Dental Anxiety Alters Stress-Related mRNA Expression and Elevates Salivary Cortisol, Alpha-Amylase.

Understanding the molecular underpinnings of dental anxiety (DA) is crucial, as it affects a significant portion of the population and often leads to avoidance of necessary dental care. Previous research has linked DA to activation of the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic-adrenal-medullary (SAM) system, evidenced by elevated salivary cortisol and alpha-amylase. However, the specific peripheral molecular mechanisms, particularly changes in gene expression related to stress response, remain largely unexplored. This study aimed to identify alterations in peripheral blood mRNA expression of key stress-related genes and their correlation with established salivary biomarkers in DA patients.

This cross-sectional study investigated 30 DA patients and 28 non-DA patients. Researchers collected peripheral blood samples to determine mRNA expression levels of glucocorticoid receptor (GR), GR transcripts containing exons 1B (GR-1B), glutamate ionotropic receptor AMPA type subunit 1 (GRIA1), oxytocin (OT), oxytocin receptor (OTR), and Poly ADP-Ribose Polymerase 1 (PARP1). These levels were quantified using real-time quantitative polymerase chain reaction (qPCR). Additionally, salivary cortisol and alpha-amylase concentrations were measured using enzyme-linked immunosorbent assay (ELISA) to correlate molecular findings with established stress biomarkers.

The study revealed significant differences in both peripheral blood mRNA expression and salivary biomarker levels between dental anxiety (DA) and non-DA groups. Specifically, GR-1B mRNA expression was significantly higher in the DA group compared to the non-DA group. Conversely, GRIA1 mRNA expression levels were significantly lower in the DA group, as were OT mRNA expression levels. These molecular changes were paralleled by alterations in established stress markers. Salivary cortisol levels were significantly higher in the DA group, indicating increased HPA axis activity. Concurrently, salivary alpha-amylase levels were also significantly higher in the DA group, reflecting heightened sympathetic-adrenal-medullary activation. No significant differences were reported for GR, OTR, or PARP1 mRNA expression in the abstract. These findings suggest a distinct molecular signature associated with dental anxiety.

GR-1B mRNA expression was significantly higher in the DA group, while GRIA1 and OT mRNA levels were significantly lower, alongside elevated salivary cortisol and alpha-amylase.