| Abstract | Slina sadrži prirođene mehanizme obrane kao dio nespecifičnoga imuniteta. Topivi
receptor CD14 (sCD14) u slini posreduje u prepoznavanju gram-negativnih i grampozitivnih bakterija, a koje mogu sudjelovati u razvoju demineralizacije tvrdih zubnih
tkiva uzrokovanih karijesom. Svrha istraživanja bila je utvrditi koncentraciju sCD14 u
nestimuliranoj i stimuliranoj slini odraslih osoba s karijesom i bez karijesa, kako bi se
odredila njegova potencijalna uloga biljega za karijes. Uzorak se sastojao od ukupno 88
zdravih ispitanika, dobi od 20 do 40 godina. Podijelili smo ih u tri skupine: 28 ispitanika
bez karijesa činili su kontrolnu skupinu, 30 ispitanika s 1 – 5 karijesa činili su prvu
eksperimentalnu skupinu (E1) te 30 ispitanika s 6 i više karijesa činili su drugu
eksperimentalnu skupinu (E2). Metode koje su se rabile za prikupljanje sline su metoda
sa stimulacijom salivacije i bez stimulacije salivacije. U uzorcima sline odredili smo
protok sline, pH-vrijednost i puferski kapacitet sline. Za određivanje koncentracije sCD14
koristili smo „sendvič“ imunokemijski test ELISA, a dentalni status registriran je pomoću
Indeksa karijesa zuba (DMFT) i Indeksa karijesa ploha (DMFS) te su se karijesne
promjene dodatno mjerile uređajem KaVo DIAGNODent Pen (DDPen) kako bi se bolje
odredila jačina demineralizacije patoloških promjena. Rezultati su pokazali statistički
značajno veću (p = 0,007) koncentraciju receptora sCD14 u nestimuliranoj slini ispitanika
s karijesom obiju eksperimentalnih skupina u odnosu na kontrolnu skupinu ispitanika.
Prediktivna vrijednost koncentracije sCD14 u nestimuliranoj slini za pojavu karijesa bila
je statistički značajna (p = 0,002). Zaključci koji se mogu izvesti iz istraživanja jesu da
povećana koncentracija receptora sCD14 u nestimuliranoj slini može biti potencijalni
biljeg za prisutnost karijesa. Osim koncentracije receptora sCD14 u nestimuliranoj slini,
kao statistički značajan prediktor pojave karijesa, pokazao se i puferski kapacitet
stimulirane sline. |
| Abstract (english) | Introduction: Caries is a microbiologically caused disease that still affects
humanity to a great extent. There has been a great deal of emphasis on the development of
methods for assessing caries risk, identification of biomarkers and vaccine development
strategies to control the incidence of caries, a disease with a known cause. Immunologic
response plays an essential role in the development of caries. Saliva contains an inherent
defense mechanisms as part of nonspecific immunity. The soluble receptor CD14 in the
saliva, mediates in the recognition of Gram-negative and Gram-positive bacteria that can
participate in the development of demineralization of hard dental tissue caused by caries.
Previous studies did not investigate the relationship of sCD14 concentration in the saliva
and caries activity, collected from adults. Only saliva collected from children and
adolescents was tested, and the results showed differing conclusions.
Objectives: The aim of this study was to determine the concentration of salivary
sCD14 and salivary flow rate, pH and buffer capacity, in order to determine its potential
role as a biomarker for caries activity. The aim was also to determine the dental status of
all participants and to evaluate the prevalence of demineralization of hard dental tissues.
Participants and methods: The sample consisted of a total of 88 healthy subjects,
20-40 years of age. Participants completed a questionnaire (illness, drugs, consummation
of acidic drinks, sugar intake, smoking habits...) and informed consent. Excluding factors
were: using anti-inflammatory drugs 2 weeks prior to saliva collection, illness, pregnancy,
and chronic and acute infectious diseases. Then a clinical examination was performed to
determine the dental status of each participant, using a mirror, dental probe and KaVo
DIAGNOdent Pen because of its diagnostic values and to determine the strength of the
demineralization of caries lesions.
Excluding factors were: bleeding on probing, calculus, inflammations of oral
mucosa, ongoing dental treatment (endodontics, sutures of oral mucosa...), and missing
majority of teeth. Dental status was recorded using the DMFT and DMFS index.
Participants were divided into three groups: 28 subjects without caries were the control
group, 30 subjects with 1-5 caries were the first experimental group (E1) and 30 subjects
with 6 and more caries were the second experimental group (E2). Methods used for
collecting saliva samples were with stimulation (by chewing paraffin wax) and without
stimulation of salivary secretion. In the saliva samples the flow of saliva, pH and buffer
capacity of saliva is then determined. The concentrations of the sCD14 in all saliva
samples were determined using matrix-matched commercial enzyme-linked
immunosorbent assay ELISA.
Results: The results showed a statistically significant (χ2 = 9.86; ss = 2; p = 0.007)
higher concentration of sCD14 in resting saliva samples of participants with caries, both
experimental groups (median E=198.0 ng/mL and E2=210.9 ng/mL) compared to the
control group (178.4 ng/mL). With the unit increase in sCD14 concentration in resting
saliva samples, the emergence of caries increased by 1%. The sensitivity of the sCD14
concentration in resting saliva for caries recognition was 68%, while the specificity was
57%. Both measures were in optimum ratio at 182.9 ng/mL concentration of sCD14 in
resting saliva. The predictive value of sCD14 concentration in resting saliva (area below
ROC curve = 0.70) for caries was statistically significant (p = 0.002). The median DMFS
index was: for the control group 32, and for groups E1 and E2 30 and 28, respectively (the
difference between the groups were not statistically significant). In this study, the control
group had a statistically significant higher number of missing tooth surfaces (p = 0.036)
and surfaces with filling (p = 0.001) compared to experimental groups. Participants of the
E2 group with caries localized in the lateral region of the dental arch exhibited a
statistically significant higher concentration of sCD14 in resting saliva (p = 0.003) with
respect to the control group, rather than the E1 group. According to the same localization
of caries in the dental arch, the difference for the E1 group was marginally statistically
significant (p = 0.058). There was no statistically significant correlation between the
concentration of sCD14 in saliva and the measurement of caries lesions by KaVo
DIAGNOdent Pen device at different localizations in the dental arch.
The median pH of resting and stimulated saliva did not show a statistically
significant difference between the groups (control=7.3, E1 and E2=7.2), and no
statistically significant association between the pH of saliva and concentration of sCD14
in saliva was observed. The higher buffering capacity of the stimulated saliva was
statistically significantly related to the lower concentration of sCD14 in the stimulated
saliva. Subjects with medium (pH 4.5-5.5) or low (pH <4.5) buffer capacity of stimulated
saliva had a four-fold greater chance of developing caries compared to subjects with high
buffering capacity (pH = 5.5).
Conclusions: The increased concentration of sCD14 in the resting saliva can be
used as a potential marker for the presence of caries. In addition to the concentration of
sCD14 in resting saliva, a statistically significant predictor of caries activity also showed
to be the buffering capacity of the stimulated saliva and the subjects with caries also had
decreased flow rate of resting saliva as an important defensive factor by the host. Saliva
collection methods and salivary sCD14 concentration determination are not standardized,
which can be a problem for the interpretation of the results, in this type of study. Further
studies in the future are required in order to achieve standardization for the collection of
saliva samples and standardization of determination of salivary sCD14 concentration for
a better performance of its role as a potential marker for carious activity. |
