From Plaque to Dysbiosis: Evolving Concepts in Periodontal Pathogenesis: A Narrative Review

Periodontal diseases are chronic inflammatory conditions and a leading cause of tooth loss globally. Traditionally viewed through a plaque-centric lens, the understanding of periodontal pathogenesis has evolved significantly from the non-specific and specific plaque hypotheses to the contemporary dysbiosis model. This narrative review explores the transition from simple bacterial infection theories to a complex framework where periodontitis is recognized as a host-mediated dysbiotic inflammatory disease. The review details the roles of "keystone pathogens" like Porphyromonas gingivalis, the "inflammophilia" of microbial communities, and the critical "IMPEDE" model which links inflammation to disease progression. Furthermore, it examines the mechanisms of host-mediated tissue destruction, including the RANK–RANKL–OPG pathway and the impact of systemic modifiers like diabetes and smoking. Integrating these modern concepts is essential for moving beyond mechanical debridement toward precision-based periodontal therapy and host modulation.