Caries Aetiology

Question 1

what is epidemiology

Answer 1

powerful research tool, populations, diseases and patterns

Question 2

what is the main acid produced by bacteria

Answer 2

lactic acid from glucose

Question 3

what is the critical pH

Answer 3

5.5

below which HA dissolves

Question 4

how is plaque pH studied

Answer 4

metal probes
glass pH electrodes
radio telemetry
removal of plaque samples

Question 5

what are the metal probes used

Answer 5

antimony

iridium

Question 6

what si the sequence if events in measuring plaque pH

Answer 6

plaque on ant teeth 
antimony electrode in plaque 
record pH 
2 min rinse - 25ml 10% glucose
record every 10 mins

Question 7

what is a stephan curve characteristic

Answer 7

rapid pH drop
slow pH rise
variable time course (15-20mins)

Question 8

why is there a rapid drop in stephan curve

Answer 8

speed microbe metab carb
- glucose and sucrose are rapid
large carbs - starch - slower

Question 9

how does plaque bac interact with glucose and sucrose

Answer 9

rapid diffusion
lots acid - lactic acid
low pH

Question 10

how does plaque bac interact with starch

Answer 10

amylase - glucose to maltose

less acid an mixed types acid not so low pH

Question 11

what does lowest pH dept on

Answer 11

microbial composition of plaque
nature of carb source
rate diffusion ira nd out of plaque

Question 12

why is there a rise in the stephan curve

Answer 12

acid diffusing out

salivary buffering

Question 13

what does CF subjects show

Answer 13

started higher and finished higher

stayed above critical pH

Question 14

what does a caries active subject show pH

Answer 14

started lower and finished lower

reined below critical pH for long periods

Question 15

what can starchy foods =

Answer 15

produce stephan like response

Question 16

what is the acidogenic potential

Answer 16

ability of food to produce acid

Question 17

what does the acidogneic potential dept on

Answer 17

nature of food
properties of host
bac in dental plaque

Question 18

what are some types of nutritive sweeteners

Answer 18

sorbitol
mannitol
xylitol

Question 19

what are nutritive sweetness

Answer 19

sugar alcohols
bulk sweetners
slowly fermented by bacteria
only slight pH drop

Question 20

what are nutritive sweetners used in

Answer 20

chewing gum - mannitol

confectionary and toothpastes - xylitol

Question 21

what is a problem of nutritive sweetners

Answer 21

potential laxative effects

Question 22

what are some alternative sweetners

Answer 22

Intense

non nutritiive

Question 23

when are intense sweetners used

Answer 23

in small quantiiees

Question 24

what are some intense sweetner examples

Answer 24

saccharin

• 300X > sucrose
• bitter aftertaste

aspartame
- candarel and nutrasweet

acmsulfame-K

• 300X sucrose
• soft drinks and sugar free gum

Question 25

what is a tooth friendly sweeter

Answer 25

if plaque pH doesnt go below 5.7 within 30 mins of ingestion in switzerland

Question 26

what are the ways theatre of the food has an affect

Answer 26

``` amount and type of ferment carb in food physical form buffering capacity sialogues sequence foods in meal ```

Question 27

what is the way the physical form changes

Answer 27

sticky and retained vs liquid and swallowed

Question 28

what is sialogues

Answer 28

saliva flow promoters

Question 29

how does the host factors affect the plaque pH

Answer 29

``` food eating habits - sequence frequency food intake buffer capacity CaPHos conc in saliva fluoride content enamel ```

Question 30

why si the summary of pattern eating

Answer 30

best to end a meal with non acidgmenic food - cheese | snacking - more low pH episodes, less time for pH to recover

Question 31

what does saliva typically contian

Answer 31

bicarb - buffer | Ca and Phos

Question 32

when does saliva inc

Answer 32

masticatory nd salivary reflexes | gustatory stimulus

Question 33

when does saliva flow decrease

Answer 33

at night | xerostomia - gland damage - radiotherapy cases this

Question 34

are the inter proximal spaces pH greater in mandible or maxilla

Answer 34

maxilla less saliva less buffer as more saliva at mandible so greater buffer efect

Question 35

why is it bad to have 1/2 apple at bedtime

Answer 35

longer pH drop and takes longer to climb as while asleep less saliva reduced less saliva buffer

Question 36

what does eating a sweet do to saliva flow and plaque pH

Answer 36

increased saliva flow | plaque pH may rise before drop

Question 37

what does eating a non fermentable substance do to saliva flow and plaque pH

Answer 37

increase saliva flow | pH inc to resting levels

Question 38

what is imp when considering saliva flow and plaque pH

Answer 38

sequence of food consumption sugar contiangi food shouldn't be last sugar free gum good

Question 39

what are some factors affecting acid production

Answer 39

``` No. acidogenic bac types of acid prod No. acid consuming bac No. base prod bac metab state bac when food is ingested ```

Question 40

what is acid erosion usually from

Answer 40

dietary acid | gastric acid

Question 41

what is the erosion histologically

Answer 41

generalised loss of enamel no zone estruture no surface layer

Question 42

what do polysaccharides and other gel like components do to dental plaque

Answer 42

reduce diffusion of dissolved enamel mineral away form tooth surface