The effect of subgingival antimicrobial therapy on the levels of stromelysin and tissue inhibitor of metalloproteinases in gingival crevicular fluid.

Recent investigations imply that a key mechanism in the pathogenesis of periodontal disease may be the ability of oral microorganisms to induce production and/or activation of matrix metalloproteinases (MMPs) in the host tissues. It has been suggested that the pharmacologic inhibition of MMP activity could play an important role in achieving a desirable outcome in periodontal therapy. The efficacy of locally delivered antibiotics on the level of gingival crevicular fluid (GCF) stromelysin (SL) and tissue inhibitor of metalloproteinases (TIMP) on sites with a history of a poor response to mechanical treatment was studied. Fifty-two patients with 4 periodontal pockets > or = 5 mm and bleeding on probing were randomized into four groups of 13 patients. One group received scaling and root planing alone and the other three groups received scaling and root planing plus a locally delivered antimicrobial system. These included 25% tetracycline fiber, 2% minocycline gel, and 25% metronidazole gel. The GCF samples taken at baseline and 6 weeks after treatments were analyzed using an enzyme linked immunosorbent assay (ELISA). GCF SL levels significantly decreased after adjunctive tetracycline fiber (paired t-test, P = 0.020) and minocycline gel (paired t-test, P = 0.023) treatments whereas it remained almost unchanged in the other two groups. While the GCF TIMP level did not change significantly in the scaling and root planing alone group, it significantly increased for all three adjunctive antimicrobial treatments (for tetracycline fiber P < 0.001, minocycline gel P = 0.005, metronidazole gel P < 0.001). The use of adjunctive locally delivered antimicrobial systems, particularly the tetracycline family, may offer an advantage in changing the metalloproteinase profile of the GCF to one more compatible with periodontal health.