SYSTEMIC ANTIMICROBIAL TREATMENT AND GUIDED TISSUE REGENERATION - CLINICAL AND MICROBIOLOGICAL EFFECTS IN FURCATION DEFECTS

The purpose of this investigation was to study the microbiota associat ed with furcation-involved teeth before and after treatment by the gui ded tissue regeneration procedure (GTR) with non-resorbable ePTFE memb ranes, and to evaluate the benefit of additional systemic antimicrobia l therapy (ornidazole). Each of 10 patients contributed 1 pair of bila teral mandibular molars with comparable furcation defects. 5 defects w ere treated with a membrane and the active drug, 5 were treated withou t a membrane but with the active drug, 5 were treated with a membrane and a placebo, and 5 were treated with neither a membrane nor the acti ve drug. Considerable differences were found in the healing response o f furcation defects treated with or without the antimicrobial agent. M ore horizontal attachment gain and increase in bone density was obtain ed in patients receiving the active drug than in patients receiving th e placebo. With 1 exception, all sites with increasing horizontal prob ing depth were found in patients of the placebo group. Treatment with membrane plus ornidazole resulted in 0.7 mm mean recession and -1.2 mm mean decrease in horizontal probing depth. Sites treated with membran es generally tended to be positive for 15 target micro-organisms more often than sites treated without a membrane. This was particularly evi dent for Fusobacterium, Plevotella intermedia and Actinomyces odontoly ticus. Whereas GTR-treated sites were often already positive upon remo val of the membrane, re-emergence of target organisms seemed to be mor e delayed in the conventionally-treated sites.