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Flashcards in Caries Microbiology Deck (23)
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1

What is Caries?

¡The process of ___ ___ ___ caused by ___ in the presence of ___ ___.

¡How is this different from generalized erosion?

¡The process of localized tooth demineralization caused by bacteria in the presence of fermentable carbohydrates.

¡How is this different from generalized erosion?

2

What is the primary etiology of caries?

3

Four Principal Factors

Tooth
Bacteria

Sugar

Time

4

Caries Risk Factors

  • ___ ____
    •  
    •  
  • ___
    •  
    •  
  • ____
    •  
  • ____
    •  
    •  
    •  

¡Plaque composition

§Acid producing bacterial community

§Biofilm formation

¡Tooth

§Fissure morphology, hygiene

¡Diet

§Carbohydrate intake and frequency

¡Saliva

§Quantity and quality

§pH neutralizing, food clearance

5

Caries is a____ mediated process, and forms at sites of ___ ___ ___.

Caries is a biofilm mediated process, and forms at sites of high plaque accumulation.

6

Types of Dental Caries

Enamel

Dentinal 

Smooth Surface

Root Surface

Recurrent

7

Tooth Enamel

___
___
____
____

___
____

Enamel made of __ ___ ___ __ _____

1) ___: gives tooth _______,___organized, arranged ____ to surface of enamel. tightly packed mass of ___.
2) ___: ___ ___ in this, ___ organized

¡Calcium

¡Phosphate

¡Carbonate

¡Other Minerals

¡Amelogenins

¡Enamelin

 

Enamel made of 2 diff [] of hydroxyapatit

1) rods: gives tooth structural strength, very organized, arranged perpendicular to surface of enamel. tightly packed mass of hydroxyapatite.
2) matrix: rods embedded in this, not as organized

8

Tooth formation & maintenance

  • ¡______
    • ___ ___
    • ___ ___
    • ___ to form ___ ___ at ___ ___
  • ¡Saliva
    • ____ ___
    • ___ ___ ___ ___ ___

¡Ameloblasts

§Create matrix

§Secrete minerals

§Crystallize to form enamel prisms, at neutral pH

¡Saliva

§Maintains pH

§Soluble minerals maintain crystal lattice

9

Biofilm interaction with Enamel

If ph gets below ___ you get ___

___ dissolves first. Why?

Start to see: ____ which are ____

Eat carbs, they diffuse into biofilm, bact produce acid. Acid is help within the community and starts to drop the pH. If pH gets bbelow 5.5 you get demineralization

Matrix dissolves first. Not as resistant to acid

Start to see whitespot lesions.

That’s very early stage of biofilm demineralization

10

Interior of demineralized enamel

___ of teeth is ___ __ when you ahve white spot lesions

Remineralize?

Structural integretity of the teeth is still there when you have white spot lesions

White line on right is the saliva trying to remineralize

11

Caries progression

1)

2)

3)

4)

5)

6)

1) no caries

2) white spot lesion

3) enamel penetrated--> decayed surface

4) Decayed tooth with restoration in which lesion has continued to expand

5) mineralization progressed to undermining tooth

6) Fracture

12

Dentinal caries

Overtime if mineral continues to be lost, the rods will break and thats when you see cavity.

This exposes the dentin

You can start to get dentinal caries

Dentin less mineralized than enamel so process goes faster

13

Bacteria in Caries

  • ¡Streptococci
    • ___ ___
    • found in __ and __ ___
    • includes ___ group
  • ¡Lactobaccilli
    • ___ caries
  • ¡Actinomyces
    • ____ caries
    • §Possibly____caries
  • ¡Veillonella
    • §___” with ____
    • §Protective or Harmful? 

  • ¡Streptococci
    • §Caries initiation
    • §Fissures/smooth surfaces
    • §Mutans group
  • ¡Lactobaccilli
    • §Dentinal caries
  • ¡Actinomyces
    • §Root caries
    • §Possibly dentinal caries
  • ¡Veillonella
    • §“symbiotic” with S. mutans
    • §Protective or Harmful? 

