microbiology of dental caries
DESCRIPTION
Describe relationship between plaque and oral diseases Describe role of plaque in development of caries Define Dental Caries Describe the aetiology and the role different factors play in ini4a4on and progression of the disease Describe the role played by different microorganismsTRANSCRIPT
![Page 1: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/1.jpg)
Dr. Ali Yaldrum SEGi UC, KD
Dental Caries Microbiology
![Page 2: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/2.jpg)
![Page 3: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/3.jpg)
Learning Outcomes
At the end of this session students should be ! Describe rela4onship between plaque and oral diseases ! Describe role of plaque in development of caries ! Define Dental Caries ! Describe the ae4ology and the role different factors play in ini4a4on and progression of the disease
! Describe the role played by different microorganisms
![Page 4: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/4.jpg)
Plaque bacteria to Caries
Relationship of
![Page 5: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/5.jpg)
Plaque & Caries
Historically for any microbe to be considered responsible for a given condi4on, Koch’s postulate was applied
![Page 6: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/6.jpg)
Koch’s Postulate
1. The microbes should be found in all cases of the disease with a distribu4on corresponding to the observed lesions
2. The microbes should be grown on laboratory media for several subcultures
3. A pure subculture should produce the disease in the suscep4ble animal
4. A high an4body 4ter to the microbe should be detected during infec4on; this may provide protec4on on subsequent reinfec4on
![Page 7: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/7.jpg)
Koch’s Postulate
1. A microbe should be present in sufficient numbers to ini4ate disease
2. The microbe should generate high levels of specific an4bodies 3. The microbe should produce relevant virulence factors 4. The microbes should cause disease in an appropriate animal
model 5. Elimina4on of the microbe should result in clinical improvement
![Page 8: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/8.jpg)
Role of Plaque
! The ‘Specific Plaque Hypothesis’ (fig.1) ! The ‘Non-‐Specific Plaque Hypothesis’ (fig.2) ! The ‘Ecological Plaque Hypothesis’ (fig.3)
![Page 9: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/9.jpg)
Specific Plaque Hypothesis
Plaque
Disease
( ) X problem disease can stil l occur in absence of these organisms
few species out of diverse resident flora are actively involved in disease {
fig.1
![Page 10: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/10.jpg)
Non-Specific Plaque Hypothesis
Plaque
Disease
( ) problem plaque mediated diseases are polymicrobial but one specif ic organism predominate
out come of the overall activity of the total plaque microflora {
fig.2
![Page 11: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/11.jpg)
Ecological Plaque Hypothesis
Plaque
Disease ( ) disease only initiates as a result of shift in the balance of resident microf lora
organisms associated with disease are already present on teeth but very low to detect {
fig.3
![Page 12: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/12.jpg)
Dental Caries
![Page 13: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/13.jpg)
Dental Caries
! It is bacterial disease of calcified 4ssue of the teeth characterized
by demineraliza4on of the inorganic and destruc4on of the organic substance of the tooth.
‘Dental Caries is known as disease of civilization’
![Page 14: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/14.jpg)
The Early theories
! The legend of Worms ! Endogenous Theory ! Chemical Theory ! Parasitic Theory ! Chemoparasitic Theory
Dental Caries
![Page 15: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/15.jpg)
! Chemoparasitic theory Miller in 1890 suggested that oral bacteria converted dietary carbohydrates into acid which solubilized the calcium phosphate of enamel to produce a caries lesion
Dental Caries
![Page 16: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/16.jpg)
Aetiology of Dental Caries
![Page 17: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/17.jpg)
Saliva
Saliva
Saliva
Saliva Time P laque Bacteria
Susceptible Surface
Sugar
Caries
aetiology of caries fig.4
![Page 18: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/18.jpg)
Role of Saliva
![Page 19: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/19.jpg)
Saliva plays a vital role in the maintenance of oral health and the integrity of oral 4ssues Saliva contains:
• exfoliated epithelial cells • oral microorganisms • food residues (carbohydrates) • an4microbial factors • minerals
Role of Saliva
![Page 20: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/20.jpg)
! Mechanical washing ac4on of saliva is very effec4ve for cleaning of teeth
! high buffering capacity neutralizes acid ! supersaturated with Calcium and phosphorus helps in remineraliza4on
Salivary flow rate: 0.8 mm /min on upper labial surface
5.0 -‐ 8.0 mm/min on lower lingual surface
Role of Saliva
![Page 21: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/21.jpg)
Susceptible Surface
![Page 22: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/22.jpg)
Susceptible Surface
Some areas of the tooth are more suscep4ble to developing caries
than others, known as ‘susceptible areas’ Suscep4bility is related to several factors ! Mineral & Fluoride Content ! Structure of that par4cular area
![Page 23: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/23.jpg)
Susceptible Surface
Susceptible tooth surfaces includes ! Pits & Fissures (fig.5) ! Approximal Enamel cervical to contact point (fig.6) ! Exposed root surface (fig.7 & 8) ! Margins of Restora4on (fig.6 & 9) ! Cervical margins of tooth (fig.10)
![Page 24: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/24.jpg)
pits & fissures caries
fig.5
![Page 25: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/25.jpg)
Approximal Caries Caries under restoration
fig.6
![Page 26: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/26.jpg)
Root surface Caries
fig.7
![Page 27: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/27.jpg)
fig.8
Root Surface Caries
![Page 28: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/28.jpg)
