Logistic regression model of multiple species and their interaction with regard to the odds of having severe periodontitis.

Abbreviations: Aa = A. actinomycetemcomitans, Pg = P. gingivalis, Td = T. denticola, and Pi = P. intermedia.
a Logistic regression analysis, controlling for age, gender, education, number of remaining teeth, smoking status, diabetes, and the effect of other species.
b “Low level” indicates the bacterial levels below these thresholds: 3.3x104, 1.9x107, and 5.1x106 cells for Aa, Td, and Pi, respectively.
c “High level” indicates the bacterial levels at or above the thresholds.
Logistic regression model of multiple species and their interaction with regard to the odds of having severe periodontitis.