Module 1

Question 1

Four exposures/risk factors for dental caries?

Answer 1

Dental plaque (cariogenic bacteria)
Dietary sucrose (and other refined carbohydrates)
Fluoride insufficiency
Saliva insufficiency

Question 2

what is an acquired pellicle?

Answer 2

acellular, homogenous organic film which forms on enamel and other hard surfaces through selective absorption of salivary proteins.

Question 3

difference between pq and calculus?

Answer 3

pq is nonmineralized whereas calculus is mineralised

Question 4

what are the observable effects of dental caries?

Answer 4

hole in the tooth or cavity

Question 5

difference between active and arrested lesion?

Answer 5

active is one that is progressing in its activity, arrested white spot lesion is the remaining scar following treatment

Question 6

what are the risk factors associated with dental caries?

Answer 6

pq, dietary sucrose or refined carbohydrates, fluoride insufficiency and saliva insufficiency.

Question 7

is dental caries considered communicable or non-communicable?

Answer 7

non-communicable.

Question 8

what process occurs in dental caries of teeth?

Answer 8

demineralisation of inorganic part of the tooth and dissolution of the organic portion.

Question 9

what are the requirements of that facilitate dental caries?

Answer 9

cariogenic/acidogenic bacteria, pq, stagnation areas, fermentable substrate for bacteria, susceptible tooth surface and time.

Question 10

how does frequent sugar exposure affect the carious process?

Answer 10

it changes the ecology of the oral cavity resulting in an upset of the balance between health and disease

Question 11

is pq alone sufficient to cause dental caries?

Answer 11

no-pq needs to be exposed to refined carbs, especially sucrose, sucrose is fermented to acid by specific bacteria and the acid is trapped against tooth surface by the pq which diffiuses through enamel layer then dentin.

Question 12

what does the acid dissolve?

Answer 12

apatite which is crystalline calcium phosphate

Question 13

what is the first sign of dental caries?

Answer 13

white spot lesion which is revealed when thick pq is removed

Question 14

what is the first radiographic sign of dental caries?

Answer 14

radiolucency on enamel

Question 15

how is saliva important in cavity development?

Answer 15

prior to cavity development, is pq is removed by TB, saliva will bathe the tooth surface and result in lesion arrest and remineralisation as saliva is alkaline and super saturated with calcium and phosphate

Question 16

fluoride is —- most common element in the earth’s surface

Answer 16

13th

Question 17

of the factors listed below which one is a specific risk factor for dental caries? manual tb, dental pq containing cariogenic bacteria, brushing twice, fl, drinking water

Answer 17

pq

Question 18

one way to distinguish active vs arrested caries?

Answer 18

active is soft, arrested is hard

Question 19

what are the cariogenic bacterial species?

Answer 19

streptococcus mutans, lactobaccilus spp, strep mitis, strep gordoni, strep sobrinus, actinomyces spp, strep oralis, strep anginosus.

Question 20

what are the steps of initiation of dental caries?

Answer 20

cariogenic diet high in refined carbs causes organisms in the pq to synthesise extraceccular polysaccharides like glucan and fructan together with intracellular polysac like glycogen, they are broken down by intrinsic enzymes to sugar, sugar is metabolized to acid causes lower pH within pq (below 6.8-7) , acid is trapped against the tooth surface by biofil, and diffisues through enamel and reaches dentin.

Question 21

what are the events are bacteria penetrate dentin?

Answer 21

dentin is less mineralised and has more proteins than enamel, other bacteria will come, continue to spread and advance towards pulp eventually infect it.

Question 22

what is the sign of loss of enamel and that dentin is reached?

Answer 22

pitting and cavitation-looks radiolucent/drk on radiograph.

Question 23

when does hole develop?

Answer 23

when enamel is lost, dentin is reached and mushy soft, brown

Question 24

what happens if the infection reaches the nerve?

Answer 24

it spreads to the bone, pus forms, abscess forms

Question 25

where does caries ususally occur?

Answer 25

sites where pq is left undisturbed i.e. along ging margins, interproximal between teeth, within grooves/pit and fissure on occlusal are the most vulnerable sites

Question 26

dental caries is mainly a ---- disease.

Answer 26

social

Question 27

is it the amount of sucrose that's important?

Answer 27

no the frequency of consuption

Question 28

how do we quantify pq?

Answer 28

pq index- score 0 no visible pq, score 1 no visible pq but it can be wiped off with perio probe, score 2 visible pq that appears after 24 h after tb, score 3 thick visible pq present for days.

Question 29

how is scoring pq calculated?

Answer 29

choose 6 teeth, score from B then L, total is out of 36, convert to %

Question 30

what is extended ecological caries hypothesis ?

Answer 30

the balance between microorganism and host is disturbed- not symbiotic anymore due to sucrose, and it changes to parasitism.

Question 31

how many species of healthy oral bacteria ?

