A ROLE FOR ANTIBIOTICS IN THE TREATMENT OF REFRACTORY PERIODONTITIS

REFRACTORY PERIODONTITIS IS CONSIDERED by many investigators to be a separate disease entity that is descriptive of a particular patient who has multiple sites, rather than a few individual sites, that do not respond to conventional periodontal treatment modalities. Such patients continue to demonstrate loss of attachment and alveolar bone despite frequent periodontal treatment which includes surgical intervention, scaling and root planing, and often systemically-administered tetracycline. Controlled clinical studies have demonstrated that both clindamycin-hydrochloride and amoxicillin/clavulanate potassium (Au) are beneficial when used in conjunction with periodontal scaling. Gordon et al. found improvements in attachment levels, inflammation, suppuration, and a decrease in pocket depths for up to 2 years following a 7-day course of clindamycin given in conjunction with a full-mouth scaling. The incidence of disease activity decreased from an annual rate of 8% of all sites prior to antibiotic treatment to 0.5% after treatment. Magnusson, reporting on a similar group treated with a 14-day course of Au, found an average loss of attachment of 2.2 mm and an increase in pocket depth of 1.5 mm in sites demonstrating disease progression prior to antibiotic treatment. At 3 months post-antibiotic therapy, these sites had regained an average of 2 mm of attachment and pocket depths had decreased an equivalent amount. Both attachment levels and pocket depths remained relatively stable for up to 12 months post-therapy. In an ongoing study, 30 subjects with refractory periodontitis were treated with either clindamycin or Au in conjunction with scaling or scaling plus a placebo. Prior to antibiotic treatment, but while being scaled at 3-month intervals, sites with disease activity lost an average 2.4 mm of attachment. At 3 months post-treatment, the clindamycin-treated group showed an average gain of 2.1 mm, the Au-treated group gained 1.9 mm, and the scaling group gained 1.4 mm in attachment. The clindamycin group remained relatively stable for up to 21 months and the Au group remained stable for about 15 months without additional treatment. Five of the 6 subjects treated with scaling alone required additional treatment within 9 months. Preliminary analyses have indicated that at least two patterns or rates of attachment loss may be associated with refractory periodontitis and that each pattern may be indicative of a different microflora. The pattern associated with a relatively rapid loss of attachment was characterized by a Gram-negative flora which contained spirochetes, P. intermedia, and Fusobacterium species. A slow, continuous rate was associated with a predominantly Gram-positive flora containing a high proportion of S. intermedius and/or a S. intermedius-like organism.