Debridement and local application of tetracycline in the management of persistent periodontitis. Clinical and microbiological results after 12 months.

AIM: The purpose of this study was to evaluate the clinical and microbiological efficacy of local delivery of tetracycline in persistent periodontal lesions after topical therapy. METHODS: A total of 44 bilateral pockets 4-5 mm deep and bleeding on probing were selected in 11 non-smokers patients, 22 treated by scaling and root planing plus tetracycline fibres (test sites) and 22 with scaling and root planing alone (control sites) in a split-mouth design. Bleeding on probing, probing depth and clinical attachment level were recorded at baseline, 6 and 12 months postoperatively. The prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus and Treponema denticola was monitored by PCR at baseline, fibres removal, 6 and 12 months following treatment. RESULTS: The improvements in clinical parameters were greater in the tetracycline than in the control group. The reduction of bleeding on probing scores was 86.4% and 40.9%, the decrease of probing depth was 2.25 mm and 1.19 mm and the gain of clinical attachment level was 2.04 mm and 0.64 mm for test and control groups, respectively, over the 12-month period. The adjunctive use of tetracycline consistently resulted in a lower percentages of sites with detectable levels of A. actinomycetemcomitans, P. intermedia and P. gingivalis, while no differences were detected between treatments in the prevalence of T. denticola and B. forsythus. The pathogens could be eliminated from 3 periodontal pockets by debridement alone and from 12 sites by tetracycline at 12 months. CONCLUSIONS: Tetracycline local delivery gave the greatest advantage in the long-term treatment of periodontal persistent lesions.