buffer capacity of saliva is an important factor,
which plays a role in the maintenance of salivary pH,
and in dental remineralization. The buf
fer capacity of
saliva basically depends on bicarbonate concentration
(27); it correlates with salivary flow rate (28), as any
factor decreasing salivary flow rate tends to decrease its
fer capacity and to increase the risk of caries devel
opment (29).
Unstimulated salivary flow rate, pH and buffer capacity of saliva
in healthy volunteers
C. Fenoll-Palomares, J. V. Muñoz-Montagud
, V. Sanchiz
, B. Herreros
, V. Hernández
, M. Mínguez
A. Benages
Medicina Familiar y Comunitaria. Centro de Atención Primaria. Rafelbunyol, Valencia.
Centro de Especialidades.
Burjassot. Valencia.
Service of Gastroenterology. Hospital Clínico Universitario. Universitat de Valencia, Spain
Copyright © 2004
Vol. 96. N.
° 11, pp. 773-783, 2004
Supported in part by a grant from the Instituto de Salud Carlos III (03/02).
Recibido: 24-06-04.
Aceptado: 30-06-04.
Correspondencia: Adolfo Benages. Servicio de Gastroenterología. Hospital
Clínico Universitario. Avda. Blasco Ibañez, 17. 46010 Valencia. e-mail:
Other factors that may influence salivary flow rate and
the buffer capacity of saliva are gender, smoking status,
and alcohol consumption. Women show a lower salivary
flow rate (30-32) and decreased buffer capacity (29). The
relationship between salivary secretion and smoking or
alcohol consumption is controversial, as normal secretion
and the presence of hyposialia have both been reported
The aim of this study was to analyze unstimulated sali-
vary flow rate, salivary pH, and salivary buffer capacity
in a group of healthy subjects, as well as their relation-
ship with age and gender, together with other individual
factors (obesity, smoking status, alcohol consumption), in
order to establish normal ranges in the healthy population
in our area.
An observational prospective study on healthy volun-
teers who signed an informed consent, from April 1998
to May 2000. Volunteers were included if they were older
than 18, did not suffer from acute or chronic diseases of
the oral mucosa or salivary glands, did not complain of
“oral dryness” or “oral burning”, did not suffer from
acute infectious diseases, systemic illness or cardiac, re-
nal, respiratory or hepatic failure, and had not received
therapeutic radiation to the head or neck region; women
were not to be pregnant or were using safe contraceptive
methods (except anovulatories). Volunteers were exclud-
ed from the study if they did not meet inclusion criteria or
did not sign an informed consent.
Every patient was explored by the same stomatologist
to rule out acute or chronic diseases of the oral mucosa or
salivary glands. Demographic features were collected
(age, gender
, height, and weight), as well as smoking sta
tus and alcohol consumption. In each patient the body
mass index was determined, and if greater than 30 the
subject was considered obese (38). The subject was con-
sidered a smoker if he smoked, regardless of the number
of cigarettes, and an alcohol consumer if alcohol intake
was greater than 60 g/day in men or 40 g/day in women.
Study of salivar
y secr
The study of salivary secretion was performed without
any stimulus in the morning (9 to 11 a.m.), under stan-
dard temperature and humidity conditions. All subjects
refrained from eating, drinking or smoking for a mini-
mum of 2 h before saliva collection.
Subjects were comfortably seated and, after a few
minutes of relaxation, they were trained to avoid swal-
lowing saliva and asked to lean forward and spit all the
saliva they produced for 10 minutes into a graduated test
tube, through a glass funnel. The whole volume collected
for 10 minutes was then measured.
To determine salivary pH and bicarbonate concentration,
an analyzer Radiometer ABL 250 was used. To diminish
the error probability, each sample was analyzed three times,
and the mean value was assumed to be the real one.
We analyzed the following variables of salivary secre-
tion: salivary flow rate (ml/min), macroscopic appear-
ance (transparent, turbid or bloody), pH, and buffer ca-
pacity expressed as bicarbonate concentration (mmol/l).
Statistical study
A descriptive analysis of variables was performed. To
assess the normal distribution of quantitative variables, a
Kolmogorov-Smirnov test was used. Variables with a nor-
mal distribution were compared using Student’s t test or an
ANOVA test (when comparing more than two groups).
Non-parametric tests (Mann-Whitney U, Kruskal-Wallis)
were used to compare variables without a normal distribu-
tion. To assess the correlation between quantitative vari-
ables, Pearson’s coefficient was used. A Chi-square test
was used to compare qualitative variables. Variables which
obtained a p value less than 0.1 were included in a multi-
variate analysis (logistic regression, step forward method).
Statistical significance was assumed if p < 0.05. The statis-
tical analysis was performed with an SPSS 11.5 pack for
Windows (SPSS Inc., Chicago, Illinois).
One hundred and fifty-nine patients made up the study
group (52 males, 107 females) (Table I). Age was similar
for both men and women (p = 0.796); obese people were
younger than non-obese individuals (31.94
± 9.64
45.52 ± 14.03 years, p < 0.001); smokers were younger
than non-smokers (36.85 ± 11.75
vs 46.69 ± 14.18 years,
p < 0.001); subjects who did not drink alcohol were older
than those with alcohol consumption (45.46 ± 14.56
± 9.54 years, p = 0.001).
y flow rate, pH and buf
fer capacity of saliva
Features of saliva are shown in table I. Unstimulated
salivary flow rate does not present a normal distribution.
According to Navazesh (39), who defined hyposialia
(basal flow rate equal or less than 0.16 ml/min), only
eight subjects (5.03%) were under this level; these sub-
jects, compared with those with a normal flow rate, have
a lower pH (6.5390 ± 0.3605
vs 6.8036 ± 0.2782, p =
1) and a lower bicarbonate concentration (3.5625
3.0654 mmol/l
vs 5.8611 ± 2.7248 mmol/l, p = 0.022). In
the subjects with hyposialia, the aspect of saliva was
more frequently turbid (6/8 subjects).
REV ESP ENFERM DIG 2004; 96(11): 773-783
A significant positive correlation was found between
salivary flow rate, pH, and bicarbonate concentration (r =
0.322, p < 0.001, and r = 0.425, p < 0.001, respectively),
and between pH and bicarbonate concentration (r =
0.736, p = 0.001).
Relationship between salivary parameters and
demographic variables
Men showed a greater flow rate than women (median
0.57 ml/min, range 0.15-2
vs 0.42 ml/min, range 0.10-2,
p < 0.001). Between men and women no differences were
found in salivary pH (6.8400 ± 0.3199 in men
vs 6.7661
± 0.2686 in women, p = 0.128), but men’s buffer capacity
was higher (6.626 ± 3.1239 mmol/l
vs 5.3171 ± 2.4989
mmol/l, p = 0.010).
To analyze the role of age, percentiles 25 and 75 were
determined (32 and 54 years, respectively). We found that
older patients presented a significant lower salivary flow
rate (Table II), but no differences were found in pH or
buffer capacity between these three age groups (Table III).
Age correlated significantly with flow rate (r = -0.222, p =
0.005), but not with pH (r = -0.106, p = 0.185) or bicar-
bonate concentration (r = -0.030, p = 0.710).
Salivary variables in obese subjects, smokers or alco-
hol consumers did not differ from those in non-obese,
non-smoking or non-alcohol consuming volunteers (Ta-
bles II and IV).
Vol. 96. N.
