The microbiological status of patients with periodontitis in southern Estonia after non-surgical periodontal therapy.

Our objective was to investigate the presence of periodontal pathogens in comparison with the total degree of microorganisms after non-surgical periodontal therapy. The study material consisted of microbiological samples from periodontal pockets originating from 140 consecutive patients with chronic generalized severe periodontitis. The subgingival samples from periodontal pockets were obtained by a sterile curette, placed into 2 ml of the VMGA III medium, homogenized and serially diluted in the Brucella broth. 100 microl aliquots from the dilutions were inoculated onto the Brucella and the TSBV agar. The plates were incubated in an anaerobic chamber and under microaerobic conditions. The isolates were identified according to colonial and cellular morphology, the potency disk pattern, and the biochemical profiles. After instrumentation, no periodontal pathogens were isolated in 46 (33%) patients, while 94 patients (67%) were infected with one to five different periodontal pathogens. However, higher degree of the total microflora was positively correlated with number of isolated pathogens, a putative indicator of their presence. Therefore, due to the occurrence of residual microorganisms after non-surgical mechanical treatment, information about the pattern of these pathogens is needed for application of antimicrobial therapy. The level of microbial load in gingival pockets, including both pathogenic and non-pathogenic species, is one of the determinants of presence of residual pathogens after non-surgical periodontal therapy.