Biofilm I - caries

Question 1

caries is basically

Answer 1

eroision of enamel

Question 2

erosion is caused by

Answer 2

weak acids

Question 3

stephen curve

Answer 3

Fermentable carbohydrate consumed can cause pH to drop below critical 5.5 causes demineralisation

Question 4

what does activity of saliva do to the pH

Answer 4

it has a buffering capacity

helps bring the pH up towards neutral

Question 5

frequent consumption of fermentable carbohydrate leads to

Answer 5

demineralisation

Question 6

4 elements need for caries

Answer 6

• Biofilm
• Fermentable carbohydrate
• Tooth
• Saliva - imp in control

Question 7

microbiology of caries

Answer 7

not one sole microorganism

Ultimately combination of bacteria forming complex plaque will lead to reduction in pH and caries

Question 8

stages leading to formation of caries

Answer 8

• adhesion
  
  • not washed away by saliva
• survival and growth
• biofilm formation
• complex plaque
  
  • range of species
• acid
• caries

Question 9

common cariogenic bacteria

Answer 9

streptococcus mutans

linked to high sugar diet

not sole

Question 10

virulence factors in its favour for strep mutans

Answer 10

• glycolytic systems – ferment carbohydrate in a specific way
• EPS/sucrose metabolism
  
  • extra polymeric material, glucans via sucrose metabolism
• attachment mechanisms (GTF, Ag I/II)
• greater acidogenicity/aciduricity c.f. competitor spp
  
  • Negatively effect other bac
• ecological competitiveness at low pH
• genomic characteristics
  
  • ability to modulate behaviour
  • competent systems to update systems

Question 11

what is key for s.mutans causing caries

Answer 11

sucrose

virulence factors are circumstanstial associations

Question 12

caries

Answer 12

≠ S.mutans

research activity focussed on it - shouldn’t be on just 1 organism

• window of infectivity
• vaccines
  
  • passive, active, various antigens
• replacement therapy, probiotics
• targeted antimicrobial peptide

Question 13

how should we target caries

Answer 13

by targeting the factors

fermentable

tooth

microorganism

time

Question 14

obstacles in determining microbial etiology of caries

Answer 14

varies

different parts of mouth might be different susceptibilities

dynamic process – things happen, changes in amounts of different MO

How many needed to be biologically significant?

Likely have different roles in different individuals at different ages

• Drive for caries still unclear*
• Many factors
• Fermentable carbohydrates clear link to caries*

Question 15

what is crucial for caries

Answer 15

retentivity of cariogenic foods

frequency of cariogenic foods

Question 16

e.g. cariogenic foods

Answer 16

not just sucrose

• carbohydrates
• cooked startched - crisps, biscuits, pretzels

‘sticky in hand doesn’t mean sticky in mouth’

Question 17

what is the issue with retentivity and caries

Answer 17

• linger around - get into fissures
  
  • More likely to be harmful

Question 18

what could be the impact of interactions of sugars and starches

Answer 18

potential driving lower pH for metabolic processes

cumulative effect?

Question 19

how should caries research go forward

Answer 19

Modulate whole group of bacteria and look at how they work better

As focus on one – Other MO take its place

Question 20

how do we know what microbial species is important

Answer 20

hard - abundance? function?

dyanmic - can favour one species but change to favour a different quickly

Question 21

when do we get mouth microorganisms

Answer 21

very early stage

• Placental MO looks like mothers oral biome

Early colonisers impacted by many things

Diversification pre dentate

• And further by dentate

Early ones critical to what you will be exposed

• Environment will change some MOs

But ultimately what begin with is key role

Question 22

broader caries aetiology

Answer 22

Hundreds or thousands of microbial species

Wide spectrum of microbial flora assoc. with caries

• Actinomyces, Abiotrophia, Atopobium, Bifidobacterium, Lactobacillus and Veillonella, Propionibacterium, Prevotella spp., S. parasanguinis, S. salivarius, S. sobrinus
• Veillonella almost ubiquitous

Subjects with no S. mutans, but with caries

• Mutans-streps presence not predictive of caries
  
  • S mutans does not = caries
  • Caries does not mean = s mutans

Question 23

caries is complex disease how

Answer 23

dynamic

• Primarily predictive by what you eat
• Organisms present to start with and then what environment they are in dictates how they will proliferate when given food source

Question 24

new molecular methods - looking at diet and microbial aetiology

Answer 24

• diet microflora and caries
• diet and severe early childhood caries
  
  • Bifidobacterium spp, lactobacilli, yeast (& MS)
• conditions to facour S.mutans
  
  • rather than s.mutans as a pre-requisite
• new methodologies created new paradigm
  
  • more complex oral microbial world

Question 25

ecological plaque hypothesis shows

Answer 25

* Need organisms * But impacts on it will lead to effect * Ever changing picture Need to try managing oral microbiome as a whole

Question 26

microbiome data sets

Answer 26

Integrate all data from control and active caries * To create a predictive algorithm for which MO associate with caries and which health Help prevention in future if ID pt microorganisms in future

Question 27

what is useful to know to figure out risk predictive tool

Answer 27

function knowing what there are and where they are

Question 28

oral microbiome as a predictor for other diseases

Answer 28

* periodontitis * caries * alzeheimers * cardiovascular * cystic fibrosis * esophageal cancer * colorectal cancer * diabetes * pancreatic cancer * rheumatoid arthritis not diagnosing - predictive tool only

Question 29

what is arguably the most important way in dealing with microbiology of caries

Answer 29

good dietary advice