Local and Systemic Responses to Experimentally Induced Gingivitis

Objectives: There is evidence for a relationship between oral infections and systemic inflammation. The objective of this study was to investigate whether the accumulation of dental plaque resulted in a systemic inflammatory response which could be detected within oral fluids. Methods: Eight systemically healthy, non-smoking females aged 17-41y participated in a 21-day experimental gingivitis model and a 14-day resolution phase. Clinical assessment included bleeding on probing (BOP) and plaque index scores before, during, and after resolution of gingival inflammation. Saliva, GCF, and peripheral blood samples were also collected. All samples were assessed for levels of 12 biomarkers including cytokines, acute phase proteins, and cell adhesion molecules using the Bio-plex platform system and high sensitivity ELISA. Results: Clinical indices increased during the experimental phase and decreased during resolution to levels lower than baseline. Within the GCF, there were no significant changes in levels of cytokines during the experimental phase; however, individual variability in cytokine profiles was noted. During resolution, mean levels of IL-2, IL-6, and TNF-a decreased and were significantly lower than baseline levels. Furthermore, changes in levels of IL-2, IL-6, and TNF-a during resolution correlated with changes in plaque index scores. Saliva showed higher levels of cytokines; however, these levels did not change over time. For both oral fluids, levels of CRP and sICAM-1 were low or undetectable. Plasma showed higher levels of these biomarkers and plasma levels of sICAM-1 significantly increased during the experimental phase and remained elevated and significantly higher than baseline levels during resolution. There were no significant changes in plasma levels of cytokines over time. Conclusions: Induction and resolution of gingivitis led to inflammatory changes which could be detected in GCF but not saliva. Systemic changes in sICAM-1 levels were not reflected in oral fluids. This study was supported by ADRF.