Buffering capacity of saliva, salivary flow rates and cortisol levels in patients with active caries
Date
2013-03-18
Authors
Hira, Priyesh Gunvant
Journal Title
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Abstract
Introduction: Dental caries is caused by the interaction of the host, oral flora and diet. Stress is
one of the host factors implicated. Studies have shown that there is an association between
stress and salivary cortisol levels. However, no studies have investigated the relationship
between stress, salivary cortisol levels and caries susceptibility. Aims and objectives: The aim
of the study was to determine whether there is a correlation between active dental caries, resting
and stimulated flow of saliva, salivary buffering capacity, saliva cortisol levels and stress in
patients attending a general dental practice in Lenasia South. Methods and materials: Sixty
subjects between the ages of 18 and 60 were included in the study. Thirty controls with no active
caries, a minimum of 28 teeth and a mean decayed, missing filled surfaces (DMFS) score of 4 or
less, and 30 subjects with active caries were included in the study and formed the experimental
group. Patients with Sjögren’s Syndrome or connective tissue diseases, on medication that may
cause xerostomia, or a history of previous or current irradiation were excluded from the study. At
the initial visit resting and stimulated saliva samples were collected and the volume was
measured. The buffering capacity and cortisol levels of the resting saliva samples were
measured. In addition the Depression Anxiety Stress Scales (DASS) questionnaire was used to
determine the stress levels of the participants. The teeth of the subjects with active caries, i.e.
the experimental group, were restored. They returned after 4 weeks for a follow up visit and their
resting and stimulated salivary flow, buffering capacity of saliva, salivary cortisol and the stress
levels were measured. The results were compared using the two sample t test, chi – squared test
and a generalized logistic regression analysis. Results: The DMFS of the control group,
0.40 + 0.97, was significantly lower (p < 0.001) than 29.27 + 21.94, in the experimental group. No
significant differences were found between the controls and caries prone subjects when the
resting flow rates, 0.37 + 0.30 ml/min and 0.32 + 0.19 ml/min; stimulated flow rates,
0.99 + 0.56 ml/min and 0.84 + 0.35 ml/min; buffering capacity of saliva,
19.16 + 4.68 ml 0.01N lactic acid and 21.73 + 9.77 ml 0.01N lactic acid, were compared and the
salivary cortisol levels of the controls 17.71 + 22.51 ng/ml, were higher than 11.80 + 14.61 ng/ml
in the the caries prone subjects. The DASS scores of the two groups were similar,
i.e. 11.33 + 8.48 and 11.2 + 9.6, respectively. After the carious teeth of the caries prone subjects
were restored, the flow rate of resting saliva increased from 0.32 + 0.19 ml/min to
0.37 + 0.16 ml/min, the stimulated saliva from 0.84 + 0.35 ml/min to 0.88 + 0.32 ml/min and the
buffering capacity of saliva from 21.73 + 9.77 ml 0.01N lactic acid to 22.25 + 7.55 ml 0.01N lactic
acid and the salivary cortisol levels decrease from 11.80 + 14.61 ng/ml to 10.00 + 12.12 ng/ml.
Again none of these differences were significant. Conclusion: These results suggest that stress
levels measured by the DASS questionnaire may not be related to caries. A less subjective
questionnaire may find a relationship between salivary cortisol levels, stress and dental caries.