Subgingival plaque sampling after combined mechanical and antibiotic nonsurgical periodontal therapy.

Aim: This study aimed to make a comparison of two sampling strategies of subgingival plaque after combined mechanical-antibiotic periodontal therapy.

Methods: Thirty patients (18 female) suffering from aggressive (n = 12) or generalised severe chronic (n = 18) periodontitis were included. Aggregatibacter actinomycetemcomitans had been detected subgingivally in all prior to anti-infective therapy (AT) and combined mechanical-antibiotic AT had been rendered. After AT clinical examinations were performed and subgingival plaque was sampled from the same four sites as prior to AT (ASPRE) as well as from the four deepest sites after AT (DEEP). Per patient two pooled samples (ASPRE/DEEP) were generated and analysed for A. actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola using a commercial 16S rRNA test.

Results: ASPRE failed to detect A. actinomycetemcomitans, DEEP detected A. actinomycetemcomitans only in two patients (7 %). Only for T. forsythia DEEP (53 %) provided higher detection frequencies than ASPRE (27 %; p = 0.005). Detection frequencies of P. gingivalis and T. denticola ranged from 47 to 53 %.

Conclusion: After combined mechanical-antibiotic AT sampling the deepest sites revealed higher detection rates. Combined mechanical-antibiotic AT suppresses A. actinomycetemcomitans to a higher extent than P. gingivalis, T. forsythia and T. denticola.