Answer 31

more than 500

Question 32

what are some bacteria species found to be abundant relatively in healthy individuals than ones with caries/

Answer 32

higher abundance of Neisseria, haemophilus, fusobacterium

Question 33

bacterial composition of white spot lesions?

Answer 33

more strep mutans than healhy enamel, but non-mutans strep are still predominant soecies

Question 34

bacterial composition in cavitated lesions?

Answer 34

strep mutans make up 30% of total flora and are associated with enamel breakdown

Question 35

bacterial composition in mushy carious dentine?

Answer 35

lactobacilli, prevotellae, bifidobacterium more prevalent

Question 36

when does pq pH rise and fall?

Answer 36

rises when saliva rate is high by chewing, gum chewing, cheese. Fall at night time when saliva slows, sugar gum is chewed, sweet foods are consumed between meals and when flow velocity of saliva is low.

Question 37

why is saliva necessary for oral health?

Answer 37

saliva has buffering and rinsing capacity , also contains calcium and phosphate ions for remin, has libricants, immunoglobulins and enzymes that assist with first stage of carb metabolism

Question 38

two bacteria species strongly associated with dental caries? and how do they function?

Answer 38

strep mutants initiates tooth decay, lactobacilli promotes progression,

Question 39

what is the primary association of dental caries disease?

Answer 39

diet related

Question 40

What is the commonly cited critical pH for enamel demineralization

Answer 40

5.5 derived from theoretical enamel solubulity in saliva, not pq.

Question 41

Q: Why does the critical pH vary?

Answer 41

It depends on the composition of plaque fluid and can be as low as 5.1, especially for dentine and cementum, which have lower mineral content

Question 42

What happens to plaque pH after sugar intake?

Answer 42

The more frequently sugar is ingested, the longer the plaque stays acidic, increasing caries risk

Question 43

How does plaque on cavity-free teeth compare to plaque on carious teeth in pH recovery?

Answer 43

Plaque on cavity-free teeth returns to resting pH values much quicker than plaque on carious lesions.

Question 44

What does slower pH recovery in plaque with caries suggest?

Answer 44

Caries-associated plaque retains acidity longer, promoting continued enamel demineralization.

Question 45

Which jaw is more prone to acidogenic plaque?

Answer 45

Plaque in the upper jaw is significantly more acidogenic than plaque in the lower jaw.

Question 46

What is the main byproduct of S. mutans sugar metabolism?

Answer 46

Lactic acid, which lowers oral pH and causes enamel demineralization.

Question 47

What metabolic process does S. mutans use to break down sugars

Answer 47

Glycolysis- glucose into lactic acid

Question 48

Why is sucrose particularly cariogenic?

Answer 48

It serves as a substrate for glucan synthesis, helping bacteria adhere to teeth and form biofilms (plaque)

Question 49

Does the same sugar intake lead to the same caries severity in different populations?

Answer 49

No, there is a 50% variance in caries severity between populations.

Question 50

list the form of sugar consuption and time of consumption from worst to less

Answer 50

worst, sticky form between meals, then sticky form with meal, then solution at meal,

Question 51

which one is more cariogenic sucrose or fructose?

Answer 51

not sure- non conclusive

Question 52

is xylitol cariogenic?

Answer 52

no- it has been shown with less pq development, less strep mutants, it also increases acticity in oq and saliva, rises ph so it could be said that its anti-cariogenic.

Question 53

refined carbs or unrefined carbs effects the same?

Answer 53

no refined is worst

Question 54

does past caries experiences makes the risks of development higher?

Answer 54

yes they are more prone

Question 55

how does fluoride incorporate into developing teeth?

Answer 55

Fluoride replaces hydroxyl groups in hydroxyapatite, forming fluorapatite, which is more resistant to acid attack.

Question 56

2️⃣ Q: Why is fluorapatite more resistant to caries?

Answer 56

A: Fluorapatite is less soluble in acid than hydroxyapatite, reducing enamel demineralization.

Question 57

What determines the optimal fluoride level in community water?

Answer 57

What determines the optimal fluoride level in community water?

Question 58

What is the optimal fluoride level in Australia?

Answer 58

1 ppm (parts per million), but in Sydney, where natural levels can reach 2 ppm, the target is 0.5 - 0.7 ppm.

Question 59

hat happens if someone consumes too much fluoride?

Answer 59

Fluorosis, which causes discoloration and mottling of enamel.

Question 60

What is the difference between mild and severe fluorosis?

Answer 60

Mild fluorosis appears as white streaks, while severe fluorosis causes brown staining and enamel pitting

Question 61

Does water fluoridation depend on socio-economic status?

Answer 61

No, but it depends on whether people actually drink tap water.

Question 62

By how much does water fluoridation reduce caries?

Answer 62

60% in permanent teeth and 50% in primary teeth.

Question 63

Why is water fluoridation important for community health?

Answer 63

It provides continuous, low-dose fluoride exposure to strengthen teeth and reduce cavities in populations.

Question 64

is the effect of water fl different in primary and permanent teeth?

Answer 64

fl water consumption effect stronger in primary dentition