The human oral cavity is a diverse environment with hard and soft tissues comprising a total area of 215cm² bathed in saliva (Eleni Kanasi,2008). The oral environment is thus optimal for their architecture and characteristics to biofilm in nature (Auschill et al.,2001). Specific to oral biofilms is the ability of sessile oral bacterial cells to tolerate short-term abundance of external nutrient supply and to withstand nutrient restraint. Nutrient deprived biofilm cells after reactivation have shown to exhibit low reactivity invitro, suggesting that slower reactivation of these cells might be a survival strategy ( Chavez de paz et al., 2008).

The oral cavity of healthy individuals contains hundreds of different bacterial, viral and fungal species. Many of these can associate to form biofilm which are resistant to mechanical stress and antibiotic treatment. It has been a long journey from the beginning to the study of oral microbiota consisting of an unknown number of bacteria. But not all species residing in the oral microbiota have been identified yet and an estimated 750 different species are anticipated (Jenkinson and Lamont, 2005;Paster et al.,2006).

Most of these micro organisms exist in our oral cavity in a symbiotic capacity maintaining relationships with the hosts that are based on mutual benefits (los Alamos National Library, 2009). Not only do they not cause harm, but also the commensal populations may keep pathogenic species in check by not allowing them to adhere to mucosal surfaces. Numer4oyus factors impede the isolation of this vast number of species. First and foremost, many of the species are not cultural with today’s laboratory technologies, and genomic similarities do not allow for organismal determination based on short read lengths. Because of the limitations, researchers have begun by identifying with the communities of healthy mouth: Streptococcus, Actinomyces, Staphylococcus, Veillonella, Neisseria, Eubacteria, Leptotrichia, Fusobacterium etc.(Jenkinson and Lamot 2005; Wilson, 2005).