Abstract: Bacteriological changes of subgingival flora of patient with chronic periodontitis and type-2 DM(diabetes mellitus) were researched by germ cultivation and PCR method in the thesis.Samples were taken from 42 patients with chronic periodontitis and type-2 DM, and 21 normal people.An isolated cultivation of subgingival plaque samples was performed by a anaerobe non-selected media, the Actinomyces, Fnusbacterium nucleatum, Eikenella corrodens, A.actinomycetemcomitans, capnocytophaga and Streptococcus spp were performed by selective media.The P.intermedia(P.i) of the black colony in the non-selective media was detected by PCR.The quantity of germs was recorded.It was discovered that the major germ of subgingival flora of type-2 DM patients with chronic periodontitis was anaerobe, the superiority germ was black germs, P.i, Fnusbacterium nucleatum and capnocytophaga.Statistical analysis of correlation between FPG、GHb and amount of black germs, capnocytophaga was made.It shows that chronic periodontitis is correlated to type-2 DM.

Key words: diabetes mellitus, periodontitis, germ