REV ESP ENFERM DIG 2004; 96(11): 773-783
Table I. Characteristics of the study group
Demographic variables
159 healthy volunteers; mean age 44.16
± 14.23 years (range 18-75)
Gender 52 men (44.58 ± 13.15 years) and 107
women (43.95 ± 14.78 years)
Obese 17 subjects (10.69%)
Smokers 41 subjects (25.78%)
Alcohol consumers 24 subjects (15.09%)
Salivary variables
Salivary flow rate Median 0.48 ml/min (range 0.10-2). Per-
centile 5 = 0.15 ml/min
pH 6.7903 ± 0.2874 (range 5.8590-7.5400)
Bicarbonate concentration 5.7455 ± 2.7783 mmol/l (range 0.3000-
Percentile 5 = 1.800 mmol/l
Macroscopic appearance Transparent in 88 subjects (55.3%)
Turbid in 61 subjects (38.3%)
Blody in 10 subjects (6.3%)
Table II. Salivary flow rate according to age, obesity, smok-
ing status and alcohol consumption
Salivary flow rate (ml/min)
Percentile Percentile Percentile Range p
25 50 75
A (41) 0.39 0.54 0.74 0.15-2
B (81) 0.35 0.52 0.72 0.10-2
C (37) 0.21 0.40 0.62 0.10-1.6
Yes (17) 0.35 0.48 0.63 0.20-1.10
No (142) 0.32 0.48 0.70 0.10-2
Yes (41) 0.40 0.52 0.76 0.18-2
No (118) 0.31 0.45 0.70 0.10-2
Alcohol consumption
Yes (24) 0.40 0.46 0.59 0.20-1.80
No (135) 0.32 0.52 0.72 0.10-2
Age: group A (under percentile 25): 18-32 years; group B (percentile 25 to 75):
33-54 years; and group C (over percentile 75): 55-75 years (Kruskal-Wallis test).
Obesity, smoking status, and alcohol consumption were analyzed using the
Mann-Whitney U test. Parenthesis: number of subjects in each group.
Table III. Salivary variables (pH and buffer capacity) accor-
ding to age (ANOVA)
Group A 6.8127 ± 0.2434
Group B 6.8085 ± 0.2710
Group C 6.7254 ± 0.3578
P 0.294
Bicarbonate concentration (mmol/l)
Group A 5.4853 ± 2.3173
Group B
± 2.7575
Group C 5.2356 ± 3.2204
p 0.224
Age: group A (under percentile 25): 18-32 years (41); group B (percentile 25 to
75): 33-54 years (81); and group C (over percentile 75): 55-75 years (37).
Table IV. Men values of salivary variables (pH and buffer ca
pacity) according to qualitative variable in the study group
(Studen’s t test)
pH Bicarbonate (mmol/l)
± 0.2698 5.7176 ± 2.5812
No 6.7953 ± 0.2900 5.7488 ± 2.8096
Yes 6.7359 ± 0.2716 5.2248 ± 2.2781
No 6.8092 ± 0.2915 5.9264 ± 2.9193
Alcohol consumption
Yes 6.7554 ± 0.2991 5.5041 ± 2.6435
No 6.7965 ± 0.2860 5.7884 ± 2.8089
p 0.521 0.646
Univariate analysis
To study salivary variables with respect to qualitative
variables and age (younger or older than the median age),
they were classified into two categories (lower or greater
than the median value). Table V shows the results of this
The variable “
hyposialia” (defined according to
Navazesh) (39), has not been analyzed, as it was present in
only 8/159 volunteers (5.03%); but it is worth noting that 6
of them were women, 7 of them were older than 44, and
none of them was obese, a smoker or an alcohol consumer.
Multivariate analysis
Salivary flow rate above the median value was associat-
ed with younger age (< 44 years) (OR 2.10, CI95% 1.08-
4.05, p = 0.027) and male gender (OR 3.19, CI95% 1.56-
6.50, p = 0.001). Women showed a pH under the median
value (OR 2.13, CI95% 1.081-4.207, p = 0.029), whereas
in men bicarbonate concentration tended to be above me-
dian values (OR 2.81, CI95% 1.39-5.67, p = 0.004).
Nowadays, to offer better health care to people a trend
is seen towards integrating medical and odontological
knowledge (40); hence, gastroenterologists should learn
about salivary disorders, as saliva is the initial responsi-
ble of the digestive process. On the other hand, the
longevity of population, novel therapeutic techniques and
increased drug usage may affect oral structures, including
salivary glands, which could favor the development of lo-
cal diseases or extra-oral disorders.
Measurement of salivary secretion can be accomplished
by different methods: a) resting or unstimulated whole sali-
va secretion; b) stimulated whole saliva secretion; and c)
glandular saliva collection (mainly from parotid glands)
with or without stimulation. Unstimulated whole saliva re-
flects basal salivary flow rate, is present in our mouths for
about 14 hours a day, and is the secretion that provides pro-
tection to oral tissues. Stimulated saliva represents the se-
cretion during food intake (physiologic stimulation), and is
present in our mouths for up to 2 hours (3). So, the study of
unstimulated salivary secretion is an accurate method to an-
alyze salivary gland status, while stimulated saliva is useful
for the study of the functional reserve. In our study we have
chosen to measure unstimulated saliva, as it is an easy, non-
invasive and comfortable procedure, which favors its use in
population studies.
Age influences salivary secretion, probably due to the
physiologic process of ageing (16-21). Our results con-
firm this aspect, as we observed than older age is associ-
ated with decreased non-stimulated salivary flow rate (r =
-0.222, p = 0.005), while in younger people (< 44 years)
flow rate is greater than in people older than 44 years
(OR 2.10).
According to our data, salivary flow is greater in men
than in women (OR 3.19); this finding is not related to
age, as both groups (men and women) did not show dif-
ferences in this variable. Similar results are shown in other
studies (30-32), and it is suggested that these differences
REV ESP ENFERM DIG 2004; 96(11): 773-783
Table V. Univariate analysis between salivary variables (classified into two groups according to median value) and qualitative
variables (Chi-square test)
Flow rate (ml/min) pH Bicarbonate (mmol/l)
< 0.48
> 0.48 < 6.8310 > 6.8310 < 5.3000 > 5.3000
Male 17 35 20 32 18 34
Female 64 43 61 46 63 44
0.001 0.028 0.004
< 44 y. 34 46 38 42 39 41
> 44 y. 47 32 43 36 42 37
0.032 0.382 0.578
No 72 70 70 72 72 70
p 0.862 0.230 0.862
Yes 19 22 21 20 26 15
60 58 55 63
p 0.494 0.967 0.064
Alcohol consumption
69 71 64 68 67
p 0.219 0.324 0.732
may be explained by salivary gland size, which is smaller
in women (41). Decreased salivary secretion in women
may be related to the greater frequency or “oral dryness”
seen in females (3).
Data about the influence of age in the literature are
controversial, and this could be a consequence of some
methodological biases: variability in age groups, collec-
tion of unstimulated and/or stimulated saliva, inclusion of
medicated subjects, etc. (30).
Our data on the buffer capacity of saliva agree with
those published in other studies (27-29), as we found a
positive correlation with flow rate and a lower bicarbon-
ate concentration in women. From our series, we may
consider that there is a decreased buffer capacity when
bicarbonate concentration is lower than 1,800 mmol/l
(percentile 5).
