Immunohistochemical, histomorphometric, and gingival crevicular fluid analysis of residual and shallow periodontal pockets in patients with periodontitis Stages III and IV.

Background: To study the differences between shallow and residual periodontal pockets in patients with periodontitis (Stages III and IV) after non-surgical periodontal treatment.

Methods: Twenty patients diagnosed of periodontitis who were scheduled for periodontal surgery were included. In each patient, a palatal shallow site (≤3 mm) and a residual site (≥5 mm) were selected and GCF samples were processed by Luminex® analysis to determine the concentrations of interleukins (IL-1β, IL-6, IL-10, and IL-17a). During the periodontal surgery gingival biopsies were collected and processed for histo-morphometric and immunohistochemical evaluation to determine the extent of connective tissue inflammatory infiltrate (CTII) using the following markers (CD4, CD5, CD8, CD14, CD19, Elastase, and Syndecan). Mean differences between shallow and residual pockets samples, as well as correlations between GCF cytokine concentrations, area of CTII, and cellularity of the CTII were calculated.

Results: A total of 15 patients were finally included, with analysis of 30 histological specimens and 30 GCF samples. Residual pockets presented significantly higher mean GCF volume, higher mean area of CTII and higher concentrations of IL-1β and IL-6 in GCF than shallow pockets. A significant correlation was detected between IL-10 levels and the CTII area, IL-10 and the percentage of Syndecan, and the area of CTII and the percentages of CD14 and Syndecan.

Conclusions: The concentration of GCF cytokines did not correlate with the area of CTII measured histologically. A residual CTII and elevated concentrations of proinflammatory cytokines and cells were present in all sites 2 months after non-surgical treatment. The lack of healthy controls does not allow to establish differences between both groups.