Fusobacterium nucleatum is a Gram-negative bacterium that is commonly found in the dental plaque of humans and is frequently associated with gum disease. This bacteria has been shown to play a central role in dental plaque formation and other diseases like gingivitis. This is due to its ability to adhere to a wide range of both Gram-positive and Gram-negative plaque microorganisms. F. nucleatum is very much associated with periodontitis, along with invasive human infections of the head and neck, chest, lung, liver and abdomen. Due to its adherence ability, it can be associated with viruses, which adhere to host tissue cells as an invasion and modulate the host's immune response . The pathogenic potential of Fusobacterium nucleatum and its significance in the development of periodontal diseases, as well as in infections in other organs, have gained new interest for several reasons. First, this bacterium has a very high chance to be pathogenic because of its high frequency in periodontal lesions, its production of irritants that affect the tissue, its ability to co-aggregate and form mutual synergisms with other bacteria in mixed infections, and its ability to form numerous aggregates with other suspected pathogens in periodontal disease. Second, F. nucleatum is very common in clinical infections of other body sites . In the last few years it is intensively investigate the role of Fusobacterium nucleatum in atherosclerosis development and in promoting or inflicting different cancers.