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Question 1
Pathological factors contributing towards caries
• frequent dietary sugars • inadequate fluoride • poor oral hygiene
Question 2
Protective factor against dental caries?
Professional topical fluoride
• healthy diet • brush 2x daily w fluoride • professional fluoride • sealants • normal salivary function
Frequent consumption of dietary sugars
Healthy diet
Question 3
Demin/Remin Formula
Ca₁₀(PO₄)₆(OH)₂ + 14H⁺ ⇌ 10Ca²⁺ + 6H₂PO₄⁻ + 2H₂O
Question 4
What is the process where tooth enamel regains minerals and becomes stronger?
Salivary function
Enamel erosion
Demineralization
Caries progression
Question 5
What is the outermost layer of a healthy tooth called?
Dentin
Cementum
Enamel
Pulp
Question 6
Where does a cavity typically start on a tooth?
Gum line
Outer surface of the tooth
Inner surface of the tooth
Root of the tooth
Question 7
What is the characteristic of the outermost layer of enamel?
Very porous
Smooth
Hardest substance in the body
Non-porous
Question 8
What is the primary component of enamel by weight?
Dentin
HA (Hydroxyapatite) - 97%
Hydroxyapatite
Collagen
Question 9
What is the predominant mineral in enamel?
Dolomite
Fluorapatite
Silica
Calcite
Question 10
What does calculus fomration begin with?
deposition of calcium and phosphate from supersaturated saliva
Question 11
What is the chemical formula for hydroxyapatite?
Ca5(PO4)3(OH)
Ca2(PO4)3(OH)
Ca3(PO4)2
Ca10(PO4)6(OH)2
Question 12
What is the primary cause of ACID (H+) production in the mouth?
Dental fillings
Saliva
Fermentable carbohydrates + oral microflora
Mineral supplements
Question 13
What does pH measure in an aqueous environment?
free hydroxide ion concentration
total hydroxide ion concentration
total hydrogen ion concentration
free hydrogen ion concentration
Question 14
What happens to HA and FA at pH 5.5
• HA in enamel begins to dissolve • FA is still stable
Question 15
How does the number of free hydrogen ions change if pH decreases from 7 to 6?
5x more
100x more
2x more
10x more
Question 16
How does the number of free hydroxide ions change if pH increases from 7 to 8?
100x more
5x more
2x more
10x less
Question 17
What is Stephan's curve
shows remin and demin over time pH vs time
Question 18
What is the ideal physiologic oral pH range according to the slide?
5.5-6.5
7.5-8.5
6.0-7.0
8.0-9.0
Question 19
Why is some biochemical activity important at physiologic pH?
Physiologic turnover
Energy production
DNA replication
Enzyme activation
Question 20
What is the chemical formula for fluorohydroxyapatite?
Ca5(PO4)3(OH)2
Ca5(PO4)3(F)2
Ca5(PO4)3(OH)(F)
Ca5(PO4)3(OH)3
Question 21
Why is fluorohydroxyapatite more stable than hydroxyapatite?
Fluoride ion is more electronegative and compact: • FA is more compact/dense • FA has higher crystallinity • FA is more stable than HA --> less likely to demin and more likely to bind
Due to higher crystallinity
Because it has more calcium
As it forms more rapidly
Question 22
What does supersaturated mean in the context of oral fluid?
A solution that can dissolve more minerals
A solution where minerals are evenly distributed
saliva full of minerals → additional will not dissolve → deposit onto available surfaces in crystalline form
A solution with very few minerals
Question 23
What minerals is the oral fluid supersaturated with?
HA and FA
Fe and Zn
Ca and Mg
Na and K
Question 24
What is the critical pH at which HA based enamel begins to demineralize?
5.5
5.0
5.8
5.2
Question 25
What is the critical pH at which FA based enamel begins to demineralize?
4.2
4.8
5.0
4.5
Question 26
What does the salivary protein buffering system do?
Salivary proteins bind to hydrogen ions so they are less reactive
Question 27
What does the dissolution of HA in enamel indicate?
Tooth sensitivity
The beginning of caries in dentin
Enamel remineralization
The beginning of caries in enamel
Question 28
What is the pH range for remineralization to occur?
between 5.0-5.5
between 4.5-5.5
between 4.0-4.5
between 6.0-6.5
Question 29
Which component is formed during the remineralization process?
