EFFECTS OF ANTIBIOTIC-TREATMENT ON CLINICAL CONDITIONS WITH GUIDED TISSUE REGENERATION - ONE-YEAR RESULTS

THE ONE-YEAR RESULTS OF A REGENERATIVE PROCEDURE in patients treated w ith or without antibiotics are presented. Expanded polytetrafluoroethy lene (ePTFE) was placed over mandibular molar Class II furcation invas ions and retained for four weeks. The patients in group 1 received no antibiotics; patients in group 2 received amoxicillin/clavulanate pota ssium during the first 10 post-operative days. The initial differences in tested microorganisms and post-surgical inflammation indicated tha t the use of the antibiotic might enhance the long-term outcome. After one year, the reduction in mean probing depth of the furcation invasi ons was 2.0 +/- 1.2 mm for group 1 and 1.8 +/- 1.1 mm for group 2. An overall gain of 0.8 mm of clinical attachment was found. Twenty-two of the 24 sites were re-entered. Wide individual variations were found b ut the changes between pre-treatment and one-year data for any of 6 li near measurements of hard tissue landmarks did not differ between grou ps or between pre-treatment and re-entry. A combination of an overall loss of 0.4 mm alveolar bone at the crest and 0.3 mm gain of bone at t he bottom of the furcation defects was found. Volumetric analysis indi cated an average 32% bone fill for both groups, ranging from a decreas e in defect volume by 84% (gain) to an increase of the size of the fur cation invasion by 66% (loss). A decrease in defect volume > 30% was f ound at 7 sites from each group. The antibiotic may have controlled in itial inflammation, but 12 months later it had no direct effect on bon e regeneration or soft tissue attachment.