Which bacteria are primarily responsible for periodontitis?

Bacteria primarily responsible for periodontitis are indeed recognized as Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola. This grouping is often referred to as the "red complex," a term that describes these specific pathogens associated with periodontal disease due to their virulence factors and ability to thrive in the oral biofilm, which contributes significantly to periodontal inflammation and tissue destruction.

Porphyromonas gingivalis is particularly notable for its role in initiating periodontal disease; it produces various enzymes and toxins that can compromise host tissue and evade immune response. Tannerella forsythia and Treponema denticola also play crucial roles in the progression of periodontal disease by promoting inflammation and enhancing the pathogenicity of other bacteria in the biofilm.

In contrast, other options consist of bacteria less commonly associated with periodontitis. For example, Streptococcus mutans and Lactobacillus casei are typically related to dental caries rather than gum disease. Escherichia coli and Staphylococcus aureus are primarily known for their relevance in systemic infections rather than periodontal disease. Similarly, while Actinomyces naeslundii and Fusobacterium nucleatum can be present in periodontal conditions, they