CaP
PO4
FA
HA
Question 30
What happens to FA if the pH is under 4.5?
remains stable
demineralize
remineralizes
dissolves
Question 31
What is needed for a patient to remineralize their teeth?
Magnesium, Calcium, Phosphorus
Sodium, Potassium, Chloride
Calcium, Phosphate, Anion (Hydroxide or Fluoride)
Iron, Zinc, Copper
Question 32
What process is occurring when the pH level is above 5.5?
Remineralization of HA but FA if F- is available
Acidification
Buffering
Neutralization
Question 33
What does the EPS of the biofilm refer to?
Extracellular Polymeric Substance
Extracellular polymeric substances of the biofilm
Enzymatic Production System
Electrical Potential Stability
Question 34
Where should pH measurements primarily be taken in the mouth?
In the oral cavity
In the saliva
At the gum line
At the site of the biofilm
Question 35
Why might the pH not be the same everywhere in the mouth?
Due to the varying EPS of the biofilm
Due to varying saliva production
Due to different food intake
Due to dental hygiene practices
Question 36
What is the process of adjusting the acidity or alkalinity of an aqueous solution to bring it closer to 7.0?
Neutralizing
Buffering
Stabilizing
Acidifying
Question 37
Which process makes an aqueous solution more resistant to pH changes?
Buffering
Neutralizing
Acidifying
Stabilizing
Question 38
How does a cavitated lesion remineralize?
improve in density of HA/FA + become more acid resistant to further demin • will still be cavitated • remineralization requires an existing framework of structured HA • NOT the de novo formation of new enamel where it does not currently exist
Question 39
WHat are the common protected sites
• overhangs/poor margins • crowding • brackets • gingival margins • Pit and fissures • Black triangle • Furcation • open/poor contact • nonfunctional surfaces
Question 40
What is the primary function of the salivary film covering teeth in a healthy patient?
regulates body temperature
prevents teeth from decaying
acts as fluid layer through which nutrients and waste products are transported and diffused
provides structural support to teeth
Question 41
What is the approximate thickness of the salivary film covering teeth in a healthy patient?
0.1-0.7mm
0.2-0.8mm
0.5-1.0mm
0.3-0.9mm
Question 42
What is the most beneficial salivary buffering system between pH 5-7?
Phosphate
Protein
Citrate
Bicarbonate buffering
Question 43
When is bicarbonate buffering activated
Sour foods
stimulated salivary flow
Sweet foods
Salty foods
Question 44
What does bicarbonate neutralize?
H+
K+
Mg2+
Na+
Question 45
What does bicarbonate convert into when neutralizing H+?
Oxalic acid
Carbonic acid
Sulfuric acid
Phosphoric acid
Question 46
What are the products of the breakdown of carbonic acid?
Water and nitrogen
Water and carbon dioxide
Water and oxygen
Water and hydrogen
Question 47
What is the optimal salivary buffering system range for phosphate?
pH 4-6
pH 7-9
pH 6-8
pH 5-7
Question 48
What role does phosphate play in saliva?
Stimulated saliva only
Saliva flow regulation
Enamel remineralization
Resting/unstimulated saliva when flow rates are low
Question 49
What is the major buffering system when pH is below 5?
Citrates
Carbonates
Salivary proteins
Phosphates
Question 50
Which salivary proteins can bind to hydrogen ions?
Collagens
Lactoferrin
Lysozyme
Histatins, Mucins, Proline-rich proteins, Albumin
Question 51
What are some other functions of salivary proteins?
Antimicrobial defense, Lubrication, Pellicle formation
Nerve conduction
Bone formation
Energy production
Question 52
What does the intake of sucrose by acidogenic microbes in the biofilm lead to?
Increased growth and metabolic activity
Increased growth and metabolic activity
Reduced metabolic activity
Decreased growth and metabolic activity
Question 53
What is the primary effect of acid release from fermented sucrose on the local pH?
Maintaining the local pH
Raising the local pH
No effect on local pH
Increasing the local pH
Question 54
What happens to the saliva's mineral saturation after buffering with phosphates?
Maintains saturation
No change in saturation
Becomes neutral
Becomes supersaturated
Question 55
What causes the undersaturation of phosphate in the saliva?
