Fluoride and Dental Caries

Question 1

When Dr.McKay discovered fluorosis in 1901, he was moving from Pennsylvania to _______ which had much higher fluoride naturally in the water.

Answer 1

Colorado Springs

Question 2

What is the ideal concentration of fluoride in drinking water that provides maximum benefit and minimum fluorosis?

Answer 2

1 ppm

Question 3

Intervention studies for fluoride began in the ________ area and water in _______ was adjusted to 1ppm.

Answer 3

Lake Michigan

Grand Rapids, MI

Question 4

Enamel is laid down by ______.

Answer 4

ameloblasts

Question 5

During the ________ phase, the ameloblasts lay down the protein matrix for the rod crystal structure and the rods begin to form.

Answer 5

Secretory

Question 6

During the _______ phase, the ameloblasts fill in the crystal structure with minerals.

Answer 6

Maturation (pre-eruptive)

Question 7

When does fluorosis occur?

Answer 7

during development only, NOT after eruption

Question 8

Very high physiologic levels of fluoride during the secretory stage can cause ______ and _______ (which is not common).

Answer 8

pitting

disturbances in form

Question 9

Chronic moderately high levels of fluoride during the _______ stage causes disruptions in crystal formation that appear chalky white and weak.

Answer 9

PRE-ERUPTIVE (maturation stage)

Question 10

At which stage of enamel formation do disruptions in crystal formations occur?

Answer 10

pre-eruptive maturation stage

Question 11

True or False: A lot of fluoride is incorporated into enamel during the pre-eruptive maturation process.

Answer 11

False (little is incorporated)

Question 12

Is there a benefit to swallowing fluoride?

Answer 12

No

Question 13

Why is there no benefit to swallowing fluoride?

Answer 13

Fluoride is on the outer and inner surfaces of the tooth, NOT within the hydroxyappetite crystals.

Question 14

Fluoride is highest pre-eruptively at the _______ surface and _______ interface.

Answer 14

enamel

dentin-pulp

Question 15

True or False: Fluoride is high at the enamel-dentin junction.

Answer 15

False

Question 16

Fluorapatite is highest on surfaces where there is ______ interaction.

Answer 16

follicular fluid

Question 17

Development and widespread adoption of _______ has impacted the prevalence and severity of caries throughout the world.

Answer 17

topical products (especially toothpaste)

Question 18

Effects of water fluoridation are ______.

Answer 18

topical

Question 19

How is fluorosis risk increased?

Answer 19

by ingestion

Question 20

How is water fluoridation still beneficial?

Answer 20

benefits those who don’t use topical products

Question 21

True or False: Topical products are lower risk than systemic supplementation.

Answer 21

True

Question 22

Systemic supplementation is still recommended for _____ risk children.

Answer 22

High

Question 23

Alteration of the enamel surface occurs during the _________ stage.

Answer 23

Post-eruptive enamel maturation

Question 24

What is enamel’s composition?

Answer 24

87% HA
11% water
2% organic matrix

Question 25

Pure Hydroxyapatite is __________ (chemical form).

Answer 25

Ca10 (PO4)6 (OH)2

Question 26

What types of impurities are often seen in newly formed crystals of a young tooth?

Answer 26

carbonate sodium other ions

Question 27

When bathed in saliva (calcium and phosphate-rich) and exposed to fluoride, the HA crystal will tend to perfect itself in a process called __________.

Answer 27

POST-eruptive enamel maturation

Question 28

What three replacements will occur during post-eruptive enamel maturation?

Answer 28

phosphate replaces carbonate calcium replaces sodium fluoride replaces hydroxyl

Question 29

Replacements during the post-eruptive maturation stage will make hydroxyapatite _______ and therefore stronger.

Answer 29

less soluble

Question 30

True or False: Young teeth or more susceptible to caries.

Answer 30

True

Question 31

How far does pH have to drop before HA dissolves?

Answer 31

below 5.5

Question 32

Hydrogen (acid) combines with _____ and ____ ions which removes solubility products from solution and drives the equilibrium toward more dissolution.

Answer 32

Phosphate (PO4) and Hydroxide (OH)

Question 33

Fluoride ions prevent dissolving of ______ ions.

Answer 33

calcium

Question 34

______ is less soluble than hydroxyapatite.

Answer 34

Fluorhydroxyapatite

Question 35

If pH remains above _____ and ____ ions are available, fluorhydroxyapatite forms on the surface after HA dissolves from the subsurface.

Answer 35

4.5 | fluoride

Question 36

When pH rises above ____, fluoride ions enhance remineralization of enamel and dentin.

