Oral Microbiology

Oral diseases such as caries and many forms of periodontal disease are initiated by oral bacteria in dental plaque, which is a form of biofilm. A good example of how dental plaque forms and matures has been shown in experimental gingivitis, where dental plaque becomes established in the following pattern:

"Please describe stages of plaque development here"

Historical ideas on how bacteria cause dental disease

1. General Plaque Hypothesis
   

2. Specific Plaque Hypothesis
   

3. Ecological Plaque Hypothesis

Bacteria Associated with Dental Caries

1. Streptococcus mutans sp.
   

2. Lactobacillus acidophilus
   

3. Other cariogenic bacteria
   

All of these bacteria are aciduric and acidophillic

Bacteria Associated with Periodontal Disease

1. Bacteria associated with Chronic Periodontitis
   

   1.a. The Red Complex
   

   1.b. Porphyromonas gingivalis
   

   1.c. Tannerella forsythia
   

   1.d. Treponema denticola
   

2. Bacteria associated with Aggressive Periodontitis
   

   2.a. Aggregatinobacter actinomycetemcomitans
   

   2.b. Organisms found in atypical severe aggressive periodontitis
   

3. Bacteria associated with gingival disease
   

   3.a. Prevotella intermedia
   

   3.b. Fusobacterium nucleatum
   

   3.c. Neisseria gonorrhea
   

   3.d. Treponema pallidum
   

4. Viruses in periodontal disease
   

   4.a Herpes viruses
   

   4.b Cytomegalovirus
   

   4.c Epstein Barr Virus
   

5. Fungi in periodontal disease
   

   5.a Candida species
   

   5.b Histoplasmosis

It is thought that the different virulence factors of these bacteria, primarily Lipopolysaccharide, proteases and noxious metabolic products induce tissue damage, which is further aggravated by the host's immune response. For further information on how the immune system is involved in periodontal disease, see Oral Immunology.