Murata/Sensi/Kaur Flashcards
Dental Caries:
- most prevalent and costly oral infection worldwide
- Streptocaccus mutans
- develop virulent biofilms
Streptococcus mutans: Virulence factors
- Biofilm formation
- composition
- Acid production
- ATPase
- Glycosyltransferase (GTF)
- GTF B & C
How do we get resident oral microflora:
- 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
oral microflora:
- 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
Key factors in S. Mutans Cariogenicity
- Adherence/colonization factors
- Acidogenicity
- Aciduricity
Adherence/Colonization factors
- Sucrose-dependent production of extracellular polysaccharides
Acidogenicity:
- very efficient uptake and metabolism of simple dietary carbohydrates to lactic acid
- glucose
- fructose
- sucrose
Aciduricity:
- maintenance of neutral intracellular pH in an low-pH microenviroment
Biofilm formation:
- initial attachment
- colonization
- formation
- mature biofilm
- dispersal/climax
Metabolism of dietary sucrose by S. mutans
Sucrose–>Glucose, Fructose–>Lactic acid–>enamel dissolution
Microbiology of root surface caries:
- 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
Carious Process
- 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
What teeth are more susceptible to dental caries
- Mandibular 1st molars
- 1st maxillary molars, 2nd mandibular molars, 2nd Maxillary molars
- 2nd premolars, maxillary incisors, and 1st premolars
- Mandibular incisors and canines (least likely
Surface susceptibility to caries:
first mandibular molars
fist maxillary molars
Maxillary lateral incisors
Secondary recurrent caries
root caries
- 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
Enamel defects:
- Nutritional deprivation
- hypoplastic enamel
- Genetic disorders
- amelogenesis imperfecta
- dentogenesis imperfecta
- High Fever
- Hypoplastic enamel-white lines
- Tetracyclines
- Advanced Fluorosis
Other factors affecting tooth susceptibliity
- Arch form and tooth position
- round vs square arch
- diastema
- misalignment, overlapping, tippint, rotation
Non-cavitated lesion
wHITE SPOT
Early lesion
Small well defined, discolored area located at the CEJ
- White spot
- especially at the gingival margin
- earliest sign of carious lesion
Active Lesion
- Yellow or light brown in color
- covered by microbial deposits
- tooth structure is soft
Slow progressing lesions
- brown to black in color
- lether consistency
Inactive/arrested lesion
dark brown and almost black
surface is shiny, smooth, hard on probing
root surface=glossy
How long does it take carious lesion to appear
- 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
4 myths of old school restorative dentistry
- ALL carious lesions need to be filled
- ALL carious lesions progress over. time
- restoractions cure caries
- placing restordations does more good than harm
How should we treat caries:
- Modern Caries management: Tx/prevention
- Chemotherapeutics/remineralization
- Risk reduction
- restorative treatment
- repair defects and aid in plaque control
Remineralization factors
- intact surface
- buffers calcium and phosphate ions
- plaque age
- fluoride
Lesion Severity Classification:
- 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
S Mutans polysaccharide production influence cariogenicity:
- EPS
- attachment of cells in plaque matrix
- acidic fermentation
- soluble or insolube
- IPS
- permits acid production in absence of dietary sugars
