Chapter 6 J: Caries Etiology And Evolution

Question 1

Dental caries is an ___ disease in which 3 factors interact in a way that increases demineralisation of the tooth?

Answer 1

Ecological, diet, host, and microbial flor

Question 2

The difference in occurrence of dental caries in different individuals of same age, sex, race and geographic area, diet, and similar living condiitons is because of?

Answer 2

Various factors that manipulate the etiology of caries such as?
1. Host (Tooth)
2. Substrate (environmental factors)
3. Microorganisms
4. Time period

Question 3

Host (tooth): 3 factors:

Answer 3

1. Variations in morphology
2. Composition
3. Position

Question 4

Lack of enamel maturation or the presence of developmental defects in enamel increase:

Answer 4

Plaque retention
Bacteria colonisation
And increase in caries risk

Question 5

Examples of lack of maturation of enamel?

Answer 5

Fluorosis, enamlogenesis imperfecta

Question 6

In what areas of the tooth is there an increment of caries risk?

Answer 6

Deep and narrow occlusal fissures, deep lingual or buccal pits, and enamel hypoplasia

Question 7

Is there a difference in the chemical composition of carious and sound enamel in contents of calcium, phosphorus, magnesium, and carbon ?

Answer 7

No but there is in fluoride (less in carious dentin)

Question 8

How can tooth position affect the initiation of dental caries?

Answer 8

In a tooth is out of position, rotated, in any abnormal position
Because it’s harder to clean, plaque retentive factor, retains more food and debris

Question 9

Other external factors related to the host that increase caries risk?

Answer 9

Retainer wear, orthodontic treatment, deficient obturations, and prosthetic clamps

Question 10

What is the body’s natural protective mechanism against decay?

Answer 10

Saliva

Question 11

The pellicle is?

Answer 11

The protective layer formed by deposition of salivary proteins onto the tooth surface that help enamel against acid dissolution

Plaque attaches deeper than the pellicle

Question 12

Functions of Salvia are:

Answer 12

• mechanical scavenging: auto cleasis
• buffering capacity
• decrease of enamel solubility
• antibacterial effect

MAD B

Question 13

What ions present in saliva help in remineralisation

Answer 13

Calcium and phosphate

Question 14

Which factors affect the susceptibility for caries:

Answer 14

• composition of saliva: saliva may affect caries rate by influencing bacteria, immune status, plaque formation
• saliva has a very important role in the balance between demineralisation and mineralisation

Question 15

What determines whether dental caries occur or not?

Answer 15

The balance between remineralisation and demineralisation

Question 16

What did primitive men eat and how did it help with the prevention of caries?

Answer 16

They ate rough and raw unrefined foods that had self cleaning capacity

Question 17

To cause demineralisation of the dental enamel, it’s essential for fermentable carbohydrates and plaque to be present on the tooth surface for?

Answer 17

A mínimum time to be metabolised by oral bacteria to produce acid

Question 18

The acids produced by these fermentable carbohydrates cause?

Answer 18

A rapid drop in plaque pH to a level which results in demineralisation of the tooth structure

Question 19

How long does it take for the pH to return to normal (remineralisation)?

Answer 19

30-60 mins

Question 20

Stephan curve:

Answer 20

• quick drop: fermentation of carbohydrates (Demineralisation)
• gradual return: buffers present in plaque and saliva (Remineralisation)
• under the line: can have caries
• above 5.5 is good

Question 21

There’s reduced caries activity with?

Answer 21

Sugar alcohols sweetness, sorbitol and xylitol

Question 22

Which carbohydrates cause more caries?

Answer 22

Low molecular weight carbohydrates since they diffuse rapidly into plaque and are metabolised quickly by bacteria as opposed to complex carbohydrates because they’re not completely digested in the mouth

Question 23

The most cariogenic sugar is?

Answer 23

Sucrose because streptococcus mutans use it to produce glucan (Extracellular polysaccharide that helps in adhesion to teeth)

Question 24

Quantity or frequency of carbohydrates ?

Answer 24

Frequency

Question 25

Deficiency of vitamin A causes?

Answer 25

Nothing

Question 26

Deficiency of vitamin B causes?

Answer 26

Its deficiency may exert a caries protect influence (important factor for acidogenic flor growth)

B6: anti cares agent (factor for non cariogenic organisms growth)

Question 27

Deficiency in vitamin C causes?

Answer 27

Its required for normal health of gingiva

Question 28

Deficiency of vitamin D causes?

Answer 28

Helps in normal development of teeth, deficiency : hypoplasia

Question 29

Do dental caries occur if there’s no bacteria in the mouth ?

Answer 29

No

Question 30

Streptococcus mutans:

Answer 30

• gram +
• acidophilus
• acidogenic
• found in fissures and inter proximal sulcus
• enamel caries

Question 31

Lactobacillus sp:

Answer 31

• gram +
• acidophilus
• acidogenic
• grows better in anaerobic conditions, deep dentin

Question 32

Actinomyces spp:

Answer 32

• gram +
• acidogenic
• sub gingival plaque and root caries
• in periodontitis

Question 33

Which bacteria is most commonly associated with dental caries?

Answer 33

Streptococcus