The Relationship Between Concentrations of Proinflammatory Cytokines Within Gingiva and the Adjacent Sulcular Depth

The objective of this study was to determine and compare concentrations and ratios of 3 proinflammatory cytokines, interleukin (IL) IL‐1β, IL‐6, and IL‐8 within gingival tissue biopsies adjacent to ≤3, 4 to 6, or >6 mm sulci. All gingiva adjacent to ≥4 mm sulci had clinical evidence of active inflammation. Factorial analysis of variance suggested significant effects of sulcus depth on the type and concentration of the three cytokines in the adjacent gingiva (P < 0.001). IL‐8 concentrations were highest in gingiva adjacent to ≤3 and lowest adjacent to >6 mm sulci (P < 0.001). In contrast, IL‐6 concentrations were lowest in gingiva adjacent to ≤6 mm and highest adjacent to >6 mm sites. IL‐1β concentrations were highest in gingiva adjacent to >6 mm and lowest adjacent to 4 to 6 mm sites; they were also higher adjacent to ≤3 mm than adjacent to 4 to 6 mm sites (P < 0.01). Multiple regression analysis suggested that sulcular depth, type of cytokine, and cytokine concentration were significantly correlated (P < 0.001). Ratios of gingival cytokines changed with increased sulcular depth. In gingiva adjacent to ≤6 mm sites, IL‐8 was the most and IL‐6 the least prevalent. In gingiva adjacent to ≥6 mm sites, IL‐8 was the least and IL‐1‐β the most prevalent. The data suggest that the characteristics of the gingival cytokine network are affected by adjacent sulcular depth. These data could be used to design adjunct diagnostic tests for progression of periodontal diseases. J Periodontol 1998;69:865–871.