Salivary biomarkers for assessing bone turnover in periodontal diseases

Abstract

Introduction: Periodontal disease is a highly prevalent chronic inflammatory condition causing alveolar bone loss and tooth instability. Therapy aims to promote regeneration. Traditional diagnostic tools are often invasive, highlighting the need for non-invasive methods capable of monitoring active bone remodeling. Objectives: This study aimed to evaluate the potential of salivary biomarkers, specifically the gene expression of RUNX2 and ALPL, as indicators of bone turnover in periodontal disease. A secondary objective was to compare gene expression levels before and after regenerative therapy, and to relate molecular changes with radiographic findings and clinical observations. Materials and Methods: Following ethical approval (October 2023), this longitudinal study collected data at baseline and approximately 3 and 6 months. Seventeen patients provided unstimulated saliva before and after surgery. Radiographs were obtained and complemented by RNA extraction, cDNA
synthesis, and analyzed by RT-qPCR. Gene expression was quantified using the 2–ΔCt method with GAPDH as reference. Results: Patients with periodontitis demonstrated increased expression of RUNX2 and ALPL post-treatment, consistent with active bone remodeling. Radiographic analysis showed reduced radiolucency in treatment areas, suggesting new bone formation. These findings were also supported by clinical observation of healthy patients showed minimal genetic expression variation. Conclusion: The integration of salivary gene expression analysis with radiographic assessment offers a promising, non-invasive method to monitor bone regeneration in periodontal therapy. Biomarkers such as RUNX2 and ALPL may support personalized evaluation of treatment outcomes.

Date of Award	25 Jul 2025
Original language	English
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Ana Sofia Duarte (Supervisor), Tiago Marques (Co-Supervisor) & Karina Mendes (Co-Supervisor)