Caries under restoration Amalgam restoration
fig.9
![Page 29: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/29.jpg)
white spot lesions
fig.9
![Page 30: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/30.jpg)
white spot lesion Cavitation
From white spot to cavity formation
earliest clinical evidence (reversible) Later clinical stage (irreversible)
![Page 31: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/31.jpg)
Sugar Substrate Time &
![Page 32: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/32.jpg)
! Direct rela4onship between intake of Carbohydrates (sugar) & Caries
! Glucose, Fructose & Sucrose are cariogenic ! Sucrose is the most cariogenic sugar
• fermentable • easily penetrates plaque
Sugar Substrate
![Page 33: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/33.jpg)
There is a direct rela4onship between caries and: ! Frequency of sucrose consump4on ! s4ckiness of the sucrose
Both affects the amount of 4me sugar stays into contact with the teeth surface
Time & Sugar Substrate
![Page 34: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/34.jpg)
Plaque Bacteria
![Page 35: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/35.jpg)
Dental Caries does not occur in vivo if microorganisms in the form of dental plaque are absent; making it clear that dental caries is a plaque mediated disease
Plaque Bacteria
‘ ‘
![Page 36: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/36.jpg)
! Streptococcus mutans ! Lactobacillus species ! Ac4nomyces Species ! Veillonella species
Plaque Bacteria
![Page 37: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/37.jpg)
The term mutans streptococci refers to a group of 7 different species, but two species are most commonly found in humans ! S. mutans (serotypes c/e/f) ! S. sobrinus (serotypes d/g)
Streptococcus species
![Page 38: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/38.jpg)
Factors related to Cariogenicity of S. mutans ! S.mutans counts in saliva and at site of lesion ! Isolated from site before the development of caries ! Efficient sugar metabolism & transport capability ! Acidogenic & acidouric ! Liele effect of pH on growth and metabolism ! Produc4on of EPS & IPS
Streptococcus species
![Page 39: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/39.jpg)
S. mutans been implicated in ! Pits & fissure caries (strong evidence) ! Root surface caries ! All forms of caries ! Some strains are more pathogenic than others
Streptococcus species
![Page 40: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/40.jpg)
! S. Sobrinus role is uncertain ! Frequently isolated from plaque but in lesser numbers ! Shares the same cariogenic proper4es as S.mutans
Streptococcus species
![Page 41: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/41.jpg)
Lactobacilli can be divided into two groups ! Homofermenta4ve species ! Heterofermenta4ve species
Lactobacillus species
![Page 42: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/42.jpg)
Homofermentative species ! L. acidophilus & L. casei ! Mainly produce lac4c acid from glucose fermenta4on
Heterofermentative species ! L. fermentum ! Produce lac4c acid and significant amounts of acetate
Lactobacillus species
![Page 43: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/43.jpg)
Most commonly isolated species from oral cavity are ! L. casei ! L. fermentum ! L. acidophilus
Lactobacillus species
![Page 44: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/44.jpg)
Factors related to Cariogenicity of Lactobacillus species ! Increased number in carious cavi4es affec4ng enamel & root surface
! Number in saliva reflect caries ac4vity ! Acidogenic and acidouric ! Few strains can produce EPS
Lactobacillus species
![Page 45: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/45.jpg)
! Have a low affinity for tooth surface ! Low in numbers at healthy site ! Implicated in progression of caries deeper into den4ne rather than ini4a4on
! Implicated in ae4ology of root surface caries
Lactobacillus species
![Page 46: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/46.jpg)
Ac8nomyces spp. form a major and complex part of the oral microflora, par4cularly at the approximal site and gingival crevice
Actinomyces species
![Page 47: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/47.jpg)
! Ac8nomyces odontoly8cus been associated with very early stages of tooth demineraliza4on
! Ac8nomyces naeslundii been associated with development of root surface caries
Actinomyces species
![Page 48: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/48.jpg)
CariesVaccination
![Page 49: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/49.jpg)
In rats , experimental dental caries have been reduced by immunizing with cell-‐wall associated an4gens or glucosyltransferase from S.mutans
Caries Vaccination
![Page 50: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/50.jpg)
The following mechanism have been suggested ! Inhib4on by secretory IgA of bacterial coloniza4on of teeth
! Interference with bacterial metabolism ! Enhancement of phagocy4c ac4vity in gingival crevices
Caries Vaccination
![Page 51: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/51.jpg)
! Dental Caries is a mul4factorial disease, strongly associated with the dental plaque
! Ecological Plaque Hypothesis caries forms as a result of disturbance in the normal balance of Oral Biota
! The main factors involved are suscep4ble tooth surfaces, 4me, sugar substrate and plaque bacteria
! Pits & fissure are the most suscep4ble areas ! Frequency of sugar intake is more decisive than total consump4on
Summary
![Page 52: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/52.jpg)
! Sucrose is the most cariogenic sugar ! Mutans streptococci are implicated in ini4a4on of pits & fissure and root caries
! Lactobacillus spp are associated with progression of caries
Summary
![Page 53: Microbiology of Dental caries](https://reader033.vdocuments.site/reader033/viewer/2022052316/5595a6421a28ab8b168b4732/html5/thumbnails/53.jpg)
! Philip D. Marsh, Michael V Mar4n, “Plaque mediated diseases-‐ Dental Caries and Periodontal diseases” in Oral Microbiology, 5th Edi4on, Churchil Livingstone, 2009, pp 104-‐117
! J. Bagg, T. W. Macfarlane, I. R. Poxton and A. J. Smith, “Dental Caries” in Essen4als of Microbiology for Dental Students, 2nd Edi4on, Oxford University Press, 2006 pp238-‐248
References