Periodontal therapy: a novel non-drug-induced experimental model to study human inflammation

Chronic periodontitis causes a low-grade systemic inflammatory response; its standard treatment, however, induces an acute inflammatory response. The aim of this study was to describe the systemic inflammatory reactions to an intensive periodontal treatment regimen.

Fourteen otherwise healthy subjects suffering from severe chronic periodontitis were enrolled in a 1 month pilot single-blind trial. Intensive periodontal treatment, consisting of full-mouth subgingival root debridement delivered within a 6-h period, was performed. Periodontal parameters were recorded before and 1 month after completion of treatment. Blood samples were taken at baseline and 1, 3, 5, 7 and 30 days after treatment. Interleukin-1 receptor antagonist (IL-1Ra), Interleukin-6 (IL-6) and C-reactive protein (CRP) serum concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Complete blood counts were also performed.

One day after treatment, mild neutrophilia and monocytosis (p < 0.05) and lymphopenia (p < 0.01) were accompanied by a sharp increase in inflammatory markers (IL-1Ra, IL-6, p < 0.01). A 10-fold increase in CRP (p < 0.001) was detected on day 1 and its kinetics followed a pattern of a classical acute phase response (significantly raised concentrations up to 1 week, p < 0.01). At 3-7 days after treatment, subjects presented also with a mild tendency towards a normocytic anaemic state (p < 0.01) and a degree of lympho-thrombocytosis (p < 0.05). The observed changes were similar to those expected following the well-characterized endotoxin-challenge model of inflammation.

Intensive periodontal treatment produced an acute systemic inflammatory response of 1 week duration and might represent an alternative to classic endotoxin-challenge or drug-induced models to study acute inflammation in humans.