Arthritis and Periodontitis: An Association Debated for Over Two Centuries.

The chronic diseases, rheumatoid arthritis (RA) and periodontal disease (PD) lead to confined destruction of soft and hard tissues as a result of inflammatory processes. Their pathogenesis is dictated by a network of inflammatory cells and its mediators. They also share some etiological risk factors and therapeutic alternatives. The evolution of focal infection theory is summarized in this review, with special reference to PD and its relationship to RA. Foci of chronic infections exist in the oral cavity and may result in anatomically distant disease in certain individuals. Recent cumulative evidences document the influence of inflammatory diseases such as RA on the development of PD. Historical evidences and new theories on the interrelationship between the two diseases have the potential to identify novel mechanisms and therapy to improve patient outcomes. This review focuses on not only the association of focal infection theory and RA, but also on the reciprocal effects of RA and PD.