The presence of sufficient H+ ions
Depletion of sodium ions
Lack of calcium ions
Increased pH levels
Question 56
What happens when salivary buffering ions are depleted?
More phosphate ions are released into the unsaturated saliva until it becomes supersaturated again
Saliva becomes supersaturated with calcium
Phosphate ions are absorbed by the enamel
Saliva loses its ability to neutralize acids
Question 57
What promotes the formation of fluorapatite (FA) over hydroxyapatite (HA)?
Absence of calcium ions
The presence of free fluoride ions
Increased sugar intake
High levels of phosphate ions
Question 58
What is the composition of a tooth's enamel immediately after eruption?
50% HA and 50% Dentin
100% HA
70% HA and 30% Fluoride
100% Dentin
Question 59
What is the primary substance covering a tooth immediately after eruption?
biofilm
dentin
enamel matrix
plaque
Question 60
What process is active on a newly erupted tooth until the biofilm is regularly disrupted?
dentin formation process
resorption process
demin/remin process
calcification process
Question 61
Steps of initiation of dental caries?
Formation of biofilm and microbial deposits
Acid production and change in pH
Susceptible tooth surface → Formation of biofilm and microbial deposits → Acid production and change in pH → Shift in dynamic equilibrium of minerals → Dissolution of minerals → Initiation of dental caries
Shift in dynamic equilibrium of minerals
Question 62
What is the process of enamel mineralization limited to the outer 50-100 microns of enamel?
Enamel formation
Dentin formation
Subsurface remineralization
Passive remineralization
Question 63
What does the term 'carious lesions' refer to in early stages of dental issues?
Severe gum disease
Detectable but not yet cavitated lesions
Healthy tooth surfaces
Fully remineralized areas
Question 64
What does remineralization help to decrease?
Tooth sensitivity
Gum recession
Tooth erosion
Tooth staining
Question 65
What is the primary cause of caries according to the slide?
Excessive sugar intake
IMBALANCE between demin and remin
Genetic predisposition
Lack of oral hygiene
Question 66
At what percentage of mineral loss does enamel become susceptible to cavitation?
60-70%
40-50%
30-40%
20-30%
Question 67
What happens to a cavitated lesion once it has formed?
It can be prevented with fluoride
It cannot reverse to an uncavitated state
It can be cured with antibiotics
It can reverse naturally
Question 68
What is the primary purpose of disclosing agents in dental care?
To whiten teeth
To reduce gum inflammation
To prevent cavities
To reveal protected sites
Question 69
What do disclosing agents target?
Plastic
Metal
Silicon
• Enamel = low porosity, few organic binding sites = minimal/no absorption • Plaque = highly organic and porous = ideal dye binding substrate
Question 70
What makes plaque an ideal dye binding substrate?
Minimal absorption
Few organic binding sites
Low porosity
Plaque is highly organic and porous
Question 71
Which dye is used to stain newer plaque?
Methylene blue
Erythrosine - pink/red
Eosin
Brilliant blue
Question 72
What shape is the demineralization?
square
concave
oval
circular
Question 73
Where is the narrowest part of the cone located?
at the surface
at the depth of the lesion
at the root
in the middle
Question 74
What is the shape of demineralization in a pit and fissure enamel lesion?
The widest part of the cone is at the depth and the narrowest part is at the surface.
The shape is a pyramid with the base at the surface.
The shape is a uniform cone.
The widest part is at the surface and the narrowest part is at the depth.
Question 75
What is the shape of the enamel lesion in a fissure described as?
Flat
Cylindrical
Oval
Spherical
Question 76
Why are pit and fissure caries larger under the surface?
Due to increased saliva flow
Due to the direction of the enamel rods and the potential need to remove any unsupported enamel above the lesion during restoration.
Due to rapid bacterial growth
Due to tooth erosion
Question 77
What does the term 'caries' refer to?
a dental cleaning procedure
a specific type of bacteria
a type of genetic disorder
a result of the past and present metabolic activities in the microbial deposits covering the tooth surface at any given site
Question 78
What does it mean that caries is caused by a complex imbalance?
it is caused by a single bacteria
demin/remin can exist in health without causing caries if it is balanced on both sides
it is caused by a lack of vitamins
it is caused by a viral infection
Question 79
Where does the acid driving the chemical reaction come from?
food consumption
the environment
endogenous microbes, not exogenous sources like diet
medications