Dental Caries

Question 1

Define plaque

Answer 1

heterogeneous, gelatinous, and complex mass of bacteria adhering to the tooth surface

Question 2

Carious lesions only occur…

Answer 2

under a mass of bacteria capable of producing a SUFFICIENTLY ACIDIC ENVIRONMENT TO DEMINERALIZE TOOTH STRUCTURE. This occurs over time

Question 3

Dental plaque begins with __________ in saliva adhering to enamel surface forming the ____ ____

Answer 3

Begins with GLYCOPROTEINS in saliva adhering to enamel surface forming the ACQUIRED ENAMEL PELLICLE (AEP)

Question 4

What does the acquired enamel pellicle allow for?

Answer 4

bacteria to ADHERE and begin colonization

Question 5

microorganisms in dental plaque ferment ___ ___ for energy and produce ___ by-products

Answer 5

microorganisms in dental plaque ferment REFINED CARBOHYDRATES for energy and produce ACIDIC by-products

Question 6

saliva contains ___ and ___ ions that serve in remineralization

Answer 6

calcium and phosphate ions.

Question 7

two main bacteria associated with dental caries

Answer 7

Streptococcus Mutans and Lactobacilli

Question 8

Aciduric vs acidogenic

Answer 8

Aciduric = tolerant of acidiv environments
Acedogenic = produce great amounts of acids

Question 9

Is S. mutan aciduric or acidogenic?

Answer 9

S. mutans is acidogenic, therefore it is associated with the PRODUCTION of caries/favourable for bacterial colonization

Question 10

Is Lactobacillus aciduric or acidogenic?

Answer 10

Aciduric. Therefore it is associated with the PROGRESSION of caries

Question 11

S. mutans and lactobacilli are stimuated by presence of ___

Answer 11

sucrose

Question 12

Dominant member of plaque flora?

Answer 12

S. Mutans

Question 13

why is low pH in the mouth bad?

Answer 13

Lower pH leads to hydroxyapatite breakdown (enamel crystal dissolution), which leaves behind more pores to which bacteria can adhere

Question 14

Critical pH for enamel vs dentin where demineralization can occur?

Answer 14

Critical pH for:
-Enamel: 5.5
-Dentin: 6.2
Therefore, dentin is more prone to acid attack than enamel

Question 15

What is remineralization?

Answer 15

• pH recovers

- Ca and PO4 re-precipitate on enamel mineral crystals as HA

Question 16

Which is a slower process, remineralization or demineralization?

Answer 16

remineralization is slower

Question 17

Components of keyes required for caries formation

Answer 17

1. fermentable carbohydrates
2. cariogenic biofilm
3. host
4. time

also primary modifying factors (ex. oral hygiene, diet, use of fluoride etc) and secondary modifying factors (ex. socioeconomic status, education, age, etc.) contribute to caries

Question 18

Cariogenicity of plaque is dependent upon

Answer 18

• acidic pH for longer than 30 mins
• Frequency of acidic environment
• stichiness of plaque
• exposure to F-
• HIGH FREQUENCY SUCROSE EXPOSURE is the most important factor in producing cariogenic plaque

Question 19

T/F: plaque growth without sucrose still leads to caries

Answer 19

False. Plaque growth without sucrose does NOT lead to caries

Question 20

Name the autoimmune disorder which affects the salivary glands and reduces salivary flow

Answer 20

Sjogrens disease

Question 21

Low salivary flow rate leads to

Answer 21

Reduced buffering capacity of saliva, which can lead to rampant caries. Presence of adequate saliva is important to neutralize and clear acids and carbs from dental plaque

Question 22

T/F: F- is naturally present in saliva

Answer 22

True. In small amounts

Question 23

How does F- inhibit demineralization?

Answer 23

-By the re-precipitation of dissolved calcium and phosphate, preventing these minerals from being leached out of enamel into the dental plaque and saliva.
HA replaced with FA (less soluble)
-Narrowing of pores in enamel, preventing diffusion pathways of acids to penetrate enamel

Question 24

Fluorhydroxyapatite is more/less soluble than hydroxyapatite

Answer 24

FA is LESS soluble than HA

Question 25

sites of carious lesions

Answer 25

pits and fissures, smooth surfaces, root surfaces

Question 26

Why does plaque adhere and colonize more easily on root surfaces as opposed to enamel

Answer 26

because root surface is rougher than enamel

Question 27

appearance of incipient caries when dessiccated

Answer 27

enamel appears chalky and opaque white when tooth is desiccated

Question 28

Should you treat incipient caries?

Answer 28

naw, has the possibility of remineralizing

Question 29

what is the deveopmental abnormality called in which areas of less mineralization spots exist in the teeth that make them more susceptible to caries, but not carious themselves

Answer 29

hypocalcified white spots

Question 30

hypocalcified white spots appearance

Answer 30

opaque even when tooth is wet

Question 31

Dentin is formed by ____ (cells)

Answer 31

odontoblasts

Question 32

Dentin resoinds to caries the following ways:

Answer 32

• sclerosis (dentinal tubules fill with peritubular dentin)
• reparative dentin
• pulpal death (necrosis)

Question 33

Pain from caries is a result of what?

Answer 33

pulpal stimulation caused by FLUID MOVEMENT through the dentinal tubules that have been exposed due to cavitation to the oral environment