Clinical and microbiological associations in chronic periodontitis.

Chronic Periodontitis is the most prevalent form of periodontal disease. The subgingival microflora has been associated with the onset and progression of the disease. The aim of this work was to establish associations and correlations between clinical indicators and subgingival plaque microbiological data in patients diagnosed with moderate or severe Periodontitis. One hundred sites with a probing depth of > or = 5 mm were selected. Plaque Index (PI), Gingival Index (GI), Bleeding on Probing (BP), Probing Depth (PD) and Clinical Attachment Level (CAL) were measured. The subgingival plaque microbiological assay comprised cultures in selective and non-selective media and identification tests for Porphyromonas gingivalis (Pg), Prevotella intermedia/nigrescens (Pi/n), Actinobacillus actinomycetemcomitans (Aa), Fusobacterium (F) and Peptostreptococcus micros (Pm). Dark field microscopy was used to analyze the relative proportions of Treponema to the total microbial morphotypes. Small Treponeina (ST), Medium Treponema (MT), Large Treponema (LT) and Total Treponema (TT) were determined. Our results showed associations and a correlation between PD and AL, r = 0.62 (p<.0001); PD and Pg X2 = 15.22, r = 0.39 (p<.001); AL and Pg X2 = 10.72, r = 0.32 (p<.001). A negative correlation was observed between Pg and Pi/n X2 = 12.65, r = -0.35 (p<.001); BP and F X2 = 8.93; GI and F X2 = 8.92. The present results reveal associations and correlations between some clinical indicators and subgingival plaque microorganisms in patients diagnosed with Chronic Periodontitis.