Evaluation of Osteoprotegerin (OPG) and Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL) Biomarker Concentrations in the Saliva of Patients with Periodontitis and Depression.

BACKGROUND AND

OBJECTIVES

Periodontitis is a chronic inflammatory disease affecting tooth-supporting structures, while depression is a common mental disorder with emotional and behavioral disturbances. Previous studies suggest a potential association between the two conditions. This study aimed to evaluate salivary concentrations of Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL) and Osteoprotegerin (OPG)-key regulators of osteoclast activity and periodontal bone resorption-in patients with periodontitis and depression.

MATERIALS AND

METHODS

In this cross-sectional study, 80 patients from Shahid Beheshti University Dental School were categorized into four groups based on the presence or absence of periodontitis and depression. Periodontitis was defined as having ≥ 2 teeth in ≥ 2 quadrants with bleeding on probing, pocket depth > 3 mm, and interdental clinical attachment loss ≥ 1 mm. Depression was assessed using the Persian PHQ-9, and individuals meeting criteria for major depressive disorder(MDD) were classified as depressed. Unstimulated saliva samples (1 mL) were collected, stored at -20°C, and analyzed for OPG and RANKL using ELISA kits. Statistical analyses included two-way ANOVA (SPSS v27; p < 0.05 significant).

RESULTS

Among 80 participants (43 females, 37 males; mean age 45.3 years), RANKL, OPG, and the RANKL/OPG ratio were higher in depressed individuals, but differences were not statistically significant (p > 0.05). RANKL levels and the RANKL/OPG ratio were significantly higher in patients with periodontitis and increased with disease severity (p ≤ 0.05), while OPG showed no significant change.

CONCLUSION

Periodontitis and its severity significantly influence salivary RANKL and the RANKL/OPG ratio, while depression does not. Within the limits of this cross-sectional design, no evidence was found that RANKL and OPG act as intermediary biomarkers linking depression and periodontitis.