[Prophylaxis--duty of the patient or challenge for the dentist?]

Effective preventive treatment requires detailed knowledge of the etiological factors which contributed to the respective disease. For this reason, the various concepts of infectious disease that were discussed at one time or another are presented here. Special attention is given to the nonspecific and the specific plaque hypotheses. Current preventive strategies are based, however, on the concept of "opportunistic infections", which is scientifically well-documented and has been described in much detail. The following three preventive strategies are feasible: (1) eliminating plaque regularly and completely; (2) eliminating plaque to the level of the individual patient's characteristic limits for the disease in question; and (3) effecting changes in the microbiological composition of the plaque in order to eliminate the more highly pathogenic organisms and possibly to replace them with less pathogenic organisms.