Oral flora composition and its connection to oral health

More than 700 species of commensal bacteria inhabit the human oral cavity, of which many have been of keen interest due to their pathogenicity in oral diseases (e.g., dental caries and periodontal diseases); however, the interactions between the pathogens and the remaining commensal bacteria are not well known, thus preventing us from understanding the genuine etiologies of oral diseases. To overcome this challenge, it is essential to comprehensively identify the species compositions of individual oral flora in order to associate them with various conditions of oral health and understand the virulence derived from the oral flora community. In this review, we refer to modern molecular genetic technologies, such as terminal restriction fragment length polymorphism, DNA microarray and pyrosequencing analyses using bioinformatics. We also discuss their potential to further our comprehension of the complexities of floral composition.