Periodontal disease is a multifactorial complex disease with various biological factors like specific nonspecific microbial species, host immune responses, genetic, epigenetic and environmental factors.  The  only  bacterial etiology for periodontitis seems unacceptable. Few of them have suggested infectious agent like virus is involved with disease mechanism while other emphasize on host immune factor and genetic characteristics.

 Previously it was thought that virus is not involved with severe cases of periodontitis. After that several studies covered the strong evidences about direct virus isolation from deep focal sites. A  very strong evidences in the involvement of human herpes virus, Epstein Barr virus, Human cytomegalovirus, Human Immunodeficiency Virus in both chronic as well aggressive periodontitis.  The compiled information and critical aspects in the area will also help to develop suitable diagnostics and therapeutics.