Periodontal disease is predominantly a bacterial infection involving the dental biofilm or dental plaque. Some of the principal periodontal pathogens of the subgingival microbiome have been identified to have virulence potential and are associated strongly with the etiology and the pathogenesis of periodontal disease. Biofilms which cause gingivitis and periodontitis are site-specific, complex polymicrobial communities that are resistant to antimicrobial agents and host defense mechanisms. However, the concept that the rate of progression, age at onset, and severity of periodontal disease in...