It has been postulated that juvenile obesity is a risk
factor of oral disorders (42), caries among them (43); the
work of Power et al. (44) did not show any differences in
salivation patterns between obese and non-obese sub-
jects, while other authors found that in young obese peo-
ple salivary secretion was higher than in the control
group (45). Smoking increases salivary flow in the short
term (46), but in long-term smokers no differences have
been shown
versus non-smokers in flow rate (47,48); it
has been reported a decrease of pH (47) and buffer capac-
ity (49) in smokers, but normal values of both parameters
have also been described (48,50). Acute intake of alco-
holic drinks decreases salivary secretion (37); however,
in chronic alcoholism, with or without hepatic disorder,
data are controversial, as a decrease in salivary flow has
been reported (34,51), as well as a normal (35) or in-
creased flow (52).
In our study, obesity, smoking, and alcohol consump-
tion do not imply alterations on salivary features (flow
and buf
fer capacity); however
, we cannot draw firm con-
clusions due to the low number of subjects with these
Reduction of salivary flow has been related to a sensa-
tion of “
y mouth
”; despite frequent complaints about
this symptom and the impairment in quality of life that it
involves, it has only been trivially studied in clinical
practice (11,53). Xerostomia is mainly related to drug in-
gestion (anticholiner
gics, sympatheticomimetics, drugs
acting on serotonin or noradrenalin receptors, etc.) (54),
therapeutic radiation of the head and neck, and autoim-
mune diseases such as Sjögren’s syndrome. In a study of
100 patients older than 60 years who complained of xe-
rostomia, the most prevalent etiology was Sjögren’
s syn-
drome, followed by iatrogenic xerostomia and idiopathic
xerostomia; the authors found hyposialia (unstimulated
flow rate < 0.2 ml/min) in 65% of patients (55).
The diagnostic of hyposialia can be established accord-
ing to flow rate, but no consensus has been reached re
garding cut-off values, which makes it difficult to com-
pare studies of salivary secretion and “dry mouth”. In our
series, we considered hyposialia if salivary flow was low-
er than percentile 5 (0.15 ml/min), which is similar to the
value found by Navazesh (0,16 ml/min) (8); in the litera-
ture, values to define hyposialia vary from 0.10 (56) to
0.20 ml/min (55). In our series, four healthy volunteers
had hyposialia without a sensation of “
dry mouth” (2.5%);
all of them were women older than the median age, non-
obese, non-smokers, and who did not consume alcohol.
To evaluate our results about the flow rate and buffer
capacity of saliva in healthy subjects, and to demonstrate
its diagnostic usefulness (especially the cut-off value to
define hyposialia), it would be necessary that patients di-
agnosed with xerostomia be studied.
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REV ESP ENFERM DIG 2004; 96(11): 773-783
Débito basal, pH y capacidad tampón de la secreción salivar en
sujetos sanos
C. Fenoll-Palomares, J. V. Muñoz-Montagud
, V. Sanchiz
, B. Herreros
, V. Hernández
, M. Mínguez
A. Benages
Medicina Familiar y Comunitaria. Centro de Atención Primaria. Rafelbunyol, Valencia.
Centro de Especialidades.
Burjassot, Valencia.
Servicio de Gastroenterología. Hospital Clínico Universitario. Universitat de Valencia
Objetivos: conocer el débito, pH y capacidad tampón de la sa
liva en sujetos sanos y sus relaciones con edad, sexo, obesidad y há
bitos tabáquico y alcohólico, así como establecer la definición de hi-
Métodos: estudio observacional prospectivo en 159 volun-
tarios sanos (> 18 años, sin factores conocidos que disminuyan
la secreción salivar). Se ha recogido la saliva total, sin estímulo,
durante 10 minutos, determinando su débito (ml/min), pH y ca-
pacidad tampón (concentración de bicarbonato en mmol/l) me-
diante autoanalizador Radiometer ABL 520. Se han calculado
los límites inferiores del débito salivar y concentración de bicar
bonato por el percentil 5.
Resultados: la mediana del débito salivar es 0,48 ml/min
(rango 0,1-2). La mayor edad condiciona una disminución del
débito salivar; los sujetos con edad < 44 años presentan mayor
flujo salivar respecto a edad superior (OR 2,10). Los hombres
presentan mayor secreción salivar respecto a las mujeres (OR
3,19). La concentración de bicarbonato se correlaciona positi-
vamente con el débito salivar; los hombres presentan una ma-
yor capacidad tampón respecto a las mujeres (OR 2,81). Los lí-
mites inferiores de la normalidad del débito y concentración de
bicarbonato son 0,15 ml/min y 1,800 mmol/l, respectivamen
te. La obesidad y los hábitos tabáquico y alcohólico no modifi-
can las características de la secreción salivar.
Conclusiones: la edad y sexo influyen sobre el débito sali-
var; la capacidad tampón se relaciona positivamente con el -
bito salivar. Los hábitos tabáquico y alcohólico, así como la obesi-
dad no modifican la secreción salivar.
Palabras clave: Saliva. Débito salivar. Capacidad tampón salivar.
La saliva es el principal elemento para la homeostasis
bucal, ya que modula el ecosistema de la cavidad oral (1).
Entre las funciones salivares destacan la lubrificación del
bolo alimenticio facilitando la deglución, la protección
contra virus, bacterias y hongos, su capacidad tampón, la
protección y reparación de la mucosa oral y remineraliza-
ción dental (2-4). Por ello, las alteraciones en la secreción
salivar, cuantitativas y/o cualitativas, tienen efectos ad-
versos locales (caries, mucositis oral, candidiasis, infec-
ciones orales, dificultades masticatorias, etc) y extraora-
les (disfagia de penetración, halitosis, pérdida de peso)
La disminución de la secreción salivar se expresa clí-
nicamente por la sensación de “boca seca” o xerostomía,
aunque esta puede también aparecer, en ocasiones, sin
descenso del flujo salivar (8). La xerostomía es una situa-
ción clínica frecuente (9) que motiva numerosas consul
tas a diferentes especialistas (gastroenterólogos, dentis-
tas, internistas), ya que puede ser un síntoma en el curso
de enfermedades locales y sistémicas (síndrome de Sjö-
gren, diabetes mellitus, secundaria a medicamentos, irra-
diación sobre cabeza-cuello, etc.) (10-13), pero en pa-
cientes de mayor edad puede aparecer sin patología
subyacente conocida (14-15) por disminución de la se-
creción salivar ligada a la edad.
Se ha postulado que la edad condiciona una disminu
ción de la secreción salivar como consecuencia del pro-
ceso fisiológico de envejecimiento con atrofia parenqui-
matosa (16-21). Por el contrario, otras investigaciones
demuestran que los sujetos ancianos sanos presentan un
flujo salivar normal con gran reserva funcional, especial
mente en las glándulas parotídeas (22-26).
La capacidad tampón de la saliva es un factor impor-
tante, que influye en el pH salivar y en el proceso de re
mineralización dental, siendo la concentración de bicar
bonato su principal componente (27); se relaciona con el
flujo salivar (28), ya que cualquier circunstancia que dis-
minuya el flujo salivar tiende a disminuir su capacidad
tampón e incrementa el riesgo de caries (29).
Otros factores que pueden influir sobre el flujo y ca-
pacidad tampón de la saliva son el sexo, el hábito tabá-
quico y la ingesta alcohólica. Las mujeres presentan
menor débito salivar (30-32) con descenso de su capa-
cidad tampón (29). La relación entre secreción salivar y
los hábitos tabáquico y alcohólico ofrece datos contra-
dictorios, ya que se han descrito tanto secreción salivar
normal como hiposialia (33-37).
