Oral microbiology is a complex ecological system where up to 700 species of microorganisms that have been identified .Some of the predominant groups present in the mouth includes Streptococcus, Neisseria, Veillonella, Actinomyces and other obligate anaerobes. These organisms maintain a mutualistic relationship with the host by preventing pathogenic species from adhering to the mucosal surface. Oral microflorae can cause dental plaques and are also a common cause dental caries and periodontal disease. Oral disease in an individual can be caused due to a combination of lack of oral hygiene and factors influencing the oral microbial community structure, such as diet. An understanding of the oral environment and microbial interactions leads to understanding the main causes for the onset of oral diseases.