Altered Peripheral Blood mRNA and Salivary Biomarkers in Dental Anxiety: A Cross-Sectional Study

Introduction: Previous studies show that the hypothalamic pituitary adrenal (HPA) axis and sympathetic adrenal medulla (SAM) in saliva of patients with dental anxiety (DA) exhibit elevated salivary cortisol and amylase. However, underlying molecular mechanisms remain unclear. This study quantitatively analyzed the mRNA expression of glucocorticoid receptor (GR), GR transcripts containing exons 1B (GR-1B), GRIA1 (Glutamate Ionotropic Receptor AMPA Type Subunit 1), oxytocin (OT), oxytocin receptor (OTR), and Poly ADP-Ribose Polymerase 1 (PARP1) in peripheral blood, and measured salivary cortisol and alpha-amylase to explore their correlation with dental anxiety. Methods This study included a total of 30 DA patients and 28 non-DA patients. The peripheral blood mRNA expressions for GR, GR-1B, GRIA1, OT, OTR, PARP1 genes were determined by real-time quantitative polymerase chain reaction. Salivary cortisol and alpha-amylase concentrations were determined via Enzyme linked immunosorbent assay. Results The expression levels of GR-1B mRNA in DA were significantly higher than those in non-DA, while the expression levels of GRIA1 and OT mRNA were lower than those in non-DA. Concurrently, salivary cortisol and alpha-amylase levels were significantly higher in DA. Conclusion Dental anxiety may be related to HPA axis related expression. Salivary biomarkers (cortisol/α-amylase) and peripheral blood mRNA markers (GR1B, GRIA1, OT) may serve as potential screening tools.