IL1B and periodontitis: Another study [26] assessed gingival crevicular fluid (GCF) IL-1β levels in 128 postmenopausal women (64 in subantimicrobial-dose doxycycline (SDD) antibiotic group and 64 in placebo group) with chronic periodontitis, however there was no significant difference in the median GCF IL-1β levels between the two treatment groups after one-year or two-years’ time-point, as reported by the study authors.