El objetivo de nuestro estudio ha sido analizar el débi-
to, pH y capacidad tampón de la secreción salivar basal
en un grupo de sujetos sanos y su relación con la edad y
sexo, así como con otras variables individuales (obesi-
dad, hábito tabáquico e ingesta alcohólica), intentando
establecer los rangos de normalidad de la población ge-
neral sana en nuestro ámbito.
Estudio observacional prospectivo realizado en sujetos
sanos que dieron su consentimiento informado para parti-
cipar en el estudio; los criterios de inclusión han sido:
edad > 18 años; buen estado de salud; ausencia de enfer-
medad sistémica crónica; no enfermedades agudas o cró-
nicas de la mucosa oral y/o de las glándulas salivares; no
ingesta de fármacos; no sensación de “boca seca” ni de
“boca ardiente”; ausencia de enfermedad infecciosa agu-
da; no insuficiencia cardiaca ni renal ni respiratoria ni he-
pática; no haber sido sometido a tratamiento mediante
irradiación sobre cuello y/o cabeza; no embarazo; las mu-
jeres en edad fértil sólo se han incluido cuando aseguran
utilizar métodos anticonceptivos seguros. Como criterios
de exclusión se han tomado los siguientes: no cumpli
mentación de cualquiera de los criterios de inclusión; uti
lización de anovulatorios como método anticonceptivo y
negativa a participar en el estudio. El estudio fue realiza-
do entre abril de 1998 y mayo de 2000.
Metódica de estudio
odos los sujetos remitidos para su estudio se sometie
ron a una exploración de la cavidad oral, por el mismo es-
tomatólogo, para descartar la presencia de enfermedades
agudas o crónicas de la mucosa oral y/o de las glándulas
salivares. Se registraron sus características demográficas
(edad, sexo, peso, talla) y hábitos tabáquico y alcohólico;
se determinó el índice de masa corporal (IMC), conside-
rándose como obesidad cuando el IMC era superior a 30
(38). Se ha considerado como fumador cuando el sujeto
refería hábito activo, independientemente del número de
cigarrillos/día y se ha considerado como hábito alcohóli-
co cuando la ingesta alcohólico es superior a 60 g/día
(hombres) o 40 g/día (mujeres).
Vol. 96. N.
REV ESP ENFERM DIG 2004; 96(11): 773-783
El estudio de la secreción salivar se ha realizado sin
estímulo alguno, entre las 9 y 11 horas en condiciones de
temperatura y humedad similares en todos los casos; la
saliva se ha recogido tras un periodo de dos horas sin co-
mer ni beber ni fumar. Se invita al sujeto a sentarse có-
modamente y tras unos minutos de relajación se le re-
quiere a que incline la cabeza levemente hacia delante y
expulse toda la saliva producida durante 10 minutos a
una probeta de cristal milimetrada, a través de un embudo
de cristal; al sujeto se le explica la importancia de evitar
la deglución de la menor cantidad de saliva.
Tras la correspondiente medición del volumen total re-
cogido en 10 minutos, una alícuota se pasa a una jeringui-
lla de plástico estéril para realizar el análisis bioquímico
por el mismo operador y con idéntica metódica; se ha uti-
lizado un autoanalizador Radiometer ABL 520 que de
forma automatizada nos ofrece el pH y bicarbonato
(mmol/l) de la muestra; cada muestra se ha analizado tres
veces para disminuir la posibilidad de error, tomándose
como válido el valor promedio.
Las variables salivares han sido: débito salivar
(ml/min), aspecto macroscópico de la saliva (transparen-
te, turbia y sanguinolenta), pH y tasa de bicarbonato
(mmol/l) como expresión de su capacidad tampón.
Método estadístico
Se ha realizado un estudio descriptivo de todas las va-
riables. El test de Kolmogorov-Smirnov se ha utilizado
para constatar la distribución normal de las variables
cuantitativas; si estas presentaban una distribución nor-
mal se han analizado mediante la t de Student o mediante
ANOVA (más de dos grupos), mientras aquellas que no
siguen una distribución normal lo han sido por la U de
Mann-Whitney o mediante el test de Kruskal-W
allis (más
de dos grupos). La correlación entre variables cuantitati
vas se ha realizado mediante el coeficiente de Pearson.
La distribución de las variables cualitativas en los grupos
de estudio se ha analizado mediante el estadístico Chi-
cuadrado. Las variables que han obtenido una p < 0,1 se
han incluido en un análisis de regresión logística (adelan
te condicional). Se ha tomado como límite de la significa-
ción estadística una p < 0,05. El tratamiento estadístico se
ha realizado con el paquete SPSS 1
El grupo de estudio está constituido por 159 volunta-
rios sanos (52 hombres y 107 mujeres) cuyas característi-
cas demográficas se expresan en la tabla I; la edad es si
milar entre ambos sexos (p=0,796); los sujetos obesos
eran más jóvenes que los no obesos (31,94 ± 9,64
45,52 ± 14,03 años, p=0,000); los sujetos con hábito ta-
báquico eran más jóvenes que los no fumadores (36,85 ±
vs 46,69 ± 14,18 años, p=0,000) y los abstemios
eran de mayor edad respecto a los sujetos con ingesta al-
cohólica (45,46 ± 14,56
vs 36,83 ± 9,54 años, p=0,001).
Débito salivar basal, pH y capacidad tampón
Las características salivares se muestran en la tabla I.
Hay que señalar que el débito salivar basal (ml/min) no
sigue una distribución normal; tomando el criterio de Na-
vazesh (39) para definir la hiposialia (débito basal igual o
inferior a 0,16 ml/min), sólo en ocho sujetos (5,03%) se
obtiene un débito salivar inferior a esta cifra que presen-
tan, además, un pH salivar menor que aquellos con débito
normal (6,5390 ± 0,3605
vs 6,8036 ± 0,2782, p=0,011) y
una menor concentración de bicarbonato (3,5625 ±
3,0654 mmol/l
vs 5,8611 ± 2,7248 mmol/l, p=0,022). En
estos sujetos con hiposialia predomina un aspecto turbio
de la saliva (6/8 sujetos).
Hay una correlación positiva significativa del débito con
pH y concentración de bicarbonato (r = 0,322, p=0,000
y r = 0,425, p=0,000, respectivamente), así como entre es-
tas dos últimas variables (r = 0,736, p=0,001).
Relaciones entre parámetros salivares y variables
Los hombres presentan mayor débito que las mujeres
(mediana de 0,57 ml/min, rango 0,15-2
vs mediana de 0,42
ml/min, rango 0,10-2, p=0,000). No se han constatado dife-
rencias significativas en el pH salivar (6,8400 ± 0,3199 en
REV ESP ENFERM DIG 2004; 96(11): 773-783
Tabla I. Características del grupo de estudio
Variables demográficas
Sujetos 159 voluntarios sanos; edad media
44,16 ± 14,23 años (rango 18 y 75)
Sexo 52 hombres (44,58 ± 13,15 años) y
107 mujeres (43,95 ± 14,78 años)
Obesidad 17 sujetos (10,69%)
Hábito tabáquico 41 sujetos (25,78%)
Hábito alcohólico 24 sujetos (15,09%)
Variables salivares
Débito salivar Mediana 0,48 ml/min (rango 0,10 y
2). Percentil 5 = 0,15 ml/min
0,2874 (rango de 5,8590 y
Concentración de bicarbonato 5,7455 ± 2,7783 mmol/l (rango de
0,3000 y 13,2000)
Percentil 5 = 1,800 mmol/l
Aspecto macroscópico
Transparente en 88 sujetos (55,3%)
Turbidez en 61 sujetos (38,3%)
Sanguinolenta en 10 sujetos (6,3%)
los hombres y 6,7661 ± 0,2686 en las mujeres, p=0,128),
pero sí en la capacidad tampón (6,6269 ± 3,1239 mmol/l en
hombres y 5,3171 ± 2,4989 mmol/l en mujeres, p=0,010).
