The study design and baseline characteristics of a multicenter trial to test the effectiveness and safety of locally delivered tetracycline for treatment of adult periodontitis are described. Local delivery was provided by 0.5 mm diameter ethylene vinyl acetate copolymer fibers loaded 25% with tetracycline hydrochloride which were placed into periodontal pockets and maintained by an adhesive for 10 (+/- 2) days. A total of 113 subjects (56 male and 57 female; mean age 49.3 yr) at five centers participated in the study. Subjects were selected who had 4 nonadjacent teeth with 6-10 mm pockets that bled on probing. The selected sites in each subject were randomly assigned to 4 test groups: tetracycline fiber, control fiber, scaling with root planing, or untreated. A balanced experimental design was thereby established in which each subject contributed equally by providing 4 clinically comparable sites for evaluation. To provide a more specific model for testing periodontitis therapy, gingivitis was treated prior to the initiation of the study by prophylaxis with supragingival calculus removal and home care instruction. Clinical response variables measured were pocket depth reduction, attachment level gain and bleeding on controlled-force probing measured at baseline, 30 d, and 60 d. Levels of 6 bacterial species selected as probable periodontal pathogens were measured by DNA probe analysis of plaque samples. The design of this study provided several unique analytical opportunities. Controls included a comparison with conventional treatment, analysis of vehicle effects, and effects at untreated sites. Comparison of the test group with controls permitted evaluation of the principal variables that could effect interpretation of results.(ABSTRACT TRUNCATED AT 250 WORDS)

The safety and efficacy of periodontal disease treatment by intrapocket placement of tetracycline (TC) fibers was investigated in a 60-day multicenter study conducted by selecting 4 sites in each subject with 6-10 mm pockets that bled on probing. Sites were randomly assigned to 1 of 4 test groups: TC fiber therapy, scaling, control fiber (fibers without drug), or untreated. TC fibers and control fibers were placed to fill the pocket and were maintained with a cyanoacrylate adhesive for 10(+/- 2) d. Scaling was performed for a minimum of 5 min under local anesthesia. Following initial tooth cleaning procedures, pocket depth, attachment level and bleeding on controlled-force probing were measured at baseline and at 30 d, and 60 d following therapy. Analysis of data from 107 subjects who had complete clinical data sets indicated that TC fiber therapy significantly decreased pocket depth, increased attachment level, and decreased bleeding on controlled-force probing to a greater extent than observed in all other test groups including scaling. These effects were greater than, and in addition to, effects that occurred due to prophylaxis and improved home care. No serious adverse side-effects attributed to TC fiber therapy were observed. No TC fiber-treated sites abscessed and superinfection was not noted. A transient redness at fiber removal was seen at 21% of the sites. Although fibers were placed without anesthesia, mild pain on initial placement was infrequent (19%) and abated rapidly. The results indicate that TC fiber placement provides a safe and effective means for treatment of periodontal infections.