DEFINITION

• Periodontitis: a common complex chronic inflammatory disease characterized by destruction of the supporting structures of the teeth (the periodontal ligament and alveolar bone).
• In its early stages, the condition is typically asymptomatic, and many patients are unaware of the condition until it has progressed enough to result in tooth mobility.
• There are greater than 700 species of bacteria in the oral environment and 100 billion bacteria in the oral biofilm; and is a continuous source of infectious agents that could serve as an important risk factor.
• Periodontal pathogens alone are insufficient to provoke the disease process:a genetically ’susceptible host’ is required.
• There is a clear ’two way’ relationship between the degree of hyperglycemia and severity of periodontitis compared with patients with normal glucose tolerance.
• The inflammatory response is characterized by dysregulated secretion of host-derived mediators of inflammation and tissue breakdown.
• Differences in clinical disease expression are related to both variations in pathogens and host response.