Clinical significance of bacterial resistance to tetracyclines in the treatment of periodontal diseases.

Tetracyclines are frequently employed during the treatment of clinical infections in medicine and dentistry, however, emergence of resistant bacterial strains has decreased the utility of these drugs. Accordingly, there is concern that indiscriminant administration of tetracyclines during periodontal therapy will further contribute to the development of additional resistant microorganisms which can complicate infectious disease therapy. This review paper briefly discusses the utility of tetracyclines as an antimicrobial agent in the treatment of periodontal diseases. It then focuses on the clinical significance of bacterial resistance to tetracyclines. Patterns of resistance that may be associated with the following scenarios are addressed: short- and long-term antibiotic therapy, individuals with a history of prior tetracycline therapy, patients with refractory periodontitis, and following controlled local drug delivery. It appears that selection and development of bacterial resistant strains is an inevitable consequence of antibiotic therapy. Nevertheless, prudent administration of tetracyclines may help delay or prevent the emergence of resistant microorganisms.