Table 1 Selected studies for the systematic review

Publication

1. Rai K et al., 2010 India [44]

Study design

Quasi-experimental study (experimental group with 5 or more active caries lesions, history of pain; controls without caries history)

Study Sample

n = 60, children aged 5–10 years

Stressor/Stress measure

Dental treatment (e.g., oral prophylaxis, fluoride application, sealants, pulp therapy); done only for the experimental group

Stress measure: saliva cortisol

Salivary parameters

Unstimulated whole saliva;

Saliva cortisol collected before treatment and in 1, 2, 3 months after treatment; the time of the day was not indicated

Measurement method: ELECSYS Immunoassay

Follow-up

No follow-up measurement for the control group

Caries measurement

DMFT and dmft index, WHO, 1997

Statistical test

Willcoxon signed rank test

Main results

Children with rampant caries had higher saliva cortisol level at the baseline then control group (p < 0.05). The baseline salivary cortisol level in children with rampant caries decreased gradually when observed for a period of three months following dental treatment.

Publication

2. Kambalimath et al., 2010 India [43]

Study design

Quasi-experimental study (experimental group with at least one carious lesion; controls without obvious caries)

Study Sample

n = 30, children aged 4–5 years

Stressor/Stress measure

Oral prophylaxis and topical fluoride treatment done for experimental and control groups

Stress measure: saliva cortisol

Salivary parameters

Unstimulated whole saliva;

Saliva cortisol collected before/after treatment (between 1 pm to 4 pm) at first and second appointments;

Measurement method: Radioimmunoassay

Follow-up

Yes (first appointment post- treatment; recall appointment in one week)

Caries measurement

Not reported

Statistical test

T-test

Main results

No significant differences were found between the salivary cortisol levels prior to treatment, post oral prophylaxis, or post fluoride treatment at the first and second appointments of both groups (p > 0.05).

Publication

3. Yfanti et al., 2014 Greece [40]

Study design

Quasi-experimental study

dmft≥3 – high degree of dental caries;

dmft≤2 – low degree of dental caries

Study Sample

n = 97, children aged 6–10 years

Stressor/Stress measure

Dental treatment: a cleaning with rotary instruments or a small restorative procedure with the use of local anesthesia

Stress measures: saliva cortisol; dental anxiety questionnaires

Salivary parameters

Stimulated whole saliva;

Saliva cortisol collected before, after treatment (in 30 min) same day, same night, next morning, at recall Measurement method: Electrochemiluminescence

Saliva alpha amylase collected before and after treatment, at recall.

Measurement method: Enzymatic chromatometry

Follow-up

Yes (post-treatment, same night, next morning, recall visit in 7–14 days)

Caries measurement

DMFT (S), dmft (s), Koch criteria, 1970

Statistical test

Univariable linear regression

Main results

No significant associations were detected between cortisol and sAA levels and caries (p > 0.05).

Publication

4. Boyce et al., 2010 USA [30]

Study design

Cross-sectional study

Study Sample

n = 94, children ages 5–6 years from low SES families participating in a longitudinal study

Stressor/Stress measure

SES, family financial stress;

Stress measure: saliva cortisol

Salivary parameters

Stimulated whole saliva;

Salivary cortisol collected at first and last 20 min of the morning /evening school class, at the same time on each of three consecutive days.

Measurement method: Immunoassay

Follow-up

No

Caries measurement

DMFS, WHO, 1997

Statistical test

Multivariate Poisson regression

Main results

Low SES, higher basal salivary cortisol secretion, and larger numbers of cariogenic bacteria associated with higher number of caries lesions (p < 0.001). The strongest risk factor for development of dental caries was the joint presence of heightened expression of salivary cortisol and high levels of cariogenic bacteria.

Publication

5. Barbosa et al., 2012 Brazil [31]

Study design

Cross-sectional study

Study Sample

n = 145, school children aged 8–14 years, low socio-economic status

Stressor/Stress measure

Stress measures: saliva cortisol; RCMAS (revised children’s manifest anxiety scale); CDI (children’s depression inventory)

Salivary parameters

Stimulated whole saliva;

Diurnal decline (morning-night) in salivary cortisol

Measurement method: Immunoassay

Follow-up

No

Caries measurement

dmft, DMFT, WHO, 1997

Statistical test

T test

Main results

Participants who experienced more dental caries had lower diurnal declines of salivary cortisol concentrations than participants with low caries experience (p < 0.05). No differences in anxiety and depression scores between individual with and without caries.

Publication

6. Pani et al., 2013 Saudi Arabia [45]

Study design

Cross-sectional study

Study Sample

n = 64, college-educated, working mothers aged 24–31 years

n = 64 first born children aged 49–70 months

Stressor/Stress measure

Stress measure: salivary cortisol

Salivary parameters

Unstimulated whole saliva;

Saliva cortisol collected two hours after waking up.

Measurement method: Immunoassay

Follow-up

No

Caries measurement

DMFT (mothers) or dmft (children), WHO, 1997; bitewing radio-graphs

Statistical test

Mann-Whitney U test; Logistic regression

Main results

The mean salivary cortisol levels of children with ECC were significantly higher than caries free children (p < 0.001). The mean salivary cortisol levels of mothers of children with ECC were significantly higher than those of mothers of caries free children (p < 0.05). A significant correlation was determined between the salivary cortisol level of the mother and that of the child (p < 0.001).