TISSUE CONCENTRATION AND LOCALIZATION OF TETRACYCLINE FOLLOWING SITE-SPECIFIC TETRACYCLINE FIBER THERAPY

THE PRIMARY OBJECTIVE OF THIS STUDY was to evaluate the concentration and location of tetracycline hydrochloride in tissue adjacent to periodontal pockets treated with a tetracycline impregnated fiber. A secondary objective was to determine if the presurgical placement of fibers had any adverse effects on healing following periodontal surgery. The study population consisted of 10 patients with at least 2 pockets in both maxillary quadrants of greater-than-or-equal-to 5 mm in depth and exhibiting bleeding on probing. After an initial scaling and root planing, placebo or tetracycline fibers were randomly assigned by quadrant to 2 non-adjacent pockets. Fibers were removed at the time of surgery; i.e., day 8, and periodontal surgery was performed utilizing a flap incision that allowed biopsy of 1 interdental papilla from each of the 2 test sites in each quadrant. One biopsy was analyzed for tetracycline concentrations by high performance liquid chromatography (HPLC). The second biopsy was examined by both light and ultraviolet fluorescence microscopy to determine the location of residual tetracycline and the intensity of inflammatory cell infiltrates. Results showed that the tissue concentration of the antibiotic in tetracycline treated sites was 64.4 +/- 7.01 ng/mg (ng of tetracycline/mg tissue weight) which corresponds to 43 mug of tetracycline and was below levels of accurate measurement in placebo treated sites. Tetracycline tissue concentrations corresponded to the ultraviolet fluorescence microscopy with a Pearson correlation coefficient of r = 0.92. Tetracycline fluorescence was noted in the soft tissue wall ranging from 1 to 20 mum. No significant difference was noted when comparing 3 and 6 months post-surgery attachment levels, probing depths, bleeding points, or gingival health between placebo and tetracycline fiber treated sites, indicating no adverse effects on healing and probing depth reductions. These results indicate that presurgical use of site-specific, controlled delivery of tetracycline does not interfere with post-surgical healing.