Antimicrobial agents in the treatment of periodontal diseases: special aspects on tetracycline and doxycycline.

Increasing evidence for the involvement of specific microorganisms in the etiology of human periodontal diseases has appeared during the last few years. The microorganisms most likely to cause periodontal disease are Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, Bacteroides intermedius and Capnocytophaga species. Many of the strains are resistant to tetracycline and doxycycline. Recently penicillin-resistant B. gingivalis and B. intermedius have also been described. A. actinomycetemcomitans strains and capnocytophaga strains are sensitive to tetracycline and doxycycline. This has raised the question if periodontal diseases are possible to treat with antimicrobial agents alone or in combination with scaling of the teeth and surgery. Although numerous studies with different antimicrobial agents have been published it is still controversial if antimicrobials agents have a role in the treatment of human periodontal diseases. Comparative randomized long term studies are still needed to answer this question.