BUFFERING CAPACITY OF SALIVA, SALIVARY FLOW RATES AND CORTISOL LEVELS IN PATIENTS WITH ACTIVE CARIES

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 Sjogren’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.