Abstract: Periodontitis is a bacterial infectious disease caused by microbial pathogens, and Porphyromonas gingivalis（P.gingivalis） is one of the prominent pathogens. Hen immunized with certain micro-organism can produce specific antibodies against the micro-organism，which can be transferred to the egg yolk in large numbers. The purification of the antibodies is also known as the immunoglobulin yolk（IgY）. Anti-P.gingivalis IgY may provide a promising insight into the prevention and treatment of periodontitis. This review reported the research progress of the nature and characteristic of IgY and the use of IgY in prevention and treatment of periodontitis research.

Key words: Porphyromonas gingivalis, immunoglobulin yolk, antibody, immunity