Answer 36

5.5

Question 37

The surface of enamel has more fluoride and less ______.

Answer 37

carbonate

Question 38

______ enamel is less soluble than _____ enamel.

Answer 38

Outer | Inner

Question 39

True or False: fluoride does not diffuse well into the body of a lesion.

Answer 39

True

Question 40

What kind of lesions will often have a very high fluoride concentration on their surface due to demin-remin cycles?

Answer 40

White-spot lesions

Question 41

Areas covered by plaque have ______ fluoride levels.

Answer 41

HIGHER

Question 42

Areas worn by erosion or abrasion will have _____ fluoride levels.

Answer 42

LOW

Question 43

Why should you avoid wearing away the white-spot lesion?

Answer 43

the surface is very hard but the subsurface is very porous and changes become very rapid

Question 44

When topical fluoride concentrations are low, 50ppm or less, _________ is formed on the outermost layers of enamel.

Answer 44

fluorhydroxyapatite

Question 45

When topical fluoride concentrations are high, above 100ppm, ________ precipitates.

Answer 45

Calcium Fluoride

Question 46

How does acid assist with deposition of calcium fluoride?

Answer 46

By making calcium ions available

Question 47

What shape are the globules that precipitate on the surface, in crevices, and in plaque?

Answer 47

spherical

Question 48

A ________ effect occurs due to deposition of globules in micropores of initial lesions.

Answer 48

cariostatic

Question 49

Name four ways in which calcium fluoride deposition is increased?

Answer 49

1. increasing concentration of fluoride 2. increasing exposure time (aka varnish) 3. lowering pH (makes Ca available to F) 4. Protecting (limit rinsing, use varnish)

Question 50

Saliva is supersaturated with _____ and _____ so that teeth don't dissolve.

Answer 50

calcium | phosphate

Question 51

What kind of proteins coat the enamel and prevent crystal growth from occurring?

Answer 51

salivary pellicle proteins

Question 52

What are the three salivary pellicle proteins that are important in preventing crystal growth?

Answer 52

1. tyrosine-rich peptides 2. statherin 3. Proline-rich proteins

Question 53

Spontaneous precipitation in salivary ducts results in ______.

Answer 53

sialoliths (calcium stones)

Question 54

Interbacterial fluid in the _________ can have high concentrations of calcium and phosphate that assists in _______ BUT can also lead to _______.

Answer 54

plaque biofilm remineralization calculus formation

Question 55

True or False: Fluorosis typically occurs during puberty when growth hormone levels are high.

Answer 55

FALSE. it occurs during tooth development

Question 56

True or False: There is a homeostatic mechanism in place to control fluoride concentration.

Answer 56

False. Levels are dependent on daily intake and bone stores (released during remodeling =cumulative effect)

Question 57

Where in teeth is the fluoride concentration highest?

Answer 57

on the surface

Question 58

Surface concentration of fluoride is dependent on ______, ________, and _______.

Answer 58

topical exposure to F acid exposure wear

Question 59

True or False: Exposure to fluoride during development is not a major determinant of fluoride levels in enamel.

Answer 59

True

Question 60

Fluorosis is an increase in enamel ______ that appears as ________.

Answer 60

Porosity | chalky white

Question 61

Exposure to higher levels of fluoride during tooth development will determine ____ and _____ or fluorosis.

Answer 61

extent | severity

Question 62

If fluorosis is severe, enamel may be ______.

Answer 62

fragile

Question 63

Pits, bands, and lost areas of enamel will occur ______.

Answer 63

post-eruptively

Question 64

When and why does brown discoloration associated with fluorosis occur?

Answer 64

post-eruptively due to staining and browning of exposed protein

Question 65

Brown discoloration can also occur during growth of already seeded crystals during ________ ________.

Answer 65

enamel maturation (pre-eruptive)

Question 66

What are the three variations in appearance of fluorosis?

Answer 66

mild white mottling severe pitting brown staining

Question 67

True or False: There is a threshold for exposure to fluoride before discoloration effects are seen.

Answer 67

FALSE. no threshold

Question 68

True or False: Mild flourosis is sometimes perceived as attractive.

Answer 68

True

Question 69

____mg/kg is considered high risk for cosmetically objectionable fluorosis.

Answer 69

0.1

Question 70

On which teeth and at what age is there the greatest risk for fluorosis?

Answer 70

Upper central incisors | 15-30 months

Question 71

Fluoride inhibits enzymes and regulatory proteins by binding to sites that would normally bind to ____.

Answer 71

OH-

Question 72

True or False: Fluoride is highly concentrated in plaque.

