ABSTRACT: The current paradigm in relation to the etiology of periodontal disease was described in the 60's, itsubscribes to the non especific plaque hypothesis which asignes an increase of bacteria due to build up of plaque and calculus on the teeth. The bacterial products such as endotoxins, organic acids, enzymes etc overcome the host's ability to neutralize them. The disease will develop and progress in severity in a linear fashion until with age the teeth will be lost. The plaque forms in an universal and natural way in all people and if allow it will reach noxious levels within several days. The quality of plaque being present in healthy mouth when compared to the one found in periodontal and caries diseases do not show great difference. By the middle of the 70's the research progress in the anaerobic cuantitative culturing techniques and this gave rised to the specific plaque hypothesis which asignes specific bacteria with certain forms of in periodontal disease. The direct bacterial penetration of the tissues as an attacque mechanism conforms the scope of true infection in some forms of periodontal disease. Different therapeutic approaches have been utilized after the failure in arresting the disease by traditional procedures as mechanical instrumentation alone in the search of antherapeutic modality towards the specific etiologic agent.