THE EFFECT OF CYCLOSPORINE-A ON THE ORAL MICROFLORA AT GINGIVAL SULCUS OF THE FERRET

The effect of cyclosporin-A (CyA) on the dentogingival flora of ferret s with healthy and experimentally induced periodontal breakdown was st udied, Five animals were given 10 mg/kg/d CyA. At the start of the exp eriments (day 0), ligatures were placed around 4 teeth in the right up per and lower jaws; corresponding contralateral teeth on the left side served as control. On days 0 and 28 (end of the experiment), microbio logical samples were collected from the gingival sulcus of the experim ental and the control teeth and from closely located gingival mucosa m embrane. The samples were subjected to viable counts and to darkfield microscopic analyses. On day 0, facultative anaerobic rods, mainly Pas teurella spp, Alcaligenes spp, Corynebacterium spp. and Rothia spp dom inated in the viable counts, No anaerobic bacteria were detected in th e viable counts. On day 28 spirochetes increased in the experimental g ingival sulcus samples and anaerobic bacteria appeared in most of the samples and constituted 40-60% of the total cultivable flora; Fusobact erium necrophorum and Eubacterium spp. predominated in the samples fro m the experimental sites. The results of the present study were compar ed with those of our previous investigation of ferrets not medicated w ith cyclosporin but also subject to experimental ligature periodontiti s, Eubacterium spp. were absent in the animals not treated with cyclos porin, while this species was frequently present in the immunosuppress ed ferrets. The results indicate that the presence of the large number s of gram negative rods and of anaerobic bacteria may have enhanced th e inflammatory process and further provoked the gingival overgrowth ob served.