14

Gram Positive Streptococci
 

  • ¡Streptococci
  • O2?
  • ___  ___ of oral bacteria
  • ___ of cultivable bacteria from ___ and ___
  • ___ from ___
  • ____, adhere to the ___
  • ____ complex
  • ▪Divided into __ groups
    • ____
    • ___
    • ___
    • ___

¡Streptococci

§Facultative anaerobes

§Largest group of oral bacteria

▪50% of cultivable bacteria from saliva and tongue

▪30% from plaque

▪Pioneers, adhere to the pellicle

▪Yellow complex

▪Divided into 4 groups

▪Salivarius

▪Oralis

▪Mutans

▪Milleri

15

Non-cariogenic oral streptococci

  • ¡Oralis group
    • §Associated with ___ and ___ ___
    • hemolytic 
    • Species
      • ___
      • ___
      • ___
      • ____
      • ▪Biovar I prefers __
      • ▪Biovar II prefers __
  • Salivarius group
    • Species _____
    • Prefers ____
    • Found on ____
    • Hemolytic 
    • Associated with ___ and ___ ___
  • Milleri group
    • ____ ____
    • __ hemolytic
    • Species
      • ____
      • ___
    • O2
    • Found ________
    • Associated with 
    • Commonly found in__ and ___ ____, with ___ __ (___)
    • ___ complex

¡Oralis group

§Associated with gingival and enamel heath

§Alpha hemolytic (viridans)

§S. gordonii 

§S. sanguis

§S. oralis

§S. mitis

▪Biovar I prefers pellicle

▪Biovar II prefers non-keratinized surfaces (buccal)

Salivarius group

S. salivarius

Prefers keratinized surface

Tongue

Alpha-hemolytic on blood (viridan strep)

Associated with gingival and enamel heath

Milleri group

Opportunistic pathogens

Beta hemolytic

S. constellatus

S. anginosus

Strict anaerobes

Subgingival plaque

Gingivitis

Commonly found in dental and brain abscesses, with other bacteria (polymicrobial)

Orange complex

16

Gram Positive Oral Bacteria

  • ¡Mutans group 
  • Species:
    • §S.
    • §S. 
  • ___-hemolytic on blood 
  • §Most strongly associated with___
  • §Colonizes____ and ____
  • §Produces ___ to aid in___
  • §Produce ___

¡Mutans group 

§S. mutans

§S. sobrinus

§Alpha-hemolytic on blood (viridan strep)

§Most strongly associated with caries

§Colonizes tooth surfaces and fissures

§Produces glucans to aid in colonization

§Produce acid 

17

Streptococci serology

¡Mutans group serotypes __-__

¡Mutans group serotypes a-h

§

§S. mutans   c e f

§S. rattus   b

§S. sobrinus   d g h

§S. cricetus  a

§

18

S.mutans is strongly associated with caries

¡Epidemiology-___ ____ with disease

¡Low numbers in___

¡Grows at___ pH values

¡Causes caries in ____ animal models

¡Epidemiology-high correlation with disease

¡Low numbers in health

¡Grows at low pH values

¡Causes caries in germ-free animal models

19

Factors related to cariogenicity of S Mutans

20

S. mutans Virulence Factors

____- 

____- 

___ ___ to ___ __

  • ___ ____
  • §SpaP (AgI/II)- 
  • §Gbp A/B/C- 

¡Acidogenic- Produces acids as byproduct of metabolism

¡

¡Aciduric- tolerates and adapts to low acid conditions

¡

¡Adheres tightly to tooth surface

§Glucan production

§SpaP (AgI/II)- adhesin for pellicle agglutinin

§Gbp A/B/C- glucan producing and binding proteins

21

S. mutans Sugar Metabolism

¡Caries most often found in ___ ___

¡

____ is ___ nutrient of S. mutans

¡

¡Colonization of the mouth occurs in presence of ___, but not ___ or ___

¡

¡Caries most often found in industrialized countries

¡

¡Sucrose (table sugar) is favored nutrient of S. mutans

¡

¡Colonization of the mouth occurs in presence of sucrose, but not fructose or glucose

¡

22

okSucrose metabolism

23