This special issue focuses on the critical role of biomarkers in understanding oral diseases and the progression of periodontitis. Oral health is intimately linked to systemic well-being, and periodontitis remains one of the most prevalent chronic inflammatory conditions worldwide, often leading to tooth loss and contributing to systemic disorders such as diabetes and cardiovascular disease. Recent advances in molecular biology and diagnostic technologies have expanded the search for reliable biomarkers that can aid in early detection, monitoring disease activity, predicting treatment outcomes, and assessing individual susceptibility. 

The issue highlights a wide spectrum of biomarkers, ranging from classical inflammatory mediators such as cytokines and matrix metalloproteinases to emerging molecular indicators, including microRNAs, salivary proteins, and metabolites identified through high-throughput omics platforms. Special attention is given to non-invasive approaches, particularly salivary and gingival crevicular fluid analysis, which offer promising avenues for personalized diagnostics. Additionally, contributions examine how biomarker research intersects with precision medicine, opening possibilities for tailored interventions and improved patient management.

By integrating clinical, molecular, and translational perspectives, this collection aims to advance the understanding of oral disease mechanisms and support the development of biomarker-based strategies that enhance early diagnosis, guide therapeutic decisions, and ultimately improve oral and systemic health outcomes.