Pathogenic Mechanisms of Periodontal Pathogens: Implications for Diagnosis and Therapy

Periodontitis is prevalent chronic inflammation of the oral cavity that significantly affects world oral health and has intimate relationships with systemic diseases, such as cardiovascular illness and diabetes mellitus. Probing and scaling with adjunctive antibiotics are limited by sensitivity, specificity, and long-term success. Increasing evidence proves that periodontopathogenic microbes are centrally involved in disrupting hostmicrobe homeostasis and perpetuating chronic inflammation. Among the most characterized species, Porphyromonas gingivalis, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans harbor virulence components, such as adhesins, proteases, and leukotoxins, that enable epithelial invasion, modulation of immune responses, and breakdown of the extracellular matrix, leading ultimately to progressive destruction of tissues and alveolar bone resorption. The pathogens also induce host immune signal pathways, such as NF-B and MAPK cascades, thereby augmenting inflammatory responses and immune escape. Novel advancements of identification of diagnosable biomarkers, molecular detection strategies, and host-modulatory interventions have broadened the horizons of management. Nevertheless, huge challenges persist because of microbial diversity, stability of biofilms, and individual variability. This review aims at fostering mature understanding of interactions of microbes with the host at periodontitis and at outlining modalities of targeted interventions, immunomodulation, and preventive strategies resulting in successful management at the clinic.