Answer 72

True

Question 73

True or False: Bacteria are able to eventually build up resistance to fluoride.

Answer 73

False!

Question 74

Which enzyme of the glycolytic pathway (lactate production) will be inhibited by fluoride?

Answer 74

enolase

Question 75

True or False: Binding of fluoride is enhanced by acidification.

Answer 75

True

Question 76

At low pH, bacterial intracellular concentrations of fluoride will _____ due to increased _____ crossing the membrane.

Answer 76

increase | HF

Question 77

When is fluoride most effective against glycolysis?

Answer 77

at low pH

Question 78

How does fluoride affect the ecology of biofilms?

Answer 78

by reducing enrichment of acid-tolerant species

Question 79

True or False: Fluoride has inhibitory effects at high or low pH.

Answer 79

False. No affect at high pH

Question 80

Does fluoride affect growth of bacteria at normal pH?

Answer 80

NO

Question 81

What are the three methods of fluoride delivery?

Answer 81

1. Community-based water fluoridation 2. Self-Applied 3. Professionally applied

Question 82

Is there a direct benefit to swallowing fluoride?

Answer 82

NO

Question 83

When does fluoride present the greatest benefit?

Answer 83

when present during acid challenge

Question 84

______ fluoride is key.

Answer 84

topical

Question 85

______ is deposited on surface when topical fluoride is greater than 100ppm.

Answer 85

Calcium fluoride

Question 86

Studies of water fluoridation show that it is highly _______ but less beneficial than ______.

Answer 86

cost-effective | fluoride toothpaste

Question 87

How much fluoride is provided in toothpaste in the United States?

Answer 87

1000ppm

Question 88

In Europe do they provide more or less fluoride in toothpaste?

Answer 88

more, 1500ppm

Question 89

What was the first type of fluoride available in toothpaste?

Answer 89

stannous (1955 P&G)

Question 90

After fluoride was introduced in toothpaste, there was a _____% reduction in caries over 2-3 years.

Answer 90

25

Question 91

True or False: It is not ethical to use nonfluoridated toothpaste as a control in studies.

Answer 91

True. therefore, no new studies can be done

Question 92

What are the three varieties of fluoride available at equivalent concentrations and effectiveness?

Answer 92

NaF2 MFP SnF2 (stannous)

Question 93

Which variety of fluoride is compatible with chalk-based formula and which is not?

Answer 93

Chalk-based: MFP | Non-Chalk: NaF2

Question 94

Which fluoride variety requires more expensive silca-based formula?

Answer 94

NaF2

Question 95

Up to _____ppm toothpastes are available by prescription.

Answer 95

5000

Question 96

True or False: there is no relationship between amount of toothpaste and caries.

Answer 96

True

Question 97

________ matters and _____ rinsing is better in measuring benefits of toothpaste.

Answer 97

Frequency | Less

Question 98

What is the safe amount of toothpaste for preschool children? Children less than two?

Answer 98

pea-sized | rice-sized

Question 99

Fluoride is indicated on toothpaste as %_____ or %______.

Answer 99

weight/weight | weight/volume

Question 100

Over the counter fluoride rinses contain _____% fluoride (200ppm).

Answer 100

0.02%

Question 101

Why is there a benefit to OTC rinses despite the low concentration of fluoride?

Answer 101

no rinsing!

Question 102

Professional fluoride products typically come as ____, ____, and ______.

Answer 102

foams gels rinses

Question 103

How often are professional F products (foam/gel/rinse) applied? What are the fluoride contents?

Answer 103

twice or more per year 1. 23% acidulated phosphate (1230 ppm) 0. 9% NaF2 (900ppm)

Question 104

The ____% reduction in caries from professional foams/gels is only a reduction in the amount left after effects of toothpaste use.

Answer 104

30

Question 105

Fluoride varnish contains _____% fluoride as _____. What is the resultant reduction in caries seen due to varnish?

Answer 105

2.2% NaF | 40% reduction

Question 106

Topical products deposit _____ on the surface of the tooth which acts as a temporary reservoir that will be lost over time due to ______ and _____.

Answer 106

CaF | dissolution and wear

Question 107

During acid attack, CaF2 will _____ and _________ in order to become incorporated into fluorapatite.

Answer 107

dissolve | increase remineralization

Question 108

True or False: Water fluoridation deposits CaF onto the surface of the tooth.

Answer 108

False

Question 109

True or False: Incorporation of fluoride into enamel during development provides significant anti-caries benefit.

Answer 109

False, it does not

Question 110

True or False: Ingestion of fluoride carries a risk for fluorosis.

Answer 110

True