Topical application of tetracycline-HCl in human periodontitis.

Previous in vitro studies have suggested that tetracycline-HCl (TTC-HCl) is adsorbed and actively released from root dentin. The aim of the current study was to evaluate the binding to and release of TTC-HCl from human root dentin surfaces in vivo, and to evaluate the clinical utility of TTC-HCl irrigation as an adjunct to scaling and root planing. Experiment I utilized two contralateral mandibular single-rooted teeth which were examined in four adults with severe generalized periodontitis. One tooth in each patient was carefully scaled and root planed, under local anesthesia, and the other used as an unscaled control. Each subgingival root surface was irrigated for 5 min with an aqueous TTC-HCl solution at a concentration of 100 mg/ml. Gingival crevicular fluid samples were collected on paper strips for the next three weeks. The TTC-HCl concentrations in each sample were determined by the inhibition zone of B. cereus cultured on agar plates. The TTC-HCl concentrations in gingival crevicular fluid collected 15 min after irrigation were 3100 +/- 670 micrograms/ml from the scaled lesions and 4700 +/- 1300 micrograms/ml from the unscaled root surfaces. The antibiotic concentrations decreased logarithmically over the next 7 days; 1500 +/- 270 micrograms/ml and 1100 +/- 330 micrograms/ml at 2 h, 880 +/- 350 micrograms/ml and 1300 +/- 360 micrograms/ml at 6 h and 19 +/- 5 micrograms/ml and 31 +/- 26 micrograms/ml at 1 week for scaled and unscaled root surfaces, respectively. Results for week two and three indicated an average of over 8 micrograms/ml.(ABSTRACT TRUNCATED AT 250 WORDS)