Periodontitis and systemic inflammation : exploring the nature of the association
Periodontitis has been associated with elevated inflammatory markers in otherwise healthy populations. However the nature of this association has not been determined. The aim of this work was to establish whether or not periodontitis causes systemic inflammation. A first pilot intervention trial indicated that standard periodontal therapy, in a cohort of 94 individuals suffering from severe generalized periodontitis, produced a 0,5 mg/L decrease in serum CRP concentration 6 months after therapy. This decrease was affected by the degree of clinical periodontal response and carriage of specific polymorphisms in inflammatory genes (IL-1 A, IL-6). Periodontal treatment, on the other hand, produced a moderate acute phase response of one week duration 10-fold increase in CRP (P<0.001) . Carriage of rare alleles in the CRP gene was associated with a greater acute CRP response to periodontal therapy after correcting for conventional cardiovascular and inflammatory factors. Standard (SPT) and an intensive periodontal therapy (IPT, including local delivery of antimicrobials) resulted in a significant reduction in serum CRP compared to an untreated control 2 months after treatment (0.5 0.2 mg/L, P=0.030 and 0.8 0.2 mg/L, P=0.001 respectively) in a randomized controlled trial involving 65 healthy subjects with severe generalized periodontitis. The IPT group showed also a decrease in total cholesterol and LDL-cholesterol. These data were confirmed by the results of a second randomized trial where a cluster of inflammatory and metabolic parameters were evaluated at baseline, 1, 2 and 6 months after either a SPT or IPT regimen. IPT patients showed significant reductions in inflammatory markers at one (p=O.04O6) and two (p=0.0060) months together with an improved metabolic state (2-6 months reduction in lipid markers p=0.0320 and p=0.0432 respectively). Periodontitis causes an increased reversible systemic inflammatory burden and an intensive therapy regimen is more effective in re-establishing a more favourable systemic homeostasis.