PHARMACOLOGICAL CONTROL OF PERIODONTAL-DISEASE .2. ANTIMICROBIAL AGENTS

Antimicrobial agents are of value in the management of certain types o f periodontal disease, notably early onset, juvenile and refractory pe riodontitis. The diagnosis of these conditions is often made on clinic al grounds but microbial sampling of the pocket flora is of value in d etermining the type of antimicrobial therapy. Routine systemic use of these drugs in the management of chronic adult periodontitis is contra indicated, and is no substitute for root surface debridement and thoro ugh supragingival plaque control. Tetracyclines and metronidazole are the agents most frequently used in the management of periodontal disea se. Both drugs can be given systemically or applied topically into the periodontal pocket. The latter route is preferred since the dose is r educed considerably, but the local tissue concentration is increased. The efficacy of local drug delivery is dependent upon the release kine tics of the drug from the delivery vehicle. Although local application can be time consuming, it reduces the risk of adverse reactions and d rug interactions. The tetracyclines have the additional advantage of i nhibiting collagenases. This property may facilitate repair and new at tachment formation. Systemic metronidazole appears to be useful as an adjunct to conventional periodontal therapy. The combination of metron idazole 250 mg and amoxycillin 375 mg has been shown to be effective i n the treatment of refractory periodontitis, including cases which are resistant to tetracycline. Clindamycin has also been used in the mana gement of refractory periodontitis, but the unwanted effects of this d rug must limit its systemic use for this purpose.