What type of bacteria predominate in a periodontal pocket?

As periodontal disease progresses and pockets deepen, the subgingival microbial environment shifts toward a predominance of Gram-negative, anaerobic organisms (such as Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola), in contrast to the largely Gram-positive, aerobic flora of healthy sulci.