This thesis looks at the similarity in the pathophysiology of rheumatoid arthritis and periodontal disease and how the therapy of one may affect or influence the other. Both conditions share a complex host mediated pathophysiology driven by inflammatory pathways causing periodontal and synovium inflammation thus leading to tooth loss and joint damage. Within the thesis we highlight the evidence that supports the used of non-surgical periodontal therapy to improve rheumatoid arthritis disease activity, and the use of anti-rheumatic drugs to improve the management of periodontal diseases.