A six-month comparison of three periodontal local antimicrobial therapies in persistent periodontal pockets

Background: Currently, several local antimicrobial delivery systems are available to periodontists. The aim of this 6-month follow-up parallel study was to evaluate the efficacy of three commercially available local delivery systems as adjuncts to scaling and root planing in the treatment of sites with persistent periodontal lesions. Methods: Seventy-nine patients with 4 pockets greater than or equal to 5 mm and bleeding on probing and/or suppuration were randomized into 4 treatment groups which included: scaling and root planing alone (S) (20 patients), or in conjunction with the application of 25% tetracycline fibers (S+Tet) (19 patients), or 2% minocycline gel (S+Min) (21 patients), or 25% metronidazole gel (S+Met) (19 patients). Clinical measurements were taken at baseline, 6 weeks, 3 months, and 6 months after antimicrobial application. Treatments were applied using the distributors' recommended protocols. Results: All 4 therapies resulted in significant improvements from baseline in probing depth, attachment level, bleeding on probing, and the Modified Gingival Index (MGI) scores. The improvements in clinical parameters were greater in all 3 adjunctive treatment groups than scaling and root planing alone. The mean probing depth reductions at 6 months were: scaling + tetracycline = 1.38 mm; scaling + metronidazole = 0.93 mm; scaling + minocycline = 1.10 mm; and scaling alone = 0.71 mm. The probing depth reduction at all time points was significantly greater in the scaling plus tetracycline fiber group than the scaling and root planing alone group (P<0.01). There was also a significant improvement for scaling plus tetracycline fiber application over scaling and metronidazole at both 6 weeks and 3 months, although this did not remain significant at the 6-month visit. While the frequency of sites with suppuration was markedly reduced following all antimicrobial treatments, the most effective reductions were seen in the scaling plus tetracycline fiber group, followed by the minocycline group. Conclusions: Although all 3 locally applied antimicrobial systems seem to offer some benefit over scaling and root planing alone, a treatment regimen of scaling and root planing plus tetracycline fiber placement gave the greatest reduction in probing depth over the 6 months after treatment.