Para analizar la influencia de la edad, se han calculado
sus percentiles 25 y 75 (32 y 54 años, respectivamente);
la edad influye significativamente sobre el débito salivar
(menor en el grupo de mayor edad) (Tabla II), pero no so-
bre el pH y concentración de bicarbonato (Tabla III).
Sólo la edad se correlaciona negativamente con el débito
salivar (r = -0,222, p=0,005), mientras que no alcanza
significación estadística con el pH (r = -0,106, p=0,185)
ni con la tasa de bicarbonato (r = -0,030, p=0,710).
Las variables salivares en los sujetos obesos, fumado-
res o con ingesta alcohólica no se diferencian estadística-
mente de los obtenidos en sujetos sin estas condiciones
(Tablas II y IV).
Análisis univariante
Las variables salivares se han clasificado en dos cate-
gorías (inferior y superior a la mediana) para el estudio
respecto a las variables cualitativas y edad (clasificada en
inferior y superior a la mediana). En la tabla V se muestran
los resultados de este análisis.
La variable hiposialia (según Navazesh) (39) no ha
sido analizada estadísticamente, dado que sólo se presen-
ta en 8/159 sujetos (5,03%); pero hay que señalar que 6/8
son mujeres, con edad superior a 44 años en 7/8 casos y
en ningún caso hay hábito tabáquico ni ingesta alcohólica
ni obesidad.
Análisis multivariante
La menor edad (< 44 años) condiciona mayor débito
salivar (OR 2,10, IC95% 1,08-4,05, p=0,027) y esta si
tuación también se observa en el sexo masculino (OR
3,19, IC95% 1,56-6,50, p = 0,001); el sexo femenino
condiciona una secreción salivar con un pH por debajo de
la mediana (OR 2,13, IC95% 1,081-4,207, p = 0,029),
mientras que en los hombres se observa una mayor tasa
de bicarbonato (OR 2,81, IC95% 1,39-5,67, p = 0,004).
En el momento actual, se tiende a la integración de los
conocimientos médicos y odontológicos para una mejor
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Tabla II. Débito salivar según edad, obesidad, hábito
tabáquico y alcohólico
Débito salivar (ml/min)
Percentil Percentil Percentil Rangp p
25 50 75
A (41) 0,39 0,54 0,74 0,15-2
B (81) 0,35 0,52 0,72 0,10-2 0,046
C (37) 0,21 0,40 0,62 0,10-1,6
Sí (17) 0,35 0,48 0,63 0,20-1,10
No (142) 0,32 0,48 0,70 0,10-2
Hábito tabáquico
Sí (41) 0,40 0,52 0,76 0,18-2
No (118) 0,31 0,45 0,70 0,10-2
Hábito alcohólico
Sí (24) 0,40 0,46 0,59 0,20-1,80
No (135) 0,32 0,52 0,72 0,10-2
Grupo A (hasta percentil 25):18-32 años; grupo B (entre percentil 25-75): 33-54
años; y grupo C (superior percentil 75): 55-75 años (análisis mediante prueba de
Kruskal-Wallis). Las restantes variables se han analizado mediante la U de Mann-
Whitney. Entre paréntesis figuran el número de sujetos en cada subgrupo.
Tabla III. Variables salivares (pH y capacidad tampón)
según la edad (percentiles 25 y 75)
Grupo A
6,8127 ± 0,2434
Grupo B
Grupo C
p 0,294
Tasa bicarbonato (mmol/l)
Grupo A
Grupo B 6,1101 ± 2,7575
Grupo C 5,2356 ± 3,2204
p 0,224
El análisis estadístico se ha realizado mediante ANOVA. Grupo A (hasta percentil
25): 18-32 años (n. 41). Grupo B (entre percentil 25-75): 33-54 años (n. 81). Gru-
po C (superior percentil 75): 55-75 años (n. 37).
Tabla IV. Valores promedio de las variables salivares
(pH y capacidad tampón), según variables
cualitativas del grupo de estudio
pH Bicarbonato (mmol/l)
6,7482 ± 0,2698 5,7176 ± 2,5812
No 6,7953 ± 0,2900 5,7488 ± 2,8096
p 0,525 0,965
Hábito tabáquico
6,7359 ± 0,2716 5,2248 ± 2,2781
No 6,8092 ± 0,2915 5,9264 ± 2,9193
p 0,160 0,119
Ingesta alcohólica
6,7554 ± 0,2991 5,5041 ± 2,6435
No 6,7965 ± 0,2860 5,7884 ± 2,8089
p 0,521 0,646
El análisis de las variables salivares se ha realizado mediante la t de Student.
asistencia sanitaria a los ciudadanos (40); por ello cree-
mos pertinente que el gastroenterólogo conozca los pro-
blemas relacionados con la saliva, ya que es la responsa-
ble más inicial de todo el proceso digestivo. Por otra
parte, la mayor longevidad, las nuevas técnicas terapéuti-
cas y el mayor consumo de medicamentos pueden afectar
a las estructuras orales, incluidas las glándulas salivares,
lo que, a su vez, puede favorecer la aparición de enferme-
dades locales y a distancia.
El análisis de la secreción salivar puede realizarse con
técnicas diferentes: a) secreción total no estimulada; b)
secreción total tras estimulación; y c) colección de saliva
de glándulas concretas, especialmente parótidas, con o
sin estimulación. La saliva total sin estímulo refleja el
flujo salivar basal y está presente en la cavidad oral du
rante largos periodos de tiempo (unas 14 horas), por lo
que es la principal responsable de sus propiedades pro-
tectoras, mientras que la saliva total estimulada represen
ta la situación tras la ingesta (estimulación fisiológica)
por lo que su acción sólo la ejerce durante unas dos horas
(3). Por lo tanto, el estudio de la secreción salivar total no
estimulada es un buen método para el análisis del estado
de las glándulas salivares, mientras que la obtenida tras
estimulación representaría la capacidad funcional de re
serva de estas. La facilidad en la recogida de la saliva to-
tal no estimulada y las mínimas molestias para el sujeto
hacen que esta técnica sea la más idónea para estudios
amplios de población; por estas razones hemos elegido
esta metódica en nuestro estudio.
La edad influye sobre la secreción salivar, probable-
mente por el propio proceso fisiológico de envejecimien
to (16-21). Nuestros resultados confirman estos datos, ya
que se objetiva que la mayor edad condiciona un descen-
so significativo del débito salivar no estimulado (r =
-0,222, p=0,005), mientras que en los sujetos más jóve-
nes (< 44 años) el flujo salivar es mayor respecto a los su-
jetos con edad > 44 años (OR 2,10).
Según nuestros datos, el débito salivar es mayor en
hombres respecto a las mujeres (OR 3,19) y este dato no
puede relacionarse con el factor edad, dado que ambos
grupos (hombres y mujeres) presentan una edad similar.
Resultados similares se describen en otros estudios (30-
32) y se sugiere que puede deberse al menor tamaño de las
glándulas salivares en las mujeres (41). Esta menor secre-
ción salivar en mujeres podría estar en relación con la ma-
yor frecuencia de “boca seca” en el sexo femenino (3).
