The Effect of Stress and Meditation on Salivary Protein and Bacteria: A Review and Pilot Study

Abstract

Dentally-induced stress and relaxation-induced anxiety reduction have been correlated with salivary changes in dental patients in two recent studies. In two subsequent studies, test anxiety-induced stress and relaxation-induced anxiety reduction were correlated with salivary changes in dental students. In another study using the resazurin dye indicator, increased salivary bacterial levels were correlated with an increased dental caries incidence. As a result of these findings, it was decided to reinvestigate the effects of stress and relaxation on salivary changes and in addition to examine the effects of those conditions on salivary bacteria. The hypotheses under consideration were: (1) Salivary changes from stress to relaxation will be from opaque to translucent and from high to low protein levels; and (2) salivary bacteria will increase under the condition of stress and decrease under the condition of relaxation. The subjects were twelve dental students. Stress and relaxation were evaluated before and after meditation by verbal reports and examination of saliva for opacity, translucency, protein and bacteria (resazurin dye method). There were significant anxiety-reduction changes by the end of the meditation sessions (p < 0.001) as measured by increased salivary translucency, decreased salivary protein and reduced subjective evaluation of stress. Using the resazurin dye method, bacterial levels showed a significant decrease by the end of the meditation sessions (p < 0.001). The results support hypothesis 1 and reaffirm previous findings in regard to the effectiveness of: (1) salivary changes as measures of stress and relaxation; and (2) meditation to induce deep relaxation. The finding of high bacteria levels under stress and lower bacterial levels under relaxation supports hypothesis 2 and indicates that stress may contribute to dental caries and relaxation may have an anti-caries effect.