Non-surgical mechanical treatment associated with the use of amoxicillin and metronidazole led to an improvement in all clinical parameters studied, except for CAL, and significantly reduced the amount of subgingival Tf and Td.

Smokers showed significantly greater amounts of P. gingivalis, A. actinomycetemcomitans, and T. forsythia than never-smokers. There was a significant association between smoking and the presence of A. actinomycetemcomitans.

The aims of this cross-sectional study were to evaluate the presence and subgingival quantity of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola and Dialister pneumosintes, in individuals with Gingivitis associated with dental plaque only, Chronic Periodontitis and Aggressive Periodontitis, and correlate the quantitative results with periodontal clinical parameters (PD and CAL). Clinical data and subgingival plaque samples were collected from a total number of 176 individuals, among whom there were 67 individuals with Gingivitis associated with dental plaque only (Group G), 71 with Chronic Periodontitis (Group CP) and 38 with Aggressive Periodontitis (Group AP). The clinical samples were processed by real-time PCR with the use of specific primers and probes for regions of the highly conserved 16S rRNA gene of each bacterial species. The results demonstrated the detection of the five pathogens in the three analyzed groups, and there was significant association between the group and presence of the bacteria for P. gingivalis, T. forsythia, T. denticola and D. pneumosintes (p<0.01). The bacterium A. actinomycetemcomitans presented similar frequencies of detection under the periodontal conditions analyzed (Group G, 100%; Group CP, 94.4%; Group AP, 92.1%), and there was no significant association between group and the presence of this bacterium (p=0.09). The subgingival quantities of A. actinomycetemcomitans and T. forsythia were significantly higher in