OBJECTIVETo investigate the prevalence of Actinobacillus actinomycetemcomitans (Aa) in whole saliva of different types of periodontitis and compare the detections of Aa between saliva and pooled subgingival plaque sample, and analyze the relationship between Aa and clinical conditions.

METHODSUnstimulated whole saliva samples and pooled subgingival samples were collected from 50 aggressive periodontitis (AgP) patients, 48 chronic periodontitis (CP) patients and 25 subjects with no periodontitis, and Aa was detected in these samples by PCR method.

RESULTSThe prevalence of Aa in whole saliva of AgP patients was significantly higher than in subjects with no periodontitis (32% vs. 4%, P<0.01) and CP patients (32% vs. 15%, P<0.05). Aa was also more frequently detected in whole saliva sample than in pooled subgingival sample of AgP patients (32% vs. 16%, P<0.05). Subjects younger than 30 years old were more likely to present Aa in whole saliva ( OR = 3.23, P<0.05) and percentage of sites with bleeding index (BI) > or = 3 over 70% was a risk indicator for the presence of Aa in whole saliva

CONCLUSIONSThe detection of Aa in whole saliva sample of AgP patients was more frequent than in pooled subgingival plaque samples, and also more frequent than in CP patients and subjects with no periodontitis, which suggest that Aa may participate in the initiation and progression of aggressive periodontitis.