The oral cavity is comprised of many surfaces, each coated with a plethora of bacteria,  the  proverbial  bacterial  biofilm. Some of these bacteria have been implicated in oral diseases such  as  caries  and  periodontitis,  which  are  among  the  most common  bacterial  infections  in  humans.  For example, it has been estimated that at least 35% of dentate U.S. adults aged 30 to 90 years have periodontitis. In addition, specific oral bacterial species have been implicated in several systemic dis-eases, such as bacterial endocarditis, aspiration pneumonia, osteomyelitis in children, preterm low birth weight, and cardiovascular disease. Surprisingly, little is known about the micro-flora of the healthy oral cavity. More than 700 bacterial species or phylotypes, of which over 50% have not been cultivated, have been detected in the oral cavity. By using culture-independent molecular methods, the authors previously detected over 500 species or phylotypes in sub-gingival plaque of healthy subjects and subjects with periodontal dis-eases, necrotizing ulcerative periodontitis in human immune deficiency virus-positive subjects, dental plaque in children with rampant caries, Noma, and on the tongue dorsum of subjects with and without halitosis. Other investigators have used similar techniques to determine the bacterial diversity of saliva, sub-gingival plaque of a subject with gingivitis, and dentoal veolar abscesses. Over half of the species detected have not yet been cultivated. There is a distinctive bacterial flora in the healthy oral cavity which is different from that of oral disease. For example, many species specifically associated with periodontal disease, such as Porphyromonas gingivalis,Tannerella forsythia,  and Treponema denticola,  were  not  detected  in  anysites tested. In addition, the bacterial flora commonly thought to be involved in dental caries and deep dentin cavities, rep-resented  byStreptococcus mutans,Lactobacillusspp.,Bifid-obacteriumspp.,  and Atopobiumspp.,  were  not  detected  insupra- and subgingival plaques from clinically healthy teeth.

Regards
Sarah eve

Editorial Assistant

Journal of Oral Hygiene and Health