Interleukin-1β Levels in Serum and Gingival Crevicular Fluid under either Naturally-Occurring or Experimentally-induced Gingival Inflammation.

Aims: To evaluate the interleukin-1b (IL-1b) levels in gingival crevicular fluid (GCF) and serum in either naturally occurring (N-O) or experimentally induced (E-I) plaqueassociated gingivitis. Material and Methods: Thirty-seven periodontally healthy subjects were evaluated in real life conditions (N-O gingivitis) as well as after 21 days of experimental gingivitis trial (E-I gingivitis). During the experimental gingivitis trial, in one maxillary quadrant (test quadrant), gingival inflammation was induced by oral hygiene abstention, while in the contralateral (control) quadrant, oral hygiene was routinely continued. IL-1b concentrations in N-O and E-I gingivitis were investigated for IL-1B13954 and IL-1B511 gene polymorphisms. Results: (i) GCF IL-1b concentrations in E-I gingivitis were significantly higher compared with N-O gingivitis; (ii) an intra-individual correlation between GCF concentrations of IL-1b detected in N-O and E-I gingivitis was observed in control quadrants, but not in test quadrants; (iii) IL-1b concentration in GCF was associated with IL-1B13954 genotype only at test quadrants; (iv) IL-1b was detectable in serum only at low levels in a limited number of subjects, without difference between gingivitis conditions. Conclusions: Aspects of the bacterial challenge to the gingival tissues, such as the amount of plaque deposits and plaque accumulation rate, appear to affect the IL-1b levels in GCF in subjects with a specific IL-1B genotype.