Topical tetracycline: potential for allergic reaction or bacterial resistance.

The high incidence of allergic reactions to some common dental antibiotics, primarily topical penicillins, has led to general concerns about all topical antibiotics. The development of resistant bacterial strains and efforts to reserve key antibiotics for life-threatening infections have also limited topical use of antibiotics. Delivery technologies providing for site-specific drug delivery have renewed interest in the use of topical antimicrobials to treat adult periodontitis. Topical tetracycline has an extremely low sensitizing potential and is not one of the antibiotics reserved by the medical community for use in life-threatening situations. Despite tetracycline's widespread dermatologic use and increasing use in adjunctive treatment of adult periodontitis, the incidence of allergic response to topical tetracycline is very low. Also, it is unlikely to cause resistance when used locally for short durations--particularly at the high per-site concentrations achieved with tetracycline periodontal fiber. Studies with tetracycline fiber showed no significant change in the tetracycline susceptibility of gram-negative periodontal microorganisms.