RESUMEN
Multifactorial nature of chronic periodontitis is well known. The data indicate that the bacteria of subgingival biofilm (with their presence at high levels, too), as well as the immune response of the organism, genetic components and environmental factors play a significant role in the development of periodontal destructive disease. On the one hand the strong relationship between microorganisms from the "red complex" has been proved. On the other hand the initiation and progression of chronic periodontitis has been verified, as well. The presence of bacterial metabolic products and other substances (lipopolysaccharides, enzymes and toxins) results in increased expression of proinflammatory cytokines and release of active agents leading to the development of a local tissue lesion. Thus, the negative (destructive) side of the immune response is expressed and associated with the immunopathological nature of periodontitis. Literary data testify the importance of interleukin-8 (IL-8) in regulating the inflammatory response to bacterial infection and suggest its association with susceptibility to periodontitis.