Mechanisms of Action Fluoride Flashcards
How much ppm of F- is in water? How does that compare to toothpaste?
1 ppm in water
1000-5000 ppm in toothpaste
How much fluoride is in flouride tray applcations?
9000-12300 ppm
What are 2 reasons why fluoride is important in dentistry?
Promote formation of fluorapatite
Fluorapatite is more stable than HA
What are the two theories surrounding the caries preventive effects of fluoride?
Systemic theory
Topical action theory
What is the systemic theory?
F- is incorporated into teeth as FA and protects against dental caries.
It’s known as the bound-only theory
What is the topical action theory?
F- ions that bathe the teeth throughout life prevent caries
also known as free-ion theory
What are the limitations of the systemic theory?
need high amounts of F- in tooth structure to affect solubility
studies that show increased caries risk in populations that move from fluoridated to non-fluoridated regions
potential fluorosis risk
1) Enamel Surface
2) DEJ
3) Dentine-pulp interface
Order the numbers above from highest fluoride concentration to lowest.
3, 1, 2
Deep dentine has more fluoride than surface enamel. True or false?
True
What does this graph show?
Sharks nearly have pure FA in their teeth
Humans do not have pure FA in their teeth
pure FA = 34000
This graph shows the depth of demineralization in enamel. What does this graph demonstrate?
Why is it interesting?
Rinsing with a F- solution almost had the lesion reducing effect as pure HF in sharks.
Interesting because it shows that F- does not need to be chemically bound to teeth to elicit effect (supports free-ion theory)
Second graph to prove the point
What are the conclusions of the shark enamel - human enamel study?
look at slide
What are the products of HA dissociation?
OH- , Ca2+, PO43-
What is this diagram showing?
Write out the chemical formula associated with this diagram
Showing that calcium deficient apatite reprecipitates into HA, and HA reprecipitates into FA at the surface layer, where F concentration is high
The journey is more important than the destination
- James Fernando
Explain what this means and what theory it applies to
topical application theory (2)
Continued supply of F- ions allow products of dissoluted HA to be redeposited into FA, preventing net demineralization. The resulting formation of FA is more stable and less soluble.
Essentially F- intercepts Ca2+ and phosphate ions, before it leaves the tooth.