RESUMO
The oral cavity present itself as a home to a rich flora of bacteria; more than 500 distinct microbial species are found in dental plaque. Mycoplasma, yeast, protozoa and viruses are found in the plaque as the non-bacterial microorganism. Viruses are known to be immunosuppressive and facilitate establishment of subgingival pathogens and have been detected in the gingival crevicular fluid. Viruses infect the inflammatory cells of the periodontium; they are present more frequently in diseased sites than in healthy sites. Traditional methods such as in vitro cultivation presents difficulty in detecting viruses. The field of virology has advanced greatly over the past two decades because of the introduction of sophisticated molecular tools, such as monoclonal antibodies, polymerase chain reaction based amplification, DNA sequencing, DNA and protein micro array chip assays, rapid diagnostic tests. These technologies identify the viral bodies, proteins and nucleic acids in body fluids and tissue samples.