Oral ecology and its pathogenic relation with the origin of primary periodontitis associated with plaque.

Microbial factors involved in the genesis of periodontitis are related with supragingival (coronal) and subgingival plaque. The microorganisms in the supragingival plaque reach the gingival sulcus, and are influenced by ecological determinants in this zone which condition the establishment of adherent plaque. This plaque may subsequently form the substrate for particularly periodon to pathogenic bacteria, which may then form plaques adhered to the epithelium, or develop as floating (nonadhered) populations. After microbial colonization of the gingival sulcus, bacteria or substances they produce may reach the junctional epithelium and alveolar bone, leading to direct tissular destruction to an extent determined by the host's immune response. Damage may be local or generalized, depending on additional factors.