IL1B and periodontitis: Table 6 depicts the results of the Poisson regression analyses showing that antimicrobials, female gender, smoking status, severe forms periodontitis (≥ 10 sites with PD ≥ 6 mm at baseline) and initial CAL-loss, BOP at baseline, detection of A. actinomycetemcomitans and T. denticola at 12 months as well as initial detection if IL-1β statistically significantly influenced the residual number of deep sites at 12 months (p < 0.05).