Los datos recogidos en la literatura sobre la influencia
de la edad sobre la secreción salivar son contradictorios y
ello puede ser consecuencia de varios sesgos metodológi-
cos: grupos etarios con puntos de corte muy diferentes,
recogida de la saliva basal y/o estimulada, inclusión de
sujetos con ingesta medicamentosa, etc. (30).
Nuestros datos sobre la capacidad tampón de la saliva
(correlación positiva con el débito y menor concentración
de bicarbonato en mujeres) coinciden con los resultados
reseñados en la literatura (27-29). En nuestra serie se
puede considerar como disminución de la capacidad tam-
pón de la saliva no estimulada, una concentración de bi-
carbonato < 1,800 mmol/l (percentil 5).
Se ha postulado que la obesidad infanto-juvenil pre-
dispone a las enfermedades orales (42), incluida la ca-
ries (43); el estudio de Powers y cols. (44) no observa
diferencias entre los patrones de salivación entre obesos
y no obesos, aunque otros autores comprueban mayor
REV ESP ENFERM DIG 2004; 96(11): 773-783
Tabla V. Análisis univariante (Chi cuadrado) entre las variables salivares (categorizadas por su mediana)
y las variables cualitativas
Débito (ml/min) pH Bicarbonato (mmol/l)
< 0,48 > 0,48 < 6,8310 > 6,8310 < 5,3000 > 5,3000
Hombre 17 35 20 32 18 34
Mujer 64 43 61 46 63 44
0,001 0,028 0,004
< 44 y. 34 46 38 42 39 41
> 44 y. 47 32 43 36 42 37
0,032 0,382 0,578
9 8 11 6 9 8
No 72 70 70 72 72 70
p 0,862 0,230 0,862
hábito tabáquico
19 22 21 20 26 15
No 62 56 60 58 55 63
p 0,494 0,967 0,064
Ingesta alcohólica
15 9 10 14 13 11
No 66 69 71 64 68 67
p 0,219 0,324 0,732
secreción salivar en muchachos obesos respecto al gru-
po control (45). A corto plazo el hábito tabáquico incre-
menta el flujo salivar (46), pero a largo plazo no se de-
muestran diferencias en el débito salivar entre
fumadores y no fumadores (47,48); se han descrito des-
censos del pH (47) y de la capacidad tampón (49), pero
también la normalidad de ambos parámetros en los suje-
tos fumadores (48,50). El consumo agudo de bebidas al-
cohólicas disminuye la secreción salivar (37), pero en el
alcoholismo crónico, con o sin lesiones hepáticas, los
datos son contradictorios, ya que se ha comunicado tan-
to la disminución de la secreción salivar (34,51), como
un débito normal (35) o aumentado (52).
En nuestro estudio la obesidad, hábitos tabáquico y al-
cohólico no marcan diferencias sobre las características
salivares (débito y capacidad tampón), aunque el escaso
número de sujetos con estas características no nos permi-
te realizar afirmaciones categóricas.
La reducción del flujo salivar se ha relacionado con la
sensación de “boca seca”; a pesar de su frecuencia y el
deterioro de la calidad de vida que conlleva, este síntoma
ha sido valorado de forma trivial en la práctica clínica
(11,53). La xerostomía se asocia preferentemente con la
toma de ciertos medicamentos (anticolinérgicos, simpati-
comiméticos, agentes que actúan sobre la serotonina y la
noradrenalina, etc. (54), como secuela del tratamiento ra-
dioterápico (cabeza y cuello) y ligada a conectivopatías,
tipo síndrome de Sjögren (12). En una revisión sobre 100
pacientes mayores de 60 años con xerostomía, la causa
más prevalente es el síndrome de Sjögren, seguido de la
xerostomía iatrogénica y sin causa conocida (xerostomía
idiopática); los autores observan una hiposialia (débito
salivar no estimulado < 0,2 ml/min) en el 65% de los pa-
cientes (55).
El diagnóstico de hiposialia puede establecerse por el
débito salivar, pero no hay una cifra consensuada como
punto de corte; la falta de uniformidad en este parámetro
dificulta la comparación de los distintos estudios sobre
secreción salivar y “boca seca”. En nuestra serie, hemos
considerado como hiposialia cuando el débito salivar cae
por debajo del percentil 5 (0,15 ml/min) similar a la obte-
nida por Navazesh (0,16 ml/min)(8); otras cifras relata-
das en la literatura oscilan entre 0,10 (56) y 0,20 ml/min
(55). Nuestros cuatro voluntarios sanos (2,5%), sin sensa-
ción de “boca seca”, con hiposialia, presentan unas carac-
terísticas comunes (mujeres, edad superior a la mediana,
no obesas y sin hábitos tabáquico ni alcohólico).
Para evaluar nuestros resultados sobre débito y capaci-
dad tampón salivares en sujetos sanos y demostrar su uti-
lidad diagnóstica, especialmente el punto de corte para la
consideración de hiposialia, sería necesario el estudio de
pacientes diagnosticados clínicamente de xerostomía.
Vol. 96. N.
REV ESP ENFERM DIG 2004; 96(11): 773-783
... [11] Ageing leads to decreased SFR because of parenchymal atrophy. [12] In some studies, men showed a greater flow rate than women. There is a correlation between pH changes in the plaque and sugar clearance from the saliva. ...
... The salivary pH is negatively correlated with age; that is, as the age increases, the salivary pH decreases. [12] Formation of reactive oxygen species in the oral cavity during betel quid chewing leads to a decrease in pH as well. A decrease in SFR also results in a decrease in pH [26] and vice versa, that is, alteration in electrolyte and ion constituents of saliva, [23] that is, a decrease in bicarbonate content of saliva. ...
... [25,27] Females usually show a lower SFR and decreased buffer capacity. [12] This difference is explained by the salivary gland size, which is smaller in women. Decreased salivary secretion is also related to a greater frequency of oral dryness seen in females. ...
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Introduction Tobacco and areca nuts release carcinogens, which cause alterations in saliva. Evaluation of these changes through estimation of salivary flow rate and pH was performed in tobacco and areca nut chewers and apparently healthy subjects. Material and Methods The study group for this comparative study comprised 60 subjects with 20 areca nut chewers (group 1), 20 tobacco chewers (group 2), and 20 non-tobacco and areca nut chewers (group 3) in the ages between 18 and 75 years. After collection of saliva from each subject, the salivary flow rate (SFR) was measured by using graduated tubes, whereas salivary pH was measured using a digital salivary pH meter. Tukey HSD post hoc test was performed for comparison of mean SFR and mean pH between study group subjects. Analysis of variance (ANOVA) test was used to find the mean difference in SFR and pH in duration, intensity, and frequency among various types of areca nut and tobacco users. A ”P” value of less than 0.05 was considered as statistically significant. Results The mean age among groups 1, 2, and 3 was 37.70 ± 10.44, 39.75 ± 10.16, and 37.90 ± 10.52 years, respectively, with a statistically insignificant difference. The mean salivary flow rate (ml/20 min) was maximum in group 3 (13.23), followed by group 2 (11.75) and group 1 (10.48), with the statistically significant difference as P < 0.05. The mean salivary pH was maximum in group 3 (7.07), followed by group 2 (6.86) and group 1 (6.49), with the statistically significant difference as P < 0.05. Conclusion Long-term use of tobacco and areca nuts in a chewable form can significantly reduce the salivary flow rate and salivary pH. Hence, these measurements can be used as chair side, non-invasive measures for assessing pathological changes in oral mucosa linked to vulnerable effects among people addicted to these adverse habits; thereby, early re-organization can prevent mobility and mortality.
