The mainstay of treatment for patients with periodontal disease involves mechanical methods—professional cleaning and mechanical débridement of the plaque or calculus, including both the supragingival and infragingival plaque. The infragingival plaque is the plaque that forms inside the gingival pockets. If the gingival pockets are deep enough, surgery may be required to reduce pocket depth, thereby helping to limit the buildup of bacteria.
In addition to mechanical treatment, the use of antimicrobial agents, both systemic and topical, has been increasing because of the realization that periodontal disease is not merely an overgrowth of bacteria, but also a shift in bacterial species.
6,8 Topical treatment with either antibiotics or antiseptics has the advantage of delivering the antibacterial agent directly to where it is needed. Topical antibiotics include medications in the tetracycline family (eg, doxycycline, metronidazole, minocycline, and ofloxacin). Topical antiseptics include chlorhexidine-containing formulations, povidone-iodine, and sodium hypochlorite.
Systemic antibiotics reach the gingival pockets through the gingival crevice fluid, which is a type of transudate. Adding systemic treatment to topical treatment also addresses the problem of bacteria on the tongue and oral mucosa, thereby reducing potential sources of recolonization of the gingival pockets. Furthermore, when bacteria invade periodontal tissue, systemic antibiotics will destroy the microorganisms deep in the crevices, in areas that may be missed in the application of topical treatments. Common systemic antibiotics include clindamycin, metronidazole, penicillins, and tetracyclines. Most of the studies discussed in the present review involved the use of antibiotics in the tetracycline family, which are the most commonly used systemic antibiotics for these patients.
Although research has shown that tetracycline concentration in the gingival crevice fluid varies substantially from patient to patient,
8 an advantage of using antibiotics in the tetracycline family is that, in addition to their antimicrobial action, they also inhibit the activity of metalloproteinases. Metalloproteinases are zinc-dependent enzymes. Tetracyclines cause chelation of zinc (as well as calcium), which inhibits the activity of the enzymes. Tetracyclines may also decrease intracellular expression of metalloproteinases.
9 Doxycycline has been shown to be the most effective of the tetracyclines at inhibiting metalloproteinases.
9 This inhibitory action prevents the degradation of collagen in the periodontal ligaments and the resulting formation of gingival pockets and loss of tooth attachment.
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