Biomarkers in Gingival Exudate and Blood Serum Before and After Surgical Treatment of Periodontitis

Periodontitis, a disease affecting the tissue supporting the tooth, is initiated by microbes colonizing the tooth causing an inflammation of the soft tissue around the tooth. In some sensitive individuals the inflammatory response leads to loss of jawbone, which affect the bone support of the tooth and may end up in loss of teeth. Periodontitis is the sixth most prevalent disease in the world, 40% of the population with affected jawbone support and approximately 10% of the population suffer from severe loss of the supporting jawbone at teeth. Periodontitis may be halted or resolved by removing the microbial biofilm from the teeth root and in severe cases combined with surgical treatment removing inflammatory tissue. The genetic factors explain approximately 50% of the disease, and but the etiology is in parts unclear and effective therapy in sensitive individuals is still missing.

The inflammatory response initiated by microbes leads to degradation of the tooth supporting tissues. The current view is that pro-inflammatory cytokines and prostaglandins, produced by leukocytes and cells of mesenchymal origin in the inflamed tissue are responsible for recruiting and activation of bone-resorbing cells, osteoclasts. The inflammatory biomarkers and tissue degradation products will leak out into the exudate in the gingival pocket next to the root surface. The bone resorption activity connected to changes in biomarkers levels and clinical parameters, during healing after periodontal treatment seem to be of value to study. The analysis of the local exudate (gingival crevicular fluid, GCF) could be used for predicting and monitoring periodontitis, as well as finding new targets for treatment.

Periodontitis could also have a systemic effect, as locally released inflammatory mediators might enter the systemic circulation and influence the development of inflammatory conditions such as cardiovascular disease (CVD), diabetes and rheumatoid arthritis. Earlier studies have shown that a low-grade chronic inflammation plays an important role in the pathogenies in atherosclerosis. Substances that indicate low-grade chronic inflammation in blood serum is for example levels of C-reactive protein (CRP), fibrinogen, and adhesion-molecules, and these biomarkers are related to CVD. The question is if periodontal treatment could change/reduce the systemic inflammatory burden of inflammatory biomarkers (CRP, fibrinogen, interleukins, and matrix metalloproteinases (MMP)).

We know today that there is association between oral health and CVD, but we do not know if the relationship it is of a causal nature. There are some intervention studies that indicate that the oral inflammatory burden may have a systemic effect. To better understand the role of the oral inflammation in development of atherosclerosis, it is important to study biomarkers at different timepoints both from the local sites (GCF) and the general systemic environment in blood. If there is a co-variation in levels of inflammatory biomarkers locally in the GCF and in the systemic circulation, this could be a strong indication of a more causal nature of the association, but we need more studies.

The value of the study is to better understand what drives the local disease progression in periodontitis and also increase the knowledge by which mechanism the oral inflammation could exert its systemic effect. Measuring levels of biomarkers in GCF and serum at several timepoints after treatment we may contribute with new insights in the role of inflammatory inducing molecules in periodontal disease, but also if there exists any systemic effect from locally released inflammatory mediators. The possibility that some molecules co-variate with disease progression or regression is of great value.