Murata/Sensi/Kaur

Question 1

Dental Caries:

Answer 1

• most prevalent and costly oral infection worldwide
• Streptocaccus mutans
  
  • develop virulent biofilms

Question 2

Streptococcus mutans: Virulence factors

Answer 2

• Biofilm formation
  
  • composition
• Acid production
  
  • ATPase
• Glycosyltransferase (GTF)
  
  • GTF B & C

Question 3

How do we get resident oral microflora:

Answer 3

• New born mouth is sterile
  
  • Main route of transmission=Saliva
  • Vertical transmission of
    
    • Oral Streptococci and Gram-negative species in children from their mother
• First months: Diversity increases
  
  • Pioneer species: streptococci salivarius, mitis and oralis
• Then: Grame negative anerobes:
  
  • Prevotella melan
  • Fusobacterium nucleatum
  • Veillenella spp.
• Teetth Eruption
  
  • novel habitat for microbial colonization
  • non shedding surface
• After tooth eruption:
  
  • S. Mutans
  • S. Sanguinis
• 19-31 months: colonization of S. Mutans
  
  • “Winndow of infectivity”
• increase climax community

Question 4

oral microflora:

Answer 4

• Microbial Homeostasis=stable
• Dynamic equilibrium b/w resident microflora and enviromental conditions
  
  • attempt t implant specific strains have failed
• Change in microflora
  
  • effect of aging

Question 5

Key factors in S. Mutans Cariogenicity

Answer 5

• Adherence/colonization factors
• Acidogenicity
• Aciduricity

Question 6

Adherence/Colonization factors

Answer 6

• Sucrose-dependent production of extracellular polysaccharides

Question 7

Acidogenicity:

Answer 7

• very efficient uptake and metabolism of simple dietary carbohydrates to lactic acid
  
  • glucose
  • fructose
  • sucrose

Question 8

Aciduricity:

Answer 8

• maintenance of neutral intracellular pH in an low-pH microenviroment

Question 9

Biofilm formation:

Answer 9

• initial attachment
• colonization
• formation
• mature biofilm
• dispersal/climax

Question 10

Metabolism of dietary sucrose by S. mutans

Answer 10

Sucrose–>Glucose, Fructose–>Lactic acid–>enamel dissolution

Question 11

Microbiology of root surface caries:

Answer 11

• 60% of people over 60 in the West
• accompanied by gingival recession
• soft cemental surfaces-highly susceptable to microbial colonization
  
  • irregular and rough surfces
• Mainly Lactobacilli

Question 12

Carious Process

Answer 12

• disequilibrium b/w demineralization and remineralization
• helps with biofilm accumulation
• synergistic acceleration of in cariogenic biofilm community
• expansion of demineralization with expanded cavitation
• rapid progresing destruction of tooth structure
• When careis reach DEJ, it expands rapidly bc dentin is much lesss resistant to acid demineralization

Question 13

What teeth are more susceptible to dental caries

Answer 13

1. Mandibular 1st molars
2. 1st maxillary molars, 2nd mandibular molars, 2nd Maxillary molars
3. 2nd premolars, maxillary incisors, and 1st premolars
4. Mandibular incisors and canines (least likely

Question 14

Surface susceptibility to caries:

first mandibular molars

fist maxillary molars

Maxillary lateral incisors

Secondary recurrent caries

root caries

Answer 14

• Mandibular molars
  
  • O>B>M>D>L
• Maxillary Molars:
  
  • O>M>L>B>D
• Maxillary lateral incisors
  
  • L>B
• Secondary/recurrent caries
  
  • gingival margin of restorations
• Root caries
  
  • close to gingival margin

Question 15

Enamel defects:

Answer 15

• Nutritional deprivation
  
  • hypoplastic enamel
• Genetic disorders
  
  • amelogenesis imperfecta
  • dentogenesis imperfecta
• High Fever
  
  • Hypoplastic enamel-white lines
• Tetracyclines
• Advanced Fluorosis

Question 16

Other factors affecting tooth susceptibliity

Answer 16

• Arch form and tooth position
  
  • round vs square arch
  • diastema
  • misalignment, overlapping, tippint, rotation

Question 17

Non-cavitated lesion

Answer 17

wHITE SPOT

Question 18

Early lesion

Answer 18

Small well defined, discolored area located at the CEJ

• White spot
• especially at the gingival margin
  
  • earliest sign of carious lesion

Question 19

Active Lesion

Answer 19

• Yellow or light brown in color
• covered by microbial deposits
• tooth structure is soft

Question 20

Slow progressing lesions

Answer 20

• brown to black in color
• lether consistency

Question 21

Inactive/arrested lesion

Answer 21

dark brown and almost black

surface is shiny, smooth, hard on probing

root surface=glossy

Question 22

How long does it take carious lesion to appear

Answer 22

• enamel: slow in most cases
  
  • white spot: >2 years
  • Cavitation: > 4 years
• Most susceptible time:
  
  • 2 years after erruption
• slower when Fluoride exposure is regular
• caries progression through dentin may also be slow

Question 23

4 myths of old school restorative dentistry

Answer 23

1. ALL carious lesions need to be filled
2. ALL carious lesions progress over. time
3. restoractions cure caries
4. placing restordations does more good than harm

Question 24

How should we treat caries:

Answer 24

• Modern Caries management: Tx/prevention
  
  • Chemotherapeutics/remineralization
  • Risk reduction
  • restorative treatment
    
    • repair defects and aid in plaque control

Question 25

Remineralization factors

Answer 25

• intact surface
• buffers calcium and phosphate ions
• plaque age
• fluoride

Question 26

Lesion Severity Classification:

Answer 26

• E0
  
  • no lesion
• E1
  
  • outer half of enamel
• E2
  
  • inner half of enamel
• D1
  
  • outer third of dentin
• D2
  
  • middle third of dentin
• D3
  
  • inner third of dentin
• D4
  
  • penetrated pulp

Question 27

S Mutans polysaccharide production influence cariogenicity:

Answer 27

• EPS
  
  • attachment of cells in plaque matrix
  • acidic fermentation
  • soluble or insolube
• IPS
  
  • permits acid production in absence of dietary sugars