REVIEW – November 2003

The spectrum of periodontal pathogens after the first-line treatment in patients with periodontitis in Southern Estonia


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Periodontitis is a chronic infectious disease which leads to the destruction of the gingiva

and alveolar bone until tooth loss. The evidence of bacterial specification in periodontitis

patients has led to periodontal instrumentation combined with systemic antibiotic

treatment. The main objectives of the study were 1) to evaluate the efficacy of

instrumentation according to the presence of pathogens, 2) to determine the spectrum of

pathogens and 3) to compare the total degree of colonisation with the number of the


Altogether 140 patients aged 13–68 years were studied. Samples from the

periodontal pockets were placed in anaerobic transport vials; five-fold dilutions were

made and seeded onto the Brucella and BVTS agar plates. The pathogens were identified

according to their colonial and cellular morphology, the potency disk pattern and the

biochemical profiles.

After periodontal instrumentation no pathogens were isolated in 46 patients,

94 were colonised with 1–5 pathogenic species. Fifty-three patients harboured one

pathogen, 27 harboured two, 12 three and two patients harboured 5 pathogens. The total

load of colonisation varied from 0 to 8.4 CFU/mL (median 5.5 CFU/mL), being

positively correlated with the number of isolated pathogens (p<0.001). The P.

intermedia/nigrescens group was present in 37, A. actinomycetemcomitans in 36 P.

micros in 12, P. gingivalis in 7, B. forsythus in 4 and C. rectus in 2 patients. Higher

colonisation with oral bacteria indicates presence of periodontal pathogens. Of these

patients 33% remained pathogen-free, indicating the success of primary mechanical

therapy. However, 67% of the patients were also colonised with one to five different

pathogens. Therefore, for the successful diagnosis and therapy of periodontal diseases,

individual microbiological examination of each patient is recommended.