... In the present study, similar to the previous study [24], total or rest saliva was used because of its long time contact with the teeth. Total saliva, compared to the limited secretion of stimulated saliva; is imparted in our mouth for approximately 14 hours a day [25]. As there is hormonal and physiological difference between two genders, we selected our subjects to be only male individuals in order to reduce inter and intra group differences. ...
... The results of the present study similar to the results of Palomares et al. [25], Kitasako et al. [38] and Farsi et al. [39], showed that there is no relationship between age and salivary buffering capacity. ...
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Statement of Problem: Tooth caries is influenced by different biochemical characteristics of saliva. As hydroxyapatite is the main component of enamel, salivary ion activity product for hydroxyapatite (I PHA) as well as alkaline phosphatase may be attributed to dental caries.
... Whole unstimulated saliva was collected in the present study as the basal salivary flow rate is reflected by unstimulated whole saliva, and the same is favored by most of the population studies [19,20]. ...
... Hypo salivation criteria for whole stimulated saliva is <0.7 mL/min [32], whereas for whole unstimulated saliva is 0.12-0.16 mL/min [19], and unstimulated flow rates <0.1 mL/min or 0.30 mL/min [20]. We collected saliva by using the passive drool method and which was similar to Dawes method 11. ...
Background: Tobacco use by youth is ever-demanding, and it is increasingly distributed not only in India but also globally. Saliva is a complex oral bio-fluid, freely available, performing absolute tasks for maintaining oral health and homeostasis. It contains a plethora of significant constituents such as proline-rich proteins (PRPs), immunoglobulins, IgA, enzymes lysozyme, lactoferrin, peroxidases, amylase, etc. The basic ecological balance of the oral cavity is stabilized via salivary clearance by reduced aggregation and adherence of microorganisms by direct microbial activity. This balance of oral activity is also done by indirect mechanisms by immunological as well as non-immunological means and also by effectively regulating salivary pH flow rate. This institutional observational study was planned to assess and compare salivary parameters (pH, salivary flow rate), total proteins, α-amylase, calcium, phosphate, and IgA, of unstimulated whole saliva of both tobacco abusers and tobacco non-users. Methods: The Study consisted of 270 participants (Tobacco habit) group, n = 135 and Control (Healthy) group, n = 135 and were in the age range of 20-50 years. They were assessed for oral health status, followed by the analysis of salivary pH, flow rate, total proteins, amylase, calcium, phosphates, and IgA of unstimulated whole saliva. Results: Comparative evaluation of salivary parameters among groups found that varying tobacco abusers had increased salivary amylase, protein levels, and phosphate whereas decreased salivary pH, flow rate, IgA, and in the whole unstimulated saliva samples than those of non-tobacco users. This difference among groups was statistically significant. (p < 0.05), and calcium levels were not altered significantly. Conclusions: This study concludes that salivary parameters are altered in tobacco abusers when compared to those of non-abusers, and it was more significant in smokeless tobacco abusers than in any other form of tobacco abuse.
... While saliva research has predominantly focused on the development of technologies for biomarker analysis [2,4,26,27], the influence of different saliva sampling methods remains largely unexplored. Collecting a reliable saliva sample can be challenging, as the variability in results can depend on various factors, including the type of saliva collected (whole saliva or gland-specific), circadian rhythm [28] and the presence or absence of stimuli [29][30][31][32][33][34][35]. Notably, the lack of standardized methodology may introduce variability in outcomes, subsequently affecting the interpretation and future prospects. ...
... However, there is no evidence showing that a decrease in the salivary flow rate directly leads to a decrease in salivary pH, leading to reduced buffering capacity in patients of all age groups with xerostomia. In a study involving healthy volunteers, reduced salivary flow rate and buffer capacity were observed in people older than 44 years and in females; however, these findings did not correlate with salivary pH 48) . A decrease in chewing ability and salivary gland stimulation and function is expected to reduce the amount of saliva and alter its composition to reduce salivary pH and buffer capacity. ...
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Purpose: We aimed to investigate the objective cutoff values of unstimulated flow rates (UFR) and stimulated salivary flow rates (SFR) in patients with xerostomia and to present an optimal machine learning model with a classification and regression tree (CART) for all ages. Materials and Methods: A total of 829 patients with oral diseases were enrolled (591 females; mean age, 59.29±16.40 years; 8~95 years old), 199 patients with xerostomia and 630 patients without xerostomia. Salivary and clinical characteristics were collected and analyzed. Result: Patients with xerostomia had significantly lower levels of UFR (0.29±0.22 vs. 0.41±0.24 ml/min) and SFR (1.12±0.55 vs. 1.39±0.94 ml/min) (P<0.001), respectively, compared to those with non-xerostomia. The presence of xerostomia had a significantly negative correlation with UFR (r=–0.603, P=0.002) and SFR (r=–0.301, P=0.017). In the diagnosis of xerostomia based on the CART algorithm, the presence of stomatitis, candidiasis, halitosis, psychiatric disorder, and hyperlipidemia were significant predictors for xerostomia, and the cutoff ranges for xerostomia for UFR and SFR were 0.03~0.18 ml/min and 0.85~1.6 ml/min, respectively. Conclusion: Xerostomia was correlated with decreases in UFR and SFR, and their cutoff values varied depending on the patient’s underlying oral and systemic conditions.
... Stimulated and Unstimulated saliva can be collected with or without masticatory or mechanical action or exogenous gustatory stimulation. 2 Despite the wide use of preventive measures, dental caries, and dental fluorosis in children always outrank other oral diseases in occurrence and result in the alteration of a few physicochemical properties of saliva. ...
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Background Saliva is one of the most important aids in the diagnosis of various oral diseases. Few physicochemical properties of saliva such as flow rate, pH, and buffering capacity often vary with the occurrence of dental caries, fluorosis, and other systemic conditions. Purpose The aim of the study was to evaluate the relationship between the salivary flow rate, pH, and buffering capacity in healthy children, children with caries, children with fluorosis, and children with both caries + fluorosis. Materials and methods The study population consisted of 144 children aged 7–14 years and were divided into four groups of 36 children each. Group I, 36 healthy children with no caries and fluorosis; group II, 36 children with caries (dmfs ≤ 10); group III, 36 children with fluorosis (moderate to severe); and group IV, 36 children with caries + fluorosis. Unstimulated saliva is collected from all the selected subjects and evaluated for the salivary flow rate, pH, and buffering capacity. The recorded data were tabulated and statistically analyzed using a paired t-test. Results The mean salivary flow rate and buffering capacity were found to be highest in group III when compared with all the other groups. The mean pH was greater in group I when compared with groups I, II, and III. Conclusion The physicochemical properties of saliva like pH, buffering capacity, and salivary flow rate alter with caries and fluorosis conditions. Hence, more clinical and laboratory studies are needed to determine the exact relationship between these physicochemical properties of saliva in dental caries and fluorosis. How to cite this article E RR, S S, M K, et al. Evaluation of Flow Rate, pH, and Buffering Capacity of Saliva in Children with Caries, Fluorosis, and Caries with Fluorosis. Int J Clin Pediatr Dent 2023;16(4):587–590.
... Stimulated saliva showed a higher buffering capacity in both the patient and control group, compared to unstimulated saliva in both groups, i.e., stimulated saliva is more resistant to pH changes caused by HCl titration. This result is in agreement with Moritsuka's research [21]. In the control group in unstimulated saliva, the average buffering capacity value is 7.842, and in the patient group it is 7.561. ...
