Discriminating Life Forms in Oral Biofilms

The bacteria colonizing the hard and soft tissues of the oral cavity are known to signifi - cantly influence oral health and disease. Recent studies of subgingival dental plaque, based on different identification methods, provide direct evidence of substantial diversity of plaque microbiota. Till date only about 280 bacterial species have been isolated by cultiva ble methods, characterized and formally named out of this enormous microbial diversity of oral biofilms. As a consequence, there is a complete lack of information about the prop erties of a substantial proportion of the plaque microbiota, apart from their position in the taxonomic hierarchy of bacteria. This limited knowledge about the behavior and proper -ties, combined with recognition of the considerable diversity that exists within individual species, raises serious questions to the foundations on which previous conclusions, con cerning the etiology of periodontal diseases, rest. The emerging realization is it is impos - sible to fully understand oral health and disease without identifying and understanding the pathogenic potential of all of the bacteria that colonize the oral cavity. The current chapter shall provide an update on current status of oral microbiota, ecological significance of their biofilm life style and various methods to study microbes residing in oral biofilms.