Well studied Periodontal pathogens are

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

that have been shown to significantly contribute to

periodontitis Periodontal disease, also known as gum disease, is a set of inflammatory conditions affecting the tissues surrounding the teeth. In its early stage, called gingivitis, the gums become swollen and red and may bleed. It is considered the main cau ...

Dental plaque Dental plaque is a biofilm of microorganisms (mostly bacteria, but also fungi) that grows on surfaces within the mouth. It is a sticky colorless deposit at first, but when it forms tartar, it is often brown or pale yellow. It is commonly found be ...

, the precursor of periodontal disease, is a complex biofilm consisting mainly of bacteria, but also

archaea Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...

, protozoa, fungi and viruses. Viruses that specifically infect bacteria - bacteriophages - are most common in the oral cavity. Viral roles in the progression of periodontal disease as of 2017 remains poorly explored. Although approximately 700 bacterial species have been identified in the

oral cavity In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on t ...

and nearly 300 species have been cultured and found to contribute to the

biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular ...

of the

periodontal pocket Gingival and periodontal pockets (also informally referred to as gum pockets) are dental terms indicating the presence of an abnormal depth of the gingival sulcus near the point at which the gingival tissue contacts the tooth. Tooth gingival inte ...

, there is a much smaller number of species that have been shown to be more closely related to the initial incidence and continued persistence of periodontitis, including: * ''

Aggregatibacter actinomycetemcomitans ''Aggregatibacter actinomycetemcomitans'' is a Gram-negative, facultative anaerobe, nonmotile bacterium that is often found in association with localized aggressive periodontitis, a severe infection of the periodontium. It is also suspected to b ...

'' * ''

Porphyromonas gingivalis ''Porphyromonas gingivalis'' belongs to the phylum ''Bacteroidota'' and is a nonmotile, Gram-negative, rod-shaped, anaerobic, pathogenic bacterium. It forms black colonies on blood agar. It is found in the oral cavity, where it is implicate ...

'' * ''

Tannerella forsythia ''Tannerella forsythia'' is an anaerobic, Gram-negative bacterial species of the Bacteroidota phylum. It has been implicated in periodontal diseases and is a member of the red complex of periodontal pathogens. ''T. forsythia'' was previously n ...

'' (formerly ''Bacteroides forsythus'') * ''

Treponema denticola ''Treponema denticola'' is a Gram-negative, obligate anaerobic, motile and highly proteolytic spirochete bacterium. It is one of four species of oral spirochetes to be reliably cultured, the others being ''Treponema pectinovorum, Treponema socra ...

'' * ''

Fusobacterium nucleatum ''Fusobacterium nucleatum'' is a Gram negative, anaerobic oral bacterium, commensal to the human oral cavity, that plays a role in periodontal disease. This organism is commonly recovered from different monocultured microbial and mixed infection ...

'' * ''

Prevotella intermedia ''Prevotella intermedia'' (formerly ''Bacteroides intermedius'') is a gram-negative, obligate anaerobic pathogenic bacterium involved in periodontal infections, including gingivitis and periodontitis, and often found in acute necrotizing ulcerat ...

'' * ''

Prevotella nigrescens ''Prevotella nigrescens'' is a species of bacterium. ''Prevotella nigrescens'' has a gram negative gram stain. When ''P. nigrescens'' microflora colonize they trigger an over-aggressive response from the immune system and increase the incidence ...

'' * ''

Eikenella corrodens ''Eikenella corrodens'' is a Gram-negative facultative anaerobic bacillus that can cause severe invasive disease in humans. It was first identified by M. Eiken in 1958, who called it ''Bacteroides corrodens''. ''E. corrodens'' is a rare pericar ...

'' * ''

Eubacterium nodatum ''Eubacterium nodatum'' is a Gram positive member of the oral flora of some patients with chronic periodontitis Chronic periodontitis is one of the seven categories of periodontitis as defined by the American Academy of Periodontology 1999 cla ...

'' * ''

Parvimonas micra ''Parvimonas micra'' is a Gram positive anaerobic coccus which is frequently isolated from dental plaque in patients with chronic periodontitis. It is the only species in its genus, and is a common constituent of mixed anaerobic infections such ...

'' (formerly '' Peptostreptococcus micros or Micromonas micros)'' * '' Streptococcus intermedius'' * ''

Campylobacter rectus ''Campylobacter rectus'' is a species of '' Campylobacter''. It is implicated as a pathogen in chronic periodontitis, which can induce bone loss. This motile bacillus is a Gram negative, facultative anaerobe. ''C. rectus'' is associated with hyp ...

'' * '' Capnocytophaga sp.'' A number of types of fungi, especially '' Candida'' spp., also play a smaller but not insignificant role in periodontal disease.

Periodiontal disease and obesity initiation marker

Selenomonas noxia Selenomonas noxia is gram-negative crescent-shaped bacteria included in the genus ''Selenomonas''. Its increase is associated with periodontitis Periodontal disease, also known as gum disease, is a set of inflammatory conditions affecting the ...

References

{{Periodontology Dentistry Periodontology

Periodiontal disease and obesity initiation marker

See also

References