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Introduction: Buffer capacity is the “resistance” of saliva to change pH when treated with acid or base. In other words, saliva has a greater buffering capacity to which more acid or base needs to be added in order for its pH to decrease or increase by a certain value. Aim: Laboratory examination of the buffering capacity of unstimulated and stimulated saliva in patients of the experimental group and subjects of the control group in relation to age and gender. Material and method: Determination of the pH value of saliva is done with a pH meter (HANNA instruments 8521). The obtained amount of saliva is diluted with distilled water. Each sample is divided into two equal parts, and the pH value of the sample is measured. Saliva titration is done with acid (HCl) and base (NaOH), adding 100μl of HCl to each sample and 100μl of NaOH to each sample, in the range from pH 3 to pH 11. Results: There is no statistical significance of the differences in the mean values of the buffer capacity. Conclusion: There is a difference in the mean values of the buffer capacity in favor of men, which explains that in men a larger amount of spent buffer is needed to change the pH by one unit.
With the number of dental implants placed per year rising exponentially, peri-implant disease prevalence is also steadily increasing. Peri-implant tissue status is assessed using radiographic and clinical methods that have significant drawbacks, not least of which is that they are only capable of detecting disease once it has already occurred. When this is considered together with the unpredictable outcome of peri-implantitis treatment, the need for a low-cost, specific, and sensitive non-invasive test that can diagnose the shift from health to disease is highlighted. An understanding of biomarkers associated with disease initiation, progression, and regression have a critical role in the ongoing monitoring and maintenance of osseointegrated implants.
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This document was produced by the 'EU-Working Group† on Tobacco and Oral Health' supported by the EU Commission (the 'Europe Against Cancer' programme).
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There is considerable difficulty in the making of initial clinical decisions as to whether a given patient has salivary gland hypofunction, and hence requires additional salivary gland evaluation. This study identified a set of four clinical measures that, together, successfully predicted the presence or absence of salivary gland hypofunction. The four measures were: dryness of lips, dryness of buccal mucosa, absence of saliva produced by gland palpation, and total DMFT; they were derived from discriminant analysis of data collected from 71 individuals with normal and low salivary flow rates. These measures are proposed as criteria for clinical decision-making, as well as for classification of patients in studies of salivary gland dysfunction syndromes. This study also identified unstimulated whole salivary flow rates of 0.12-0.16 mL/min as the critical range separating individuals with salivary gland hypofunction from those with normal gland function.
Although oral candidiasis is frequently seen in the elderly, the factors determining candidal growth have insufficiently been explored. Hence, we examined the influence of aging on candidal adhesion and growth-inhibitory agents in saliva in 45 healthy volunteers and 60 patients with oral candidiasis. Both non-stimulated and stimulated salivary flow rates (SFRs) in the healthy controls decreased with aging. A gradual decrease of SFRs with aging was also observed in the patients, and the SFR levels were markedly lower than those in the controls. Although the salivary glucose levels were almost constant in all age groups, secretory immunoglobulin A and lactoferrin levels in saliva were significantly decreased statistically with age, and a marginal age-associated decrease in transferrin levels was also observed. In addition, the generation of superoxide from neutrophils in saliva and their Candida killing activity decreased with age, and these phenomena were more apparent in the patients. Furthermore, a larger number of Candida adhered to oral keratinocytes obtained from the elderly healthy controls than to those obtained from young controls. Correspondingly, keratinocytes from the aged controls showed more concanavalin-A binding sites than those from the young controls. However, oral Candida did not increase with increasing age in the controls, although an age-associated increase of oral Candida was observed in the patients. Taken together, these results indicate that the decreases of SFRs and salivary anti-candidal factors, suppression of salivary neutrophil function and the increase of candidal adhesion sites on keratinocytes predispose elderly individuals to oral candidiasis.
Eighteen patients with alcoholic cirrhosis were examined, and parotid saliva was collected. Enlargements of the parotid glands were seen in eleven of the eighteen patients (61%). This percentage is in accord with the data previously reported. The salivary findings of increased flow rate, protein, and amylase levels indicate that hypertrophy and increased acinar function may be a component of the parotid enlargement and that, furthermore, a fatty replacement of functional gland tissue is probably not involved. In addition, the salivary electrolyte changes found, increased potassium with effectively decreased sodium excretion, suggest that the elevated aldosterone level commonly found in cirrhotic patients affects salivary secretions in these patients in much the same way as it does in patients with hypertension.
The volumes of 153 submandibular salivary glands were determined by a method of differential weighings in air and in a fluid of low density. Volumes ranged from below 2 cm3 to over 15 cm3. Male glands were larger than female glands on average by 50 per cent. In old age a reduction in gland volume was noted. Frequent individual contralateral volume differences were found. 8.5 per cent of submandibular glands were directly continuous with the sublingual gland. Inaccuracies in methods employing a direct estimation of volume were overcome in the present method in which direct measurements were made only of weights. For the clinician, the present finding of a wide range of inter- and intra-subject variability in size and shape of submandibular glands is of both diagnostic and surgical importance.
Parotid saliva samples from 24 alcoholic subjects without evidence of cirrhosis were analyzed for changes in flow rate, composition, and epidermal growth factor (EGF) secretion. Mean (+/- SE) stimulated parotid saliva flow rate (ml/min/gland) was significantly (p less than 0.01) lower in alcoholic subjects than in matched control subjects. Reduction in parotid saliva flow rate was associated with significant (p less than 0.05) decrease in total protein and amylase secretion in this group of patients. In addition, secretion of immunoreactive EGF, a specific salivary protein, was also markedly reduced (p less than 0.05) in alcoholic patients. None of the parotid saliva samples from the alcoholic subjects had detectable bioactivity of EGF in saliva. These data suggest that chronic alcohol ingestion is associated with significant changes in parotid saliva secretion and its composition, which may perpetuate and compound ethanol-induced injury to the upper gastrointestinal tract.
Salivary gland dysfunction is uniformly detrimental to the oral cavity. Its effects on the GI tract have begun to be explored. Dry mouth is a common complaint among older adults, probably due to systemic disease and its therapy rather than the aging process per se. Evaluation of complaints of dry mouth should include medical history, sialometry and physical examination. Numerous medications can elicit drug-induced xerostomia. Patients who have received radiation therapy to the head and neck region often have permanent radiation-induced xerostomia, which has been linked to esophagitis. SS is an autoimmune systemic exocrinopathy resulting in irreversible salivary gland dysfunction. SS has numerous GI manifestations, including dysphagia, temporal defects of deglutition, esophageal dysmotility, gastritis, pancreatitis and liver disease. Management of salivary hypofunction is directed toward preserving the dentition and improving patient comfort. Drug-induced xerostomia is often correctable by altering the therapeutic modality.
We have evaluated the possible relationship between major salivary gland fluid secretion rate and characteristics of the oral phase of swallowing in 35 different-aged, healthy men and women. All subjects displayed normal function of the parotid and submandibular glands and oral swallow patterns on ultrasound evaluation that were comparable to previous reports. In this study group we found no significant relationships between salivary flow rates (unstimulated, stimulated) and any oral swallow measure. Evidence of a subtle, age-related oral motor change (multiple hyoid and tongue gestures) was seen but swallow duration times did not show a linear relationship to age. This study demonstrates that healthy individuals, despite a wide range in their salivary gland fluid secretory capacity, are generally similar in the characteristics of their oropharyngeal swallow.